FitSugar

DrSugar Answers: Postworkout Weakness?

DrSugar — Wed, 03 Dec 2008 05:30:00 -0800

DrSugar is in the house and answering your questions.

Dear DrSugar,
Sometimes after a rigorous cardio workout (one hour, doing intervals for the first half hour and steady pace for the second half), I come home and start feeling queasy and weak, then need to lie down. Sometimes I feel this way for an hour or more postworkout, well after I've showered and eaten. There have been a few times when I've lost my stomach as well. But it usually goes away after an hour or so of resting/lying down. What's going on? I try to be well hydrated and have a little snack a bit before working out, but sometimes, it doesn't seem to help.
- Workout Weary Wendy

If you're curious to see how DrSugar answers this question, just read more.

Feeling queasy or weak following or during rigorous exercise could be due to a variety of factors; however, lactic acidosis is the most likely cause of your symptoms. Lactic acid is produced by muscles during anaerobic metabolism. Lactic acidosis most commonly occurs after long, rigorous exercise like you’ve described. Common symptoms of lactic acidosis include nausea, weakness, fast heart rate, hyperventilation, and sometimes even anxiety. Lactic acidosis can be more of a problem when coupled with dehydration, prolonged exercise, starvation, alcohol use, and strenuous exercise when not in excellent physical condition.

Preventing lactic acidosis can be difficult if your goal is prolonged anaerobic exercise such as sprints or intervals. The first step is to maintain adequate hydration before, during, and after your workouts. Another way to avoid this problem is to separate your aerobic and anaerobic workouts on alternate days by jogging Mondays, Wednesdays, and Fridays and doing sprints, intervals, and/or weights Tuesdays and Thursdays.

The other possible cause of your symptoms is low blood sugar, which can also cause weakness or queasiness during or after exercise. To prevent low blood sugar you can avoid prolonged exercise on an empty stomach, before breakfast, or before dinner if you didn’t eat an adequate lunch. And, of course, always avoid starvation diets. They don’t work and they are dangerous. Sometimes these post-exercise symptoms can be related to an underlying metabolic problem such as diabetes or liver disease, therefore it is highly recommended that you see a physician if the problem persists.

If you have a question for DrSugar, send me a private message here and I will forward it to the good doctor.

DrSugar's posts are for informational purposes only and should not be considered medical advice, diagnosis, or treatment recommendations. Click here for more details.

The Ultimate Date: Indoor Rock Climbing

Fit Community — Tue, 10 Nov 2009 10:00:32 -0800

Women That Rock (Climb) community members Spacekatgal and her husband Spacekatdude give you their take on why indoor rock climbing makes a perfect fitness-inspired date.

Spacekatdude and I are married, so we're always looking for fun new things to do. Recently, we decided to give indoor rock climbing a shot! We totally loved it! We wanted to post a bit about it for newbies.

We each signed up for a $160 class, which included gym membership for two weeks. We got free equipment rental and a really great instructor named Nate that taught us the basics, focusing on safety. We were taught to tie our own knots and how to "belay" your partner safely, meaning how to catch them if they fall off the wall.

I will be honest and say it's a real trust building exercise. I love my husband dearly, but I also know it's in his nature to be distracted. It was a little hard for me to put my life into his hands and trust him to catch me if I fell. Throwing myself off the wall for the first time was very scary - but I quickly learned that I could count on him for this. Working as a team to guide the other person up the wall is both fun and good for your relationship!

It's also a great workout. Within a few weeks of rock climbing, I've greatly increased my upper body strength. If you have moxie, I would definitely say it's a sport you should try!

To hear Spacekatdude's perspective, read more.

A guy's perspective - Spacekatdude here. Rock climbing is awesome. It's not just a physical thing - it's very mental, as you try to figure out set paths up the wall, only being allowed to touch rock outcroppings of a particular color - very challenging. Whenever we go to the gym there are a lot of women there, and it's great to watch those who love the challenge and love to push themselves, I think that's awesome. Our instructor Nate also told us that it was great for kids - one of the best rock climbers he knew was an eight-year-old girl, who showed him some excellent routes during an outdoor climb.

I mentioned that climbing is a mental exercise. This is because you have to constantly concentrate on what you're doing. If you go in mentally weak or lazy, bad things can happen: I read of some climbers who went to Half Dome at Yosemite, all ready to hammer in their own ropes to descend from the top. But there were ropes already there, embedded in the rock, and they just used those. As they climbed down, the ropes gave way, and they fell to their deaths. So laziness has no place in rock climbing.

Also, as you climb, it's important to remember to use your feet for power, and not to try to pull yourself up by your arms. So the mental challenge is to keep concentrating the entire time you're roping yourself in, climbing, and belaying.

Share your climbing tales in the Women That Rock (Climb) group and spread the love! Not a climber? Be sure to take a look at our other community groups - there's something for everyone!

Source: Flickr User Charlie Brewer

Exercise

FitSugar — Wed, 08 Oct 2008 17:35:02 -0700

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Chronic Conditions and Exercise:

A new study found that aerobic and resistance training significantly reduced fatigue in men undergoing radiation treatments for prostate cancer. Fatigue is a common side effect of such treatments.
Doctors at the Mayo Clinic found that exercise improves the physical and emotional well-being of patients with Alzheimer's disease. The patients exercised for as little as 60 minutes each week. Doctors noted improvements in areas ranging from depression to wandering.

Exercise and Smoking:

A 2007 review of existing studies found that moderate exercise, for as little as 5 minutes, can help combat the nicotine withdrawal symptoms people experience when they try to stop smoking.

Exercise and Aging:

A 2006 report found that older and elderly adults who exercised twice a week for 4 months significantly increased their body strength, flexibility, balance, and agility. The average age of the study participants was 83.5.

Before and After Exercising:

You should do warm-up exercises for 5 - 10 minutes at the beginning of an exercise session. Low-level aerobic exercise is the best warm-up.
To cool down, you should walk slowly until your heart rate is 10 - 15 beats above your resting heart rate. Stopping too suddenly may sharply reduce blood pressure or cause muscle cramping.
You must be careful when stretching during your warm-up to avoid injuring cold muscles.

Definitions:

Aerobic exercise: Aerobic exercise forces the heart and lungs to work harder for longer periods. It builds endurance, improves blood flow throughout the body, and increases the levels of "good" cholesterol.
Resistance Training: Resistance training works muscles against a force (usually weights). It burns fat and builds muscle.

Introduction

Everyone's goal of living a long and healthy life should include a healthy diet, regular exercise, and maintaining normal weight. The combination of inactivity and eating the wrong foods is the second most common preventable cause of death in the United States (smoking is the first).

Most research on the benefits of exercise focuses on heart protection. Studies clearly show that exercise helps the heart. In addition, new studies are reporting that even people at higher risk for heart disease may lower their risk of dying from it if they exercise.

Evidence suggests that our genes evolved to favor exercise. In other words, during prehistoric times, if a person couldn't move quickly and wasn't strong, he or she died. Those who were fit survived to reproduce and pass on these "fitter" genes. Some researchers believe that with our current inactive lifestyle, these genes produce a number of bad effects, which can lead to many chronic illnesses.

The benefits of exercise include:

Improved oxygen delivery throughout the body
Improved metabolic processes - the way the body breaks down and builds necessary substances
Improved strength and endurance
Decreased body fat
Improved movement of joints and muscles
Improved sense of well-being

In addition, exercise can help change other dangerous lifestyle habits. A 2007 review of existing studies found that moderate exercise, for as little as 5 minutes at a time, can help combat the nicotine withdrawal symptoms people experience when they try to stop smoking.

No one is too young or too old to exercise. The United States Surgeon General recommends at least 30 minutes of moderate exercise, such as brisk walking, nearly every day. However, vigorous exercise carries risks that people should discuss with a doctor. You should always check with your doctor before starting a new exercise program, especially if you have any of the following risk factors:

History of smoking
Obesity
Family history of a long-term disease
A symptom you haven’t told your doctor about
Chest pain
Shortness of breath
Heart palpitations
Blood clots
Infections
Fever
Unexplained weight loss
Foot or ankle sores that won’t heal
Joint swelling
Pain or trouble walking after a fall
Eye injury or eye surgery
Hernia
Hip surgery

Fifty percent of all people who begin a vigorous training program drop out within a year. The key to reaching and maintaining physical fitness is to find activities that are exciting, challenging, and satisfying.

Recommended Exercise Methods

A few simple rules are helpful as you develop your own routine.

Don't eat for 2 hours before vigorous exercise.
Drink plenty of fluids before, during, and after a workout.
Adjust your activity level according to the weather, and reduce it when you are fatigued or ill.
When exercising, listen to the body's warning symptoms, and consult a doctor if exercise causes chest pain, irregular heartbeat, undue fatigue, nausea, unexpected breathlessness, or light-headedness.

Heart rate is the standard guide for determining aerobic exercise intensity. It can be determined by counting one's own pulse or with the use of a heart rate monitor. To feel your own pulse, press the first two fingers of one hand gently down on the inside of the wrist or under the jaw on the right or left side of the front of the neck. You should feel a faint pounding as blood passes through the artery. Each pounding is a beat.

Click the icon to see how to take a radial pulse

Click the icon to see how to take a carotid pulse.

There are different types of heart rates.

Resting heart rate. The average heart rate for a person at rest is 60 - 80 beats per minute. It is usually lower for people who are physically fit, and often rises as you get older. You can determine your resting heart rate by counting how many times your heart beats in one minute. The best time to do this is in the morning after a good night’s sleep before you get out of bed.

Maximum heart rate. To determine your own maximum heart rate per minute subtract your age from 220. For example, if you are 45, you would calculate your maximum heart rate as follows: 220 - 45= 175.

Target heart rate. Your target rate is 50 - 75% of your maximum heart rate. You should measure your pulse off and on while your exercise to make sure you stay within this range. After about 6 months of regular exercise, you may be able to increase your target heart rate to 85% (but only if you can comfortably do so).

Certain heart medications may lower your maximum and target heart rates. Always check with your doctor before starting an exercise program.

Note: Swimmers should use a heart rate target of 75% of the maximum and then subtract 12 beats per minute. The reason for this is that swimming will not raise the heart rate quite as much as other sports because of the so-called "diving reflex," which causes the heart to slow down automatically when the body is immersed in water.


Age	Low	High
	(50% max.)	(75% max.)
20	100	150
30	95	142
40	90	135
50	85	127
60	80	120
Source: American Heart Association

VO2 Max. Serious exercisers may use a VO2 max calculation, which measures the amount of oxygen consumed during intensive, all-out exercise. The most accurate testing method uses computers, but anyone can estimate V02 without instrumentation (with an accuracy of about 95%):

After running at top pace for 15 minutes, round off the distance run to the nearest 25 meters.
Divide that number by 15.
Subtract 133.
Multiply the total by 0.172, then add 33.3.

Olympic and professional athletes train for VO2 max levels above 80. But for the average person interested in fitness, a VO2 max equaling between 50 and 80 is considered an excellent score for overall fitness.

Click the icon to see an image on exercise and heart rate.

Warming up and cooling down are important parts of every exercise routine. They help the body make the transition from rest to activity and back again, and can help prevent soreness or injury, especially in older people.

Warm-up exercises should be practiced for 5 - 10 minutes at the beginning of an exercise session. Older people need a longer period to warm up their muscles. Low-level aerobic exercise such as brisk walking, swinging the arms, or jogging in place, is the best approach.
To cool down, you should walk slowly until the heart rate is 10 - 15 beats above your resting heart rate. Stopping too suddenly can sharply reduce blood pressure, and is dangerous for older people. It may also cause muscle cramping.
Stretching may be appropriate for the cooling down period, but it must be done carefully for warming up because it can injure cold muscles. (There is no clear evidence, however, that stretching reduces muscle injuries.)

Warming up before exercise and cooling down after is just as important as the exercise itself. By properly warming up the muscles and joints with low-level aerobic movement for 5 - 10 minutes, one may avoid injury and build endurance over time. Cooling down after exercise by walking slowly, then stretching muscles, may also prevent strains and blood pressure fluctuation.

For most people, exercise may be divided into three general categories:

Aerobic or endurance
Strength or resistance
Flexibility

A balanced program should include all three. Speed training is also a major category, but generally only competitive athletes practice it.

Benefits of Aerobic Exercise. Regular aerobic exercise provides the following benefits:

Builds endurance
Keeps the heart pumping at a steady and high rate for a long time
Boosts HDL ("good") cholesterol levels
Helps control blood pressure
Strengthens the bones in the spine
Helps maintain normal weight
Improves one's sense of well-being

Types of Aerobic Exercise. Aerobic exercise is usually categorized as high or low impact. Examples of each include the following:

Low- to moderate-impact exercises: Walking, swimming, stair climbing, step classes, rowing, and cross-country skiing. Nearly anyone in reasonable health can engage in some low- to moderate-impact exercise. Brisk walking burns as many calories as jogging for the same distance and poses less risk for injury to muscle and bone.
High-impact exercises: Running, dance exercise, tennis, racquetball, squash. High-impact exercises should be performed no more than every other day, and less often for those who are overweight, elderly, out of condition, or have an injury or other medical problem that would rule out high-impact.

Click the icon to see an image of aerobic exercise.

Aerobic Regimens. As little as one hour a week of aerobic exercises is helpful, but 3 - 4 hours per week are best. Some research indicates that simply walking briskly for 3 or more hours a week reduces the risk for coronary heart disease by 65%. In general, the following guidelines are useful for most individuals:

For most healthy young adults, the best approach is a mix of low- and higher-impact exercise. Two weekly workouts will maintain fitness, but three to five sessions a week are better.
People who are out of shape or elderly should start aerobic training gradually. For example, they may start with 5 - 10 minutes of low-impact aerobic activity every other day and build toward a goal of 30 minutes per day, three to seven times a week. (For heart protection, frequency of exercises may be more important than duration.)
Swimming is an ideal exercise for many elderly and certain people with physical limitations, including pregnant women, individuals with muscle, joint, or bone problems, and those who suffer from exercise-induced asthma.
People who seek to lose weight should aim for six to seven low-impact workouts a week.

One way of gauging the optimal intensity of exercise is to aim for a "talking pace," which is enough to work up a sweat and still be able to converse with a friend without gasping for breath. As fitness increases, the "talking pace" will become faster and faster.

Shoes. All that's really necessary for a workout is a good pair of shoes that are made well and fit well. They should be broken in, but not worn down. They should support the ankle and provide cushioning for impact sports such as running or aerobic dancing. Airing out the shoes and feet after exercising reduces chances for skin conditions such as athlete's foot.

Clothing. Comfort and safety are the key words for workout clothing. For outdoor nighttime exercise, a reflective vest and light-colored clothing must be worn. Bikers, roller bladers, and equestrians should always wear safety devices such as helmets, wrist guards, and knee and elbow pads. Goggles are mandatory for indoor racquet sports. For vigorous athletic activities, such as football, ankle braces may be more effective than tape in preventing ankle injuries.

Aerobic-Exercise Equipment. Home aerobic exercise machines can be adapted to any fitness level and used day or night. Before investing in any exercise machine, however, it is wise to first test it at a gym. In addition, initial supervised training when using these machines can reduce the risk of injury that might occur with self-instruction.

Very inexpensive exercise machines tend to be flimsy and hard to adjust, but many sturdy machines are available at moderate prices. The higher-end models may utilize computers to record calories burned, speed, and mileage. While their readouts may provide motivation and gauge the intensity of a workout, however, they are not always accurate.

The following are a few observations on specific equipment:

A good floor mat is important to provide cushioning for all home exercises.
A simple jump rope improves aerobic endurance for people who are able to perform high-impact exercise. Jumping rope should be done on a floor mat plus a surface that has some give to avoid joint injury.
For burning calories, the treadmill has been ranked best, followed by stair climbers, the rowing machine, cross-country ski machine, and stationary bicycle. (Elliptical trainers, however, may be even better than treadmills for increasing heart rate, calorie expenditure, and oxygen consumption.)
Stationary bikes condition leg muscles and are fairly economical and easy to use safely. The pedals should turn smoothly, the seat height should adjust easily, and the bike's computer should be able to adjust intensity.
Stair machines also condition leg muscles. They offer very intense, low-impact workouts and may be as effective as running with less chance of injury.
Rowing and cross-country ski machines exercise both the upper and lower body.


Aerobic dancing	Sufficient cushioning to absorb shock and pressure that are many times greater than ordinary walking. Arches that maintain side-to-side stability. Thick upper leather support. Toe-box. Orthotics may be required for people with ankles that over-turn inward or outward. Soles should allow for twisting and turning.
Cycling	Rigid support across the arch to prevent collapse during pedaling. Heel lift. Cross-training or combination hiking/cycling shoes may be sufficient for casual bikers. Toe clips or specially designed shoe cleats for serious cyclers. In some cases, orthotics may be needed to control arch and heel and balance forefoot.
Running	Sufficient cushioning to absorb shock and pressure. Fully bendable at the ball of the foot. Sufficient traction on sole to prevent slipping. Consider insoles or orthotics with arch support for problem feet.
Tennis	Allow side-to-side sliding. Low-traction soles. Snug fitting heels with cushioning. Padded toe box with adequate depth. Soft-support arch.
Walking	Lightweight. Breathable upper material (leather or mesh). Wide enough to accommodate ball of the foot. Firm padded heel counter that does not bite into heel or touch ankle bone. Low heel close to ground for stability. Good arch support. Front provides support and flexibility.

Benefits of Strength Exercise. While aerobic exercise increases endurance and helps the heart, it does not build upper body strength or tone muscles. Strength-training exercises provide the following benefits:

Build muscle strength while burning fat
Help maintain bone density
Improve digestion

It is also associated with a lower risk for heart disease, possibly because it lowers LDL (the so-called "bad") cholesterol levels.

Click the icon to see an image of cholesterol.

Strength exercise is beneficial for everyone, even people in their 90s. It is the only form of exercise that can slow and even reverse the decline in muscle mass, bone density, and strength that occurs with aging. Please note: People at risk for cardiovascular disease should not perform strength exercises without checking with a doctor.

Types of Muscle Contractions. There are three types of muscle contractions involved in strength training:

Isometric contractions do not change the length of the muscle. An example is pushing against a wall.
Concentric contractions shorten muscles. An example is the "up" phase of a bicep curl.
Eccentric contractions lengthen muscles. An example is the "down" phase as weights are lowered.

Click the icon to see an image of isometric exercise.

Strength-Training Regimens. Strength training involves intense and short-duration activities. For beginners, adding 10 - 20 minutes of modest strength training two to three times a week may be appropriate. The following are some guidelines for starting a strength regimen:

The sequence of a strength training session should begin with training large muscles and multiple joints at higher intensity and end with small muscle and single joint exercises at lower intensities.
Both shortening and lengthening muscle actions should be performed. Emphasizing the movements that lengthen muscles is of increasing interest. This approach involves slowing and increasing the duration of these "down" movements. It appears to significantly increase blood flow, and some evidence suggests it may achieve stronger muscles more quickly. It may also improve heart function compared to standard movements. Exercises that lengthen muscles may be particularly beneficial for older people and some people with chronic health problems. This type of training increases the risk for muscle soreness and injury, however, and this approach is still controversial.
Strength training involves moving specific muscles in the same pattern against a resisting force (such as a weight) for a preset number of times. This is called a repetition. Students should first choose a weight that is about half of what would require a maximum effort in one repetition. In other words, if it would take maximum effort to do a single repetition with a 10-pound dumbbell, the person would start with a five-pound dumbbell. In the beginning, most people can start with one set of 8 - 15 repetitions per muscle group with low weights. As individuals are able to perform one or two repetitions over their routine, weights can be increased by 2 - 10%.
Breathe slowly and rhythmically. Exhale as the movement begins. Inhale when returning to the starting point.
The first half of each repetition typically lasts 2 - 3 seconds. The return to the original position lasts 4 seconds.
An alternative technique called "super slow" training stretches out one repetition to a 14-second count. This method places far more stress on the muscle group, so fewer repetitions are needed. A full week of recovery is required before repeating this workout. The goal is to initiate changes in the muscles so that the body continues to burn calories after the exercise. Some people report dramatic results from this approach, but scientific proof of these claims is not available. It is a very tedious workout, and people have a hard time sticking with it. People with high blood pressure should not use this approach.
Joints should be moved rhythmically through their full range of motion during a repetition. Do not lock up the joint while exercising it.
For maximum benefit, one should allow 48 hours between workouts for full muscle recovery.

Click the icon to see the proper way to breathe during exercise.

Strength-Training Equipment. Unlike aerobic exercise, strength training almost always requires some equipment. Strength-training equipment does not, however, have to cost anything.

Any heavy object that can be held in the hand, such as a plastic bottle filled with sand or water, can serve as a weight.
Dumbbells (1 - 10 pounds) and resistance bands are inexpensive, portable, and effective.
Wearable weights help strengthen and tone the upper body.
Ankle weights strengthen and tone muscles in the lower body. Wearable ankle weights should not be worn during high-impact aerobics or jumping.
Hand grips strengthen arms and are good for relieving tension.
A pull-up bar can be mounted in a doorway for chin-ups and pull-ups.

More elaborate and expensive home equipment for working body muscles is also available, costing from $100 to over $1,000. No one should purchase or use strength-training equipment without instruction from a professional.

Benefits of Flexibility Training. Flexibility training uses stretching exercises. Many stretching exercises are particularly beneficial for the back. In general, flexibility training provides the following benefits:

Prevents cramps, stiffness, and injuries
Improves joint and muscle movement (improved range of motion)

Certain flexibility practices, such as yoga and tai chi, also involve meditation and breathing techniques that reduce stress. Such practices appear to have many health and mental benefits. They may be very suitable and highly beneficial for older people, and for patients with certain chronic diseases.

Click the icon to see an image of flexibility exercise.

Flexibility Training Regiments. Doctors recommend performing stretching exercises for 10 to 12 minutes at least three times a week. The following are some general guidelines:

When stretching, exhale and extend the muscles to the point of tension, not pain, and hold for 20 - 60 seconds. (Beginners may need to start with a 5- to 10-second stretch.)
Breathe evenly and constantly while holding the stretch.
Inhale when returning to a relaxed position. Holding your breath defeats the purpose; it causes muscle contraction and raises blood pressure.
When doing stretches that involve the back, relax the spine to keep the lower back flush with the mat, and to work only the muscles required for changing position (often these are only the abdominal muscles).

Studies continue to show that it is never too late to start exercising. A report published in the February 2006 Journal of Aging and Health found that elderly adults who exercised twice a week for four months significantly increased their body strength, flexibility, balance, and agility. The exercise program included walking and lifting weights. The average age of the study participants was 83.5. The study adds further evidence that even small improvements in physical fitness and activity can prolong life and independent living.

Still, about half of Americans over 60 describe themselves as sedentary (inactive). According to a 2004 report by the Centers for Disease Control and Prevention, approximately 12% of people aged 65 - 75 years and 10% of people aged 75 years or older meet current recommendations for strength training.

The following tips for exercising may be helpful:

Any older person should have a complete physical and medical examination, as well as professional instruction, before starting an exercise program.
Start low and go slow. For sedentary, older people, one or more of the following programs may be helpful and safe: Low-impact aerobics, gait (step) training, balance exercises, tai chi, self-paced walking, and lower legs resistance training, using elastic tubing or ankle weights. Even in the nursing home, programs aimed at improving strength, balance, gait, and flexibility have significant benefits.
Strength training assumes even more importance as one ages, because after age 30 everyone undergoes a slow process of muscular erosion. The effect can be reduced or even reversed by adding resistance training to an exercise program. As little as one day a week of resistance training improves overall strength and agility. Strength training also improves heart and blood vessel health.
Power training, which aims for the fastest rate at which a muscle or muscle group can perform work, may be particularly helpful for older women in strengthening muscles and preventing falls.
Flexibility exercises promote healthy muscle growth and help reduce the stiffness and loss of balance that accompanies aging.
Chair exercises may be performed by people who are unable to walk.
Older women are at risk for incontinence accidents during exercise. This can be reduced or prevented by performing Kegel exercises, limiting fluids (without risking dehydration), going to the bathroom frequently, and using leakage prevention pads or insertable devices.

Exercise's Effects on the Heart

Inactivity is one of the major risk factors for heart disease. However, exercise helps improve heart health, and can even reverse some heart disease risk factors.

Like all muscles, the heart becomes stronger as a result of exercise, so it can pump more blood through the body with every beat and continue working at maximum level, if need be, with less strain. The resting heart rate of those who exercise is also slower, because less effort is needed to pump blood.

A person who exercises often and vigorously has the lowest risk for heart disease, but any amount of exercise is beneficial. Studies consistently find that light-to-moderate exercise is even beneficial in people with existing heart disease. Note, however, that anyone with heart disease should seek medical advice before beginning a workout program.

The heart is a large muscular organ that pumps blood throughout the body. Valves inside the heart open and close. This controls how much blood enters or leaves the heart.

Exercise has a number of effects that benefit the heart and circulation (blood flow throughout the body). These benefits include improving cholesterol and fat levels, reducing inflammation in the arteries, assisting weight loss programs, and helping to keep blood vessels flexible and open. Studies continue to show that physical activity and avoiding high-fat foods are the two most successful means of reaching and maintaining heart-healthy levels of fitness and weight.

The American Heart Association recommends that individuals perform moderately-intense exercise for at least 30 minutes on most days of the week. This recommendation supports similar exercise guidelines issued by the Centers for Disease Control and Prevention, and the American College of Sports Medicine.

Coronary Artery Disease. People who maintain an active lifestyle have a 45% lower risk of developing heart disease than do sedentary people. Experts have been attempting to define how much exercise is needed to produce heart benefits. In 2002, a well-conducted study on overweight adults confirmed previous research that reported beneficial changes in cholesterol and lipid levels, including lower LDL levels (bad cholesterol), even when people performed low amounts of moderate- or high-intensity exercise such as walking or jogging 12 miles a week. However, more intense exercise is required to significantly change cholesterol levels, notably increasing HDL (good cholesterol). An example of this kind of program would be jogging about 20 miles a week. Such benefits in the study occurred even with very modest weight loss, suggesting that overweight people who have trouble losing pounds can still achieve considerable heart benefits by exercising.

Some studies suggest that for the greatest heart protection, it is not the duration of a single exercise session that counts but the total daily amount of energy expended. Therefore, the best way to exercise may be in multiple short bouts of intense exercise, which can be particularly helpful for older people.

Resistance (weight) training has also been associated with heart protection. It may offer a complementary benefit to aerobics by reducing LDL levels. Exercises that train and strengthen the chest muscles may prove to be very important for patients with angina.

Effects of Exercise on Blood Pressure. Regular exercise helps keep arteries elastic (flexible), even in older people. This, in turn, ensures good blood flow and normal blood pressure. Sedentary people have a 35% greater risk of developing high blood pressure than athletes do.

Click the icon to see the risks associated with untreated hypertension.

It should be noted that high-intensity exercise may not lower blood pressure as effectively as moderate-intensity exercise. In one study, moderate exercise (jogging 2 miles a day) controlled high blood pressure so well that more than half the patients who had been taking drugs for the condition were able to discontinue their medication. However, a small study published in 2005 suggests that moderate exercise does not have a significant impact on systolic blood pressure (the top number) in older adults. While those who exercised did have notable drops in both the top and lower (diastolic) blood pressure levels, the only statistically significant change was the decrease in the lower number.

Experts recommend at least 30 minutes of exercise on most -- if not all -- days. Studies show that yoga and tai chi, an ancient Chinese exercise involving slow, relaxing movements, may lower blood pressure almost as well as moderate-intensity aerobic exercises.

Click the icon to see an image of someone practicing yoga.

Anyone with existing high blood pressure should discuss an exercise program with their doctor. Before starting to exercise, people with moderate-to-severe high blood pressure should lower their pressure, and be able to control it with medications. Everyone, and especially people with high blood pressure, should breathe as normally as possible through each exercise. Holding the breath increases blood pressure.

Effects of Exercise on Heart Failure. Traditionally, heart failure patients have been discouraged from exercising. Now, exercise performed under medical supervision is proving to be helpful for select patients with stable heart failure.

Studies continue to report benefits from exercise training. In one study, heart failure patients as old as 91 years old increased their oxygen use significantly, after 6 months of supervised treadmill and stationary bicycle exercises.
Progressive resistance training may be particularly useful for heart failure patients, since it strengthens muscles, which commonly weaken in this disorder. Even simply performing daily handgrip exercises can improve blood flow through the arteries.

Experts warn, however, that exercise is not appropriate for all heart failure patients.

All stroke survivors should have a pre-exercise evaluation done by their doctor before starting an exercise program.

The effects of exercise on stroke are less established than those on heart disease, but most studies show benefits. The following are some examples:

According to one major analysis, men cut their risk for stroke in half if their exercise program was roughly equivalent to about an hour of brisk daily walking 5 days a week. In the same study, exercise that involved recreation was more protective against stroke than exercise routines consisting simply of walking or climbing.
A 2000 study of women also found substantial protection from stroke in brisk walking or striding (rather than casual walking).

Anyone with heart disease or risk factors for developing heart disease or stroke should seek medical advice before beginning a workout program. Patients with heart disease can nearly always exercise safely as long as they work out under medical supervision. Still, it is often difficult for a doctor to predict health problems that might arise as the result of an exercise program. At-risk individuals should be very aware of any symptoms warning of harmful complications while they exercise.

Some experts believe that anyone over 40 years old, whether or not they are at risk for heart disease, should have a complete physical examination before starting or intensifying an exercise program. Some doctors use a questionnaire for people over 40 to help determine whether they require such an examination. The questions they use are as follows:

Has any doctor previously recommended medically supervised activity because of a heart condition?
Is chest pain brought on by physical activity?
Has chest pain occurred during the previous month?
Does the person faint or fall over from dizziness?
Is bone or joint pain intensified by exercise?
Has medication been prescribed for hypertension (high blood pressure) or heart problems?
Is the person aware of or has a doctor suggested any physical reason for not exercising without medical supervision?

Those who answer "yes" to any of the above questions should have a complete medical examination before developing an exercise program.

Stress Test. A stress test helps determine the risk for a heart problem resulting from exercise. Anyone with a heart condition or history of heart disease should have a stress test before starting an exercise program. Experts currently also recommend this test before a vigorous exercise program for older persons who are sedentary, even in the absence of known or suspected heart disease. The test is expensive, however, and some experts believe that it may not be necessary for many older people with no evident health problems or risk factors.

A small percentage of heart attacks occur after heavy physical work.

High-Risk Individuals. In general, the following people should avoid intense exercise or start it only with careful monitoring:

People who have certain medical conditions: These conditions include uncontrolled diabetes, uncontrolled seizures, uncontrolled high blood pressure, a heart attack within the previous 6 months, heart failure, unstable angina, significant aortic valve disease, or aortic aneurysm.
People with moderate-to-severe hypertension: Experts generally recommend that moderate or severe high blood pressure (systolic blood pressure over 160 mm Hg or diastolic (bottom number) pressure over 100 mm Hg) should be brought to lower levels before a person starts a vigorous exercise program.
Sedentary people should be cautious. One major study found that sedentary people who throw themselves into a grueling workout significantly increase their risk of heart attack.
Episodes of exercise-related sudden death in young people are rare but of great concern. Some are preceded by fainting, which is due to a sudden and severe drop in blood pressure. It should be noted that fainting is relatively common in athletes, and is dangerous only in people with existing heart conditions. Young people with genetic or congenital (present at birth) heart disorders should avoid intensive competitive sports.
Anabolic steroids or products containing ephedra have been associated with cases of stroke, heart attack, and even death.

The risk for heart attack from exercise should be kept in perspective, however. Some form of exercise, carefully personalized, has benefits for most of the individuals mentioned above. In many cases, particularly when the only risk factors are a sedentary lifestyle and older age, exercise can often be increased over time until it is intense.

Hazardous Activities for High-Risk Individuals. The following activities may pose particular dangers for high-risk individuals:

Intense workouts (snow shoveling, slow jogging, speed walking, tennis, heavy lifting, heavy gardening) may be particularly hazardous for people with risk factors for heart disease, especially older people. They tend to stress the heart, raise blood pressure for a brief period, and may cause spasms in the arteries leading to the heart. (See image: Coronary Artery Spasm)
Some studies suggest that competitive sports, which couple intense activity with aggressive emotions, are more likely to trigger a heart attack than other forms of exercise.

Listening for Warning Signs. It should be noted that according to one study, at least 40% of young men who die suddenly during a workout have previously experienced, and ignored, warning signs of heart disease. In addition to avoiding risky activities, the best preventive tactic is simply to listen to the body and seek medical help at the first sign of symptoms during or following exercise. These symptoms include the following:

Irregular heartbeat
Shortness of breath
Chest pain

Click the icon to see an image of a coronary artery spasm.

Click the icon to see an image of stable angina.

Exercise's Effects on Diabetes

Moderate aerobic exercise can lower your risk for type 2 diabetes. An important study found that adults who worked out 2 and 1/2 hours a week cut their risk by 58%.

Exercise has positive benefits for those who have diabetes. It can lower blood sugar, improve insulin sensitivity, and strengthen the heart. Strength training, which increases muscle and reduces fat, may be particularly helpful for people with diabetes, but more evidence is needed to confirm this theory. One study reported that yoga helped patients with type 2 diabetes reduce their need for oral medications.

In 2005, researchers found that people with type 2 diabetes who walked a minimum of 3 miles every day were in better health, and had lower medical expenses, after 2 years of such exercise. Those who remained sedentary for that time period experienced a decline in their overall health and higher health care-related expenses. Study participants who worked out for an average of 38 minutes per day lowered their blood pressure, cholesterol ,and A1C levels (glucose concentration over time). These participants also had lower heart disease risk, even if they didn't lose weight. The increase in the study participants' activity equaled about 2,200 extra steps a day. The findings were reported in the journal Diabetes Care.

An earlier study found that healthy lifestyle changes may work better than the prescription medication metformin (Glucophage), when it comes to preventing metabolic syndrome. Metabolic syndrome is a combination of risk factors including abdominal obesity, insulin resistance, high triglycerides, and hypertension.

The following are precautions for all people with diabetes, whether type 1 or 2:

Because people with diabetes are at higher than average risk for heart disease, they should always check with their doctors before starting a demanding exercise program. For best and fastest results, frequent high-intensity (not high-impact) exercises are best for people who are cleared by their doctor. For people who have been sedentary, or have other medical problems, lower-intensity exercises are recommended, using programs the patients designed with their doctors.
Strenuous strength training or high-impact exercise is not recommended for people with uncontrolled diabetes. Such exercises can strain weakened blood vessels in the eyes of patients with retinopathy (a common diabetic complication). High-impact exercise may also injure blood vessels in the feet.

Patients who are taking medications that lower blood glucose, particularly insulin, should take special precautions before starting a workout program.

Glucose levels swing dramatically during exercise. People with diabetes should monitor their levels carefully before, during, and after workouts.
Patients should probably avoid exercise if glucose levels are above 300 mg/dL or under 100 mg/dL.
To avoid hypoglycemia (low blood sugar), people with diabetes should inject insulin in sites away from the muscles they use the most during exercise.
People with diabetes should drink plenty of fluids. Before exercising, they should avoid alcohol, which increases the risk of hypoglycemia.
Insulin-dependent athletes may need to decrease insulin doses, or take in more carbohydrates, prior to exercise. However, they may need to take an extra dose of insulin after exercise. Stress hormones released during exercise may increase blood glucose level (in people without diabetes, insulin is released to control this increase). People with diabetes must regularly test their blood sugar, and take any medications as instructed by their doctor.

A person with diabetes must regularly check their blood sugar (glucose) level.

Exercise's Effects on Bones and Muscles

Exercise is critical for strong muscles and bones. Muscle strength declines as people age, but studies report that when people exercise they are stronger and leaner than others in their age group.

Exercise helps kids lower their risk of chronic pain in the future. Research has shown that it helps them prevent back and neck pain. The more flexible men are as teenagers, the lower their risk of neck tension in the future, according to a study published in the February 2006 British Journal of Sports Medicine. The same report found that women who had the greatest endurance strength as teenagers had a lower risk of tension neck than those with lower teenager endurance strength. However, men with the greatest endurance strength had higher rates of knee injuries later on.

Joints are complex structures. They are designed to bear weight and move the body. Above the knee is the femur (thigh bone). Below the knee is the tibia (shin bone) and fibula. The kneecap is also called the patella. It rides on top of the lower portion of the femur and the top portion of the tibia. The muscles and ligaments connect these bones and the space between them is cushioned by fluid-filled capsules (synovia) and cartilage. When you exercise, the muscles pull on the bones, strengthening them. The range of motion of a joint represents how far it can be flexed (bent) and extended (stretched).

Joints require motion to stay healthy. Long periods of inactivity cause the arthritic joint to stiffen and the adjoining tissue to weaken. A moderate exercise program that includes low-impact aerobics, power, and strength training has benefits for osteoarthritic patients, even if exercise does not slow down the disease progression. Many patients who start an exercise program report less disability and pain. They are also better able to perform daily chores, and remain independent longer than their inactive peers. Older patients and those with medical problems should always check with their doctor before starting an exercise program.

Click the icon to see an image of osteoporosis.

The following are useful exercises for osteoarthritis patients:

Strengthening exercises builds muscle strength. Some experts encourage patients to emphasize strengthening leg muscles as a first treatment step, even before using pain relievers. They fear that patients who rely on painkilling drugs may overuse knees, which do not have strong enough muscle tissue to protect the joints from further damage. Strengthening the thigh muscles is certainly protective for those who have not developed osteoarthritis.
Range-of-motion exercises increase the amount of movement in a joint and muscle. The best examples are yoga and tai chi, which focus on flexibility, balance, and proper breathing. In one 2001 study, older adults who practiced the gentle movement, breathing, and meditation exercises of tai chi for 10 weeks reported less pain than their peers who did not learn the technique.
Low-impact aerobic workouts help stabilize and support the joints. Cycling and walking are beneficial, and swimming or exercising in water is highly recommended for people with arthritis. Patients with arthritis should avoid high-impact sports, such as jogging, tennis, and racquetball.
Some researchers are now focusing on "power" training, which involves improving the muscle's ability to move more rapidly against resisting forces, such as gravity. For example, such training helps people stand up or climb stairs more quickly. Muscle power declines more rapidly than muscle strength, and may be particularly important in older people.

Exercise is very important for slowing the progression of osteoporosis, and extremely important for reducing the risk of falling, which causes fractures. Falls are one of the leading causes of death in people over the age of 65. Exercise helps build balance and flexibility, which reduces the risk of falling.

Specific exercises may be especially helpful for reducing the risk of fractures:

Weight-bearing exercise is very beneficial for bones in people of all ages, even older people. This approach applies tension to muscle and bone, and the body responds to this stress by increasing bone density, in young adults by as much as 2 - 8% a year. Careful weight training can also be very beneficial for elderly people, particularly women. In addition to improving bone density, weight-bearing exercise reduces the risk of fractures by improving muscle strength and balance, thus helping to prevent falls.
Regular brisk long walks improve bone density and mobility. In one 2002 study, for example, older women reduced their risk of hip fracture by over 40% by working out just four hours a week.
Exercises specifically targeted to strengthen the back can be beneficial in improving posture, and may even reduce kyphosis (hunchback) in people with osteoporosis.
Low-impact exercises, particularly yoga and tai chi, which improve balance and strength, have been found to decrease the risk of falling. In one study, tai chi reduced this risk by almost half.

Click the icon to see an image of the bone-building exercise.

Note on Female Athlete Triad. Some young female athletes who exercise very intensely, and are subject to intense pressure to remain thin, are at risk for the female athlete triad. This syndrome is a combination of three disorders -- an eating disorder, loss of menstrual periods, and osteoporosis.

People who do not exercise regularly face an increased risk for low back pain, especially during times when they suddenly have to perform stressful, unfamiliar activities. These activities may include shoveling, digging, or moving heavy items. Although no definitive studies have been done to prove the relationship between lack of exercise and low back pain, sedentary living is probably a primary nonmedical cause contributing to this condition.

Lack of exercise leads to the following conditions that may threaten the back:

Muscle inflexibility can restrict the back's ability to move, rotate, and bend.
Weak stomach muscles can increase the strain on the back and can cause an abnormal tilt of the pelvis (hip bones).
Weak back muscles may increase the load on the spine and the risk of disk compression.
Obesity puts more weight on the spine and increases pressure on the vertebrae and disks. Studies report only a weak association between obesity and low back pain, however.

Benefits for Chronic Back Pain. People in with sudden and severe back pain should not exercise. Exercise plays a very beneficial role in relieving chronic back pain, however. In one study, patients with back pain lasting for an average of 18 months were assigned eight 1-hour exercise sessions over 4 weeks. They showed greater improvement in nearly every area, including reduced pain, compared to patients who did not exercise.

Exercise should be considered as part of a broader program to return to normal home, work, and social activities. In this way, the positive benefits of exercise not only affect strength and flexibility but they also alter and improve the patients' attitudes toward their disability and pain.

Repetition is the key to increasing flexibility, building endurance, and strengthening the specific muscles needed to support the spine. Some exercise programs used for prevention or treatment of chronic low back pain include the following:

Low-impact Aerobic Exercises: Low-impact aerobic exercises, such as swimming, bicycling, and walking, can strengthen muscles in the abdomen and back without over-straining the back. Programs that use strengthening exercises while swimming may be a particularly beneficial approach for many patients with back pain. In one study, for example, pregnant women who engaged in a water gymnastics program had less back pain, and were able to continue working longer.
Lumbar Extension Strength Training: Exercises called lumbar extension strength training are proving to be effective. Generally, these exercises attempt to strengthen the abdomen, and improve lower back mobility, strength, and endurance. They also enhance flexibility in the hip and hamstring muscles, and in the tendons at the back of the thigh.
Yoga, Tai Chi, and Chi Kung: These exercises combine low-impact physical movements and meditation. They are based on principles of disciplining the mind to achieve a physical and mental balance, and can be very helpful in preventing recurrences of low back pain. In one study of Pilates, an exercise practice that uses yoga principles, the exercises were helpful in a woman with progressive and disabling severe low back pain resulting from early scoliosis. This approach deserves further research.
Flexibility Exercises: Whether flexibility exercises alone offer any significant benefit for chronic back pain is uncertain. One study suggested that any benefits derived from flexibility exercises are lost unless the exercise programs are sustained.
Retraining Deep Muscles: Studies are finding a link between low back pain and poor motor control of deep muscles in the back and trunk. According to these studies, contraction exercises specifically designed to retrain these muscles may be effective for patients with both acute and chronic pain.

It is important for any person who has low back pain to have an exercise program guided by professionals who understand the limitations and special needs of back pain and who can address individual health conditions. One study indicated that patients who planned their own exercise did worse than those in physical therapy or doctor-directed programs.

Hazardous Effects on the Back. Improper or excessive exercise can also cause back pain.

Exercise's Effects on the Lungs

Patients with chronic lung problems have difficulty exercising. Shortness of breath is a major limitation in most patients, but in about a third, muscle fatigue is an even greater problem. Although exercise does not improve lung function, training helps many patients with chronic lung disease by strengthening their limb muscles, thus improving endurance and reducing breathlessness.

In people who already have colds, exercise has no effect on the illness' severity or duration. People should avoid strenuous physical activity when they have fevers, muscle aches, or other symptoms of a widespread viral illnesses.

Long-term exercise may help control asthma and reduce hospitalization. One 2000 study found that aerobic exercise improves breathing capacity and function in patients with mild asthma. People with asthma who enjoy running should probably choose an indoor track, to avoid pollutants. Swimming is particularly excellent for people with asthma. Yoga practice, which uses both stretching, breathing, chest expansion, and meditation techniques may have specific benefits that include stress reduction as well as airway opening. One study reported that two thirds of patients who practiced yoga regularly were able to reduce or eliminate their asthma medications.

Exercise-Induced Asthma. About 40 - 90% of asthma cases are exercise-induced asthma (EIA), in which exercise triggers coughing, wheezing, or shortness of breath. It occurs most often in children and young adults and during intense exercise in cold dry air. EIA is triggered only by exercise. Unlike allergic asthma, there is no long-term increase in airway activity. People who only have EIA do not require long-term maintenance therapy. The warm-up and cool-down periods, which are important for any exercise regimen, may help reduce EIA events. A study of military recruits found that exercise-induced asthma attacks did not hinder their ability to perform or train, suggesting that EIA is not a reason to exclude people from physically demanding occupations.

Exercise-induced asthma is distinct from allergic asthma in that it does not produce long-term increase in airway activity. People who only experience asthma when they exercise may be able to control their symptoms with preventive measures such as warm-up and cool-down exercises.

Walking is the best exercise for people with emphysema. Patients should try to walk three to four times daily for 5 - 15 minutes each time. Devices that assist ventilation may reduce breathlessness that occurs during exercise.

Inspiratory muscle training involves exercises and devices that make inhaling (breathing in) more difficult, in order to strengthen breathing muscles. In a 2001 study, patients who took part in an inspiratory muscle training group improved their breathing, walking capacity, and quality of life. Yoga or martial arts exercises, such as tai chi, which emphasize breathing techniques and balanced movements, may be particularly beneficial for patients with emphysema.

Exercise's Effects on Weight

Exercising helps people reduce their weight, maintain weight loss, and fight obesity. Research has shown that women who regularly exercise but do not change their diet can lose significantly more weight than less active women.

Thirty minutes of moderate-intensity exercise may be adequate to maintain cardiovascular health, but it might not prevent weight gain. Recommendations published in 2003 and 2004 suggest that 45 - 60 minutes of exercise per day is necessary to promote weight loss. Children may need more activity.

Losing significant weight requires both exercise and calorie restriction. In addition, if a person exercises without dieting, any actual weight loss may be minimal because dense and heavier muscle mass replaces fat. Nonetheless, regardless of weight loss, a fit body will look more toned and be healthier.

People who exercise are more apt to stay on a diet plan. Exercise improves psychological well-being and replaces sedentary habits that usually lead to snacking. Exercise may even act as a mild appetite suppressant.

Exercising without dieting still adds health benefits. One study found that overweight but fit people have half the death rate of overweight, unfit people. Research suggests that people who have trained for a long time develop more efficient mechanisms for burning fat and are able to stay leaner.

Lifting weights builds muscle, which burns calories more efficiently than other body tissues.

The following are some suggestions and observations on exercise and weight loss:

The treadmill burns the most calories of standard aerobic machines. It may be particularly effective when used in short multiple bouts during the day. Exercise sessions as short as 10 minutes, which are done frequently (about four times a day), may be the most successful program for obese people.
The more strenuous the exercise, the longer the body continues to burn calories before returning to its resting level. This state of fast calorie burning can last for as little as a few minutes after light exercise, to as long as several hours after prolonged or heavy exercise.
Resistance (strength) training is excellent for replacing fat with muscles. It should be performed two or three times a week.
Fidgeting may be very helpful in keeping pounds off. Regular exercise is certainly the best course, but for people who must sit for hours at work, frequently shifting positions while sitting may have some benefit.
It is important to realize that as people slim down, they burn fewer calories per mile of walking or jogging. The rate of weight loss slows down, sometimes discouragingly so, after an initial dramatic head start using diet and exercise combinations. People should be aware of this trend and keep adding to their daily exercise routine.
Changes in fat and muscle distribution may differ between men and women as they exercise. Men tend to lose abdominal fat (which lowers their risk for heart disease faster than reducing general body fat). Exercise, however, does not appear to have the same effect on weight distribution in women. A study of women who practiced aerobic and strength training showed the training resulted in fat loss in the women's arms and trunk. However, they did not gain muscle tissue in those areas.

Because obesity is one of the risk factors for heart disease, anyone who is overweight must discuss their exercise program with a physician before starting.

Exercise's Effects on Other Conditions

Physical activity makes you healthier. It lowers your risk for cardiovascular disease and reduces bone loss. Physical activity also helps the body use calories more efficiently, which helps you eliminate body fat and lose weight. It also helps you maintain weight loss by increasing your metabolism and reducing your appetite.

A number of studies have indicated that regular exercise may reduce the risk of breast, colon, and possibly prostate cancers.

Studies confirm that exercise significantly reduces the risk of both colon cancer (by up to 50%) and breast cancer (by up to 30%).

A 2006 study found that, though protection from breast cancer may vary among the types of tumor, exercise offered the most marked protection from the more aggressive tumors. A second study, also done in 2006, supported this finding. Several studies also suggested that more intense exercise is more protective against breast cancer. Exercising consistently throughout life gives the best protection. Exercise not only lowers a woman's chance of getting breast cancer, it can help those who have received chemotherapy for the disease fight off fatigue.

While endurance athletes may suffer from stomach problems, low intensity exercise has a marked protective effect against colon cancer, according to studies, including the Nurses Health Study and the American Cancer Society's Cancer Prevention Study II. Furthermore, a 2006 study found that people with colon cancer who exercise reduce their risk of a recurrence.

Exercise also has a beneficial effect on people receiving treatment for prostate cancer. A new study found that aerobic and resistance training significantly reduced fatigue in men undergoing radiation treatments for prostate cancer. Fatigue is a common side effect of such treatments. In this study, 122 patients received supervised aerobic training, resistance training, or neither. At the end of 24 weeks, participants in both exercise groups noted significant improvement in their fatigue symptoms, compared to the control group. Participants in the resistance training group also lost a significant percentage of their body fat.

Endurance athletes often report stomach problems, such as bloating, diarrhea, and gas, even at rest. Experts suggest that moderate regular exercise might reduce the risk for some intestinal disorders. These disorders include ulcers, irritable bowel syndrome, indigestion, and diverticulosis. Older people who exercise moderately may have a lower risk for severe gastrointestinal bleeding.

Patients with end-stage kidney disease who exercise four to five times per week have better survival rates than those who are less active, according to researchers involved in the Dialysis Morbidity and Mortality Wave 2 study. However, the majority of study participants said that severe physical limitations prevented them from exercising so often.

Studies have shown that regular exercise, particularly walking, helps reduce one's risk for memory loss. A 2005 study found that older men who walked less than a mile daily had a 71% higher risk of dementia than those who walked more than two miles a day. A 2006 study found that people older than 65 who exercise regularly had lower risk of developing dementia, particularly Alzheimer's disease. An earlier study found that walking regularly protects women from mental decline. To date, there are no clear explanations for this apparent benefit. A preliminary study in mice suggests that physical activity changes the way brain-damaging proteins are processed in the brain, thus slowing the development of Alzheimer's disease. Aerobic exercise has been linked with improved reaction time, perception, and math skills in people of all ages.

Doctors found that exercise improves the physical and emotional well-being of patients who already have Alzheimer's disease. The patients exercised moderately for as little as 60 minutes each week. Doctors noted patients who exercised were less depressed, wandered away less, suffered fewer falls, and were placed in nursing homes later, compared to patients who did not exercise.

People with existing neurological diseases, such as multiple sclerosis, Parkinson's disease, and Alzheimer's disease, should be encouraged to exercise. Specialized exercise programs that improve mobility are particularly valuable for patients with Parkinson's disease. Patients with neurological disorders who exercise experience less stiffness, as well as reduction in, and even reversal of, muscle wasting. In addition, the psychological benefits of exercise are extremely important in managing these disorders. Exercise machines, aquatic exercises, and walking are particularly useful.

Some research has suggested that exercise may have antidepressant effects. Although there is little strong evidence that exercise can help manage depression, a number of studies have suggested benefits. Research findings include:

Just 30 minutes of brisk exercise three times a week was as effective as medication in relieving symptoms, and reducing relapse, in many patients with mild-to-moderate depression.
Over half of older women with depression that did not respond to medication improved with 10 weeks of exercise. (About a third of women who did not exercise also improved during that time.)
Studies on elderly, depressed patients report modest benefits from exercise, even in those who do not response to antidepressants. Simply participating in a group activity may help improve mood.
Teenagers who are active in sports have a greater sense of well-being than their sedentary peers. The more vigorously they exercise, the better their emotional health.
Physical inactivity is strongly linked to depression in children 8 - 12 years of age.

Specific exercises may be particularly beneficial:

Aerobics. Either brief periods of intense training or prolonged aerobic workouts can raise levels of certain chemicals in the brain. These chemicals -- which include endorphins, adrenaline, serotonin, and dopamine -- produce the so-called runner's high. Weight loss and increased muscle tone can boost self-esteem.

Yoga. Yoga practice, which involves rhythmic stretching movements and breathing, has been found to positively affect mood. It may have clinical potential as a technique for improving and stabilizing mood. A study comparing yoga to aerobic exercise found that men have significantly lower levels of tension, fatigue, and anger after yoga, compared with levels after swimming. Yoga and swimming tended to produce equal benefits in women.

Click the icon to see an image of the benefits of yoga.

Moderate exercise in healthy pregnant women does not increase the risk for miscarriage, preterm labor, or rupture of the membrane. Not exercising increases the risk for complications, including low-birth weight babies. Exercising increases the fetal heart rate, which in turn protects the baby.

Healthy women with normal pregnancies should exercise at least three times a week, being careful to warm up, cool down, and drink plenty of liquids. Many prenatal calisthenics programs are available.

The following are specific exercises that may benefit the pregnant woman:

Swimming and water aerobics may be the best option for most pregnant women. Swimming has special benefits for those with fluid buildup. Water exercises involve no impact, overheating is unlikely, and swimming face down promotes optimum blood flow to the uterus.
Performing yoga exercises under the guidance of informed instructors can be very helpful.
Walking is also beneficial.

To strengthen pelvic muscles, women should perform Kegel exercises at least six times a day. This involves contracting the muscles around the vagina and urethra for three seconds 12 - 15 times in a row.

Experts generally recommend the following precautions for pregnant women who exercise:

Fit women who have exercised regularly before pregnancy may work out intensely as long as the doctor approves and no discomfort occurs.
As a rule for previously sedentary, low-risk expectant mothers, the pulse rate should not exceed 70 - 75% of the maximum heart rate, or more than 150 beats per minute. Any sedentary expectant mother should check with her doctor before starting an exercise program.
According to one study, vigorous exercise may improve the chances for a timely delivery. All pregnant women, however, should avoid high-impact, jerky, and jarring exercises, such as aerobic dancing, which can weaken the pelvic floor muscles that support the uterus.
During exercise, women should monitor their temperature to avoid overheating, a side effect that can damage the fetus. (Pregnant women should also not use hot tubs or steam baths, which can cause fetal damage and miscarriage.)

Note: Strenuous exercise may affect the flavor of breast milk for a short time afterward. Nursing mothers who engage in such activity might want to wait about an hour after exercising before they feed their infant.

Complications

Exercise may lead to injury if not done properly. Always exercise with care.

Competitive running or high-impact aerobics pose a high risk of a number of injuries to the bones and muscle. The effect of high-impact exercise on the back is not entirely clear. Some research suggests that over time, high-impact exercise may increase the risk for degenerative disk disease. A survey of people who played tennis, however, found no increased risk for low back pain or sciatica.

High-impact exercise can also cause dizziness, ringing in the ear, motion sickness, or loss of high-frequency hearing.

Some research further suggests that in people unused to exercise, intense activity increases production of harmful particles in the body called free radicals. These unstable oxygen particles injure muscle tissue. Muscle pain in this case does not occur until 24 - 48 hours after exercise.

Some people have a higher than average risk for injury:

About half of people at any age who participate in competitive running or high-impact aerobics experience minor injuries at least once a year. Young, intensely competitive athletes may be at risk for permanent injury. Studies are mixed over whether intensive high-impact sports in younger people cause long-term degenerative joint disease.
As the number of older people who start exercising increases, there has also been an increase in injuries for this age group. Between 1990 and 1996, injuries from active sports increased by 54% in people age 65 and older.
Women are far more likely than men to suffer knee injuries.
Urinary incontinence affects many female athletes who engage in high-impact exercise.
Tennis players are at high risk for injuries from repetitive force on the shoulder joint.

Preventing High-Impact Injuries. The following may be helpful for preventing injury:

Wear shock-absorbing footwear with weight-dampening inserts.
Combine weight lifting with jumping exercises. This may prevent injury by strengthening hamstrings and improving coordination.
Vary training and alternate easy and harder workouts.
Be careful to warm up, cool down, and stretch. Flexibility is the key to preventing many muscle strains.
Take days off now and then. The risk of injury increases when athletes train more than five times a week.

Because of the association between high-impact exercises and oxidation, some experts suggest eating foods rich in antioxidants, such as vitamins A, C, and E. Such foods, which may protect against damage from free radicals, include many fresh fruits and vegetables.

Treating Minor Injuries. Most mild or moderate injuries respond well to a simple, four-step treatment: rest, ice, compression, and elevation (RICE). This combination works well for both spot injuries and chronic problems. Ice packs, which reduce inflammation and pain, can help new injuries, and can be useful for the first few hours after a chronically injured area is exercised. How much or how long to compress the injury is unclear.

Evidence suggests that early movement is helpful, although taping or bracing in people with a recurrent ankle sprain is known to be protective. It may not be helpful in those without a previous ankle injury.

Minor injuries like sprains may be treated at home if broken bones are not suspected. The acronym RICE can help you remember how to treat minor injuries: "R" stands for rest, "I" is for ice, "C" is for compression, and "E" is for elevation. Pain and swelling should decrease within 48 hours. Gentle movement may help, but pressure should not be put on a sprained joint until pain is completely gone. This can take up to a few weeks.

Heat, ultrasound, whirlpool, and massage may speed healing if applied a day or two after the initial injury or for warm-up before another workout session.

Some young female athletes who exercise very intensely, and are subject to intense pressure to remain thin, are at risk for a syndrome known as the female athlete triad. This combination of symptoms includes loss of menstruation, eating disorders, and osteoporosis. Eating disorders among young female athletes are estimated at 15 - 62%. Women at higher risk include ballet dancers, gymnasts, and divers. Continued intense exercise causes a stress response in which estrogen (the primary female hormone) is lost. Estrogen loss can lead to infertility and osteoporosis. Iron loss and anemia may also be a problem in women who exercise frequently, even at moderate intensity. A doctor should be consulted for any of these concerns.

Incorrect movements can literally cause mechanical problems in the muscles. These problems are usually the result of improper exercise instruction, and lack of attention. A single jerky golf swing, or the incorrect use of exercise equipment (especially free weights, nautilus, and rowing machines), can cause serious back injuries.

Between 30 - 70% of cyclists experience low back pain. Pain may be improved by adjusting the angle of the bicycle seat.

Everyone should drink lots of fluid during intense exercise. Thirst is often a poor indicator of dehydration in people who exercise, particularly older people. During a tough workout in a hot environment, the body can lose two liters of fluid per hour through sweat.

Anyone who exercises intensely should take the following precautions:

Drink 6 - 8 ounces of fluid about 15 minutes before a workout, and then pause regularly during exercise to drink more.
Water is the best choice for replenishing body fluids. Glucose-sodium-potassium solutions, the so-called "sports drinks," which promise instant energy, appear to be no better than water at improving endurance during prolonged intense running.
Caffeinated beverages like coffee and soft drinks give short bursts of energy, but can actually cause fluid loss. Caffeine before a workout has been shown to temporarily raise blood pressure, and reduces blood flow to inactive limbs.

Contrary to popular belief, drinking fluids will not cause cramps. Drinking enough, in fact, helps prevent the painful involuntary muscle spasms that sometimes occur during exercise.

Overheating, or hyperthermia, can be a problem with hard exercise, or when working out in hot weather. Overheating can cause mild to life-threatening conditions. Heat exhaustion, a moderate form of hyperthermia, is characterized by the following symptoms:

Lightheadedness, nausea, headache, hyperventilation, fatigue, and loss of concentration
A high temperature (above 103° F), possibly accompanied by complaints of chills and clammy skin

Individuals should rest in a cool, dry place, drink plenty of fluids, and bring down their body temperature with ice packs pressed against the skin.

Heatstroke. Heatstroke is the most dangerous complication of hyperthermia. The victim may suddenly stop sweating, after which symptoms such as altered consciousness, seizures, and even coma may quickly follow. Heat stroke is a medical emergency and requires immediate cooling of the victim in an ice-water bath or with ice packs. One study suggests that risk for serious complications from exercising in high temperatures may persist as late as the following day, even if the weather has cooled down.

Click the icon to see an image of the dangers of heatstroke.

Precautions are also necessary in cold weather. When exercising in winter dress in layers, including gloves and socks, which create insulated air pockets that trap heat. In cold weather, wear shoes with less ventilation than those worn in the summer. Fingers, toes, ears, and nose are most susceptible to frostbite. Frostbite progresses from stinging or aching to numbness. Fingers and toes may become white. Soaking the hands and feet in warm water can help, but only once there is no risk of refreezing, since a second bout of frostbite after thawing can quicken tissue damage.

Hypothermia can be life-threatening and can occur even after long exposure to temperatures that are above freezing. The condition is characterized by extreme fatigue, mental confusion, apathy, and a lack of coordination. The victim should be warmed as soon as possible with blankets, body heat, and warm fluids.

Motivation

Motivation, or a lack thereof, is one reason many people stop exercising. Here are some tips for avoiding burnout:

Think of exercise as a menu rather than a diet. Choose a number of different physical activities that are personally enjoyable such as sports, dancing, or biking. Although experts say you should get 30 minutes of aerobic exercises at least five times a week, those times can be divided into shorter periods -- such as 10 minute sessions. In addition, people can achieve health benefits from other exercise programs, including weight training, yoga, or tai chi.
Stick to a prepared schedule and record progress.
Develop an interest or hobby that requires physical activity.
Adopt simple routines such as climbing the stairs instead of taking the elevator, walking instead of driving to the local newsstand, or canoeing instead of zooming along in a powerboat.
Try cross training (regularly switching from one type of exercise to another). Studies suggest it is more beneficial than focusing only on one form of exercise.
Exercise with friends.
Join a gym or take classes. Many affordable programs are available.
For those who can afford them, personal trainers can be very helpful and are available in many gyms and exercise clubs. Personal trainers without any connection to a well-reputed gym or fitness club should be certified by a major fitness organization, such as the Aerobics and Fitness Association of America (AFAA) or the American Council on Exercise.
Exercise videos may also be helpful, but people should be sure they are suited to their individual age and health needs, and bear the seal of the AFAA.
Consider getting a dog. A study in the February 2006 American Journal of Preventive Medicine found that dog owners in Canada walk almost twice as much as those who don’t own a dog. Regular walking is a good way to improve health.

Differences in Motivation Between Men and Women. Motivation factors may differ by gender, and women appear to have a harder time. In one study, weight loss was the greatest motivator to exercise for women, and muscle tone was the primary motivator for men. Unfortunately, effects on appearances may take a long time to show, discouraging people from continuing an exercise program even though their health is improving.

Overweight among children and adolescents has now become an epidemic in the United States. Experts say that children should be vigorously active for at least 20 - 60 minutes 3 - 5 days a week. Parents and schools must be imaginative and rigorous in encouraging children to exercise.

Role of Parents. Parents must make conscious efforts to limit sedentary activities, and to encourage physical ones for their children. This includes monitoring the time children spend on the computer, in front of the TV, or playing video games. Parents should suggest different forms of entertainment. Even children who aren't interested in joining a Little League team may enjoy a round of catch with their parents, walking in the park, or swimming in a local lake.

Role of Schools. Early school physical education programs can make a significant difference and the earlier these routines are learned, the more likely they will be carried forth into a healthy adulthood. Schools should emphasize team cooperation or individual improvement and self-mastery. Studies have shown that people tend to give up more quickly and feel less competent if their perceptions of success are based only on comparison to their peers.

People mature at different rates, and there seems to be a genetic component to coordination, strength, speed, and one's response to resistance exercise. Nonetheless, everyone should strive to be as fit as they possibly can, given their strengths and limitations.

The decision to adopt a healthier behavior -- whether it's more exercise, weight loss, or quitting smoking -- is not as simple as just deciding to do it. Behavior change expert James Prochaska and his colleagues outlined a theory, which has been supported by numerous studies, showing that people cycle through a variety of stages before a new behavior is successfully adopted over the long term. It may help you to understand how this works. As you read the description of each stage -- specifically as it relates to exercise -- you may find yourself nodding and saying to yourself, "Yes, that's me!"

Stage 1: Pre-Contemplation. People at this stage have no plans or desire to exercise. They aren't even considering exercising. They are generally unaware of the specific benefits that exercise can bring -- exercise may seem more like a hassle than something worth doing. Or, they may simply have "failed" in the past and have given up.

There's no point in talking about how to start an exercise program if you are at this stage. Instead, it is important to think about how exercise might be good for you personally -- by helping you to lose weight, feel better, have more confidence, live longer, sleep better, or reduce your stress levels. The benefits must be identified before a person will consider exercise.

If you are at this stage, a good activity is to ask four friends or family members why they exercise. Their answers may show you some real-life benefits, and inspire enough interest to compel you to take the next step.

Stage 2: Contemplation. A person at this stage is thinking, "I think I should probably exercise, but I need help getting started." People at this stage know that exercise is good for them, but it seems like a daunting task or they don't think they can pull it off. Some may have tried and "failed" in the past, but they are still receptive to another go-round.

It's important for people at this stage to consider some of the truths and falsehoods of exercise. For example, it is helpful to know that there are many forms of physical activity to select from, and that you can do your exercising in small chunks. It is not true that exercise has to be painful, or that you either succeed or fail. There is no such thing as "failure" -- people become more or less active at different stages of their lives, and it is never too late to get moving again. And people at this stage should find assurance that an exercise plan can be very simple.

If you are at this stage, a good activity is to write down all the things that you believe make exercise difficult -- and to learn strategies for overcoming or side-stepping those hurdles. People at this stage might benefit from making a pledge, contract, or other commitment that they are going to get more active in the near future. The goal is to get un-stuck by identifying the roadblocks and the ways to overcome these roadblocks. The final goal at this stage is to make a commitment.

Stage 3: Preparation. These folks are primed and motivated. They are ready to give exercise a try. The goal of this stage is to create a specific action plan that takes all factors into account, so that the "launch" is successful. People at this stage need to know how much they should be exercising, their target heart rate, and the types of exercises. They should explore the different kinds of exercises and decide which ones to try.

At this stage, people will evaluate exercise machines and health plans, if that interests them, pick the proper clothing or accessories, and consult a doctor if necessary. They also need to think about how they are going to fit their exercise plans into their daily and weekly schedule.

If you are at this stage, you should also consider some backup plans -- what to do if it rains, or if you don't feel like exercising. That way you are prepared to overcome that hurdle when you encounter it. You should be aware of what to expect realistically at the beginning -- for example, be aware that weight loss takes time, but health benefits begin immediately.

Stage 4: Action! People at this stage have just started exercising. This stage is where the biggest behavior change occurs -- these people have started to exercise but it is not yet a long-term, ingrained habit. This stage requires significant commitment and energy.

If you are at this stage, keep talking to friends and family for inspiration. Review your backup plans. Reward yourself for small achievements. Give yourself notes and reminders to exercise. Having a friend to exercise with can be very helpful as you get through this stage. You want to build and maintain momentum, because exercising gets easier once it is a habit!

Stage 5: Maintenance. The people at this stage have been exercising for at least 6 months. At this point, exercising has started to become a habit. The goal here is to prevent relapse. If you are at this stage, identify ways that you can fine-tune your program. Continue to identify roadblocks and improve your backup plans. Think about what you have found most enjoyable about exercising.

What benefits have you gained? Keep reminding yourself of these perks. If giving yourself a challenge was part of your initial motivation, set new goals and find new challenges. If you risk getting bored with your routine, find ways to vary it. Or maybe you have found a comfortable routine that you enjoy -- if it's working, great! There is no need to change it. You might want to read or learn more about your method of exercising, and develop a deeper level of understanding about it. Soon you'll be a pro!

One point about this theory is that people do not proceed from one stage to another in a simple, step-by-step fashion. They actually cycle or spiral back and forth, so that they may move from stage 1 to 2 to 3, and then back to 2 again. They may stay in maintenance mode for years and then fall back to stage 2. Remember that this is normal -- if you tried exercising in the past and didn't stick with it, don't consider yourself a failure. Just know that it's time to try again!

Resources

http://fitness.gov -- The President's Council on Physical Fitness and Sports
www.ncppa.org --National Coalition for Promoting Physical Activity
www.acefitness.org --American Council on Exercise
www.arthritis.org --The Arthritis Foundation offers tips on exercising with arthritis
www.justmove.org -- Just Move (American Heart Association)

References

Taylor, A.H., Ussher, M., & Faulkner, G. The acute effects of exercise on cigarette cravings, withdrawal symptoms, affect and smoking behaviour: a systematic review. Addiction. 2007;102:534-543.

Kruk J. Lifetime physical activity and the risk of breast cancer: a case-control study. Cancer Detect Prev. 2007;31(1):18- 28.

Tehard B, Friedenreich CM, Oppert JM, et al. Effect of physical activity on women at increased risk of breast cancer: results from the E3N cohort study. Cancer Epidemiol Biomarkers Prev. 2006 Jan;15(1):57-64.

Adams SA, Matthews CE, Hebert JR, et al. Association of physical activity with hormone receptor status: the Shanghai Breast Cancer Study. Cancer Epidemiol Biomarkers Prev. 2006 Jun;15(6):1170-8.

Larson EB, Wang L, Bowen JD et al. Exercise is associated with reduced risk for incident dementia among persons 65 years of age and older. Ann Intern Med. 2006 Jan 17;144(2):73-81.

Meyerhardt JA, Heseltine D, Niedzwiecki D, et al. Impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803. J Clin Oncol. 2006 Aug 1;24(22):3535-41.

Slattery ML. Physical activity and colorectal cancer. Sports Med. 2004;34(4):239-52.

Peters HP, De Vries WR, Vanberge-Henegouwen GP et al. Potential benefits and hazards of physical activity and exercise on the gastrointestinal tract. Gut. 2001 Mar;48(3):435-9.

Abbott, RD, White, LR, G. Ross, W, et al. Walking and Dementia in Physically Capable Elderly Men. JAMA. 2004;292:1447-1453

Calton BA, Lacey JV Jr, Schatzkin A, Schairer C, Colbert LH, Albanes D, Leitzmann MF. Physical activity and the risk of colon cancer among women: A prospective cohort study (United States). Int J Cancer. 2006 Feb 17; [Epub ahead of print]

Di Loreto C, Fanelli C, Lucidi P, et al. Make your diabetic patients walk: long-term impact of different amounts of physical activity on type 2 diabetes. Diabetes Care. 2005 Jun;28(6):1295-302.

Mikkelsson LO, Nupponen H, Kaprio J, Kautiainen H, Mikkelsson M, Kujala UM. Adolescent flexibility, endurance strength, and physical activity as predictors of adult tension neck, low back pain, and knee injury: A 25 year follow up study. Br J Sports Med. 2006 Feb;40(2):107-13.

Brown SG, Rhodes RE. Relationships among dog ownership and leisure-time walking in Western Canadian adults. Am J Prev Med. 2006 Feb;30(2):131-6.

Simons R, Andel R. The effects of resistance training and walking on functional fitness in advanced old age. J Aging Health. 2006 Feb;18(1):91-105.

Review Date:
4/30/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

A.D.A.M. Copyright

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2009 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com

In Case You Missed It: FitSugar Printables

FitSugar — Fri, 19 Dec 2008 11:00:00 -0800

We all know that fitness doesn't really begin at the computer. And healthy eating doesn't really either. That is why I have created a few workouts and health tools for you to print and use in your life away from your PC or Mac.

All Body Circuit Workout: This workout contains only nine moves and takes just about 20 minutes. It works your entire body as well as your heart. This circuit was designed for your living room and requires no props other than a chair.
Back Workout: Most of us forget to work our backs when we train. Not only can this lead to weakness and pain, but a toned back is a sexy back. Plus a strong back helps you stand and sit up straight, which not only makes you look powerful, but good posture can make you look thinner, too.
Arm Plan: You need strong arms to shovel Winter snow and tote all your holiday shopping about. This workout works all the muscles in the arms and shoulders to give them a sleek and sexy look.
Food Journal: Keeping track of what you eat is one of the best ways to maintain and lose weight. My food journal can help you keep track of your calories as well as your vegetable and water intake.
Exercise Journal: Plan your workouts before heading to the gym with this exercise journal. It will help you keep track of your strength-training routine as well as your cardio schedule.

Diabetes - type 1

FitSugar — Wed, 08 Oct 2008 17:35:05 -0700

In This Report

Highlights
Introduction
Causes
Risk Factors
Symptoms
Life-Threatening Complicati...
Diagnosis
Dietary Goals and Exercise...
Treatment
Monitoring Tests
Long-Term Complications
Transplantation Procedures...
Prevention
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

New Continuous Glucose Meter System

In 2007, the FDA approved the STS-7 System, which monitors glucose levels every 5 minutes during a 7-day period. The STS-7 System, like other continuous glucose meter systems, is designed to be used in combination with traditional fingerstick tests and meters. It does not replace them. But the system can track trends and fluctuation patterns in blood sugar levels that fingerstick tests cannot detect.

Type 1 Diabetes Gene Discovered

In 2007, scientists announced the discovery of a gene that may increase the risk of developing childhood type 1 diabetes.

Anemia Drugs Warning

In 2007, following the publication of several studies in the New England Journal of Medicine, the FDA warned that erythropoiesis-stimulating drugs (used to treat anemia) can increase the risk for blood clots, strokes, and heart attacks when excessive doses are given. The FDA has set new dosing and hemoglobin target levels for these drugs. Anemia is a common complication of end-stage kidney disease.

Cell Transplantation Research

Islet cell transplantation using the Edmonton protocol is a promising treatment for type 1 diabetes, suggests a 2006 study published in the New England Journal of Medicine. The Edmonton protocol involves isolating islet cells from donor pancreases and then injecting the cells into the patient. In the first international multicenter trial of this investigational procedure, 44% of 36 patients were able to temporarily suspend insulin injections, while 28% achieved partial islet function.
Stem cell transplantation using cells harvested and re-infused from the patient’s own body may help increase beta cell function and eliminate the need for insulin injections, according to a small, preliminary study published in 2007 in the Journal of the American Medical Association.

Type 1 Diabetes Prevention Research

Scientists around the world are investigating new ways to prevent type 1 diabetes or at least delay its onset. Experimental preventive measures include treatment with oral insulin and with drugs that may prevent the immune system’s attack on beta cells.

Introduction

The two major forms of diabetes are type 1, previously called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes, and type 2, previously called non-insulin-dependent diabetes mellitus (NIDDM) or maturity-onset diabetes.

Both type 1 and type 2 diabetes share one central feature: elevated blood sugar (glucose) levels due to absolute or relative insufficiencies of insulin, a hormone produced by the pancreas. Insulin is a key regulator of the body's metabolism. It works in the following way:

During and immediately after a meal the process of digestion breaks carbohydrates down into sugar molecules (of which glucose is one) and proteins into amino acids.
Right after the meal, glucose and amino acids are absorbed directly into the bloodstream, and blood glucose levels rise sharply. (Glucose levels after a meal are called postprandial levels.)
The rise in blood glucose levels signals important cells in the pancreas, called beta cells, to secrete insulin, which pours into the bloodstream. Within 20 minutes after a meal insulin rises to its peak level.
Insulin enables glucose and amino acids to enter cells in the body, particularly muscle and liver cells. Here, insulin and other hormones direct whether these nutrients will be burned for energy or stored for future use. (It should be noted that the brain and nervous system are not dependent on insulin; they regulate their glucose needs through other mechanisms.)
When insulin levels are high, the liver stops producing glucose and stores it in other forms until the body needs it again.
As blood glucose levels reach their peak, the pancreas reduces the production of insulin.
About 2 - 4 hours after a meal both blood glucose and insulin are at low levels, with insulin being slightly higher. The blood glucose levels are then referred to as fasting blood glucose concentrations.

The pancreas is located behind the liver and stomach. In addition to secreting digestive enzymes, the pancreas secretes the hormones insulin and glucagon into the bloodstream. The release of insulin into the blood lowers the level of blood glucose (simple sugars from food) by enhancing glucose to enter the body cells, where it is metabolized. If blood glucose levels get too low, the pancreas secretes glucagon to stimulate the release of glucose from the liver.

In type 1 diabetes, the disease process is more severe than with type 2 diabetes, and onset is usually in childhood:

Beta cells in the pancreas that produce insulin are gradually destroyed. Eventually insulin deficiency is absolute.
Without insulin to move glucose into cells, blood glucose levels become excessively high, a condition known as hyperglycemia.
Because the body cannot utilize the sugar, it spills over into the urine and is lost.
Weakness, weight loss, and excessive hunger and thirst are among the consequences of this "starvation in the midst of plenty."
Patients become dependent on administered insulin for survival.

Type 2 diabetes is the most common form of diabetes, accounting for 90% of cases. About 20 million Americans have type 2 diabetes and half are unaware they have it. The disease mechanisms in type 2 diabetes are not wholly known, but some experts suggest that it may involve the following three stages in most patients:

The first stage in type 2 diabetes is the condition called insulin resistance. Although insulin can attach normally to receptors on liver and muscle cells, certain mechanisms prevent insulin from moving glucose (blood sugar) into these cells where it can be used. Most patients with type 2 diabetes produce variable, even normal or high, amounts of insulin, and in the beginning this amount is usually sufficient to overcome such resistance.
Over time, the pancreas becomes unable to produce enough insulin to overcome resistance. In type 2 diabetes, the initial effect of this stage is usually an abnormal rise in blood sugar right after a meal (called postprandial hyperglycemia). This effect is now believed to be particularly damaging to the body.
Eventually, the cycle of elevated glucose further impairs and possibly destroys beta cells, thereby stopping insulin production completely and causing full-blown diabetes. This is made evident by fasting hyperglycemia, in which elevated glucose levels are present most of the time.

Maturity-Onset Diabetes in Youth. Maturity-onset diabetes in youth (MODY) is a rare genetic form of type 2 diabetes that develops only in Caucasian teenagers. It accounts for 2 - 5% of type 2 cases.

Gestational Diabetes. An estimated 5% of pregnant women develop a form of type 2 diabetes in their third trimester called gestational diabetes. Gestational diabetes is usually temporary. [See In-Depth Report #60: Diabetes - type 2.]

Conditions that damage or destroy the pancreas, such as pancreatitis, pancreatic surgery, or certain industrial chemicals can cause diabetes. Certain drugs can also cause temporary diabetes, including corticosteroids, beta-blockers, and phenytoin. Rare genetic disorders (Klinefelter's syndrome, Huntington's chorea, Wolfram's syndrome, leprechaunism, Rabson-Mendenhall syndrome, lipoatrophic diabetes, and others) and hormonal disorders (acromegaly, Cushing syndrome, pheochromocytoma, hyperthyroidism, somatostatinoma, aldosteronoma) also increase the risk for diabetes.

Causes

Type 1 diabetes is usually a progressive autoimmune disease, in which the beta cells that produce insulin are slowly destroyed by the body's own immune system. It is unknown what first starts this cascade of immune events, but evidence suggests that both a genetic predisposition and environmental factors, such as a viral infection, are involved.

Islets of Langerhans contain beta cells and are located within the pancreas. Beta cells produce insulin which is needed to metabolize glucose within the body.

Certain factors are thought to be important in this process:

White blood cells called T lymphocytes produce immune factors called cytokines that attack and gradually destroy the beta cells of the pancreas. Important cytokines are interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma.
Specific proteins are also critical in the process. They include glutamic acid decarboxylase (GAD), insulin, and islet cell antigens. These proteins serve as autoantigens. That is, they trigger the self-attack of the autoantibodies on the body's own beta cells.

Progression from the first stage, known as insulitis, to full-blown diabetes can take 7 years or longer. Unfortunately, by the time a person is aware that something is wrong and goes to the doctor with symptoms of type 1 diabetes, about 80 - 90% of the beta cells have been destroyed.

More than half of patients with insulitis do not develop diabetes. Researchers are greatly interested in discovering any factors that prevent the disease.

Researchers have found at least 18 genetic locations, labeled IDDM1 - IDDM18, that are related to type 1 diabetes. The IDDM1 region contains the HLA genes that encode proteins called major histocompatibility complex. The genes in this region affect the immune response. New advances in genetic research are identifying other genetic components of type 1 diabetes. In 2007, scientists announced that they had discovered a gene, KIAA0350, on chromosome 16. Variations in this gene appear to increase the risk of a child developing type 1 diabetes. The research team expects to identify an additional 15 - 20 genes associated with type 1 diabetes.

The odds of inheriting the disease, however, are only 10% if a first-degree relative has diabetes, and even in identical twins, one twin has only a 33% chance of having type 1 diabetes if the other has it. Children are more likely to inherit the disease from a father with type 1 diabetes than from a mother with the disorder.

Genetic factors cannot fully explain the development of diabetes. Over the past 30 years, a major increase in the incidence of type 1 diabetes has been reported in certain European countries, and the incidence has nearly tripled in the northeastern U.S. If genetic factors were the only cause of type 1 diabetes, such an increase in cases would take at least 400 years.

Some researchers believe one or more viral infections may trigger the disease in genetically susceptible individuals. Researchers suggest the following scenario:

An infection introduces a viral protein that resembles a beta-cell protein.
T cells and antibodies are tricked by this resemblance into attacking the beta protein as well as the virus.

Among the viruses under scrutiny are enteric viruses, which attack the intestinal tract. Coxsackieviruses are a family of enteric viruses of particular interest. (One study has suggested that respiratory infection in a child's first year, and not later, may be protective against diabetes, perhaps by priming the immune response so that it is better able to respond later on to other organisms.)

Risk Factors

An estimated 1 million people in the U.S. have type 1 diabetes, with about 30,000 new cases diagnosed each year. It is much less common than type 2, however, consisting of only 5 - 10% of all cases of diabetes. Nevertheless, like type 2 diabetes, the incidence of type 1 diabetes among children and adolescents has been rising over the past few decades. Experts estimate that about 1 in every 400 - 600 children and adolescents has type 1 diabetes. While type 2 diabetes has been increasing among African-American and Hispanic adolescents, the highest rates of type 1 diabetes are found among Caucasian youth.

Type 1 can occur at any age but usually appears between infancy and the late 30s, most typically in childhood or adolescence. Boys and girls are equally vulnerable. Studies report the following may be risk factors for developing type 1 diabetes:

Being ill in early infancy.
Early foods. Some studies have reported that early exposure to cow's milk in infancy and not being breast fed increased the risk for type 1 diabetes. Two studies in 2003 suggested that very early exposure to cereal -- not cow's milk -- plays a role in risk. Any risk from early dietary factors is still very low and likely to affect children who already have a genetically impaired immune response to dietary proteins. Breast milk contains factors that may help regulate the immune response and prevent diabetes in such children. National differences in risk also suggest that not all cow's milk is the same, and some proteins may confer higher risks than others.
Having a parent with type 1 diabetes.
Having an older mother.
Having a mother who had preeclampsia during pregnancy.
Obesity in children has long been linked to a higher risk for type 2 diabetes. Two 2001 studies reported an association between high weight at birth and obesity during childhood as risk factors for type 1 diabetes as well. The common risk factor may be an increase in insulin secretion, which occurs with obesity. This theoretically could overstress the beta cells so that they become susceptible to damage by overactive immune factors (particularly cytokines), and eventually to destruction in children genetically vulnerable to type 1 diabetes.

Until recently, diabetes in children was almost always type 1 diabetes. Of major concern, however, are estimates that between 8 - 45% of new diabetes cases in children are now type 2, most likely because of the increase in childhood obesity. [See In-Depth Report #60: Diabetes - type 2.]

The incidence of type 1 diabetes is higher than average among people with other autoimmune diseases, including Grave's disease, Hashimoto's thyroiditis (a form of hypothyroidism), Addison's disease, multiple sclerosis (MS), and pernicious anemia. Research has raised the possibility that all autoimmune diseases share a common genetic basis. A 2001 study found, for example, that the T-cell immune factors in type 1 diabetes target the same self-antigens as in multiple sclerosis (MS). Both diseases have been associated with cow's milk protein. Many questions are unanswered, however. It is not known why the diseases develop in different locations to cause separate disorders or why some autoimmune events occur in everyone but not everyone develops an autoimmune disease.

There is a very wide variation in incidence of type 1 among population groups. Type 1 diabetes appears to be most common in people of northern European descent and in specific Mediterranean groups (such as Sardinians). It is less common among Asians and African-Americans. Still, African-Americans with type 1 diabetes are 50% more likely to die from it than Caucasians, mostly due to lower-quality health care.

Symptoms

The process that destroys the insulin-producing beta cells can be long and insidious. At the point when insulin production bottoms out, however, type 1 diabetes usually appears suddenly and progresses quickly. Warning signs of type 1 diabetes include:

Frequent urination (in children, a recurrence of bed-wetting after toilet training has been completed)
Unusual thirst, especially for sweet, cold drinks
Extreme hunger
Sudden, sometimes dramatic, weight loss
Weakness
Extreme fatigue
Blurred vision or other changes in eyesight
Irritability
Nausea and vomiting (acute symptoms)

Children with type 1 diabetes may also be restless, apathetic, and have trouble functioning at school. In severe cases, diabetic coma may be the first sign of type 1 diabetes.

Life-Threatening Complications

Diabetic ketoacidosis (DKA) is a life-threatening complication that develops when insulin stores are depleted. It is almost always caused by noncompliance with insulin treatments. Other contributing factors are lack of health insurance and intentionally reducing insulin levels in order to lose weight. In one study, adolescent girls were at higher risk for ketoacidosis than other groups of children and young people.

Diabetic ketoacidosis often develop as follows:

The process is usually triggered in insulin-deficient patients by a stressful event, most often pneumonia or urinary tract infections. Other triggers include alcohol abuse, physical injury, pulmonary embolism, heart attacks, or other illnesses.
Severely low insulin levels cause excessive amounts of glucose in the bloodstream (hyperglycemia).
Fat breakdown then accelerates and increases the production of fatty acids.

These fatty acids are converted into chemicals called ketone bodies, which are toxic at high levels. Symptoms and complications include:

Nausea and vomiting
Deep and rapid breathing may with frequent sighing
Rapid heartbeat
Cerebral edema, or brain swelling, is a rare but very dangerous complication that occurs in 1% of ketoacidosis cases and results in coma, brain damage, or death in many cases. Research now suggests that the risk for this complication is significantly higher in children with severe ketoacidosis (indicated by low carbon dioxide levels and high nitrogen urea levels), and possibly if they are also treated with bicarbonate to reduce acid levels.
Other serious complications from DKA include aspiration pneumonia and adult respiratory distress syndrome.
If the condition persists, coma and eventually death may occur, although over the past 20 years, death from DKA has decreased to about 2% of all cases.

Life-saving treatment uses rapid rehydration with a salt (saline) solution followed by low-dose insulin and potassium replacement.

Ketoacidosis is a serious condition of glucose build-up in the blood and urine. A simple urine test can determine if high ketone levels are present.

Tight blood sugar (glucose) control increases the risk of low blood sugar (hypoglycemia). Hypoglycemia, also called insulin shock, occurs if blood glucose levels fall below normal. Hypoglycemia may also be caused by insufficient intake of food, or excess exercise or alcohol. Usually the condition is manageable, but occasionally, it can be severe or even life threatening, particularly if the patient fails to recognize the symptoms.

Risk Factors for Severe Hypoglycemia. Among young patients, the youngest children and boys of any age are at higher risk for hypoglycemia. Specific risk factors for severe hypoglycemia include:

Intensively controlling blood glucose and HbA1c levels
Having long-term diabetes
Being less educated about the condition
Being underinsured
Having psychiatric disorders

Hypoglycemia unawareness. Hypoglycemia unawareness is a condition in which people become insensitive to hypoglycemic symptoms. It affects about 25% of patients who use insulin, nearly always people with type 1 diabetes. In such cases, hypoglycemia appears suddenly, without warning, and can escalate to a severe level. Even a single recent episode of hypoglycemia may make it more difficult to detect the next episode. With vigilant monitoring and by rigorously avoiding low blood glucose levels, patients can often regain the ability to sense the symptoms. However, even very careful testing may fail to detect a problem, particularly one that occurs during sleep.

Symptoms. Mild symptoms usually occur at moderately low and easily correctable levels of blood glucose. They include:

Sweating
Trembling
Hunger
Rapid heartbeat

Severely low blood glucose levels can cause neurologic symptoms such as:

Confusion
Weakness
Disorientation
Combativeness
In rare and worst cases, coma, seizure, and death

Preventive Measures. The following tips may help avoid hypoglycemia or prepare for attacks.

Nocturnal hypoglycemia (which occurs during sleep) is a common problem for children, even those on nonintensive insulin therapy. (The risk for hypoglycemia is high in any case in children.) Bedtime snacks are advisable if blood glucose levels are below 180 mg/dL (10 mmol/L). Protein snacks may be best. (The use of the insulin pump may help prevent hypoglycemic episodes.)
Some research has suggested that children (particularly thin children) are at higher risk for hypoglycemia because the injection goes into muscle tissue. Pinching the skin so that only fat (and not muscle) tissue is gathered or using shorter needles may help.
Various insulin regimens are available that can reduce the risk. For example, taking a fast-acting insulin (insulin lispro) before the evening meal may be particularly helpful in preventing hypoglycemia.
Patients who intensively control their blood sugar should monitor blood levels as often as possible, four times or more per day. This is particularly important for patients with hypoglycemia unawareness.
In adults, it is particularly critical to monitor blood glucose levels before driving, when hypoglycemia can be very hazardous.
Patients who are at risk for hypoglycemia should always carry hard candy, juice, sugar packets, or commercially available glucose substitutes.

Family and friends should be aware of the symptoms and be prepared:

If the patient is helpless (but not unconscious), family or friends should administer three to five pieces of hard candy, two to three packets of sugar, half a cup (four ounces) of fruit juice, or a commercially available glucose solution.
If there is inadequate response within 15 minutes, additional oral sugar should be provided or the patient should receive emergency medical treatment, possibly including the intravenous administration of a glucose solution.
Family members and friends can learn to inject glucagon, a hormone, which, in contrast to insulin, raises blood glucose.

Click the icon to see an example of a glucagon kit.

Experts have been concerned that the increased incidence of hypoglycemia accompanying strict blood glucose control could cause mental deterioration over time, but a 6-year study has found no evidence of this in adolescents and adults. (The effect on young children, however, is not known.)

Diagnosis

Fasting Plasma Glucose. The fasting plasma glucose (FPG) test is the standard test for diagnosing diabetes. It is a simple blood test taken after 8 hours of fasting. In general, results indicate the following:

FPG levels are considered normal up to 100 mg/dL (or 5.5 mmol/L).
Levels between 100 - 125 mg/dL (5.5 - 7.0 mmol/L) are referred to as impaired fasting glucose or pre-diabetes. These levels are considered to be risk factors for type 2 diabetes and its complications.
Diabetes is diagnosed when FPG levels are 126 mg/dL (7.0 mmol/L) or higher.

The FPG test is not always reliable, so a repeat test is recommended if the initial test suggests the presence of diabetes, or if the tests are normal in people who have symptoms or risk factors for diabetes. For example, people who take the test in the afternoon and show normal results may actually have abnormal levels that would be revealed if they are tested in the morning.

Glucose Tolerance Test. The oral glucose tolerance test (OGTT) is more complex than the FPG and may overdiagnose diabetes in people who do not have it. Some experts recommend it as a follow-up after FPG, if the latter test results are normal but the patient has symptoms or risk factors of diabetes. The test uses the following procedures:

It first uses an FPG test.
A blood test is then taken 2 hours later after drinking a special glucose solution.

The following results suggest different conditions:

OGTT levels are normal up to 140 mg/dL.
Levels between 140 - 199 mg/dL are referred to as impaired glucose tolerance or pre-diabetes.
Diabetes is diagnosed when OGTT levels are 200 mg/dL or higher.

Both the FPG and OGTT tests require that the patient not eat for at least 8 hours prior to the test.

The oral glucose tolerance test is used to diagnose diabetes. The first portion of the test involves drinking a special glucose solution. Blood is then taken several hours later to test for the level of glucose in the blood. Patients who have diabetes will have higher than normal levels of glucose in their blood.

Test for Glycated Hemoglobin. Another test examines blood levels glycated hemoglobin, also known as hemoglobin A1c (HbA1c). Measuring glycated hemoglobin is not currently used for an initial diagnosis, but it may be useful for determining the severity of diabetes.

The basis for its use as a diagnostic measurement in diabetes is as follows:

Hemoglobin is a protein molecule found in red blood cells. When glucose binds to it, the hemoglobin becomes modified, a process called glycation.
Glycation affects a number of proteins, and elevated levels of glycolated hemoglobin is strongly associated with complications of diabetes.
A glycated hemoglobin level of 1% above normal range identifies diabetes in 98% of patients. Normal HbA1c levels do not necessarily rule out diabetes, but if diabetes is present and levels are normal, the risk for complications is low.

The test is not affected by food intake so it can be taken at any time. A home test has been developed that might make it easier to measure HbA1c. In general, measurements suggest the following:

Normal HbA1c levels should be below 7%.
Levels of 11 - 12% glycolated hemoglobin indicate poor control of carbohydrates. High levels are also markers for kidney trouble.

Testing for Insulin Resistance. Investigators hope that some day a simple test for insulin resistance will be available to identify people at risk for diabetes. Some research suggests that measuring insulin and triglyceride levels during a fasting period may predict a person's sensitivity to insulin.

Type 1 diabetes is characterized by the presence of a variety of antibodies that attack the islet cells. These antibodies are referred to as autoantibodies because they attack the body's own cells -- not a foreign invader. Blood tests for these autoantibodies can help differentiate between type 1 and type 2 diabetes.

Screening for Heart Disease. All patients with diabetes should be tested for high blood pressure (hypertension) and unhealthy cholesterol and lipid levels and given an electrocardiogram. For cholesterol, people with diabetes should aim for LDL levels below 100 mg/dL, HDL levels over 50 mg/dL, and triglyceride levels below 150 mg/dL. Blood pressure goals should be 130/80 mmHg or lower. Other tests may be needed in patients with signs of heart disease.

High blood pressure is strongly associated with diabetic nephropathy (kidney disease). In fact, patients with type 2 diabetes who show signs of microalbuminuria typically already have hypertension. Type 1 diabetes patients with microalbuminuria, on the other hand, usually have normal blood pressure readings in the doctor's office. A 2002 study using home monitors, however, found that in patients with type 1 diabetes, high systolic blood pressure during sleep often occurs before development of nephropathy. (Systolic pressure is the first and higher number in a blood pressure reading.) Home blood pressure monitoring, may help identify patients with type 1 diabetes who are at risk for kidney damage.

Click the icon to see an image of an ECG.

Screening for Kidney Damage. The earliest manifestation of kidney disease is microalbuminuria, in which tiny amounts (30 - 300 mg per day) of protein called albumin are found in the urine. Microalbuminuria is also a marker for other complications involving blood vessel abnormalities, including heart attack and stroke.

The American Diabetes Association recommends that people with diabetes receive an annual microalbuminuria urine test. Patients should also have their blood creatinine tested at least once a year. Creatinine is a waste product that is removed from the blood by the kidneys. High levels of creatinine may indicate kidney damage. A doctor uses the results from a creatinine blood test to calculate the glomerular filtration rate (GFR). The GFR is an indicator of kidney function; it estimates how well the kidneys are cleaning the blood.

Screening for Retinopathy. The American Diabetes Association recommends that patients with type 1 diabetes have an annual comprehensive eye exam, with dilation, to check for signs of retina disease (retinopathy). Patients at low risk may need exams only every 2 - 3 years.

Screening for Neuropathy. All patients should be screened for nerve damage (neuropathy), including a comprehensive foot exam. Patients who have loss of sensation in their feet should have a foot exam every 3 - 6 months to check for ulcers or infections.

Screening for Thyroid Abnormalities. Thyroid function tests should be administered.

Dietary Goals and Exercise

The treatment goals for a diabetes diet are:

Achieve near-normal blood glucose levels. People with type 1 diabetes must coordinate calorie intake with medication or insulin administration, exercise, and other variables to control blood glucose levels. New forms of insulin now allow more flexibility in timing meals.
Protect the heart and aim for healthy lipid (cholesterol and triglyceride) levels and control of blood pressure.
Achieve reasonable weight. A reasonable weight is usually defined as what is achievable and sustainable, rather than one that is culturally defined as desirable or ideal. Children, pregnant women, and people recovering from illness should be sure to maintain adequate calories for health.
Manage or prevent complications of diabetes. People with diabetes, whether type 1 or 2, are at risk for a number of medical complications, including heart and kidney disease. Dietary requirements for diabetes must take these disorders into consideration.
Promote overall health.

Overall Guidelines. There is no such thing as a single diabetes diet. Patients should meet with a professional dietitian to plan an individualized diet within the general guidelines that takes into consideration their own health needs.

Healthy eating habits along with good control of blood glucose are the basic goals, and several good dietary methods are available to meet them. General dietary guidelines for diabetes recommend:

Carbohydrates should provide 45 – 65% of total daily calories. The type and amount of carbohydrate are both important. Best choices are vegetables, fruits, beans, and whole grains. These foods are also high in fiber. Patients with diabetes should monitor their carbohydrate intake either through carbohydrate counting or meal planning exchange lists
Fats should provide 25 – 35% of daily calories. Monounsaturated (olive, peanut, canola oils; avocados; nuts) and omega-3 polyunsaturated (fish, flaxseed oil, walnuts) fats are the best types. Limit saturated fat (red meat, butter) to less than 7% of daily calories. Choose nonfat or low-fat dairy instead of whole milk products. Limit trans-fats (hydrogenated fat found in snack foods, fried foods, commercially baked goods) to less than 1% of total calories.
Protein should provide 12 – 20% of daily calories, although this may vary depending on a patient’s individual health requirements. Patients with kidney disease should limit protein intake to less than 10% of calories. Fish, soy, and poultry are better protein choices than red meat

[See In-Depth Report #42: Diabetes diet.]

Weight gain is a potential side effect of intense diabetic control with insulin. Being overweight can increase the risk for health problems. On the other hand, studies suggest that more than one-third of women with diabetes omit or underuse insulin in order to lose weight. Eating disorders have become a serious problem within the general population and are especially dangerous in patients with diabetes. Some evidence suggests that they contribute to about 20% of cases of recurrent ketoacidosis in young women. Ketoacidosis is a significant complication of insulin depletion and can be life threatening.

Aerobic exercise has significant and particular benefits for people with type 1 diabetes. It increases sensitivity to insulin, lowers blood pressure, improves cholesterol levels, and decreases body fat. Because glucose levels swing dramatically during workouts, people with type 1 diabetes need to take certain precautions:

Monitor glucose levels carefully before, during, and after workouts.
Avoid exercise if glucose levels are above 300 mg/dL or under 100 mg/dL.
To avoid hypoglycemia, inject insulin in sites away from the muscles they use the most during exercise.
Before exercising, avoid alcohol and if possible certain drugs, including beta-blockers, which increase the risk of hypoglycemia.
Insulin-dependent athletes may need to decrease insulin doses or take in more carbohydrates, especially in the form of pre-exercise snacks. Skim milk is particularly helpful. They should also drink plenty of fluids.
Good, protective footwear is essential to help avoid injuries and wounds to the feet.

Resistance or high impact exercises should be avoided. They can strain weakened blood vessels in the eyes of patients with retinopathy. High-impact exercise may also injure blood vessels in the feet. Because patients with diabetes may have silent heart disease, they should always check with their doctors before undertaking vigorous exercise.

A 2006 study of over 19,000 children with type 1 diabetes found that regular physical activity helps improve blood sugar levels without increasing the risk of severe hypoglycemia. The researchers suggest that doctors recommend regular exercise for pediatric patients with type 1 diabetes.

Various fraudulent products are often sold on the Internet as “cures” or treatments for diabetes. These dietary supplements have not been studied or approved. In 2006, the FDA and Federal Trade Commission (FTC) launched a crackdown on these scams. The FDA and FTC warn patients with diabetes not to be duped by bogus and unproven remedies.

Treatment

Insulin is essential for strict control of blood glucose levels in type 1 diabetes. Tight blood glucose control is the best way to prevent major complications in type 1 diabetes including those that affect the kidneys, eyes, nerve pathways, and blood vessels. Intensive insulin treatment in early diabetes may even help preserve any residual insulin secretion for at least 2 years.

There are, however, some significant problems with intensive insulin therapy:

There is a higher risk for low blood sugar (hypoglycemia).
Many patients experience significant weight gain from insulin administration, which may have adverse effects on blood pressure and cholesterol levels. It is important to manage heart disease risk factors that might develop as a result of insulin treatment.

A diet plan that compensates for insulin administration and supplies healthy foods is extremely important. [See In-Depth Report #42: Diabetes diet.] Pancreas transplantation eventually may be recommended for patients who cannot control glucose levels without frequent episodes of severe hypoglycemia.

The goal of intensive insulin therapy is to keep blood glucose levels as close to normal as possible. In one major study, even when levels were 40% higher than nondiabetic levels, benefits were still observed.


	Normal	Goal
Blood glucose levels before meals	Less than 110 mg/dL (or 6.1 mmol/L)	90 - 130 mg/dL (or 5 - 7.2 mmol/L)
Bedtime blood glucose levels	Less than 120 mg/dL (6.6 mmol/L)	110 - 150 mg/dL (or 6.1 - 8.3 mmol/L)
Glycated hemoglobin (HbA1c) levels	4 - 6%	Less than 7%
Source: National Diabetes Information Clearinghouse, National Institutes of Diabetes and Digestive and Kidney Diseases.

Standard insulin therapy usually consists of one or two daily insulin injections, one daily blood sugar test, and visits to the health care team every 3 months. For strictly controlling blood glucose, however, intensive management is required. The regimen is complicated although newer insulin forms may make it easier.

There are two components to flexible insulin administration and a number of variations of insulin delivery for accomplishing them:

Basal insulin administration. The basal component of the treatment attempts to provide a steady amount of background insulin throughout the day. Basal insulin levels maintain regular blood glucose needs. Insulin glargine now offers the most consistent insulin activity level, but other intermediate and long-acting forms may be beneficial when administered twice a day. Short-acting insulin delivered continuously using a pump is proving to a very good way to provide basal rates of insulin.
Mealtime insulin administration. Meals require a boost (a bolus) of insulin to regulate the sudden rise in glucose levels after a meal.

In achieving insulin control the patient must also take other steps:

The patient should perform four or more blood glucose tests during the day.
Patients should coordinate insulin administration with calorie intake. In general, they should eat three meals each day at regular intervals. Snacks are often required.
Insulin requirements vary depending on many non-nutritional situations during the day, including exercise and sleep. People are at enhanced risk for low blood sugar during exercise. Some patients experience a sudden rise in blood glucose levels in the morning -- the so-called "dawn phenomenon."
The patient must also maintain a good diet plan and should visit the health care team of doctors, nurses, and dietitians once a month.

Because of the higher risk for hypoglycemia in children, experts recommend that intensive treatment be used very cautiously in children under 13 and not at all in very young children.

Insulin cannot be taken orally because the body's digestive juices destroy it. Injections of insulin under the skin ensure that it is absorbed slowly by the body for a long-lasting effect. The timing and frequency of insulin injections depend upon a number of factors:

The duration of insulin action. Insulin is available in several forms, including: standard, intermediate, long-acting, and rapid-acting.
Amount and type of food eaten. Ingestion of food makes the blood glucose level rise. Alcohol lowers levels.
The person's level of physical activity. Exercise lowers glucose levels.

Fast-Acting Insulin. Insulin lispro (Humalog) and insulin aspart (Novo Rapid, Novolog) lower blood sugar very quickly, usually within 5 minutes after injection. Insulin peaks in about 4 hours and continues to work for about 4 hours. This rapid action reduces the risk for hypoglycemic events after eating (postprandial hypoglycemia). Optimal timing for administering this insulin is about 15 minutes before a meal, but it can be also taken immediately after a meal (but within 30 minutes). Fast-acting insulins may be especially useful for meals with high carbohydrates.

Regular Insulin. Regular insulin begins to act 30 minutes after injection, reaches its peak at 2 - 4 hours, and lasts about 6 hours. Regular insulin may be administered before a meal and may be better for high-fat meals.

Intermediate Insulin. NPH (neutral protamine Hagedorn) insulin has been the standard intermediate form. It works within 2 - 4 hours, peaks 4 - 12 hours later, and lasts up to 18 hours. Lente (insulin zinc) is another intermediate insulin that peaks 4 - 12 hours and lasts up to 18 hours.

Long-Acting (Ultralente) Insulin. Long-acting insulins, such as insulin glargine (Lantus), are released slowly. Insulin glargine matches parts of natural insulin and maintains stable activity for more than 24 hours. Studies suggest that it poses less of a risk for hypoglycemia and weight gain than NPH. It has a higher incidence of pain at the injection site than NPH. Ultralente insulin peaks at 10 hours and lasts up to 20 hours but varies greatly in activity from day to day.

Combinations. Regimens generally include combinations of short and longer-acting insulins to help match the natural cycle. For example, one approach in patients who are intensively controlling their glucose levels uses 3 injections of insulin, which includes a mixture of regular insulin and NPH at dinner. Another approach uses 4 injections, including a separate short-acting form at dinner and NPH at bedtime, which may pose a lower risk for nighttime hypoglycemia than the 3-injection regimen.

Insulin Pumps. An insulin pump can improve blood glucose control and quality of life with fewer hypoglycemic episodes than multiple injections. The pumps correct for the “dawn phenomenon” (sudden rise of blood glucose in the morning) and allow quick reductions for specific situations, such as exercise. Many different brands are available.

The typical pump is about the size of a beeper and has a digital display. Some are worn externally and are programmed to deliver insulin through a catheter in the skin or the abdomen. They generally use rapid-acting insulin, the most predictable type. They work by administering a small amount of insulin continuously (the basal rate) and a higher dose (a bolus dose) when food is eaten.

Many adults, adolescents, and school children use insulin pumps. A 2006 study found that even very young children (ages 2 - 7 years) can successfully use insulin pumps and that the pumps provided better blood sugar control than twice-daily insulin injections.

The catheter at the end of the insulin pump is inserted through a needle into the abdominal fat of a person with diabetes. Dosage instructions are entered into the pump's small computer, and the appropriate amount of insulin is then injected into the body in a calculated, controlled manner.

Learning to use the pump can be complicated, although over time most patients find the devices are fairly easy to use. To achieve good control, patients and parents of children must undergo some training. The patient and doctor must determine the amount of insulin used -- it is not automatically calculated. This requires an initial learning period, including understanding insulin needs over the course of the day and in different situations and knowledge of carbohydrate counting. Frequent blood testing is very important, particularly during the training period.

Insulin pumps are more expensive than insulin shots and occasionally have some complications, such as blockage in the device or skin irritation at the infusion site. In spite of early reports of a higher risk for ketoacidosis with pumps, more recent studies have found no higher risk.

Insulin Pens. Insulin pens, which contain cartridges of insulin, have been available for some time. Until recently, they were fairly complicated and difficult to use. Newer, prefilled pens (Humulin Pen, Humalog) are disposable and allow the patient to dial in the correct amount.

Inhaled Aerosol. In 2006, the FDA approved the first non-injected form of insulin. Exubera is an inhaled form of insulin. It is approved for adults but should not be used by patients who smoke or have quit smoking within the past 6 months. Patients with asthma, bronchitis, or emphysema should also not use inhaled insulin. Scientists are also developing other types of non-injected insulin, including spray formulas.

Other Alternative Insulin Delivery Methods. Another promising avenue of investigation for delivering insulin is the use of ultrasound pulses.

Pramlintide (Symlin) is a new type of injectable drug that can help control postprandial hyperglycemia, the sudden increase in blood sugar after a meal. Pramlintide is injected before meals and can help lower blood sugar levels in the 3 hours after meals. Pramlintide is used in addition to insulin for patients who take insulin regularly but still need better blood sugar control. The FDA approved this drug in 2005 for adults with type 1 and type 2 diabetes. Pramlintide and insulin are the only two drugs approved for treatment of type 1 diabetes.

Pramlintide is a synthetic form of amylin, a hormone that is related to insulin. Side effects may include nausea, vomiting, abdominal pain, headache, fatigue, and dizziness. Patients with type 1 diabetes have an increased risk of severe low blood sugar (hypoglycemia) that may occur within 3 hours following a pramlintide injection. This drug should not be used if patients have trouble knowing when their blood sugar is low or have slow stomach emptying (gastroparesis).

CD3-Antibodies. A new type of drug called a CD3 antibody is showing promise for helping patients newly diagnosed with type 1 diabetes. In phase II clinical trials, patients received the drug for 6 days. Results from a 2005 trial published in the New England Journal of Medicine indicated that the CD3 antibody helped stimulate the patients’ natural insulin production and decreased their need for insulin drug therapy. The beneficial effects lasted up to 18 months after CD3 treatment. Researchers think that this drug affects the autoimmune response involved in type 1 diabetes and helps preserve the residual beta cell function of the pancreas.

Monitoring Tests

Both low blood sugar (hypoglycemia) and high blood sugar (hyperglycemia) are of concern for patients who take insulin. It is important, therefore, to carefully monitor blood glucose levels. In general, patients with type 1 diabetes need to take readings four or more times a day. Patients should aim for the following measurements:

Pre-meal glucose levels of between 90 - 130 mg/dL
Bedtime levels of between 110 - 150 mg/dL

Different goals may be required for specific individuals, including pregnant women, very old and very young people, and those with accompanying serious medical conditions.

Finger-Prick Test. A typical blood sugar test includes the following:

A drop of blood is obtained by pricking the finger.
The blood is then applied to a chemically treated strip.
Monitors read and provide results.

Home monitors are about 10 - 15% less accurate than laboratory monitors are and many do not meet the standards of the American Diabetes Association. Most doctors believe, however, that they are accurate enough to indicate when blood sugar is too low.

To monitor the amount of glucose within the blood a person with diabetes should test their blood regularly. The procedure is quite simple and can often be done at home.

Some simple procedures may improve accuracy:

Testing the meter once a month.
Recalibrating it whenever a new packet of strips is used.
Using fresh strips; outdated strips may not provide accurate results.
Keeping the meter clean.
Periodically comparing the meter results with the results from a laboratory.

Supplementary Monitoring Devices. Other devices are available for monitoring blood glucose. These devices are used in addition to traditional fingerstick test kits and glucose meters but do not replace them:

Continuous glucose monitoring systems (CGMS) use a needle-like sensor inserted under the skin of the abdomen to monitor glucose levels every 5 minutes. In 2007, the STS-7 System was approved. Using a disposable sensor, the STS-7 measures glucose levels for up to a week. An alarm will sound if glucose levels are too high or low. The older Minimed system measures glucose over a 72-hour period and has wireless communication between the monitor and an insulin pump.
GlucoWatch is a battery-powered wristwatch-like device that measures glucose by sending tiny electric currents through the skin, a technique called reverse iontophoresis. It is painless and has a warning device when detecting high glucose levels. It takes 2 hours to warm up, and the sensor pads need to be changed every day. Glucowatch measures glucose levels three times per hour for up to 12 hours. About a quarter of the time, the results differ significantly from actual fingerstick tests, however.

Hemoglobin A1c (also called HbA1c , HA1c, or A1C) is measured periodically every 2 - 3 months to determine the average blood-sugar level over the lifespan of the red blood cell. Normal A1C levels should be below 7%. Home tests are also available for measuring A1C.

Urine tests are useful for detecting the presence of ketones. These tests should always be performed during illness or stressful situations, when diabetes is likely to go out of control. The patient should also undergo yearly urine tests for microalbuminuria (small amounts of protein in the urine), a risk factor for future kidney disease.

Long-Term Complications

Type 1 diabetes reduces the normal lifespan by an average of 5 - 8 years. However, survival rates are improving in all ethnic groups and both genders. Longer survival rates are probably due to improvements in monitoring and tighter control of blood glucose. There are two important approaches to preventing complications from type 1 diabetes:

Intensive control of blood glucose and keeping glycosylated hemoglobin (HbA1c) levels below 7%. This approach is proving to prevent complications due to vascular (blood vessel) abnormalities and nerve damage (neuropathy) that can cause major damage to organs, including the eyes, kidneys, and heart.
Managing risk factors for heart disease. Blood glucose control helps the heart, but it is also very important that people with diabetes control blood pressure, cholesterol levels, and other factors associated with heart disease.

Patients with type 1 diabetes have a 10 times greater risk of heart disease than healthy patients. Heart attacks account for 60% and strokes for 25% of deaths in patients with diabetes. Diabetes affects the heart in many ways:

Both type 1 and 2 diabetes accelerate the progression of atherosclerosis (hardening of the arteries). Diabetes can adversely affect blood lipid levels by lowering HDL ("good cholesterol") and increasing triglycerides. This can lead to coronary artery disease, heart attack, or stroke.
In type 1 diabetes, high blood pressure (hypertension) usually develops if the kidneys become damaged. High blood pressure is another major cause of heart attack, stroke, and heart failure. Children with diabetes are also at risk for hypertension.
Impaired nerve function (neuropathy) associated with diabetes also causes heart abnormalities. Some experts estimate that the mortality rates from neuropathy-related heart conditions ranges from 15 - 53%.

Atherosclerosis is a disease of the arteries in which fatty material is deposited in the vessel wall, resulting in narrowing and eventual impairment of blood flow. Severely restricted blood flow in the arteries to the heart muscle leads to symptoms such as chest pain. Atherosclerosis shows no symptoms until a complication occurs.

Click the icon to see an image of the kidney.

Results from the Diabetes Control and Complications Trial (DCCT) prove that intensive blood sugar control reduces the long-term risk of heart disease complications by 50%. The results indicate that intensive blood sugar control is even more important in reducing these risks than blood pressure- and cholesterol-lowering drugs. Original participants in the trial received intensive blood glucose control for 6 years during the 1980s. Researchers continued to follow these patients’ progress during the next 17 years. A follow-up study, published in 2005 in the New England Journal of Medicine, found that the benefits of tight blood glucose control persisted over time and halved the risk of heart attack, stroke, angina, or coronary artery disease.

Aspirin for Reducing the Risk for Blood Clots. Taking a daily aspirin reduces the risk for blood clotting and may help protect against heart attacks. In a 2000 study, low-dose aspirin was associated with a 30% lower risk for death from heart disease in adults with type 2 diabetes.

Reducing Blood Pressure. Strict control of blood pressure is critical for preventing complications of diabetes and has proven to improve survival rates. Patients should strive for blood pressure levels of less than 130/80 mm Hg (systolic/diastolic). (Controlling systolic pressure may be especially important for reducing the risk for kidney complications.)

Dozens of anti-hypertensive drugs are available. Most fall into the following categories:

Diuretics rid the body of extra sodium (salt) and water. There are three main types of diuretics: Potassium-sparing, thiazide, and loop.
Angiotensin-converting enzyme (ACE) inhibitors reduce the production of angiotensin, a chemical that causes arteries to narrow.
Angiotensin-receptor blockers (ARBs) block angiotensin.
Beta-blockers block the effects of adrenaline and ease the heart’s pumping action.
Calcium-channel blockers (CCBs) decrease the contractions of the heart and widen blood vessels.

Many patients require more than one type of drug to control blood pressure. For patients with diabetes who have microalbuminuria, the ADA strongly recommends ACE inhibitors or ARBs. Microalbuminuria is an accumulation of protein in the blood, which can signal the onset of kidney disease (nephropathy).

Anti-hypertensive drugs that block or reduce angiotensin are the first option for many people with diabetes. Angiotensin is a natural chemical that influences all aspects of blood pressure control and also interferes with insulin's normal metabolic signaling. In fact, angiotensin may be the common factor linking diabetes and high blood pressure.

The 2005 landmark Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicated that a thiazide-type diuretic works as well as an ACE inhibitor or CCB for patients with type 2 diabetes and high blood pressure. Compared with ACE inhibitors or CCBs, diuretics appeared to be better at lowering systolic blood pressure and preventing heart failure. In addition, the trial suggested that diuretics are especially helpful for African-Americans, by offering greater protection than ACE inhibitors or CCBS in preventing strokes. [See In-Depth Report #14: High blood pressure.]

Improving Cholesterol and Lipid Levels. Abnormal cholesterol and lipid levels are common in diabetes. High LDL (“bad”) cholesterol should always be lowered, but people with diabetes also often have additional harmful imbalances, including low HDL (“good”) cholesterol and high triglycerides. Patients should aim for LDL levels below 100 mg/dL, HDL levels over 50 mg/dL, and triglyceride levels below 150 mg/dL. Patients with diabetes and existing heart disease should strive for even lower LDL levels; the American Diabetes Association recommends LDL levels below 70 mg/dL for these patients.

Statins are the best cholesterol-lowering drugs. They include atorvastatin (Lipitor), lovastatin (Mevacor and generics), pravastatin (Pravachol), simvastatin (Zocor and generics), fluvastatin (Lescol), and rosuvastatin (Crestor). These drugs are very effective for lowering LDL cholesterol levels. Recent studies indicate that aggressive high-dose statin therapy may be an important treatment approach for high-risk patients who need to substantially lower their LDL levels. A 2006 study found that patients with diabetes and heart disease who were treated with 80 mg daily of atorvastatin had a 25% lower risk of heart attack and stroke than patients who received a 10 mg daily dose.

The primary safety concern with statins has involved myopathy, an uncommon condition that can cause muscle damage and, in some cases, muscle and joint pain. A specific myopathy called rhabdomyolysis can lead to kidney failure. People with diabetes and risk factors for myopathy should be monitored for muscle symptoms.

Although lowering LDL cholesterol is beneficial, statins are not as effective as other medications -- such as fibrates, niacin, ezetimbe, or bile acid sequesters -- in addressing HDL and triglyceride imbalances. This is a common problem in type 2 diabetes. Combining a statin with one of these drugs may be helpful for people with diabetes who have heart disease, low HDL, and near-normal LDL levels. Although combinations of statins and fibrates or niacin increase the risk of myopathy, both combinations are considered safe if used with extra care.

Fibrates, such as gemfibrozil (Lopid) and fenofibrate (Tricor), are usually the first choice. Niacin has the most favorable effect on raising HDL and lowering triglycerides of all the cholesterol drugs. However, about 30% of patients who take high-dose niacin experience increased blood glucose levels. Moderate doses of niacin can achieve lipid control without causing serious blood glucose problems. [See In-Depth Report #23: Cholesterol.]

Kidney disease (nephropathy) is a very serious complication of diabetes. With this condition, the tiny filters in the kidney (called glomeruli) become damaged and leak protein into the urine. Over time this can lead to kidney failure. Urine tests showing microalbuminuria (small amounts of protein in the urine) are important markers for kidney damage.

Treatment and Prevention of Nephropathy. Tight control of blood sugar and blood pressure is essential for preventing the onset of kidney disease. Long-term studies report that strict control of these two conditions produces a 60% reduction in new cases of nephropathy and a delay in progression of the disease. Research indicates that ACE inhibitors are the best class of blood pressure medications for delaying kidney disease and slowing disease progression in patients with type 1 diabetes. Angiotensin-receptor blockers (ARBs) are also very helpful.

A doctor may recommend a low-protein diet for patients whose kidney disease is progressing despite tight blood sugar and blood pressure control. Protein-restricted diets can help slow disease progression and delay the onset of end-stage renal disease (kidney failure). However, patients with end-stage renal disease who are on dialysis generally require higher amounts of protein. [See In-Depth Report #42: Diabetes diet.]

Diabetic nephropathy, the leading cause of end-stage renal disease (ESRD), occurs in about 20 - 40% of patients with diabetes. Patients with ESRD have 13 times the risk of death compared to other patients with type 1 diabetes. If the kidneys fail, dialysis is required. Symptoms of kidney failure may include swelling in the feet and ankles, itching, fatigue, and pale skin color. On an encouraging note, a 2005 study in the Journal of the American Medical Association reported that the prognosis of end-stage renal disease has greatly improved during the last 4 decades for patients with type 1 diabetes. The outlook was best for patients who were diagnosed with diabetes at a young age (under 5 years old). In addition, the study found that fewer people with type 1 diabetes are developing ESRD.

Anemia is a common complication of end-stage kidney disease. Patients on dialysis usually require injections of erythropoiesis-stimulating drugs to increase red blood cell counts and control anemia. Patients with end-stage kidney disease should be aware of the current controversies surrounding the dosing of these drugs.

In 2006, two important New England Journal of Medicine studies indicated that aggressive dosing to completely normalize hemoglobin levels does not work better than standard dosing that only partially corrects anemia. In 2007, the FDA issued new warnings on darbepoetin alfa (Aranesp) and epoetin alfa (Epogen and Procrit). The warnings describe an increased risk for blood clots, strokes, and heart attacks in patients with end-stage kidney disease when these drugs were given at higher than recommended doses. The FDA has set new dosing and hemoglobin target levels for these drugs.

The FDA recommends that patients with end-stage kidney disease who receive erythropoiesis-stimulating drugs should:

Maintain hemoglobin levels that do not exceed 12 g/dL
Receive frequent blood tests to monitor hemoglobin levels
Contact their doctors if they experience such symptoms as shortness of breath, pain, swelling in the legs, or increases in blood pressure

[See In-Depth Report #57: Anemia.]

Diabetes reduces or distorts nerve function, causing a condition called neuropathy. Neuropathy refers to a group of disorders that affect nerves. The two main types of neuropathy are:

Peripheral (affects nerves in the toes, feet, legs, hand, and arms)
Autonomic (affects nerves that help regulate digestive, bowel, bladder, heart, and sexual function)

Peripheral neuropathy particularly affects sensation. It is a common complication that affects nearly half of people with type 1 or type 2 diabetes after 25 years. The most serious consequences of neuropathy occur in the legs and feet and pose a risk for ulcers and, in very severe cases, amputation. Peripheral neuropathy usually starts in the fingers and toes and moves up to the arms and legs (called a stocking-glove distribution). Symptoms include:

Tingling
Weakness
Burning sensations
Loss of the sense of warm or cold
Numbness (if the nerves are severely damaged, the patient may be unaware that a blister or minor wound has become infected)
Deep pain

Autonomic neuropathy can cause digestive problems (constipation, diarrhea, nausea, vomiting), bladder infections, and erectile dysfunction. In some cases, neuropathy may mask angina, the warning chest pain for heart disease and heart attack. Patients with diabetes should be aware of other warning signs of a heart attack, including sudden fatigue, sweating, shortness of breath, nausea, and vomiting.

Blood sugar control is the only treatment for neuropathy. Studies show that tight control of blood glucose levels delays the onset and slows progression of neuropathy. A 2005 study also suggested that heart disease risk factors can increase the likelihood of developing neuropathy. Lowering triglycerides, losing weight, reducing blood pressure, and quitting smoking may help prevent the onset of neuropathy.

Pain-Relief Treatment for Peripheral Neuropathy. A number of different drugs are used for peripheral neuropathy pain relief: They include:

Nonprescription analgesics, such as aspirin, acetaminophen, and non-steroidal anti-inflammatory drugs (NSAIDs). (Patients with stomach or kidney problems should check with their doctors before using these drugs.)
Prescription painkillers, such as tramadol (Ultram). Tramadol is a drug that is similar to opioids. It can help relieve pain but has significant side effects, including nausea, constipation, and headache.
Topical medications, particularly capsaicin (the active ingredient in hot peppers), are applied to the skin to relieve minor local pain. A 5% lidocaine patch has also shown good results in clinical trials.
Tricyclic antidepressants, such as amitriptyline (Elavil) or doxepin (Sinequan), are effective in reducing pain from neuropathy in up to 75% of patients. A combination of doxepin and capsaicin (applied to the skin) may be particularly beneficial. Unfortunately, tricyclics may cause heart rhythm problems.
Duloxetine (Cymbalta) is a serotonin and norepinephrine reuptake inhibitor, a newer type of antidepressant, which was approved in 2004 for treatment of pain associated with diabetic peripheral neuropathy.
The anti-convulsant drug pregabalin (Lyrica) was approved in 2004 for neuropathic pain management. It is classified as a controlled substance (like narcotics), which indicates a potential risk for abuse. Other anti-seizure drugs used for peripheral neuropathy pain relief include gabapentin (Neurontin) and valproate (Depakote).

Treatments under investigation include acetyl-l-carnitine and intravenous alpha-lipoic acid. Patients may also benefit from transcutaneous electrostimulation (TENS), a treatment that involves administering mild electrical pulses to painful areas. Alternative treatments such as hypnosis, biofeedback, relaxation techniques, and acupuncture have helped some patients manage pain. Doctors also recommend lifestyle measures, such as walking and wearing elastic stockings.

Treatments for Other Complications of Neuropathy. Neuropathy also impacts other functions, and treatments are needed to reduce their effects. If diabetes affects the nerves in the autonomic nervous system, then abnormalities of blood pressure control and bowel and bladder function may occur. Erythromycin, domperidone (Motilium), or metoclopramide (Reglan) may be used to relieve delayed stomach emptying caused by neuropathy.

Erectile dysfunction is also associated with neuropathy. Studies indicate that phosphodiesterase type 5 (PDE-5) drugs, such as sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis), are safe and effective, at least in the short term, for patients with diabetes. Typical side effects are minimal but may include headache, flushing, and upper respiratory tract and flu-like symptoms.

Perhaps the most serious consequences of diabetic neuropathy occur in the lower limbs. An estimated 15% of patients with diabetes experience serious foot problems. They are the leading cause of hospitalizations for these patients.

Diabetes is responsible for more than half of all lower limb amputations performed in the U.S. Each year there are about 88,000 non-injury amputations, 50 - 75% of them due to diabetes. The number is increasing as the prevalence in diabetes type 2 rises. According to a 2005 study in the Lancet, every 30 seconds someone in the world receives a lower limb amputation due to diabetes. About 85% of amputations start with foot ulcers, which develop in about 12% of people with diabetes.

In general, foot ulcers develop from infections, such as those resulting from blood vessel injury. A 2006 study reported that people with diabetes who develop foot infections are 155 times more likely to have an amputation than people who did not develop infections. Foot infections often develop from injuries. Even minor infections can develop into severe complications. Numbness from nerve damage, which is common in diabetes, compounds the danger since the patient may not be aware of injuries. About one-third of foot ulcers occur on the big toe.

A 2003 government survey found that those at higher risk for foot ulcers tend to be people with diabetes who are overweight, smokers, and those with a long history of diabetes. People who have the disease for more than 20 years and are insulin-dependent are at the highest risk. Related conditions that put people at risk include peripheral neuropathy, peripheral artery disease, foot deformities, and a history of ulcers. [See In-Depth Report #102: Peripheral artery disease and intermittent claudication.]

Charcot Foot. Charcot foot or Charcot joint (medically referred to as neuropathic arthropathy) occurs in up to 2.5% of people with diabetes. Early changes appear like an infection, with the foot becoming swollen, red, and warm. A seriously affected foot can become deformed. The bones may crack, splinter, and erode, and the joints may shift, change shape, and become unstable. It typically develops in people who have neuropathy to the extent that they cannot feel sensation in the foot and are not aware of an existing injury. Instead of resting an injured foot or seeking medical help, the patient often continues normal activity, causing further damage.

Charcot foot is initially treated with strict immobilization of the foot and ankle; some centers use a cast that allows the patient to move and still protects the foot. A 2001 study in the U.K. concluded that a single dose of pamidronate, a bisphosphonate, reduces bone turnover, symptoms, and disease activity. When the acute phase has passed, patients usually need lifelong protection of the foot using a brace initially and custom footwear.

Measures to Prevent Foot Ulcers. Preventive foot care can significantly reduce the risk of ulcers and amputation. Some tips for preventing problems include:

Patients should inspect their feet daily and watch for changes in color or texture, odor, and firm or hardened areas, which may indicate infection and potential ulcers.
When washing the feet, the water should be warm (not hot) and the feet and areas between the toes should be thoroughly dried afterward. Check water temperature with the hand or a thermometer before stepping in.
Moisturizers should be applied, but not between the toes.
Corns and calluses should be gently pumiced and toenails trimmed short and the edges filed to avoid cutting adjacent toes.
Patients should not use medicated pads or try to shave the corns or calluses themselves.
Well-fitting footwear is very important. People should be sure the shoe is wide enough; according to a 2001 study, 30% of patients with diabetes wear shoes that are too narrow. Patients should also avoid high heels, sandals, thongs, and going barefoot. Shoes with a rocker sole (LucRo) reduce pressure under the heel and front of the foot by 35 - 65% and may be particularly helpful. Custom-molded boots increase the surface area over which foot pressure is distributed. This reduces stress on the ulcers and allows them to heal.
Shoes should be changed often during the day.
Wear socks, particularly with extra padding (which can be specially purchased).
Patients should avoid tight stockings or any clothing that constricts the legs and feet.
Foot pain, numbness, or tingling is worse at night; diphenhydramine (Benadryl) may help.
A specialist in foot care should be consulted for any problems.

Click the icon to see an image of foot inspection.

Treating Foot Ulcers in Diabetes. About one-third of foot ulcers will heal within 20 weeks with good wound care treatments. Some treatments are as follows:

Antibiotics are generally given. In some cases, hospitalization and intravenous antibiotics for up to 28 days may be needed for severe foot ulcers.
In virtually all cases, wound care requires debridement, which is the removal of injured tissue until only healthy tissue remains. Debridement may be accomplished using chemical (enzymes), surgical, or mechanical (irrigation) means.
Hydrogels (Nu-Gel, Intrasite Gel, Scherisorb, Clearsite, Duoderm, Geliperm) are helpful in healing ulcers and are noninvasive and soothing.
Felted foam may be helpful in healing ulcers on the sole of the foot. Felted foam uses a multi-layered foam pad over the bottom of the foot with an opening over the ulcer.

Other Treatments for Foot Ulcers. Doctors are also using or investigating other treatments to heal ulcers. These include:

Administering hyperbaric oxygen (oxygen given at high pressure) is showing promise in promoting healing. In one study, patients who had had ulcers that had not responded to treatment for over 3 months received daily treatments that lasted 90 minutes for 2 weeks. About 15 days after completion, patients who received oxygen had significant reduction in ulcers, sometimes with complete healing. Other studies are also demonstrating good results.
Monochromatic near-infrared photo energy (MIRE) uses light therapy to improve sensation in the feet of patients with peripheral neuropathy.
Total-contact casting (TCC) uses a cast that is designed to match the exact contour of the foot and to distribute weight along the entire length of the foot. It is usually changed weekly. It may be helpful for ulcer healing and for Charcot foot. Although it is very effective in healing ulcers, recurrence is common.

Diabetes accounts for 12,000 - 24,000 of new cases of blindness annually and is the leading cause of new cases of blindness in adults ages 20 - 74. The most common eye disorder in diabetes is retinopathy. People with diabetes are also at higher risk for developing cataracts and certain types of glaucoma. [See In-Depth Report #26: Cataracts and In-Depth Report #25: Glaucoma.]

Description of Retinopathy. Retinopathy is a condition in which the retina becomes damaged. The two primary abnormalities that occur are a weakening of the blood vessels in the retina and the obstruction in the capillaries -- probably from very tiny blood clots. Retinopathy generally occurs in one or two phases:

Click the icon to see an image of diabetic retinopathy.

The early and more common type of this disorder is called nonproliferative or background retinopathy. The blood vessels in the retina are abnormally weakened. They rupture and leak, and waxy areas may form. If these processes affect the central portion of the retina, swelling may occur, causing reduced or blurred vision.
If the capillaries become blocked and blood flow is cut off, soft, "woolly" areas may develop in the retina's nerve layer. These woolly areas may signal the development of proliferative retinopathy. Often there are no symptoms of progressing retinopathy. In this more severe condition, new abnormal blood vessels form and grow on the surface of the retina. They may spread into the cavity of the eye or bleed into the back of the eye. Major hemorrhage or retinal detachment can result, causing severe visual loss or blindness. The sensation of seeing flashing lights may indicate retinal detachment.

According to a 2003 study, about 40% of young adults with type 1 diabetes had developed retinopathy within 10 years of diagnosis. (Although this rate is high, it is significantly lower than in previous years when blood glucose control was not as strict.) The risk is lower in patients with type 2, although in one study over 20% had signs of retinopathy 6 years after diagnosis. In general, all patients with diabetes should have a yearly eye examination. Patients with no signs of retinal damage or low risk factors for retinopathy may only require screening every 2 - 3 years.

Click the icon to see an animation on diabetic retinopathy.

Prevention of Retinopathy. Fortunately, severe and even moderate vision loss is largely preventable with tight control of blood glucose levels. (Intense glucose control can cause early worsening of retinopathy, although this is nearly always counterbalanced by long-term benefits.) Tight control of blood pressure can also help protect against retinopathy. Aspirin therapy does not help prevent retinopathy.

Treatment of Retinopathy. Patients with severe diabetic retinopathy or macular edema (swelling of the retina) should be sure to see an eye specialist who is experienced in the management and treatment of diabetic retinopathy. Once damage to the eye develops, laser eye surgery may be needed. Laser surgery can help reduce vision loss in high-risk patients.

Studies indicate that patients with type 2 diabetes face a higher than average risk of developing dementia caused either by Alzheimer's disease or problems in blood vessels in the brain. Problems in attention and memory can occur even in people under age 55 who have had diabetes for a number of years. In one study of people with type 1 diabetes, high glucose levels (hyperglycemia) were associated with slower brain function, including less verbal fluency and slow ability to do mental arithmetic.

Respiratory Infections. People with diabetes face a higher risk for influenza and its complications, including pneumonia, possibly because the disorder neutralizes the effects of protective proteins on the surface of the lungs. In fact, deaths among people with diabetes increase by 5 - 15% during flu epidemics, and they are six times more likely to be hospitalized with complications from flu than nondiabetic patients who have flu. Everyone with diabetes should have annual influenza vaccinations and a vaccination against pneumococcal pneumonia.

Urinary Tract Infections. Women with diabetes face a significantly higher risk for urinary tract infections, which are likely to be more complicated and difficult to treat than in the general population.

Diabetes doubles the risk for depression. Furthermore, depression, in turn, increases the risk for hyperglycemia and complications of diabetes, according to one study. Restoring mental health, both through medication and psychotherapy, not only improves quality of life but may help patients control their blood sugar levels.

Diabetes changes bone quality and density, but the effects differ depending on type:

Type 1 diabetes is associated with a slightly reduced bone density, putting patients at risk for osteoporosis and possibly fractures. The best medications for bone loss in patients with diabetes are bisphosphonates, such as alendronate (Fosamax) and risedronate (Actonel). They not only help prevent bone loss but may even reduce daily insulin requirements in patients taking insulin. [See In-Depth Report #18: Osteoporosis.]
Type 2 diabetes, on the other hand, is associated with an increased bone density but is also associated with fractures. In such cases, the bone quality itself may be impaired.

Older patients with either type of diabetes are at risk for falling, which compounds the risk for fracture.

Diabetes increases the risk for other conditions, including:

Hearing loss
Periodontal disease
Carpal tunnel syndrome
Nonalcoholic fatty liver disease, also called nonalcoholic steatohepatitis (NASH); a particular danger for people who are obese
Colorectal cancer
Uterine cancer

Diabetes and Pregnancy. Both temporary diabetes that occurs during pregnancy (gestational diabetes) and pregnancy in a patient with existing diabetes can increase the risk for birth defects. Studies indicate that high blood sugar levels (hyperglycemia) may affect the developing fetus as soon as it is conceived.

Because glucose crosses the placenta, a woman with diabetes can pass high levels of blood glucose to the fetus. In response, the fetus secretes large amounts of insulin. This combination of high fetal blood levels of insulin and glucose can have significant effects:

Excessive fetal weight gain, which can lead to complications during delivery
Birth defects
Breathing problems and delayed lung development
Low blood sugar
Higher future risk for obesity and diabetes

In addition to endangering the fetus, diabetes also presents risks to the pregnant woman, particularly preeclampsia, which is a potentially dangerous condition involving very high blood pressure during pregnancy. Pregnant women with diabetes are also at greater risk for retinopathy.

Some recommendations for preventing complications include:

Intensive blood sugar control during pregnancy may reduce the risk for problems in the infant.
Monitoring blood glucose after meals may protect against preeclampsia more effectively than monitoring before meals.
Aerobic exercise before and during pregnancy can lower glucose levels. (All pregnant women, particularly those with diabetes, should check with their doctors before embarking on a rigorous exercise regimen.)
To prevent birth defects that affect the heart and nervous system, women with diabetes should take a higher dose of folic acid from the time of conception up to week 12 of pregnancy. They should also be checked for any heart problems.
Women with diabetes should have an eye examination during pregnancy and up to a year afterward.

Although there was some concern that short-acting insulin lispro might increase the risk for birth defects, the most recent evidence suggests that it does not. In fact, some experts believe it achieves a better outcome and should be preferred to regular insulin in pregnant women. More research is needed.

Effect on Estrogen. Diabetes appears to blunt some of the effects of estrogen, which may increase the risk for heart disease. Women with diabetes have a higher risk for early menopause, which, in one study, occurred at an average age of about 41 years.

Reproductive Cancers. Women with type 1 diabetes often have lumps in the breast that are benign but which make mammograms difficult to interpret. It is not clear whether these lumps are risk factors for breast cancer. One study indicated that women with diabetes have a higher risk for endometrial cancer and possibly for breast cancer.

Lack of Blood Glucose Control. Control of blood glucose levels is generally very poor in adolescents and young adults. Adolescents with diabetes are at higher risk than adults for ketoacidosis resulting from noncompliance. In a British study of young adults with type 1 diabetes, 15% were already hypertensive, and about half of these young people had signs of kidney damage. Young people who do not control glucose are also at high risk for permanent damage in small vessels, such as those in the eyes.

Self-Destructive Behaviors. One study found that young people with diabetes have a higher than average rate of suicidal fantasies. Although the actual rate of suicide was no higher than that of their nondiabetic peers, such thoughts are strongly associated with self-destructive behavior.

Of particular note, up to one-third of young women with type 1 diabetes have eating disorders and under-use insulin to lose weight. Anorexia and bulimia pose significant health dangers in any young person -- but they can be especially severe in people with diabetes.

Transplantation Procedures

Major advances in islet-cell transplantation are allowing more patients to come off insulin or reduce their use of it.

Major clinical trials are now using a specific islet-cell (also called beta-cell) transplantation procedure called the Edmonton protocol, which usually involves the following steps:

As soon as there are sufficient numbers of islets available for transplantation, the patient is given intravenous antibiotics and oral vitamins E, B6, and A.
A machine isolates islet cells taken from donor pancreases, generally from cadavers. Two or three organs are usually needed in order to supply enough islet cells to have any effect on insulin production. (This is a major limitation of the procedure.)
Once the islets have been isolated, they are injected directly in a major vein in the patient's liver.
The islets are carried to capillaries in the liver where they produce insulin.
Specific drugs, such as tacrolimus, sirolimus, or rapamycin (Rapamume), are used to suppress the immune system. (Unlike immunosuppressant drugs used in other transplantation procedures, these drugs do not contain steroids, which destroy islet cells.) Immunosuppressants are needed for the rest of the patient's life so that the body does not reject these foreign islet cells.
The procedure has to be performed two or more times over a period of 2 - 3 months. This generally requires multiple pancreas donors in order to achieve complete independence from insulin therapy. This is a major limitation to the procedure.

In 2006, the New England Journal of Medicine published the results of the first multicenter trial of the Edmonton protocol. The results indicated that this treatment may benefit some patients with severe type 1 diabetes. Of the 36 patients who underwent the transplant procedure, 44% no longer needed insulin injections a year after the final treatment. However, two-thirds of these insulin-independent patients needed to resume insulin injections within 2 years.

The Edmonton protocol achieved partial islet function in 28% of patients, which helped control hypoglycemic unawareness, a serious complication of diabetes. (In hypoglycemic unawareness, patients no longer recognize the symptoms of severe low blood sugar.) Even though these patients still needed insulin shots, they had better control of their diabetes. Researchers are continuing to work on refining the Edmonton protocol so that its benefits can be more sustainable and long lasting.

A major obstacle for the islet cell transplantation is the need for two or more donor pancreases to supply sufficient islet cells. Unfortunately, there are not enough pancreases available to make this procedure feasible for even 1% of patients. Researchers, then, are looking for alternative sources for islet cells. In one center, for example, researchers used pig islet cells as the donor source in children and did not administer immunosuppressant drugs. Half the children responded well to this approach. Another study reported that select patients may require only one donor.

Other research is focusing on umbilical cord cells, embryonic or adult stem cells, bone marrow transplantation, and other types of cellular therapies. These studies are still in very early stages, but experts predict that there will be major research advances in these fields in the coming years. A small, preliminary study published in 2007 in the Journal of the American MedicalAssociation looked at the effects of autologous nonmyeloablative hematopoietic stem cell transplantation (AHST) in patients newly diagnosed with type 1 diabetes. AHST is an experimental treatment for type 1 diabetes. It involves treating a patient with high doses of drugs to suppress the immune system, then harvesting the patient’s own blood cells and re-infusing them back into the body. In the study, 14 out of 15 patients who underwent AHST were able to stop taking insulin shots.

Whole pancreas transplants and double transplants of pancreases and kidneys are proving to have a good long-term success rate for some patients with type 1 diabetes. The operations help to prevent further kidney damage, and long-term studies indicate that they may even eventually reverse some existing damage. There is some evidence that heart disease and diabetic neuropathy improve after pancreas transplantation (although not retinopathy). One 10-year study reported that survival rate at 10 years was 76%, and two-thirds of the patients had both pancreas and kidney function. Immunosuppressive drugs are needed lifelong with this procedure. Experts generally recommend transplants in cases of end-stage kidney failure or when diabetes poses more of a threat to the patient's life than the transplant itself.

Uncontrolled diabetes causes damage to many tissues of the body, including the kidneys. Kidney damage caused by diabetes most often involves thickening and hardening of the internal kidney structures. Strict blood glucose control may delay the progression of kidney disease in type 1 and type 2 diabetics.

Prevention

Fingerstick blood tests are now available that can test for autoantibodies that identify children who are at high risk for developing type 1 diabetes. At this time, however, there is no way to prevent type 1 diabetes, and all preventive therapies are investigative. Until there are ways to prevent the condition, such screening tests are expensive and provide little value.

Investigational approaches focus on preventing type 1 diabetes or at least delaying it as long as possible. Preventive measures are sometimes defined as primary and secondary:

Primary prevention attempts to preserve all beta cells before the disease process starts.
Secondary prevention aims to deter further beta cell destruction once it has started and before symptoms arise.

For primary prevention, one experimental approach involves oral insulin, which is taken as a pill once a day. Unlike insulin injections that lower blood sugar, oral insulin does not affect blood glucose levels because it is quickly broken down in the digestive system. It may, however, help calm the immune system and prevent its attack on beta cells. Another study is exploring whether docosahexaenoic acid (DHA), an omega-3 fatty acid, can help prevent development of autoimmune type 1 diabetes in newborns who are at high risk for the disease.

Secondary prevention focuses on preserving beta cells and their insulin-producing function. Researchers are exploring several treatments for patients who are newly diagnosed with type 1 diabetes. These experimental therapies include:

Rituximab (Rituxan), a monoclonal antibody drug used for treatment of rheumatoid arthritis and non-Hodgkin’s lymphoma, is being studied in patients with type 1 diabetes for its effects on disrupting the immune system’s attack on beta cells.
Immune-suppressing drugs, such as mycophenolate mofetil (MMF) alone or in combination with daclizumab (DZB), are used to prevent rejection in organ transplantation. Researchers hope that these drugs may be able to slow or stop the autoimmune disease process of type 1 diabetes.
CD3-antibody drug therapy is showing promise in retaining newly diagnosed patients’ natural insulin production and decreasing their need for insulin therapy.

Resources

www.diabetes.org -- American Diabetes Association
www.niddk.nih.gov -- National Institute of Diabetes and Digestive and Kidney Diseases
www.jdrf.org -- Juvenile Diabetes Research Foundation
www.nei.nih.gov -- National Eye Institute
www.eatright.org -- American Dietetic Association
www.kidney.org -- National Kidney Foundation
www.diabetestrialnet.org -- Type 1 Diabetes International Clinical Trial Net
www.medicalert.org -- Bracelets or neck chain emblems with personal medical information
www.childrenwithdiabetes.com -- Children with diabetes online community

References

American Diabetes Association (ADA). Standards of medical care in diabetes. VI. Prevention and management of diabetes complications. Diabetes Care. 2007 Jan;30(Suppl 1):S15-24.

Drueke TB, Locatelli F, Clyne N, Eckardt KU, Macdougall IC, Tsakiris D, et al. Normalization of hemoglobin level in patients with chronic kidney disease and anemia. N Engl J Med. 2006 Nov 16;355(20):2071-84.

Hakonarson H, Grant SFA, Bradfield JP, Marchand L, Kim CE, Glessner JT, et al. A genome-wide association study identifies KIAA0350 as a type 1 diabetes gene. Nature. Published online 15 July 2007.

SEARCH for Diabetes in Youth Study Group , Liese AD, D'Agostino RB, Hamman RF, Kilgo PD, Lawrence JM, et al. The burden of diabetes mellitus among US youth: prevalence estimates from the SEARCH for Diabetes in Youth Study. Pediatrics. 2006 Oct;118(4):1510-8.

Shapiro AM, Ricordi C, Hering BJ, Auchincloss H, Lindblad R, Robertson RP, et al. International trial of the Edmonton protocol for islet transplantation. N Engl J Med. 2006 Sep 28;355(13):1318-30.

Singh AK, Szczech L, Tang KL, Barnhart H, Sapp S, Wolfson M, et al. Correction of anemia with epoetin alfa in chronic kidney disease. N Engl J Med. 2006 Nov 16;355(20):2085-98.

Skyler JS. Cellular therapy for type 1 diabetes: has the time come? JAMA. 2007 Apr 11;297(14):1599-600.

Vardi M, Nini A. Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus. Cochrane Database Syst Rev. 2007 Jan 24(1):CD002187.

Voltarelli JC, Couri CE, Stracieri AB, Oliveira MC, Moraes DA, Pieroni F, et al. Autologous nonmyeloablative hematopoietic stem cell transplantation in newly diagnosed type 1 diabetes mellitus. JAMA. 2007 Apr 11;297(14):1568-76.

Writing Group for the SEARCH for Diabetes in Youth Study Group , Dabelea D, Bell RA, D'Agostino RB, Imperatore G, Johansen JM, et al. Incidence of diabetes in youth in the United States. JAMA. 2007 Jun 27;297(24):2716-24.

Review Date:
7/19/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com

DrSugar Answers: Exercising and Leg Pain?

DrSugar — Mon, 09 Mar 2009 08:00:00 -0700

DrSugar is in the house and he's answering your health questions.

Dear DrSugar,
I am 20 years old and I have been exercising regularly for about a year and a half. Although I don't belong to a gym or use a personal trainer, I run around my neighborhood, use my stationary bike, do workout videos, and occasionally go to a yoga class. My question is this: Recently I have started having a lot of pains and I think they are from over-exercising. I have pain in my hips and thighs mostly and they seem to alternate legs. Why is this happening? I work out usually 4-5 days a week for about an hour. Am I not getting enough protein? Not stretching enough? Help!
- Into Fitness

To see what DrSugar has to say on this matter, just read more.

It does sound like you are very dedicated to fitness. Five hours of exercise five days a week sounds like a healthy amount of activity, especially if you are consistent over time. Most overuse injuries occur when you suddenly increase the amount you exercise. For instance, if you haven’t jogged on pavement for a year and suddenly start jogging an hour everyday, this can lead to overuse injuries. That is why they are referred to as “wear and tear” injuries. Overuse injuries can include muscle strains, tendonitis, and stress fractures. Usually these injuries will hurt in one consistent place where the damage has occurred. The fact that your pain is alternating from side to side makes it less likely that you have a stress fracture or another serious injury.

I think the most important issue for you is to determine which forms of exercise are creating pain. Many people develop pain and injuries from jogging on hard surfaces. Here are a few tips on how to avoid running related overuse injuries. I would suggest cutting out your highest impact exercises for a week and see if the pains improve. Dietary protein deficiency is unlikely to cause muscle pains. Protein deficiency usually causes weakness instead of pain. In terms of stretching, it is certainly a good idea to stretch after exercising to keep your muscles flexible to maintain range of motion in your joints. Make sure to warm up before working out. Walk briskly before you jog for five to ten minutes. If the pains persist I suggest seeing a doctor.

Have a question for DrSugar? Send it by private messaging me here, and I will forward it to the good doctor.

DrSugar's posts are for informational purposes only and should not be considered medical advice, diagnosis, or treatment recommendations. Click here for more details.

Fit Tip: Check Your Grip

FitSugar — Tue, 24 Feb 2009 14:30:00 -0800

Have you ever been driving on a road slick with ice or rain and noticed that your had a death grip on the steering wheel with white knuckles and tense shoulders? That death grip doesn't translate into more control over the car. Same goes for how you use your hands when working out.

You don't need to grip the weights as if you were trying to squeeze the life out of the dumbbell or hold the handles of the elliptical like you are trying to choke them. All this really does is tire out all the little muscles in your hands. Since these muscles are small and relatively weak compared to the larger muscles you are intending to work, they just tire out before your workout is done. This can create unwanted soreness in your hands. Plus, having an overly tight hand often sends signals of tension to the shoulders and neck, creating unnecessary strain.

I see this super grip when folks work with Pilates equipment, weight and cardio machines, and free weights. Next time you work out, check your grip and lighten it up.

Source

High blood pressure

FitSugar — Wed, 08 Oct 2008 17:35:08 -0700

In This Report

Highlights
Introduction
Diagnosis
Causes
Risk Factors
Complications
Symptoms
Treatment
Lifestyle Changes
Medications
Classes of Medications
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Drug Approval

In 2007, the FDA approved a new type of high blood pressure drug. Aliskiren (Tekturna) blocks renin, a kidney enzyme that is associated with blood pressure regulation. Aliskiren can be taken alone or in combination with other blood pressure drugs, but it should not be used during pregnancy.

Drug Concerns

ACE inhibitors should never be taken during the second or third trimesters of pregnancy. An important 2006 New England Journal of Medicine study extended these concerns by reporting that ACE inhibitors may cause major heart birth defects during the first trimester. Although this research is still preliminary, the FDA and the American Heart Association now recommend that women who are pregnant or considering becoming pregnant switch to another type of blood pressure drug.
Nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of developing high blood pressure in men, suggests a 2007 Archives of Internal Medicine study. Previous research indicated that these non-prescription painkillers increase high blood pressure risk in women.

Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

The ALLHAT trial has been the most important long-running clinical study for evaluating the effects of high blood pressure medications. One of its most critical findings established the importance of thiazide-type diuretics as first-line treatment for high blood pressure. Recent trial results indicate:

Diuretics are very helpful for preventing heart failure in patients with high blood pressure. In a 2006 Circulation study, diuretics outperformed ACE inhibitors and calcium channel blockers in reducing heart failure risk.
Thiazide-type diuretics may slightly increase the risk of developing diabetes more than other drug classes but their blood pressure-lowering benefits outweigh the risks, according to a 2006 Archives of Internal Medicine study. The study found that all types of blood pressure medications increase blood sugar levels and diabetes risk.

Introduction

High blood pressure, also called hypertension, is elevated pressure of the blood in the arteries. Hypertension results from two major factors, which can be present independently or together:

The heart pumps blood with excessive force
The body's smaller blood vessels (known as the arterioles) narrow, so that blood flow exerts more pressure against the vessels' walls

Blood pressure is the force applied against the walls of the arteries as the heart pumps blood through the body. The pressure is determined by the force and amount of blood pumped and the size and flexibility of the arteries.

Although the body can tolerate increased blood pressure for months and even years, eventually the heart may enlarge (a condition called hypertrophy), which is a major factor in heart failure.

Click the icon to see an image of hypertrophic cardiomyopathy.

Such pressure can also injure blood vessels in the heart, kidneys, the brain, and the eyes.

Two numbers are used to describe blood pressure: the systolic pressure (the higher and first number) and the diastolic pressure (the lower and second number). Health dangers from blood pressure may vary among different age groups and depending on whether systolic or diastolic pressure (or both) is elevated. A third measurement, pulse pressure, may also be important as an indicator of severity.

Blood pressure is measured in millimeters of mercury (mm Hg). According to current adult guidelines, blood pressure is categorized as normal, prehypertensive, and hypertensive (which is further divided into Stage 1 and 2, according to severity). People in normal health should have a blood pressure reading of 120/80 mm Hg or less. High blood pressure is generally considered to be a blood pressure reading greater than or equal to 140 mm Hg (systolic) or greater than or equal to 90 mm Hg (diastolic). Blood pressure readings in the prehypertension category (120-139 systolic or 80-89 diastolic) indicate an increased risk for developing hypertension.

Current guidelines for children are based on percentile ranges for a child’s body size. Hypertension is defined as average systolic and diastolic readings that are greater than the 95th percentile for gender, age, and height on at least three occasions. Prehypertension in children is diagnosed when average systolic or diastolic blood pressure levels are at least in the 90th percentile but less than the 95th percentile. For adolescents, as with adults, blood pressure readings greater than 120/80 are considered prehypertensive. Increasing rates of childhood obesity have lead to higher than average blood pressure levels in children.

American expert groups recommend treating any blood pressure above normal. Some experts are concerned, however, that such guidelines may unnecessarily increase the use of anti-hypertensive drugs. It is important that patients establish a relationship with a doctor whom they trust, to help them determine individual blood pressure goals and treatment regimens. For some patients, a decrease of a few points in blood pressure may not be worth the side effects caused by higher doses of anti-hypertensive drugs.

Systolic Blood Pressure. The systolic pressure (the first and higher number) is the force that blood exerts on the artery walls as the heart contracts to pump out the blood. High systolic pressure is now known to be a greater risk factor than diastolic pressure for heart, kidney, and circulatory complications and for death, particularly in middle-aged and elderly adults. The wider the spread between the systolic and diastolic measurements, the greater the danger.

Elevated systolic pressure may pose a significant danger for heart events and stroke events even when diastolic is normal -- a condition called isolated systolic hypertension. Isolated systolic hypertension is the most common form of hypertension in people older than age 50. In one study, it comprised 87% of hypertension cases in people between ages 50 and 59.

Diastolic Blood Pressure. The diastolic pressure (the second and lower number) is the measurement of force as the heart relaxes to allow the blood to flow into the heart. High diastolic pressure is a strong predictor of heart attack and stroke in young adults.

Pulse Pressure. Pulse pressure is the difference between the systolic and the diastolic readings. It appears to be an indicator of stiffness and inflammation in the blood-vessel walls. The greater the difference between systolic and diastolic numbers, the stiffer and more injured the vessels are thought to be. Although not yet used by doctors to determine treatment, evidence suggests that it may prove to be a strong predictor of heart problems, particularly in older adults. Some studies suggest that in people over 45 years old, every 10 mm Hg increase in pulse pressure increases the risk for stroke rises by 11%, cardiovascular disease by 10%, and overall mortality by 16%. (In younger adults the risks are even higher.)

Click the icon to see an animation about blood pressure.

Some experts categorize hypertension into the following types:

Essential Hypertension. Essential hypertension is also known as primary or idiopathic hypertension. About 90% of all high blood pressure cases are this type. The causes of essential hypertension are unknown but are based on complex processes in all major organs and systems, including the heart, blood vessels, nerves, hormones, and the kidneys.

Secondary Hypertension. Secondary hypertension comprises about 5% of high blood pressure cases. In this condition, the cause has been identified.

Isolated Systolic Hypertension. This occurs when systolic hypertension is over 140 mm Hg but diastolic pressure is normal. It is related to arteriosclerosis (hardening of the arteries).

Click the icon to see an image of atherosclerosis.

Pregnancy Induced Hypertension. This condition occurs during pregnancy if blood pressure increases by more than 15 mm Hg above normal.

White Coat Hypertension. This form of hypertension is elevated blood pressure that occurs only during a visit to the doctor's office, but not at home. It is a factor in about 20% of patients with mild hypertension. Although previously considered a relatively harmless condition, research now suggests that white-coat hypertension shares certain features with essential hypertension. Studies have even suggested that white-coat hypertension actually may pose a risk for future heart problems, although the increased danger appears to be small compared with the risk in those with steady mild hypertension.


Blood Pressure Category	Ranges for Most Adults (systolic/diastolic)
Normal Blood Pressure (systolic/diastolic)	Systolic below 120 mm Hg Diastolic below 80 mm Hg
Prehypertension (Formerly Normal to High-Normal Blood Pressure)	Systolic 120 - 139 mm Hg Diastolic 80 - 89 mm Hg (NOTE: 139/89 or below should be the minimum goal for everyone. People with diabetes or chronic kidney disease should strive for 130/80 or less.)
Mild Hypertension (Stage 1)	Systolic 140 - 159 mm Hg Diastolic 90 - 99 mm Hg
Moderate to Severe Hypertension (Stage 2)	Systolic over 160 mm Hg or Diastolic over 100 mm Hg
Note: If one of the measurements is in a higher category than the other, the higher measurement is usually used to determine the stage. For example, if systolic pressure is 165 (Stage 2) and diastolic is 92 (Stage 1), the patient would still be diagnosed with Stage 2 hypertension. It should be strongly noted that a high systolic pressure compared to a normal or low diastolic pressure should be a major focus of concern in most adults.

Diagnosis

Most physical exams include a blood pressure measurement. Patients should not smoke or drink caffeinated beverages within 30 minutes before their blood pressure measurement.

The standard instrument used to measure blood pressure is called a mercury sphygmomanometer. Measurements are given as units of mercury, which has filled the central column in standard sphygmomanometers for years. (Some people view the mercury sphygmomanometer as an environmental health hazard, but modern devices are designed to prevent mercury spillage.)
An inflatable cuff with a meter attached is placed around the patient's arm over the artery while the patient is seated. The inflated cuff briefly interrupts the flow of blood in the artery, which then resumes as the cuff is slowly deflated.
The person taking the blood pressure listens through a stethoscope for so-called Korotkoff sounds, which first appear as blood begins to flow through the artery and then change in tone and volume as the cuff is deflated.
If a first blood pressure reading is above normal, the health professional may take two or more measurements separated by 2 minutes with the patient sitting or lying down. Another measurement may be taken after the patient has been standing for 2 minutes.

To measure blood pressure, your doctor uses an instrument called a "sphygmomanometer," more often referred to as a blood pressure cuff. The cuff is wrapped around your upper arm and inflated to stop the flow of blood in your artery. As the cuff is slowly deflated, your doctor uses a stethoscope to listen to the blood pumping through the artery. These pumping sounds register on a gauge attached to the cuff. The first pumping sound your doctor hears is recorded as the systolic pressure, and the last sound is the diastolic pressure.

Although this test has been used for more than 90 years, it is not completely accurate or sensitive. The following factors can cause a falsely low pressure reading:

An arm cuff that is too wide
Recent exercise
Not smoking for a while after heavy, long-term smoking

Falsely high pressure can result from:

An arm cuff that is too small
Talking during the test
Recently consuming foods or beverages (such as coffee) that raise blood pressure

Office blood pressure readings taken by a doctor are more likely to be higher than readings measured at home. This so-called white-coat hypertension requires additional readings by a nurse or by the patient. Home monitoring improves the accuracy of a simple office measurement. An average of all the measurements will be considered in the diagnosis of hypertension. If high normal or high blood pressure persists, further tests should be performed to determine if the organs are affected.

Other Blood-Pressure Monitors. Alternative pressure-measuring aneroid and electronic devices are available. Aneroid instruments are round, compass-like devices that use a metal spring to measure blood pressure and are often used by doctors. Electronic devices are typically used for home monitoring.

Monitoring Equipment. A number of home tests are available for checking blood pressure between doctor visits. A doctor may loan a patient a portable unit that records blood pressure during a full day's activity. This test, known as ambulatory monitoring, is particularly useful for those who experience wide blood pressure swings, such as those who have white-coat hypertension or show resistance to drug therapy. According to one study, accurately measuring blood pressure at home over a full day was a significantly better predictor of cardiovascular risk than standard office-based measurements. To improve clinical outcomes, devices are now available that allow 24-hour ambulatory blood pressure monitoring and electronically store results for analysis by the doctor. It is not clear if their added benefits justify their expense, however.

Cuffs and Stethoscopes. Manual cuffs and stethoscopes are fairly accurate, but they require practice to use. The cuff must be the right size (one size does not fit all). Devices that use a digital readout and a cuff that can be electronically inflated and deflated are proving to be as accurate as a stethoscope.

Blood Pressure Variations at Home. In general, everyone's blood pressure varies in the same way throughout a given day. In monitoring at home, it is important to note these changes:

Blood pressure is usually highest at work.
It drops slightly at home.
It then normally dips to its lowest level during sleep. There are important exceptions. Certain people have a condition called nondipper hypertension, in which blood pressure does not fall at night. Postmenopausal women appear to be at particular risk for this phenomenon, and it may pose a special danger for heart disease and stroke (particularly in older African-American women). It has also been linked to salt-sensitivity and insulin resistance.

Click the icon to see an image of stroke.

Upon waking, pressure in most people typically increases suddenly. In people with severe high blood pressure, this is the highest risk period for heart attack and stroke.

Click the icon to see an image of a heart attack.

Some studies have reported that when patients record and report their own blood pressure, they are unreliable and don't always tell the truth. Despite the difficulties and controversy surrounding this issue, home blood pressure monitoring has been shown to encourage patients to use measures that control their blood pressure and thereby reduce the risk of cardiovascular events.

Click the icon to see an image about monitoring blood pressure.

If blood pressure is elevated, the doctor will check the patient's pulse rate, examine the neck for distended veins or an enlarged thyroid gland, check the heart for enlargement and murmurs, and examine the abdomen and the eyes.

Click the icon to see an image of the thyroid gland.

If hypertension is suspected, the doctor should obtain the following information:

A family and personal medical history, especially incidence of high blood pressure, stroke, heart problems, kidney disease, or diabetes.
Risk factors for heart disease and stroke, including tobacco use, salt intake, obesity, physical inactivity, and unhealthy cholesterol levels.
Any medications being taken.
Any symptom that might indicate so-called secondary hypertension (that is, caused by another disorder). Such symptoms include headache, heart palpitations, excessive sweating, muscle cramps or weakness, or excessive urination.
Any emotional or environmental factors that could affect blood pressure.

If a physical examination indicates hypertension, additional tests may help determine whether it is secondary hypertension or essential hypertension (no other disorder is present) and whether organ damage is present. They include the following:

Blood tests and a urinalysis. (Performed to check for a number of factors, including potassium levels, cholesterol, blood sugar, infection, kidney function, and other possible problems. Measuring blood levels of the protein creatinine, for example, is important for all hypertensive patients in order to determine kidney damage. Higher concentrations may also be an indicator of heart disease.)

An electrocardiogram (ECG).

Click the icon to see an image of an electrocardiogram.

An exercise stress test. This could be important for those with borderline hypertension. Stress-induced blood pressure in such patients has been associated with a risk for left ventricular hypertrophy, a serious complication in which the muscles on the left side of the heart become enlarged. Studies also suggest that an excessive rise in systolic pressure during exercise indicates a risk for coronary artery disease, and stroke.

Click the icon to see an image of blood pressure tests.

Causes

Hypertension is referred to as essential (primary) when the doctor is unable to identify a specific cause. It is by far the most common type of high blood pressure. The causes of this type are unknown but are likely to be a complex combination of genetic, environmental, and other factors.

Genetic Factors. A number of genetic factors or interactions between genes play a major role in essential hypertension. Experts think that the chromosomes (13 and 18) house the genes responsible for blood pressure regulation, although pinning down the range of specific genes involved in hypertension is more difficult.

Abnormalities in the Angiotensin-Renin-Aldosterone System. Genes under intense study are those that regulate a group of hormones known collectively as the angiotensin-renin-aldosterone system. This system influences all aspects of blood pressure control, including blood vessel contraction, sodium and water balance, and cell development in the heart.

Experts believed that this system evolved millions of years ago to protect early humans during drought or stress by retaining salt and water and narrowing blood vessels to ensure adequate blood flow and repair injured tissue. With industrialization, however, this system wreaks havoc on modern humans by intensifying the effects of high-salt diets and sedentary lifestyle. Of particular importance in these harmful responses are the hormone aldosterone and a peptide (a component of proteins) called angiotensin II.

Inherited Abnormalities in the Sympathetic Nervous System. Studies suggest that some people with essential hypertension may inherit abnormalities of the sympathetic nervous system. This is the part of the autonomic nervous system that controls heart rate, blood pressure, and the diameter of the blood vessels.

Insulin Resistance and Type 2 Diabetes. Hypertension is strongly associated with diabetes, both type 1 and type 2. Kidney damage is generally the cause of high blood pressure in type 1 diabetes. Obesity and insulin resistance are the factors associated with hypertension in type 2 diabetes, the more common type. People with type 2 diabetes generally have normal or high levels of insulin, a critical hormone in the metabolism of sugar. However, they are unable to use the insulin, the condition called insulin resistance. Without insulin, blood glucose (sugar) levels rise, the hallmark of diabetes.

Some research indicates that obesity is the one common element linking insulin, type 2 diabetes, and high blood pressure. Obesity is common in both type 2 diabetes and hypertension. Oddly, however, studies have found a stronger association between hypertension and insulin resistance in thin patients as well as overweight people with type 2 diabetes. Some research indicates that insulin resistance may cause sodium retention, a contributor to high blood pressure.

In any case, regardless of the causal connections, people who have insulin resistance or full-blown diabetes plus hypertension have a significantly greater chance for heart attack, kidney disease, and stroke than people who have only high blood pressure.

Obesity. Obesity on its own has a number of possible effects that could lead to hypertension. It may blunt certain actions of insulin that open blood vessels, and it may cause structural changes in the kidney and abnormal handling of sodium. It is also associated with alterations in the systems that regulate blood flow.

Low Levels of Nitric Oxide. The gas nitric oxide can be produced in the body, where it affects the smooth muscle cells that line blood vessels; it helps keep them relaxed, flexible. It may also help prevent blood clotting. Low levels of nitric oxide have been observed in people with high blood pressure (particularly in African-Americans) and may be an important factor in essential hypertension.

Secondary hypertension has recognizable causes, which are usually treatable or reversible.

Medical Conditions. A number of medical conditions can cause secondary high blood pressure:

Kidney disease is the most common cause of secondary hypertension, particularly in older people.
Sleep apnea, a disorder in which breathing halts briefly but repeatedly during sleep, is now highly associated with hypertension. A weak but still higher than normal association with high blood pressure has even been observed in those who snore or have mild sleep apnea. The relationship between sleep apnea and hypertension has been thought to be largely due to obesity, but major studies are finding a higher rate of hypertension in people with sleep apnea regardless of their weight. Treating sleep apnea with a device known as nasal continuous positive airway pressure (CPAP) may have modest benefits blood pressure as well.

CPAP is an airway treatment using slight positive pressure during inhalation to increase the volume of inspired air and to decrease the work of breathing.

Other medical conditions that contribute to temporary hypertension are pregnancy, cirrhosis, and Cushing's disease.

Click the icon to see an image of cirrhosis of the liver.

Medications. Certain prescription and over-the-counter drugs can cause temporary high blood pressure. They include:

Corticosteroids
Acetaminophen (Tylenol)
Nonsteroidal anti-inflammatory drugs (NSAIDs) -- such as ibuprofen (Motrin), naproxen (Aleve), and aspirin -- may cause secondary hypertension as well as other complications. In one important study, women who used an NSAID for 5 or more days a month had a significantly higher risk for hypertension. The more often they used these drugs, the higher the risk. A 2007 study indicated that NSAIDs also increase the risk for hypertension in men. A 2005 study found that NSAIDs increase the risk for kidney failure, and that the risk is significantly greater for all patients with hypertension. Patients who took diuretics along with NSAIDs had 11.6 times the risk of developing acute kidney failure compared to non-NSAID users. The relative risk for calcium channel blockers and NSAIDs was 7.8. The researchers advised that NSAIDs should be used with caution in patients with hypertension or heart failure.
Cold medicines containing pseudoephedrine have also been found to increase blood pressure in hypertensive people, although they appear to pose no danger for those with normal blood pressure.
Oral contraceptives ("the pill") increase the risk for high blood pressure, particularly in women who are older, obese, smokers, or some combination. Stopping the pill nearly always reduces blood pressure, although a recent study suggested that oral contraceptives may produce a small but significant increase in diastolic pressure that persists in some older women who have been off the pill for years.

Alcohol, Cigarettes, and Coffee

An estimated 10% of hypertension cases are caused by alcohol abuse (three or more alcohol drinks a day), with heavier drinkers having higher pressure. Women may be more sensitive than men to the blood pressure effects of alcohol. Moderate drinking (one or two drinks a day) has benefits for the heart and may even protect against some types of stroke. In particular, red wine may have chemicals that help blood pressure.
Smoking. Smoking is a major risk factor. One study reported that smokers have blood pressures up to 10 points higher than nonsmokers.
Caffeine. In healthy people with normal blood pressure, drinking a couple of cups of coffee a day is unlikely to do any harm. A high intake of coffee may be harmful in people with hypertension and may even increase their risk for stroke.

Other Causes of Secondary High Blood Pressure

Stress
Intense workouts (snow shoveling, jogging, speed walking, tennis, heavy lifting, heavy gardening)

Risk Factors

During the last decade, the number of Americans with high blood pressure has increased by 30%. Over 65 million American adults now have high blood pressure, and this condition affects close to 1 billion people worldwide. Less than half of these people are on medication, however, and only about half of this group have their blood pressure under good control with such drugs. Older people are less likely to be treated adequately. The majority of people with high blood pressure have the mild type, but even this condition requires attention.

Age is the major risk factor of hypertension. Blood pressure increases with age in both men and women, and in fact, the lifetime risk for hypertension is nearly 90%. Two-thirds of Americans over age 60 have hypertension. Older women (60 years and above) currently have the highest rates of hypertension, and mortality rates from hypertension are higher in women than in men. Hypertension is also becoming more common in children and teenagers.

Compared to Caucasians, African Americans have 1.8 times the rate of fatal stroke, 1.5 times the risk for fatal heart disease, and 4.2 times the rates of end-stage kidney disease. In general, about 34% of African American men and women have hypertension; it may account for over 40% of all deaths in this group.

The prevalence of high blood pressure among African Americans is among the highest in the world. The rates of hypertension in Hispanic Americans, Caucasians, and Native Americans are about equivalent (ranging from 24 - 27%). The rate is much lower in Asian/ Pacific Islanders (9.7% in men and 8.4% in women). However, nearly 75% of older Japanese American men are hypertensive.

A number of theories have addressed the reasons for this difference:

African Americans may have lower levels of nitric oxide and higher levels of a peptide called endothelin-1 (ET-1) than Caucasians. Nitric oxide keeps blood vessels flexible and open and ET-1 narrows blood vessels.
African Americans have a higher risk for an impaired response to angiotensin (Ang II), which is a peptide important in regulating salt and water balances. African Americans are more likely to be salt-sensitive than other groups.
Social and income disparities and dietary issues may explain many of the differences in blood pressure rates observed between ethnic groups. For example, while African Americans have a disproportionately high rate of hypertension, one study in rural African villages, where diets are rich in fish, reported only a 3% rate of high blood pressure among inhabitants. Another study reported that Caucasian as well as African Americans in the Southeast have a higher incidence of hypertension and stroke than people in other U.S. regions. The Southeast also has a higher rate of obesity, stress, anxiety, and depression, and diets low in potassium and high in salt, all related to a lower socioeconomic level.
African Americans have a higher prevalence of risk factors (cardiovascular disease, obesity, diabetes and kidney disease) that are associated with hypertension.

In any case, hypertension appears to be dangerously undertreated in major minority groups. Inadequately controlled hypertension is the major factor for the higher mortality rate from heart disease among African Americans, and special treatment considerations need to be addressed in this population. A 2003 treatment consensus statement released by the International Society on Hypertension in Blacks (ISHIB) advises that many African Americans may need at least two medications to help lower their blood pressure. The ISHIB's "15 over 10" rule recommends combination therapy for any patient whose blood pressure exceeds their desired goal by 15 mm Hg systolic or 10 mm Hg diastolic.

Obesity. About one-third of patients with high blood pressure are overweight. Even moderately obese adults have double the risk of hypertension than people with normal weights. Moreover, the increase in blood pressure in aging Americans may be due primarily to weight gain. (In other cultures old age does not necessarily coincide with weight gain or high blood pressure.) Children and adolescents who are obese are at greater risk for high blood pressure when they reach adulthood.

Thinness. Interestingly, thin people with hypertension are at higher risk for heart attacks and stroke than obese people with high blood pressure. Experts think that thin people with hypertension are likely to have conditions such as an enlarged heart or stiff arteries that cause the blood pressure to rise and also pose greater dangers to health.

Low Birth Weight. Low birth weight, particularly in girls, has been associated with high blood pressure in both childhood and adulthood. One study suggested that breast-feeding these babies may help reduce this risk. Another study reported high levels of stress hormones in babies with low birth weight, which could increase the risk for high blood pressure later on. Low birth weight is also associated with subsequent obesity, a major contributor to hypertension.

Up to 75% of cardiovascular problems in people with diabetes may be due to hypertension. There are strong biologic links between insulin resistance (with or without diabetes) and hypertension. It is unclear which condition causes the other. Some experts believe angiotensin may be the common factor linking diabetes and high blood pressure. This natural chemical not only influences all aspects of blood pressure control but also interferes with insulin's normal metabolic signaling. People with diabetes or chronic kidney disease need to reduce their blood pressure to 130/80 mm Hg or lower to protect the heart and help prevent other complications common to both diseases. Lowering systolic pressure may be particularly important for people with diabetes.

Spouses. Studies suggest that spouses of people with high blood pressure are at a much higher risk as well. Such findings indicate that dietary and environmental factors play a role in this disease. Some evidence also indicates that higher risk in spouses may be due to people often choosing mates who are similar to them.

Family History and Genetics. Essential hypertension may be inherited in 30 - 60% of cases. According to one study, being a brother or sister of someone with premature coronary artery disease is a greater risk factor for hypertension than having a parent with the disease. A family history of heart disease is considered to be a major risk factor for high blood pressure in adults under age 65.

Atherosclerosis is a common disorder of the arteries. Fat, cholesterol, and other substances collect in the walls of arteries. Larger accumulations are called atheromas or plaque and can damage artery walls and block blood flow. Severely restricted blood flow in the heart muscle leads to symptoms such as chest pain.

People who are anxious or depressed may have over twice the risk for high blood pressure than those without these problems.

Mental Stress. Recent evidence confirms the association between stress and hypertension. In one 20-year study, men who periodically measured highest on the stress scale were twice as likely to have high blood pressure as those with normal stress. The effects of stress on blood pressure in women were less clear. Job stress and lack of career success have been specifically linked to high blood pressure in both men and women.

Anxiety. Studies suggest that anxiety is a risk factor for hypertension, particularly in women.

Depression. Mounting evidence suggests that depression has physiological effects that impair the heart and that it contributes to destructive behaviors, such as weight gain, smoking, or alcohol abuse. In one study, those who scored highest on a depression test had about twice the risk of high blood pressure as those with the lowest score. This link was particularly strong in African Americans. Depression was the strongest risk factor in this group.

Blood pressure levels tend to be lowest during the morning and midday hours and highest at the end of the day. Seasonal changes also affect blood pressure, with hypertension increasing during cold months and declining during the summer. Blood pressure readings can vary by as much as 40% depending on the time of day and season.

Complications

Hypertension places stress on several organs (called target organs), including the kidneys, eyes, and heart, causing them to deteriorate over time. High blood pressure contributes to 75% of all strokes and heart attacks. It is particularly deadly in African-Americans.

Research suggests that prehypertension is also a serious risk factor for heart complications. A 2005 study found that people with prehypertension are three times more likely to have a heart attack, and nearly twice as likely to develop coronary artery disease as people with normal blood pressure.

Hypertension is a disorder characterized by chronically high blood pressure. It must be monitored, treated and controlled by medication, lifestyle changes, or a combination of both.

Malignant hypertension, an emergency condition resulting from untreated primary hypertension, can be lethal.

About two-thirds of people who suffer a first stroke have moderate elevated blood pressure (160/95 mm Hg) or above. Hypertensive people have up to 10 times the normal risk of stroke, depending on the severity of the blood pressure. Hypertension is also an important cause of so-called silent cerebral infarcts, blockages in the blood vessels in the brain that may predict major stroke or progression to dementia over time.

Uncontrolled chronic high blood pressure is also associated with reduced short-term memory and mental abilities. Isolated systolic hypertension may pose a particular risk for complications in the brain. Fortunately, controlling blood pressure with medications can reduce or even prevent memory loss and mental decline due to hypertension. A 2006 study of older men indicated that anti-hypertensive treatment for at least 5 years may help prevent the development of dementia. Other studies suggest that anti-hypertensive drugs may help protect against Alzheimer's disease in people with genetic susceptibility to this disease.

High blood pressure is a major risk factor for heart disease.

Heart Attack. About half of people who suffer their first heart attack have moderate hypertension (160/95 mm Hg) or greater. High blood pressure increases the risk for a heart attack by up to five times, depending on the severity of the hypertension.

Heart Failure. Hypertension precedes heart failure in 75 - 90% of heart failure cases. High blood pressure has various effects that cause the heart to fail, including:

To compensate for increased blood pressure, the heart must work harder to pump blood, and so its muscles thicken (hypertrophy), usually on the left side (left-ventricle dysfunction). These thickened muscles pump inefficiently, and, over time, the force of their contractions weakens. The heart muscles then have difficulty relaxing and filling the heart with blood. The heart begins to fail.

Click the icon to see an image of a hypertensive heart.

The failing heart then triggers a number of hormonal and neurochemical mechanisms to correct imbalances in blood pressure and flow. This response, called remodeling, is helpful in the short run but very destructive and irreversible over time.
As part of the remodeling process, the heart muscle cells elongate. The muscular walls of the heart dilate and become thinner and inefficient. The cells themselves undergo molecular changes that result in calcium loss, a mineral crucial for healthy heart contractions.
The end-result of remodeling is a falling volume of blood pumped to the kidneys; the kidneys retain water and salt in response, increasing fluid buildup in the body.
To make matters worse, the body's arteries narrow in response to a lower blood volume. This constriction forces the heart to work even harder to pump blood through these narrowed vessels, increasing blood pressure and continuing the cycle.

A 2006 analysis of ALLHAT trial data indicated that diuretics are the best first-line high blood pressure medication for preventing heart failure.

Diabetes. High blood pressure, and the medications used to treat it, can increase the risk for developing diabetes. Studies have reported that thiazide diuretics and beta blockers carry a higher risk for causing diabetes than other anti-hypertensive drugs. However, an important 2006 ALLHAT study compared the effects of various drug classes on blood sugar levels and diabetes development. The results suggested that while diuretics may slightly increase diabetes risk more than other types of anti-hypertensive drugs, this effect does not cause worse heart problems. Most experts believe that thiazide diuretics should remain the first choice for high blood pressure treatment, and that the benefit of blood pressure reduction outweighs the risk of diabetes development.

Diabetes-Related Kidney Disease. High blood pressure is strongly associated with diabetic nephropathy (diabetes-related kidney disease). Most patients with type 2 diabetes who show early signs of nephropathy already have high blood pressure. When patients with type 1 diabetes are diagnosed with early nephropathy, on the other hand, they usually have normal blood pressure readings in the doctor's office. A 2002 study using home monitors, however, found that patients with type 1 diabetes often have high systolic blood pressure during sleep -- before development of nephropathy. Home blood pressure monitoring, then, may help identify patients who are at risk for kidney damage due to high systolic pressure.

End-Stage Kidney Disease. High blood pressure causes 30% of all cases of end-stage kidney disease (medically referred to as end-stage renal disease, or ESRD). Only diabetes leads to more cases of kidney failure.

Kidney Cancer. Men with high blood pressure may also have a higher risk of kidney cancer.

High blood pressure can injure the eyes, causing a condition called retinopathy.

Click the icon to see an image of hypertensive retinopathy.

Hypertension also increases the elimination of calcium in urine, potentially leading to loss of bone mineral density, a significant risk factor for fractures, particularly in elderly women. In one study, women with the highest levels of blood pressure lost bone density at nearly twice the rate of those in the lowest range. It is not clear whether this effect occurs in men or in non-Caucasian women.

Sexual dysfunction is more common and more severe in men with hypertension and in smokers than it is in the general population. Many of the drugs that treat hypertension are thought to cause impotence as a side effect. In these cases, it is reversible when the drugs are stopped. More recent evidence suggests, however, that the disease process that causes hypertension is itself the major cause of erectile dysfunction in these men.

Newer anti-hypertensive drugs, including angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs), are less associated with erectile dysfunction. ARBs, such as losartan (Cozaar), may be particularly effective in restoring erectile function in men with high blood pressure. Sildenafil (Viagra) is successful in achieving erections in almost two-thirds of patients with controlled high blood pressure. Because sildenafil has a shorter half-life and is eliminated more quickly from the body than newer erectile dysfunction drugs, it may be a safer option for men with hypertension. In a 2003 review of safety data, sildenafil did not appear to pose a risk for men who had both high blood pressure and erectile dysfunction.

Severe, sudden high blood pressure in pregnant women is one component of a condition called preeclampsia (commonly called toxemia) that can be very serious for both mother and child. Preeclampsia occurs in up to 10% of all pregnancies, usually in the third trimester of a first pregnancy, and resolves immediately after delivery. Other symptoms and signs of preeclampsia include protein in the urine, severe headaches, and swollen ankles.

This condition may be caused by a failure of the placenta to embed properly in the uterus, which causes it to misconnect with the mother's blood vessels. As a result, the fetus does not receive a sufficient blood supply, and the mother's own blood pressure increases to replace it. The risk for preeclampsia is higher for first births, multiple births, and for very young women (teenagers) and those over age 35. Pre-existing high blood pressure, diabetes, and kidney disease also increase the risk for preeclampsia. There appears to be a genetic component for this condition, so women whose mothers experienced preeclampsia are also at higher risk.

The reduced supply of blood to the placenta can cause low birth weight and eye or brain damage in the fetus. Severe cases of preeclampsia can cause kidney damage, convulsion, and coma in the mother and can be lethal to both mother and child. Evidence also suggests that preeclampsia can lead to increased risks later in life for coronary heart disease and other heart problems.

Women at risk for preeclampsia (particularly those with existing hypertension) may benefit from having an ultrasound of uterine arteries at 20 - 24 weeks of pregnancy, followed (if abnormal) by 24-hour blood pressure monitoring. Blood pressure medications may be required. Delivery is the main cure for preeclampsia. In severe cases, the obstetrician will need to induce pre-term birth.

High blood pressure may increase the risk of developing fibroids, according to data from the Nurses’ Health Study. Tracking women for 10 years, the prospective epidemiologic study found that for every 10 mm/Hg increase in diastolic blood pressure, the risk for developing fibroids increased by 8 - 10%.

Children with high blood pressure should first be treated with lifestyle changes, including weight reduction, increased physical activity, and diet modification. If blood pressure is not controlled with lifestyle changes, drug treatment may be required. Although there are few clinical trials conducted in children, a 2005 study found that the angiotensin receptor blocker losartan was safe and effective in children. Results of studies evaluating outcomes of children with hypertension suggest that early abnormalities, including enlarged heart and abnormalities in the kidney and eyes, may occur even in children with mild hypertension. Children and adolescents with hypertension should be monitored and evaluated for any early organ damage. Secondary hypertension (high blood pressure due to another disease or drug) is more common in children than adults.

Symptoms

Hypertension has aptly been called the "silent killer" because it usually produces no symptoms. Untreated hypertension increases slowly over the years. It is important for anyone with risk factors to have their blood pressure checked regularly and to make appropriate lifestyle changes. Such recommendations are especially important for individuals who have prehypertension or hypertension, a family history of hypertension, are overweight, or are over age 40.

In rare cases (fewer than 1% of all patients with hypertension), the blood pressure rises quickly (with diastolic pressure usually rising to 130 mm Hg or higher), resulting in malignant or accelerated hypertension. This is a life-threatening condition and must be treated immediately. People with uncontrolled hypertension or a history of heart failure are at increased risk for this crisis.

People should call a doctor immediately if these symptoms occur:

Drowsiness
Confusion
Headache
Nausea
Loss of vision

Treatment

Patients with hypertension should work with their doctors to set blood pressure goals based on individual risk factors. Lifestyle and medication programs need to be planned on an individual basis.

Healthy lifestyle changes are imperative for anyone, and are critical for people with even normal blood pressure (120/80 mm Hg) and above. In appropriate patients, aggressive drug treatment of long-term high blood pressure can significantly reduce the incidence of mental decline and death from heart disease and other serious physical effects of hypertension. In people with diabetes, controlling both blood pressure and blood glucose levels prevents serious complications of that disease. Anti-hypertensive drugs may even prevent mental decline, including in people genetically susceptible to Alzheimer's disease. Nevertheless, only slightly over half of patients with hypertension are treated at all, and only a quarter have adequately controlled pressure.

It is not clear when drugs should be started, particularly for people with prehypertension or mild high blood pressure. To help make treatment choices, the U.S. National Heart, Lung, and Blood Institute has created categories (denoted as groups A, B, and C) according to a patient's risk factors for heart disease. Applying these categories to the severity of hypertension helps determine whether lifestyle changes alone or medications are needed.


Risk Groups	Blood Pressure Stages (Systolic/Diastolic)
	Prehypertension (120 - 139/80 - 89)	Mild (Stage 1) Blood Pressure (140 - 159/90 - 99)	Moderate-to-Severe (Stage 2) Blood Pressure (Systolic pressure over 160 or diastolic pressure over 100)
Risk Group A Have no risk factors for heart disease.	Lifestyle changes only. (Exercise and dietary program with regular monitoring.)	Year trial of lifestyle changes only. If blood pressure is not lower at 1 year, add drug treatments.	Lifestyle changes and medications.
Risk Group B Have at least one risk factor for heart disease* (excluding diabetes) but have no target organ damage (such as in the kidneys, eyes, or heart, or existing heart disease).	Lifestyle changes only.	6-month trial of lifestyle changes only. If blood pressure is not lower at 6 months, add drug treatments. Medications considered for patients with multiple risk factors.	Lifestyle changes and medications.
Risk Group C Have diabetes with or without target organ damage and existing heart disease (with or without risk factors for heart disease).	Lifestyle changes and medications.	Lifestyle changes and medications.	Lifestyle changes and medications.

* Risk factors for heart disease include the following: family history of heart disease, smoking, unhealthy cholesterol and lipid levels, diabetes, being over 60 years old.

Lifestyle Changes

Healthy lifestyle changes are an important first step for lowering blood pressure. Current guidelines recommend that people should:

Exercise at least 30 minutes a day
Maintain normal weight
Reduce salt intake
Increase potassium intake
Limit alcohol consumption; however, moderate alcohol consumption (1 – 2 glasses a day) may actually lower the risk for heart attack among men with high blood pressure
Consume a diet rich in fruits, vegetables, and low-fat dairy products while reducing total and saturated fat intake. (The DASH diet is one way of achieving such a dietary plan.)

The DASH diet (Dietary Approaches to Stop Hypertension) is proven to help lower blood pressure. Results are sometimes seen within a few weeks. Restricting sodium improves results. The diet appears to have antioxidant effects and may help lower LDL cholesterol levels, although beneficial HDL levels also decline. This diet is not only rich in important nutrients and fiber but also includes foods that contain far more electrolytes, potassium (4,700 mg/day), calcium (1,250 mg/day), and magnesium (500 mg/day) than are found in the average American diet.

A diet that is effective in lowering blood pressure is called Dietary Approaches to Stop Hypertension (DASH).

DASH diet recommendations:

Limit salt intake to no more than 2,300 mg a day (a maximum intake of 1,500 mg a day is an even better goal).
Reduce saturated fat to no more than 6% of daily calories and total fat to 27% of daily calories. (But, include dairy products that are non- or low-fat. Low-fat dairy products appear to be especially beneficial for lowering systolic blood pressure).
When choosing fats, select monounsaturated oils, such as olive or canola oils.
Choose whole grains over white flour or pasta products.
Choose fresh fruits and vegetables every day. In one study, people who increased their intake of fruits and vegetables experienced a drop in blood pressure after 6 months. Many of these foods are rich in potassium, fiber, or both, possibly helping lower blood pressure.
Include nuts, seeds, or legumes (dried beans or peas) daily.
Choose modest amounts of protein (no more than 18% of total daily calories). Fish, skinless poultry, and soy products are the best protein sources.
Other daily nutrient goals in the DASH diet include limiting carbohydrates to 55% of daily calories and dietary cholesterol to 150 mg. Patients should try to get at least 30 g of daily fiber.

Slight changes to the DASH diet might help further lower blood pressure, as well as improve cholesterol and lipid levels. Researchers reporting in the Journal of the American Medical Association and at the 2005 American Heart Association meeting said that replacing some carbohydrates in the DASH diet with more protein (from plant sources) or monounsaturated fats may help further reduce heart disease risk factors.

A combination of the DASH diet and salt restriction is extremely effective in reducing blood pressure. Reducing sodium may also help protect against heart failure. People with normal blood pressure should consume no more than 2,400 milligrams (about one teaspoon) of sodium each day. People with blood pressure should consume much less. (Patients should consult their doctor on individual recommendations for salt intake.) The following higher-risk groups should take particular measures to restrict salt:

People at Risk for Salt-Sensitivity. About half of people with hypertension have blood pressure that reacts significantly to salt. Such people are known to be salt-sensitive. Groups at particularly high risk for salt-sensitivity include African-Americans, the elderly, and people with diabetes. Even people with normal blood pressure can be salt-sensitive. High-salt diets in anyone who is salt-sensitive may harm the heart, kidneys, and brain and increase the risk for death, regardless of blood pressure. Because testing for salt-sensitivity is not easy, experts recommend that everyone proactively restrict their daily salt-intake.
Overweight People. Overweight individuals may absorb and retain sodium differently from people with normal weights. Reducing sodium can also help lower the risk of heart disease and stroke in people who are overweight. Unfortunately, because overweight people generally consume more calories, they are also likely take in more sodium.
People on Anti-Hypertensive Drugs. Restricting salt also enhances the benefits of many standard anti-hypertensive drugs by reducing potassium loss, and may help protect against kidney disease in patients who are also taking calcium-blocker drugs. A low-salt diet can also increase the chances for being able to stop such medications.

Simply eliminating table and cooking salt can be beneficial. Salt substitutes, such as Cardia, (containing mixtures of potassium, sodium, and magnesium) are available, but they are expensive. In any case, about 75% of the salt in the typical American diet comes from processed or commercial foods, not from food cooked at home, so the benefits of table-salt substitutes are likely to be very modest. Some sodium is essential to protect the heart, but most experts agree that the amount is significantly less than that found in the average American diet. If people cannot significantly reduce the amount of salt in their diets, adding potassium-rich foods might help to restore a healthy balance.

Evidence strongly indicates that a potassium-rich diet can help achieve healthy blood pressure levels, and that potassium supplements can lower systolic blood pressure by 1.8 m Hg and diastolic blood pressure by 1 mm Hg. Some evidence suggests that a potassium-rich diet can reduce the risk of stroke by 22 - 40%. Current expert guidelines support the use of potassium supplements or enough dietary potassium to achieve 3,500 mg per day for people with normal or high blood pressure (who have no risk factors for excess potassium levels). This goal is particularly important in people who have high sodium intake.

The best source of potassium is the fruits and vegetables that contain them. Some potassium-rich foods include bananas, oranges, pears, prunes, cantaloupes, tomatoes, dried peas and beans, nuts, potatoes, and avocados.

Excess potassium can cause abdominal distress, muscle weakness, and, in rare cases, dangerous heart events. Some people should be particularly cautious about excess potassium, including those with conditions, such as diabetes or kidney disease, that increase potassium levels. People who take medications, such as ACE inhibitors or potassium-sparing diuretics that limit the kidney's ability to excrete potassium, should not take potassium supplements.

Smoking. Everyone should quit smoking.

Alcohol. People who drink alcohol should do so in moderation. Men with hypertension should limit their intake to no more than one or two drinks a day, and women and lighter people should drink less.

Caffeine Drinks. Coffee drinking is associated with small increases in blood pressure, but the risk is very small in people with normal blood pressure. People with existing hypertension should avoid caffeine altogether.

Fiber. Fiber supplementation can help reduce blood pressure levels. It may take up to 8 weeks to achieve the maximum benefit.

Folate. Increasing folate (a B vitamin) intake to more than 800 mcg/day can help reduce blood pressure, particularly for younger women (under age 46). Dietary sources of folate include citrus fruits, leafy green vegetables, beans, and grain products. Folate helps to reduce homocysteine levels.

Fish Oil and Omega 3 Fatty Acids. Omega 3 fatty acids (docosahexaenoic and eicosapentaneoic acids) are found in oily fish. Studies indicate that they may have specific benefits for many medical conditions, including hypertension. They appear to help keep blood vessels flexible and may help protect the nervous system. Fatty acids are also available in supplements, but their long-term effects on blood pressure are unknown.

Click the icon to see an image of omega-3 fatty acids

Calcium. Calcium regulates the tone of the smooth muscles lining blood vessels. Studies have found that people who have sufficient dietary calcium have lower blood pressure than those who do not. Hypertension itself increases calcium loss from the body. The effects of extra calcium on blood pressure, however, are mixed, with some even showing higher pressure.

Click the icon to see an image of the sources of calcium.

Magnesium. Some studies reported that magnesium supplements may induce small but significant reductions in blood pressure. No major studies, however, have been done on long-term benefits or risks of magnesium supplements. A major 2001 study on diet found no effect on blood pressure from magnesium intake from foods.

Antioxidant Supplements. Antioxidants are substances that help the body eliminate oxidants, (also called oxygen-free radicals), which are damaging particles produced as part of the body's chemical processes. Some antioxidant supplements, including vitamins C and E and alpha-lipoic acid, are being studied for possible benefits in protecting against hypertension by preventing injury in the blood vessels. Vitamin C may have specific benefits for hypertension by preventing dangerous effects on nitric acid, the substance that keeps arteries flexible.

Click the icon to see an image of vitamin C sources.

Click the icon to see an image of vitamin E sources.

In people who are overweight, even modest reductions in weight, particularly in the abdominal area, can immediately reduce blood pressure. Weight loss, particularly accompanied by salt restriction, may allow patients with mild hypertension, even older people, to safely reduce or go off medications. The benefits of weight loss on blood pressure are long-lasting.

Positive Effects on Blood Pressure. Regular exercise helps keep arteries elastic, even in older people, which in turn ensures blood flow and normal blood pressure. Sedentary people have a 35% greater risk of developing hypertension than athletes.

Experts recommend at least 30 minutes of exercise on most -- if not all-days. In one study, moderate exercise (jogging two miles per day) controlled hypertension so well that more than half the patients who had been taking drugs for high blood pressure were able to discontinue their medication.

Studies have also indicated that yoga and Tai Chi, an ancient Chinese exercise involving slow, relaxing movements, may lower blood pressure almost as well as moderate-intensity aerobic exercises.

High-intensity exercise may not lower blood pressure as effectively as moderate intensity exercise and may be dangerous in people with hypertension.

Negative Effects. Each year an estimated 75,000 heart attacks (5% of all heart attacks) occur after heavy exertion, leading to 25,000 deaths. Older people and those with uncontrolled hypertension or other serious medical conditions should be cautious when exercising. Studies report that older people who begin vigorous exercise are at a slightly higher than average risk for a heart attack during the first year, but over time, regular exercise is likely to be protective.

The following activities may pose particular dangers for high-risk individuals:

Intense workouts (snow shoveling, slow jogging, speed walking, tennis, heavy lifting, heavy gardening). They tend to stress the heart, raise blood pressure for a brief period, and may cause spasms in the arteries leading to the heart.
Competitive sports, which couple intense activity with aggressive emotions.

Effects of Anti-Hypertensive Drugs on Exercise. Certain anti-hypertensive medications, including diuretics and beta-blockers, can interfere with exercise capacity. ACE inhibitors or calcium-channel blockers are the best drugs for active individuals. However, patients who take drugs that interfere somewhat with exercise capability should still adhere to an exercise program and consult a doctor on how best to balance medications with exercise.

Click the icon to see an image about lifestyle changes for hypertension.

Certain sleep disorders, especially sleep apnea, are associated with hypertension. Even chronic, insufficient sleep may raise blood pressure in patients with hypertension, placing them at increased risk of heart disease and death. Stress hormone levels increase with sleeplessness, which can activate the sympathetic nervous system, a strong player in hypertension. Patients who have chronic insomnia or other severe sleep disturbances, (particularly sleep apnea), may want to consult a sleep expert. Patients with hypertension who are habitually poor sleepers should consider long-acting blood pressure medications to help counteract the increase in blood pressure that occurs in the early morning hours.

Improving mood or relieving stress may be helpful. The following studies suggested possible benefits:

Stress reduction programs that use cognitive-behavioral therapy may reduce blood pressure.
Active religious faith was associated with healthy blood pressure levels, possibly indicating the combined benefits of a strong social network and reduced stress from spiritual activities.
A simple relaxation technique called transcendental meditation (TM), which involves silent repetition of a single sound, was associated with lower blood pressure.

Treating stress cannot cure medical problems. Stress management programs are not a substitute for standard medical treatments, but can be a very important component of a lifestyle plan.

Medications

Dozens of anti-hypertensive drugs are available. Most fall into the following categories:

Diuretics rid the body of extra water and salt. Diuretics are usually the first-line treatment for high blood pressure.
Beta-blockers block the effects of adrenaline and ease the heart's pumping action.
Angiotensin converting enzyme (ACE) inhibitorsreduce the production of angiotensin, a chemical that causes arteries to narrow.
Calcium-channel blockers (CCBs) decrease the contractions of the heart and widen blood vessels.
Angiotensin-receptor blockers (ARBs) block angiotensin, another chemical that constricts the arteries.
Vasodilators expand blood vessels.

In about half of patients a single-drug regimen can control mild to moderate hypertension. More severe hypertension often requires a combination of two or more drugs. Each drug has specific benefits, but their effects may vary depending on the individual patient.

One of the most difficult issues that patients face, particularly those with primary hypertension, is that the treatment may make them feel worse than the disease, which usually has no symptoms. Whatever the difficulties, compliance with a drug and lifestyle program is worth the effort. It is very important that patients discuss medication concerns with their doctors. If current blood pressure drugs are causing uncomfortable side effects, the doctor may adjust dosages or combinations.

Patients whose blood pressure has been well-controlled and who are able to maintain a healthy life style may choose to withdraw from medications. They should do so in a step-down manner (gradual reduction) and be monitored regularly. Stopping too quickly can have adverse effects, including serious effects on the heart. The highest success rates are more likely in those who lose weight and reduce sodium intake, in patients who have been treated with a single drug, and in those who have maintained lower systolic blood pressure during treatment. People over 75 years old may have more trouble than younger adults in maintaining normal blood pressure after withdrawal.

Classes of Medications

There are several classes of drugs used to treat hypertension.

Diuretics help the kidneys get rid of excess salt and water. They are the mainstays of anti-hypertensive therapy and are the first drug of choice for most people with hypertension. They are especially helpful for treating the elderly and African-American patients. (African-Americans are more likely to be salt-sensitive, so they respond well to these drugs.) They also work well for patients with diabetes.

Results from the long-term Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), published in the Journal of the American Medical Association in 2005, confirm that thiazide-type diuretics should be the first treatment option for most patients with hypertension. The landmark trial included over 33,000 patients (35% black) with hypertension and at least one other cardiovascular risk factor. Patients were randomized to receive a calcium channel blocker, an ACE inhibitor, or a thiazide-type diuretic.

Results suggested that the diuretic worked just as well as the newer drugs in lowering blood pressure and was more effective in preventing heart failure, heart attack, and stroke. The benefits for the diuretic were even more significant for African-American patients. Other trial results indicated that patients taking the calcium channel blocker had the greatest risk for heart failure, and that the ACE inhibitor was much less effective than the diuretic in lowering blood pressure and preventing stroke in African-American patients.

Diuretic Types and Brands. There are many brands of diuretics. They are generally inexpensive. Some need to be taken once a day, some twice a day. Low doses are usually as effective for lowering blood pressure as higher doses. Diuretics are usually used in combination with other drugs, especially ACE inhibitors and beta blockers.

There are three main types of diuretics:

Potassium-sparing diuretics. These include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
Thiazide diuretics. These include chlorothiazide (Diuril), chlorthalidone (Hygroton), indapamide (Lozol), hydrochlorothiazide (Esidrix, HydroDiuril), and metolazone (Mykrox, Zaroxolyn).
Loop diuretics. Because loop diuretics act faster than other diuretics it is important to avoid dehydration and potassium loss. Loop diuretics include bumetanide (Bumex), furosemide (Lasix), and torsemide (Demadex).

Benefits of Diuretics. Diuretics can:

Reduce the risk for stroke
Reduce the risk for heart attack and heart failure
Protect against blood clots.

Problems with Diuretics. Loop and thiazide diuretics reduce the body's supply of potassium, which, if left untreated, increases the risk for arrhythmias. Arrhythmias are heart rhythm disturbances that can, in rare instances, lead to cardiac arrest. In such cases, doctors will prescribe lower doses of the current diuretic, recommend potassium supplements, or use potassium-sparing diuretics either alone or in combination with a thiazide. Potassium-sparing drugs have their own risks, which include dangerously high levels of potassium in people with existing elevated levels of potassium or in those with damaged kidneys. However, all diuretics are generally more beneficial than harmful.

Common Diuretic Side Effects:

Fatigue
Depression and irritability
Urinary incontinence
Reduced sexual drive

Beta-blockers help slow heart rate and lower blood pressure. They are usually used in combination with other drugs such as ACE inhibitors and diuretics.

Brands. Propranolol (Inderal), acebutolol (Sectral), atenolol (Tenormin), betaxolol (Kerlone), carteolol (Cartrol), metoprolol (Lopressor), nadolol (Corgard), penbutolol (Levatol), pindolol (Visken), carvedilol (Coreg), and timolol (Blocadren). The drugs may differ in their effects and benefits.

Problems with Beta-Blockers. Evidence presented at the 2005 meeting of the American College of Cardiology suggested that an ACE-inhibitor combined with a calcium channel blocker works just as well as a beta-blocker-diuretic combination in treating hypertension, and poses less risk of diabetes. Other recent studies suggest that beta-blockers may increase the risk of stroke, and should not be a first-line choice for high blood pressure treatment.

Do not abruptly stop taking these drugs. The sudden withdrawal of beta blockers can rapidly increase heart rate and blood pressure. The doctor may want the patient to slowly decrease the dose before stopping completely.
Beta blockers are categorized as non-selective or selective. Non-selective beta blockers such as carvedilol and propranolol may sometimes narrow bronchial airways. These beta blockers should not be used by patients with asthma, emphysema, or chronic bronchitis.
Beta blockers can lower HDL (“good”) cholesterol.
These drugs can hide warning signs of low blood sugar (hypoglycemia) in patients with diabetes. When combined with a diuretic, the risk of diabetes may be increased.

Common Side Effects

Fatigue and lethargy
Vivid dreams and nightmares
Depression
Memory loss
Dizziness and lightheadedness
Reduced ability to exercise
Coldness in extremities (legs, toes, arms, hands)

Check with your doctor about any side effects. Do not stop taking these drugs on your own..

Angiotensin-converting enzyme (ACE) inhibitors open blood vessels and decrease the workload of the heart. They are used to treat high blood pressure but can also help improve heart and lung muscle function.

These drugs are particularly important for patients with diabetes. A large study reported that patients with diabetes who took these drugs had fewer heart attacks and lower overall mortality rates than patients who took other types of high blood pressure medications. ACE inhibitors may also help slow progression of kidney disease, in addition to controlling blood pressure. They may also be better at preventing the development of diabetes in patients with kidney disease than other types of blood pressure medication. In a 2006 study of African-American patients with high blood pressure and kidney disease, patients who took an ACE inhibitor had a lower risk of developing diabetes than those who took a calcium channel blocker or beta-blocker drug.

Doctors sometimes avoid giving aspirin to patients who are taking ACE inhibitors due to concerns that this drug combination can cause kidney problems. A 2005 study of patients with both coronary artery disease and heart failure indicated that an aspirin and ACE inhibitor combination is not harmful, and that aspirin can significantly reduce mortality risk for these patients.

Brands. ACE inhibitors include captopril (Capoten), enalapril (Vasotec), quinapril (Accupril), benazepril (Lotensin), ramipril (Altace), perindopril (Aceon), and lisinopril (Prinivil, Zestril).

Common Side Effects of ACE Inhibitors:

Low blood pressure is the main side effect of ACE inhibitors. This can be severe in some patients, especially at the start of therapy.
Irritating cough is a common side effect, which some people find intolerable. Although all ACE inhibitors can have this side effect, sometimes switching to another brand will reduce this symptom.
ACE inhibitors can harm a developing fetus and should not be used during pregnancy. While it has long been known that these drugs can cause problems in the second and third trimester, an important 2006 study indicated that ACE inhibitors can also cause major heart birth defects when taken during the first trimester. The FDA and the American Heart Association recommend that women who become pregnant should change from ACE inhibitors to another type of blood pressure drug as soon as possible. Women of child-bearing age who are considering becoming pregnant should also discuss alternative drugs with their doctors.

Uncommon Side Effects of ACE Inhibitors:

ACE inhibitors protect against kidney disease, but they may also increase potassium retention by the kidneys. If potassium levels become extremely high, they can cause the heart to stop beating (cardiac arrest). This side effect is rare, except in patients with significant kidney disease. Because of this risk, ACE inhibitors are not usually used in combination with potassium-sparing diuretics or potassium supplements.
A rare but severe side effect is granulocytopenia, an extreme reduction in infection-fighting white blood cells.
In very rare cases, patients suffer a sudden and severe allergic reaction, called angioedema that causes swelling in the eyes and mouth and may close off the throat.

Patients who have difficulty tolerating ACE inhibitor side effects are usually switched to an angiotensin-receptor blocker (ARB).

ARBs, also known as angiotensin II receptor antagonists, are similar to ACE inhibitors in their ability to open blood vessels and lower blood pressure. They may have fewer or less-severe side effects than ACE inhibitors, especially coughing, and are sometimes prescribed as an alternative to ACE inhibitors. ARBs are particularly important drugs for patients with diabetes. They may help protect against kidney disease and kidney failure.

A 2006 study in the New England Journal of Medicine suggested that some patients with prehypertension may benefit from treatment with an ARB drug. Patients in the study received candesartan (Atacand).

Brands. Losartan (Cozaar, Hyzaar), olmesartan (Benicar) candesartan (Atacand), telmisartan (Micardis), eprosartan (Teveten), irbesartan (Avapro), and valsartan (Diovan). A combination medication containing candesartan and the diuretic hydrochlorothiazide (Diovan HCT, Atacand HCT) is also available.

Side Effects:

Low blood pressure
Dizziness and lightheadedness
Raised potassium levels
Drowsiness
Nasal congestion
Should not be used during pregnancy

Calcium-channel blockers (CCBs), or calcium antagonists, help relax blood vessels. Along with diuretics, CCBs may work better than other drug classes for lowering blood pressure in African-Americans. Recent research indicates that newer types of drugs (CCBs, ACE inhibitors) may be a better treatment option for some patients than older drugs (especially beta blockers).

Brands. Diltiazem (Cardizem, Dilacor), amlodipine (Norvasc), felodipine (Plendil), isradipine (DynaCirc), verapamil (Calan, Isoptin, Verelan), nisoldipine (Sular), nicardipine (Cardene), nifedipine (Adalat, Procardia), lercanidipine (Zanidip), lacidipine (Motens), and nitrendipine (Nitrepin). In 2004, a dual-therapy calcium channel blocker-statin combination drug (Caduet) was approved to treat high blood pressure and high cholesterol. Caduet is a fixed-dose combination of amlodipine and atorvastatin.

Side Effects:

Swelling in the feet
Constipation
Fatigue
Erectile dysfunction
Gingivitis
Rash
Food interactions (do not take CCBs with grapefruit or Seville orange products)

Alpha blockers such as doxazosin (Cardura), prazosin (Minipress), and terazosin (Hytrin) help widen small blood vessels. They are generally not used as first-line drugs for high blood pressure, but are prescribed if other drugs do not work or as add-on medication.

Vasodilators, which help open blood vessels by relaxing muscles in the blood vessel walls. These drugs are usually used in combination with a diuretic or a beta-blocker. They are rarely used by themselves. Vasodilators include hydralazine (Apresoline), clonidine (Catapres), available in tablets or as a skin patch), and Minoxidil (Loniten). Some of these drugs should be used with caution or not at all in people who have angina or who have had a heart attack.

Aliskiren (Tekturna). In 2007, the FDA approved aliskiren for treatment of high blood pressure. Aliskiren can be taken either alone or in combination with other blood pressure medication. It should not be used during pregnancy as it can cause injury or death to the fetus. Aliskiren is the first hypertension drug that inhibits renin, a kidney enzyme that is associated with the regulation of blood pressure.

Statins. Statins, common drugs used to lower cholesterol, are proving to have many other health benefits. They include lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol), atorvastatin (Lipitor), and rosuvastatin (Crestor). In an important 2002 study, patients with high blood pressure but normal or slightly high cholesterol levels had fewer heart attacks and strokes when they took the a statin drug. In 2004, a calcium channel blocker-statin combination drug (Caduet) was approved to treat simultaneously high blood pressure and high cholesterol. Caduet is a fixed-dose combination of amlodipine and atorvastatin.

Resources

www.acc.org -- American College of Cardiology
www.americanheart.org -- American Heart Association
www.ash-us.org -- American Society of Hypertension
www.nhlbi.nih.gov/hbp -- National Heart, Lung, and Blood Institute
www.nhlbi.nih.gov/health/public/heart/hbp/dash -- DASH diet
www.ishib.org -- International Society on Hypertension in Blacks
www.eatright.org -- American Dietetic Association

References

Barzilay JI, Davis BR, Cutler JA, Pressel SL, Whelton PK, Basile J, et al. Fasting glucose levels and incident diabetes mellitus in older nondiabetic adults randomized to receive 3 different classes of antihypertensive treatment: a report from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). Arch Intern Med. 2006 Nov 13;166(20):2191-201.

Beulens JW, Rimm EB, Ascherio A, Spiegelman D, Hendriks HF, Mukamal KJ. Alcohol consumption and risk for coronary heart disease among men with hypertension. Ann Intern Med. 2007 Jan 2;146(1):10-9.

Cooper WO, Hernandez-Diaz S, Arbogast PG, Dudley JA, Dyer S, Gideon PS, et al. Major congenital malformations after first-trimester exposure to ACE inhibitors. N Engl J Med. 2006 Jun 8;354(23):2443-51.

Davis BR, Piller LB, Cutler JA, Furberg C, Dunn K, Franklin S, et al. Role of diuretics in the prevention of heart failure: the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial. Circulation. 2006 May 9;113(18):2201-10.

Djousse L, Pankow JS, Hunt SC, Heiss G, Province MA, Kabagambe EK, et al. Influence of saturated fat and linolenic acid on the association between intake of dairy products and blood pressure. Hypertension. 2006 Aug;48(2):335-41.

Forman JP, Rimm EB, Curhan GC. Frequency of analgesic use and risk of hypertension among men. Arch Intern Med. 2007 Feb 26;167(4):394-9.

Peila R, White LR, Masaki K, Petrovitch H, Launer LJ. Reducing the risk of dementia: efficacy of long-term treatment of hypertension. Stroke. 2006 May;37(5):1165-70.

Taylor EN, Hu FB, Curhan GC. Antihypertensive medications and the risk of incident type 2 diabetes. Diabetes Care. 2006 May;29(5):1065-70.

Thornley-Brown D, Wang X, Wright JT Jr, Randall OS, Miller ER, Lash JP, et al. Differing effects of antihypertensive drugs on the incidence of diabetes mellitus among patients with hypertensive kidney disease. Arch Intern Med. 2006 Apr 10;166(7):797-805.

Review Date:
4/12/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com

Osteoarthritis

FitSugar — Wed, 08 Oct 2008 17:34:56 -0700

In This Report

Highlights
Introduction
Causes
Symptoms
Conditions with Similar Sym...
Risk Factors
Diagnosis
Prognosis
Lifestyle Changes
Medications
Alternative and Complementa...
Surgery
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Pain Medications

Nonsteroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors work equally well for pain management, but both types of drugs increase the risk for heart attacks, according to an important report from the U.S. Agency for Healthcare Quality and Research.
The prescription NSAID diclofenac (Voltaren, Cataflam) may present a higher risk for heart attack than other NSAIDs, suggests a 2006 Journal of the American Medical Association study.
Standard osteoarthritis medications provide moderate pain relief for only 2 - 3 weeks, suggests a 2007 review in the European Journal of Pain.

Acupuncture

Acupuncture may be helpful for people with knee and hip osteoarthritis, according to several 2006 studies:

An Annals of Internal Medicine study of 1,007 people with chronic osteoarthritis knee pain indicated that patients who received acupuncture plus standard care had greater improvement than those who received only physical therapy and anti-inflammatory drugs.
An Arthritis and Rheumatism study of 3,663 patients with chronic osteoarthritis knee or hip pain suggested that acupuncture plus routine care can provide significant improvements in pain relief and quality of life. In both studies, the benefits of acupuncture were sustained for up to 6 months after treatment completion.

Exercise and Knee Osteoarthritis

Weight-bearing exercise (walking, jogging) neither prevents nor increases the risk of knee osteoarthritis in healthy middle-aged and elderly people, suggests a 2007 study in Arthritis and Rheumatism.

Risk of Hip Osteoarthritis

About 1 in 4 Americans can expect to develop osteoarthritis of the hip at some point in life, according to research presented at the 2006 American College of Rheumatology annual meeting. Body weight is a factor. People who are normal weight have a 20% risk, compared to those who are overweight (25%) or obese (39%).

Introduction

Osteoarthritis, also known as degenerative joint disease, is the most common form of arthritis. Scientists now believe osteoarthritis results from a combination of genetic abnormalities and joint injuries. In this disorder, an affected joint experiences a progressive loss of cartilage, the slippery material that cushions the ends of bones.

Osteoarthritis is a chronic disease of the joint cartilage and bone, often thought to result from "wear and tear" on a joint, although there are other causes such as congenital defects, trauma, and metabolic disorders. Joints appear larger, are stiff and painful, and usually feel worse with increased use throughout the day.

As a result, the bone beneath the cartilage undergoes changes that lead to bony overgrowth. The tissue that lines the joint can become inflamed, the ligaments can loosen, and the associated muscles can weaken. The patient experiences pain when using the joint. In addition to humans, nearly all vertebrates suffer from osteoarthritis, including porpoises and whales, as did long-extinct terrestrial travelers such as dinosaurs.

Click the icon to see an animation about osteoarthritis.

Joints are designed to provide flexibility, support, stability, and protection. These functions, essential for normal and painless movement, are primarily supplied by specific parts of the joint: the synovium and cartilage.

Synovium. The synovium is a membrane that surrounds the entire joint. It is filled with synovial fluid, a lubricating liquid that supplies nutrients and oxygen to cartilage.

Cartilage. The cartilage is a slippery tissue that coats the ends of the bones. Cartilage is one of the few tissues in the body that does not have its own blood supply. It has a number of essential components:

Click the icon to see an image of the synovial membrane and cartilage in the knee joint.

Chondrocytes. Chondrocytes, the basic cartilage cells, are critical for balance and function.
Water. Cartilage contains a high percentage of water, although it decreases with age. About 85% of cartilage is water in young people, and about 70% is water in older individuals.
Proteoglycans. These are large molecules that help make up cartilage. Their important value is their capacity to bond to water, which ensures the high-fluid content in cartilage.
Collagen. This is the critical protein in cartilage. It forms a mesh to give support and flexibility to the joint. Collagen is the main protein found in all the connective tissues of the body, including the muscles, ligaments, and tendons.

The combination of the collagen meshwork and the high water content, tightly bound by proteoglycans, creates a resilient and slippery pad in the joint, which resists the compression between bones during muscle movement. The synovial fluid lubricates and provides oxygen and nutrients to the bloodless cartilage.

Deterioration of Cartilage. Osteoarthritis develops when cartilage in a joint deteriorates. The process is usually slow.

In the early stages of the disease the surface of the cartilage, or even the synovium in some people, becomes inflamed and swollen. There is a loss of proteoglycan molecules and other tissue components that cause water loss. Fissures and pits appear in the cartilage.
As the disease progresses and more tissue is lost, the cartilage loses elasticity and fluid. It becomes increasingly prone to damage due to repetitive use and injury.
Eventually large amounts of cartilage are destroyed, leaving the ends of the bone within the joint unprotected.

To compound the process, bone around arthritic joints is not structurally normal. As the body tries to repair damage to the cartilage, problems can develop:

Clusters of damaged cells or fluid-filled cysts may form around the bony areas or near the fissures.
Fluid pockets may also form within the bone marrow itself, causing swelling. The marrow, which runs up through the center of bone, is rich in nerve fibers, and such injuries may be an important source of pain in many patients with osteoarthritis.
Bone cells may respond to damage by multiplying, growing, and forming dense, misshapen plates around exposed areas.
At the margins of the joint, the bone may produce outcroppings, on which new cartilage cells (chondrocytes) proliferate and grow abnormally.

Unlike some other types of arthritis, such as rheumatoid arthritis, osteoarthritis does not spread through the entire body. (In other words, it is not systemic.) Rather, it affects one or several joints. Osteoarthritis affects joints differently depending on their location in the body.

Osteoarthritis is commonly found in joints of the fingers, feet, knees, hips, and spine.
It sometimes occurs in the wrist, elbows, shoulders, and jaw, but is not common in these locations.

Causes

The biologic factors leading to the deterioration of cartilage in osteoarthritis are not entirely understood. Many experts believe that osteoarthritis results from a genetic susceptibility that causes some biologic response to injuries to the joint, which in turn leads to progressive deterioration of cartilage. In addition, the ability to make repairs becomes progressively limited as cartilage cells age.

Although osteoarthritis generally accompanies aging, osteoarthritic cartilage is chemically different from normal aged cartilage. As chondrocytes (the cells that make up cartilage) age, they lose their ability to make repairs and produce more cartilage. This process may play an important role in the development and progression of osteoarthritis.

Researchers report a high correlation of osteoarthritis between parents and children or between siblings. Genetic factors are thought to be involved in about half of osteoarthritis cases in the hands and hips and a somewhat lower percentage of cases in the knee. A number of genes are under investigation that might contribute to an inherited risk.

For example, mutations in the ank gene may be important in some cases. The ank gene regulates pyrophosphate, a chemical that inhibits the formation of mineral deposits, and may protect the cartilage in joints. Mutations in the ank gene then may result in lower pyrophosphate levels in the joint, leading to accumulation of mineral deposits and arthritis. (About 60% of people with osteoarthritis have mineral deposits in their cartilage.)

Another gene, called the osteoprotegerin gene, is important in regulating bone and cartilage formation. Mutations in this gene may play a role in osteoarthritis.

The inflammatory response is an overreaction of the immune system to an injury or other assault in the body, such as an infection. This response causes specific immune factors, called cytokines, to gather in injured areas and cause inflammation and damage to body tissue and cells. The inflammatory response plays an important role in rheumatoid arthritis and other muscle and joint problems associated with autoimmune diseases. It has generally been believed that inflammation plays at most a minor role in osteoarthritis and is more likely to be a result -- not a cause -- of the disease.

However, recent studies suggest that inflammation may play an important role in the progression of osteoarthritis and its chronic nature. For example, a 2003 study found evidence of severe inflammation in the lining of the joints in 30% of patients with osteoarthritis. Still, the effects of the inflammatory response in osteoarthritis are likely to be different from those in rheumatoid arthritis and less severe.

Some theories on how this response may contribute to osteoarthritis involve overproduction of enzymes called matrix metalloproteinases or MMPs (also called collagenases). In large amounts they break down collagen, the building blocks of cartilage. Some studies suggest that immune factors called vascular endothelial growth factor (VEGF) are overproduced during the inflammatory response and in turn increase production of MMPs.

Another theory suggests that the inflammatory response is triggered by the changes and injuries in the bone that occur during osteoarthritis. According to this theory, immune factors released in this process diffuse into the cartilage, where they suppress cartilage cell growth and activate MMPs.

Joint injuries are the starting point in the disease process. Osteoarthritis sometimes develops years after a single traumatic injury to or near a joint. One large study found that by age 65, osteoarthritis developed in almost 14% of those who had joint injuries as young adults, compared to just 6% in those without earlier injuries. Patients with knee injuries were five times more likely to have osteoarthritis in the injured knee than those without injuries, and patients with hip injuries were more than three times more likely to develop arthritis in the injured hip. Proper treatment of injuries, such as surgical repair of ligament tears in the knee with a strong rehabilitation approach, may help to prevent the development of osteoarthritis.

Other causes of osteoarthritis include:

Bleeding disorders such as hemophilia that cause bleeding to occur in the joint
Disorders such as avascular necrosis that block the blood supply near the joint
Complications of persistent, inflammatory arthritic conditions, particularly chronic gout, pseudogout, or rheumatoid arthritis
Conditions that cause iron build-up in the joints such as hemochromatosis

Symptoms

The pain of osteoarthritis typically begins gradually and progresses slowly over many years. People under age 40 may have the condition with no symptoms at all. Osteoarthritis is commonly identified by the following symptoms:

The most common symptom of osteoarthritis in any joint is pain that worsens during activity and gets better during rest. As the disease advances, the pain may occur even when the joint is at rest.
Pain is generally described as aching, stiffness, and loss of mobility.
The pain may behave like a roller coaster, with bad spells followed by periods of relative relief.
Pain seems to increase in humid weather.
Some people experience muscle spasm and contractions in the tendons.
Osteoarthritis in the knee may cause a crackling-like noise (called crepitus) when moved.

Hand. Osteoarthritis of the hand occurs most often in older women and may be inherited within families. The following joints are most frequently affected:

Distal interphalangeal (DIP) joint. The first joint below the fingertips is the most common location of osteoarthritis of the hand. These joints can develop bony growths known as Heberden's nodes.
Carpometacarpal (CMC) joint. The joint at the base of the thumb, where the thumb joint connects with the wrist, is the second most common location.
Proximal interphalangeal (PIP) joint. The middle joints of the fingers can also develop osteoarthritis. These joints may develop small, solid lumps (nodules) known as Bouchard's nodes.

Click the icon to see an image of osteoarthritis.

Recent studies suggest that osteoarthritis of the hand may predict the later development of osteoarthritis in the hip or knee. A 2005 study found that patients with hand osteoarthritis were three times more likely to develop hip arthritis. Osteoarthritis of the hand also slightly increased the risk for knee osteoarthritis.

Knee. Osteoarthritis is particularly debilitating in the weight-bearing joints of the knees. The joint is usually stable until the disease reaches an advanced stage when the knee becomes enlarged and swollen. Although painful, the arthritic knee usually retains reasonable flexibility.

Osteoarthritis can cause loss of cartilage in the knee. The meniscus, the cartilage pad between the joint formed by the thighbone and the shinbone, plays an important role in protecting the joint. It acts as a shock absorber. In knee surgery called meniscectomy, the doctor removes the damaged cartilage. However, a 2006 study suggested that preserving the meniscus, even if it is damaged, is better than removing it. Researchers showed that even a small amount of meniscus helps protect the joint and prevent osteoarthritis from worsening. Experts recommend that patients try lifestyle changes (exercise and weight loss), braces, and medication before undergoing knee surgery.

Click the icon to see an image of the knee joint.

Hips. About 1 in 4 people will develop hip arthritis over the course of their lifetime. Being obese increases the risk. Osteoarthritis frequently strikes the weight-bearing joints in one or both hips. Pain develops slowly, usually in the groin and on the outside of the hips, or sometimes in the buttocks. The pain also may radiate to the knee, confusing the diagnosis. Those with osteoarthritis of the hip often have a restricted range of motion (particularly when trying to rotate the hip) and walk with a limp, because they slightly turn the affected leg to avoid pain.

Click the icon to see an image of the hip joint.

Spine. Osteoarthritis may affect the cartilage in the disks that form cushions between the bones of the spine, the moving joints of the spine itself, or both. Osteoarthritis in any of these locations can cause pain, muscle spasms, and diminished mobility. In some cases, the nerves may become pinched, which also produces pain. Advanced disease may result in numbness and muscle weakness. Osteoarthritis of the spine is most troublesome when it occurs in the lower back or in the neck, where it can cause difficulty in swallowing.

Click the icon to see an image of the spine.

Shoulder. Osteoarthritis is less common in the shoulder area than in other joints, but it may develop in the shoulder joint (the glenohumeral joint). In such cases, it is most often associated with a previous injury, and patients gradually develop pain and stiffness in the back of the shoulder. Osteoarthritis also can develop in the acromioclavicular (AC) joint, which is between the shoulder blade and the collarbone. However, it rarely causes symptoms in this location.

Conditions with Similar Symptoms

Numerous conditions have symptoms of joint aches and pains. Something as benign as sleeping on a bad mattress to the serious afflictions associated with cancer can mirror symptoms of osteoarthritis. Other problems that can cause aches and pains in the joints include physical injuries, infections, tendinitis, and poor circulation. A number of rare genetic diseases attack the joints.

Osteoarthritis can generally be distinguished from other joint diseases by considering several factors together:

Osteoarthritis usually occurs in older people and is located in only one or a few joints
The joints are less inflamed than in other arthritic conditions
Progression of pain is usually gradual.

A few of the most common disorders that can be confused with, or may even accompany, osteoarthritis are discussed below.

Osteoarthritis may be confused with rheumatoid arthritis, particularly when osteoarthritis affects multiple joints in the body. Rheumatoid arthritis begins in the synovial membrane rather than the cartilage. It normally occurs earlier in life than osteoarthritis, often striking people in their 30s and 40s. Rheumatoid arthritis affects many joints, and often occurs symmetrically on both sides of the body. People generally have morning stiffness that lasts for at least an hour. (Stiffness from osteoarthritis usually clears up within half an hour.)

X-rays show changes in the bones that differ from those occurring in osteoarthritis. In rheumatoid arthritis, blood tests often show a specific antibody, known as rheumatoid factor, which is not present with osteoarthritis. In another blood test, levels of a factor called erythrocyte sedimentation rate (ESR) are often elevated in rheumatoid arthritis, but they are generally normal in osteoarthritis. Rheumatoid arthritis also does not usually show up in the fingertips where osteoarthritis is common.

Rheumatoid arthritis is a body-wide (systemic) autoimmune disease that initially attacks the synovium, a connective tissue membrane that lines the cavity between joints and secretes a lubricating fluid.

Click the icon to see an image of osteoarthritis vs. rheumatoid arthritis.

Chondrocalcinosis is a disease in which certain calcium crystals known as CPPD (calcium pyrophosphate dihydrate) are deposited in the joints. It affects about 25% of the population and can accompany and even worsen osteoarthritis. The problem has been called pseudogout or pseudo-osteoarthritis, in the latter case particularly when it affects the knees. A doctor can usually differentiate between the two disorders, however, because chondrocalcinosis usually damages other joints (such as wrists, elbows, and shoulders) that are not usually affected by osteoarthritis. The condition may explain why some patients with osteoarthritis receive benefit from colchicine, a drug used for gout and other crystal-induced joint diseases.

Charcot's joint occurs when an underlying disease, usually diabetes, causes nerve damage in the joint, which leads to swelling, bleeding, increased temperature, and changes in bone. There may be a loss of sensation that leads to an increased risk for injury from overuse.

Risk Factors

Osteoarthritis is the most common type of arthritis. In the U.S., about 12.1% of Americans (21 million people) age 25 and older have osteoarthritis. The prevalence in osteoarthritis increases as people age. Experts estimate that by 2030, 20% of Americans (72 million people) age 65 years and older will be at risk for developing osteoarthritis.

Before age 45, osteoarthritis occurs more frequently in males (although it is not common in younger adults). After age 55, it develops more often in females. In a 2000 study, 33% of women had osteoarthritis compared to 25% of men. Some research suggests that women may also experience greater muscle and joint pain, in general, than men. And, women also tend to be undertreated for pain compared to men. The causes of such differences in pain sensitivity and treatment are largely unknown and most likely are due to a complicated mix of biologic, psychologic, and social factors.

The incidence is highest in lower educational levels. In a 2000 study, 41% of adults with less than a high school education had arthritis compared to 21% of college graduates.

Although the average rate of osteoarthritis among older adults in the U.S. is 60%, it can vary widely in certain geographical regions. In the U.S., the rates in older adults are lowest (34%) in Hawaii and highest (70%) in Alabama. In general, the highest prevalence of arthritis in America occurs in the central and northwestern states.

The rate of osteoarthritis varies by ethnic group. In the U.S., Caucasians and African-Americans have higher rates of arthritis than Hispanics or other ethnic groups. Osteoarthritis also tends to favor specific joints over others in certain ethnic groups. The following are some examples:

Older African-American men are about 33% more likely than Caucasian men to have hip osteoarthritis. In one study, although men in both groups had equal risks for arthritic knees, African-American men were more likely to have arthritis in both knees and to have more severe cases. Although comparable disparities in knee arthritis were observed between African-American and Caucasian women, they might be explained by greater average weight among African-American women. The study could not account for the differences among men, however.
Asians appear to have a higher incidence of osteoarthritis in the knee, an equal risk for osteoarthritis in the spine, and a lower risk for osteoarthritis in the hips than Caucasians.

Genes that determine the angles, amount of force, and other structural factors in the hip joints, or genes that regulate the chemistry in the joints, may account for ethnic differences.

Some researchers suggest that a number of people have anatomical abnormalities, such as mismatched surfaces on the joints, which could be damaged over time by abnormal stress. Legs of unequal length or skewed feet can cause jerky movement and may cause osteoarthritis. One study reported that those whose knees bent inward ("knock-kneed") or outward ("bow-legged"), for example, were more likely to have progressive osteoarthritis of the knee.

Obesity, defined as being 20% over one's healthy weight, places people (particularly women) at increased risk for osteoarthritis. It also worsens osteoarthritis once deterioration begins. This higher risk is due to increased weight on the joints. However, being obese also increases the risk for osteoarthritis in the fingers as well as the knees and hips, suggesting that being overweight may contribute to osteoarthritis in other ways. Some research indicates that obesity may produce an inflammatory response, which is now a major suspect in age-related diseases -- not only osteoarthritis but also heart disease. [See In-Depth Report #53: Weight control and diet.]

Because injuries can trigger the disease process, people whose work or leisure activities place them at risk for muscle and joint injuries may face a higher risk for osteoarthritis later on.

Workers at Higher Risk. Certain occupations that require repeated stressful motions (such as squatting or kneeling with heavy lifting) can contribute to deterioration of cartilage. One study suggested that workers whose jobs require kneeling or squatting for more than an hour a day are at high risk for knee osteoarthritis. (In the study, jobs that involved heaving lifting, climbing stairs, or walking also posed some, but not as high, a risk. Being heavier compounded the chances for osteoarthritis.)

Exercise. There has been some question about the role of strenuous exercise in osteoarthritis. Sports that definitely pose a higher risk for osteoarthritis are those that require repetitive or direct joint impact (such as football), twisting, or both (baseball pitching, soccer).

Marathon runners, however, have a relatively low rate of osteoarthritis. Some scientists speculate that running enhances cartilage health because the rhythmical compression of cartilage expels wastes and promotes absorption of nutrients.

In any case, regular and moderate exercise is important for everyone and does not increase the risk for osteoarthritis. In fact, a 2006 study of middle-aged and elderly people found that recreational weight-bearing exercise (walking, jogging) neither protects against nor increases the risk for osteoarthritis. Furthermore, many factors associated with a sedentary life (muscle weakness, obesity) are associated with a higher risk for osteoarthritis.

Diagnosis

Osteoarthritis is often visible in x-rays. Cartilage loss is indicated by certain images:

If the normal space between the bones in a joint is narrowed.
If there is an abnormal increase in bone density.
If bony projections, cysts, or erosions are evident.
X-rays can also reveal any cysts that might develop in osteoarthritic joints. If other conditions are suspected or if the diagnosis is uncertain, additional tests are necessary.
An MRI may show evidence of osteoarthritis that x-rays miss.

X-rays are a form of electromagnetic radiation (like light); they are of higher energy, however, and can penetrate the body to form an image on film. Structures that are dense (such as bone) will appear white, air will be black, and other structures will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other diseases, especially when coupled with the use of barium and air contrast within the bowel.

Blood test results may help diagnose or rule out osteoarthritis. Some examples include:

Elevated levels of rheumatoid factor (specific antibodies in the synovium) and so-called erythrocyte sedimentation rates (ESR or sed rate) indicate rheumatoid arthritis.
Hyaluronic acid (HA), a joint lubricant, is being tested as a potential biomarker for osteoarthritis. High levels of HA may indicate increased risk for osteoarthritis.
Elevated levels of a factor called C-reactive protein, which is produced by the liver in response to inflammation, are proving to be good predictors of osteoarthritic progression in the knee.

If the diagnosis is uncertain or infection is suspected, a doctor may attempt to withdraw synovial fluid from the joint using a needle. There will not be enough fluid to withdraw if the joint is normal. If the doctor can withdraw fluid, problems are likely, and the fluid will be tested for factors that might confirm or rule out osteoarthritis:

Cartilage cells in the fluid are signs of osteoarthritis.
A high white blood cell count is a sign of infection.
High uric acid in the fluid is an indication of gout.

Click the icon to see an animation on gout.

Other factors may be present that suggest different arthritic conditions, including Lyme disease and rheumatoid arthritis.
In people with known osteoarthritis, researchers may look for certain factors in synovial fluid (sulfated glycosaminoglycan, keratin sulfate, and link protein) that can suggest a more or less severe condition.

Prognosis

Osteoarthritis itself is not life-threatening, but a person's quality of life can significantly deteriorate from pain and loss of mobility. The negative effects on activities and physical and mental health are significant regardless of age, educational level, or gender. Only heart disease has a greater impact on work. Five percent of those who leave the work force do so because of osteoarthritis. Unless alleviated by medication or corrected by surgery, advanced osteoarthritis can force the patient to forgo even relatively low-impact activities, such as walking. No treatment can cure osteoarthritis, and none can alter its progression with certainty, but many available therapies can relieve symptoms and significantly improve the quality of life.

Lifestyle Changes

Many doctors suggest first trying lifestyle changes to reduce stress on affected joints. Physical therapy and supportive devices can be helpful. Intensive education on how to protect and care for an osteoarthritic joint may help patients avoid multiple visits to their doctor.

Once osteoarthritis has been diagnosed, patients should reduce shock to the affected joint. Hammering away at deteriorating cartilage is likely to speed up the degeneration. People in occupations requiring repetitive and stressful movement should explore ways to reduce trauma. Adjusting the work area or substituting tasks that produce less stress on joints helps reduce shock.

Joints require motion to stay healthy. Long periods of inactivity cause the arthritic joint to stiffen and the adjoining tissue to atrophy. A moderate exercise program that includes low-impact aerobics and power and strength training has benefits for osteoarthritic patients, even if exercise does not slow down the disease progression. Exercise helps:

Reduce stiffness and increase flexibility. It may also help improve the strength and elasticity of knee cartilage.
Promote weight loss.
Improve strength, which in turn improves balance and endurance.
Reduce stress and improve feelings of well being, which helps patients cope with the emotional burden of pain.

Exercise especially helps patients with mild-to-moderate osteoarthritis in the hip or in the knee. Many patients who begin an aerobic or resistance exercise program report less disability and pain. They are better able to perform daily chores and remain more independent than their inactive peers. Older patients and those with medical problems should always check with their doctor before embarking on an exercise program.

Three types of exercise are best for people with osteoarthritis:

Strengthening exercise
Range-of-motion exercise
Aerobic, or endurance, exercise

Strengthening Exercise. Strengthening exercises include isometric exercises (pushing or pulling against static resistance). Isometric training builds muscle strength while burning fat, helps maintain bone density, and improves digestion.

Some experts encourage patients to emphasize strengthening leg muscles as a first treatment step, before using pain relievers. Patients who rely on painkilling drugs may overuse knees, which do not have muscle tissue sufficiently strong enough to protect the joints from further damage. However, some studies suggest that building up thigh muscles may worsen osteoarthritis in people whose knees are misaligned (for instance those who are "bow-legged" or "knock-kneed"). Such individuals should check with a physical therapist for the best options. Strengthening the thigh muscles is certainly protective for people who have not yet developed osteoarthritis.

Exercise, such as weightlifting, helps build muscle that is usually lost with age and puts stress on bones, helping keep them strong and healthy.

Range-of-Motion Exercise. These exercises increase the amount of movement in a joint and muscle. In general, they are stretching exercises. The best examples are yoga and tai chi, which focus on flexibility, balance, and proper breathing. In one study, older adults who practiced the gentle movement, breathing, and meditation exercises of tai chi for 10 weeks reported less pain than their peers who did not learn the technique.

Click the icon to see an image of cholesterol.

Aerobic (Endurance) Exercise. These exercises help control weight and may reduce inflammation in some joints. Low-impact workouts also help stabilize and support the joint. Cycling and walking are beneficial, and swimming or exercising in water is highly recommended for people with arthritis. (Patients with osteoarthritis should avoid high-impact sports, such as jogging, tennis, and racquetball.)

Click the icon to see an image of exercise.

In addition to exercise, manipulation of muscles and joints by a trained therapist may be helpful. In one study, patients who had a combination of physical therapy and an exercise program reported 30 - 40% improvement after only two to four visits.

Overweight patients with osteoarthritis can lessen the shock on their joints by losing weight. Knees, for example, sustain an impact three to five times the body weight when descending stairs. Losing 5 pounds of weight can eliminate 20 pounds of stress on the knee. The greater the weight loss, the greater the benefit. [See In-Depth Report #53:Weight loss and diet.]

Plant Chemicals. A large study reported significant improvement in symptoms when patients took extracts from avocados and soybeans called saponins. Another study noted that although these substances did not relieve hip pain, they did slow progression of joint deterioration. Soy has chemicals called isoflavones that may have additional benefits, such as preventing bone loss.

Fish Oil and Omega-3 Fatty Acids. Omega-3 fatty acids, which are found in fish oil, canola oil, black currant or primrose seed oils, and flax seeds, have anti-inflammatory properties and may help protect against cartilage deterioration. Supplements of omega-3 fatty acids, such as docosahexaenoic (DHA) and eicosapentaneoic (EPA) acids that are found in fish oil, are available.

Vitamin B3 (Niacin). Some research suggests that vitamin B3 may have some benefits for people with osteoarthritis.

Click the icon to see an image of the benefits of vitamin B3.

Click the icon to see an image of the sources of vitamin B3.

Calcium and Vitamin D. Calcium and vitamin D are important for strong bones. Although osteoarthritis is primarily a disease of joints, bone strength is also important, particularly in older people.

Click the icon to see an image of osteoporosis.

Many experts now recommend 1,000 mg of calcium a day for most adults and 1,200 - 1,500 mg for adolescents. Pregnant women, postmenopausal women not on estrogen therapy, and those on corticosteroids should get 1,500 mg per day; breast feeding women should get 2,000 mg/day. Because calcium supplements increase the risk for kidney stones, an upper limit of 2,500 mg is recommended.

Current guidelines recommend 400 IU of vitamin D per day and 600 IU per day after age 60. Lack of sunlight and unhealthy diets contribute to deficiencies in vitamin D. Good dietary sources include fortified milk, sardines, herring, salmon, tuna, liver, dairy products, and egg yolks. Although supplements are often necessary, vitamin D can be toxic in high doses, and no one should take more than 1,200 IU per day.

Selenium. Selenium is a trace mineral found in grains, nuts, vegetables, and some meats and seafood. Preliminary research suggests that people who do not get enough selenium in their diet may be more likely to develop knee osteoarthritis. Researchers are investigating whether selenium supplements may help protect against osteoarthritis and prevent it from worsening.

Ice. When a joint is inflamed (particularly in the knee) applying ice for 20 - 30 minutes can be effective. If an ice pack is not available, a package of frozen vegetables works just as well.

Heat Treatments. Patients afflicted with osteoarthritis of the hands can relieve pain with hot soaks and warm paraffin application. Osteoarthritis of the hip can be treated with heating pads.

Interestingly, moving to a warm climate does not seem to make much difference. According to one study, people who live in warmer places are actually more sensitive to small shifts in temperature than people who live in cold damp climates, and they experience pain as readily as their northern peers do in response to larger temperature shifts.

A wide variety of devices are available to help support and protect joints:

Splints or braces, worn while the joint is at rest or in use, help align joints and properly distribute weight. They are used most frequently to treat arthritic hands, wrists, knees, ankles, and feet. Many of these devices allow some movement within the affected joint and do not restrict nearby joints. They are usually made from lightweight metal, leather, elastic, foam, and moldable plastic with easy-to-use Velcro straps. Any brace, splint, or other device for joint protection should be custom-fitted by a physical or occupational therapist, or an orthotist. Poorly fitting or improperly used orthoses can cause more harm than good.
Using elastic supports on affected joints may benefit some people. For example, in one study, wearing insoles plus elastic straps supporting the ankle joint helped overweight women with osteoarthritis in the knee. It is important to consult with a doctor about how to use elastic supports.
Wrapping the knee with special therapeutic tape that provides support to specific parts of the joint may be effective. In one trial, patients experienced a 40% reduction in pain within a few days. They wore the tape for 3 weeks, and pain relief continued for 3 more weeks following treatment. The tape should be applied by physical therapists or other trained health professionals. Longer-term studies are needed to determine any continuous benefits.
Wearing shock-absorbing soles in shoes or orthopedic shoes can help in daily activities and during gentle exercise. Heel wedges in the shoes can sometimes help patients avoid knee replacement surgery.
A neck brace or corset may relieve back pain.
A firm mattress also often proves beneficial.
In extreme cases of back pain, lying in traction might be necessary.
Canes, crutches, or walkers offer benefits to patients with advanced arthritis.
Specially designed hip protectors, worn under the clothes, can also protect against hip fractures in elderly patients with impaired mobility who are apt to fall.

Medications

Many medications are available for relieving the symptoms of osteoarthritis. A major analysis indicated that drug therapy is generally more effective than non-drug treatments (surgery, acupuncture). However, a 2006 review of knee osteoarthritis studies found that pain-relief medications generally help only for the first 2 - 3 weeks of treatment. The following are some of the medications used in mild-to-severe cases:

Acetaminophen
Nonsteroidal anti-inflammatory drugs (NSAIDs) or COX-2 inhibitors
Capsaicin
Tramadol
Narcotic pain relievers (oxycodone, oxymorphone, or morphine)
Glucosamine and chondroitin (see Alternative and Complementary Medicine section)

Acetaminophen (Tylenol, Anacin-3, Panadal, Phenaphen, Valadol, and others) is currently the first choice for treating osteoarthritis. However, several major analyses report that acetaminophen is less effective than NSAIDs in reducing moderate-to-severe pain. Because acetaminophen has fewer side effects, most experts suggest trying this drug first, then switching to an NSAID if acetaminophen does not provide sufficient pain relief.

Side Effects. Acetaminophen is inexpensive and generally safe. It poses far less of a risk for gastrointestinal problems than NSAIDs and does not appear to increase the risk for miscarriage (as NSAIDs do), even when used regularly.

It does have some adverse effects, however, and the daily dose should not exceed 4 grams (4,000 mg). Patients who take high doses of this drug for long periods are at risk for liver damage, particularly if they drink alcohol and do not eat regularly.

The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and the stimulation of red blood cell production.

Nonsteroidal anti-inflammatory drugs (NSAIDs) block prostaglandins, the substances that dilate blood vessels and cause inflammation and pain. There are dozens of NSAIDs:

Over-the-counter NSAIDs include aspirin, ibuprofen (Advil, Nuprin, Motrin IB, Rufen), naproxen (Aleve, Naprosyn), ketoprofen (Actron, Orudis KT).
Prescription NSAIDs include ibuprofen (Motrin), naproxen (Naprosyn, Anaprox), flurbiprofen (Ansaid), diclofenac (Voltaren, Cataflam), tolmetin (Tolectin), ketoprofen (Orudis, Oruvail), nabumetone (Relafen), dexibuprofen (Seractil), indomethacin (Indocin), meloxicam (Mobic, generic).
Topical NSAIDs delivered in gels, creams, or patches do not appear to provide any long-term benefits in reducing arthritic pain. A review of clinical trial data, published in 2004, suggested that guidelines that recommend topical NSAIDs for treatment of osteoarthritis should be revised.

Many experts now recommend that patients use oral NSAIDs for only a short period of time. A 2004 review, published in the British Medical Journal, suggested that long-term use of NSAIDs does not actually reduce osteoarthritis pain and may increase patients’ risk of experiencing side effects. High dosages of NSAIDs can cause heart problems (such as increased blood pressure), kidney problems, and stomach bleeding.

In April 2005, the Food and Drug Administration (FDA) asked drug manufacturers of prescription NSAIDs to include with their products the same boxed warning used for the COX-2 inhibitor celecoxib (Celebrex). This boxed warning emphasizes an increased risk for cardiovascular events and gastrointestinal bleeding in people taking these drugs. The FDA also requested manufacturers of over-the-counter NSAIDs to revise their labels to include more specific language concerning potential cardiovascular and gastrointestinal risks. Due to its proven heart benefits, aspirin was excluded from these labeling revisions.

A 2006 comprehensive report from the U.S. Agency for Healthcare Quality and Research indicated that both NSAIDs and COX-2 inhibitors are equally effective for pain relief and pose similar risks for heart attacks. The report found that one particular NSAID, naproxen (Aleve, Naprosyn), presents less risk of heart attack for some patients. A 2006 Journal of the American Medical Association study suggested that diclofenac (Voltaren, Cataflam) may pose a higher risk for heart attack than other NSAIDs. All patients should talk to their doctors before switching any medications.

Long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) is the second most common cause of ulcers, and the rate of NSAID-caused ulcers is increasing. Such ulcers are also more likely to bleed than those caused by the bacteria H. pylori. NSAID-related bleeding and stomach problems may be responsible for 107,000 hospital admissions and 16,500 deaths each year. Because there are usually no gastrointestinal symptoms from NSAIDs until bleeding begins, doctors cannot predict which patients taking these drugs will develop bleeding.

Among the groups at high risk for bleeding are elderly people, anyone with a history of ulcers of GI bleeding, patients with serious heart conditions, alcohol abusers, and those on certain medications, such anticoagulants ("blood thinners"), corticosteroids, or bisphosphonates (drugs used for osteoporosis). Proton-pump inhibitors may help to prevent and heal ulcers caused by NSAIDs. Proton-pump inhibitors include omeprazole (Prilosec), esomeprazole (Nexium), and lansoprazole (Prevacid)

Click the icon to see an image of a gastric ulcer.

Drugs for Prevention NSAID-Induced Ulcers. If you have NSAID-induced ulcers, follow these steps:

Switch to alternative pain relievers. This is the first step in preventing or healing ulcers caused by NSAIDs. If people cannot change drugs, they should use the lowest NSAID dose possible.
Try proton-pump inhibitors (PPIs). These drugs help reduce NSAID-ulcer rates by as much as 80% compared with no treatment. Brands include omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid), rabeprazole (Aciphex), and pantoprazole (Protonix).
Try misoprostol or Arthrotec. If other drugs are inappropriate, misoprostol protects against the major intestinal toxicity of NSAIDs. It was the first drug approved for preventing NSAID-induced ulcers. It is equally, or even more, effective than some of the PPIs, but it does not heal existing ulcers and has more side effects than PPIs. Patients tend to stop using it. Arthrotec is a combination of an ulcer protective drug called misoprostol and the NSAID diclofenac. One study found that patients taking Arthrotec had 65 - 80% fewer ulcers than those who took NSAIDs alone.

Healing Existing Ulcers. A number of drugs are available to heal NSAID-induced ulcers. Treatment takes about 2 - 6 weeks. Proton-pump inhibitors are the most effective drugs. Others that may be beneficial include sucralfate or H2 blockers, such as famotidine (Pepcid AC), cimetidine (Tagamet), ranitidine (Zantac).

Coxibs inhibit an inflammation-promoting enzyme called COX-2. This drug class was initially thought to provide benefits equal to NSAIDs but cause less gastrointestinal distress. However, following numerous reports of cardiovascular events, as well as skin rashes and other adverse effects, the FDA has been re-evaluating the relative risks and benefits of this drug class. Rofecoxib (Vioxx) and valdecoxib (Bextra) have been withdrawn from the United States market. Celecoxib (Celebrex) is still available, but patients should discuss with their doctors whether this drug is appropriate and safe for them.

A newer COX-2 inhibitor, etoricoxib (Arcoxia) is approved in 60 countries but not the United States. A 2006 Lancet study indicated that etoricoxib is similar to the NSAID diclofenac in risks for heart attack and stroke. (However, diclofenac has already been shown to have a higher risk of heart attack than any other NSAID, so some experts do not find this study result reassuring.) Etoricoxib caused more high blood pressure and fluid retention (edema) than diclofenac. Etoricoxib appeared to pose a lower risk than diclofenac for uncomplicated upper gastrointestinal problems, (obstruction, perforation, bleeding, ulcers), but there was little difference between the two drugs for more serious gastrointestinal complications. In 2007, the FDA rejected an application to market etoricoxib in the U.S.

Capsaicin is a component of hot red peppers and may bring pain relief when used as a skin cream (Zostrix). This is the only skin preparation that does more than just mask pain or reduce it temporarily. Capsaicin seems to reduce a substance in the body, known as substance P, which contributes both to inflammation and the delivery of pain impulses from the central nervous system. A small amount of capsaicin must be applied to the area of inflammation about four times a day. During the first few days of use, the patient will experience a warm, stinging sensation when the cream is applied. This sensation goes away, and pain relief usually begins within 1 - 2 weeks.

Tramadol (Ultram) is a pain reliever that has been used as an alternative to opioids. It has opioid-like properties but is not as addictive. (Dependence and abuse have been reported, however.) It can cause nausea but does not cause severe gastrointestinal problems, as NSAIDs can. Some patients experience severe itching. A combination of tramadol and acetaminophen (Ultracet) is now available and provides more rapid pain relief than tramadol alone with more long-lasting benefits than acetaminophen. Side effects are the same as for each of these drugs.

Narcotics, pain-relieving and sleep-inducing drugs that act on the central nervous system, are the most powerful medications available for the management of moderate to severe pain. There are two types of narcotics:

Opiates, which are derived from natural opium (morphine and codeine).
Opioids, which are synthetic drugs. They include oxycodone (Percodan, Percocet, Roxicodone, Oxycontin), hydrocodone (Vicodin), oxymorphone (Numorphan), and fentanyl (Duragesic).

Although the use of narcotics for arthritic pain is controversial, many studies have suggested that they are rarely addictive for pain sufferers except among patients with a history of substance abuse. Some experts believe that opioids have a place in osteoarthritis treatment when milder drugs are not effective or appropriate. For example, a 2006 study suggested that a fentanyl skin patch may offer pain relief and improved function to some patients with severe knee or hip osteoarthritis who have not been helped by, or who cannot tolerate, NSAIDs or weaker opioids.

The use of such drugs may be beneficial when included as part of a comprehensive pain management program. Such a program involves screening prospective patients for possible drug abuse and then regularly monitoring those who are taking it, adjusting the dose as necessary to achieve an acceptable balance between pain relief and side effects. Common side effects include anxiety, constipation, nausea and vomiting, dizziness, drowsiness, paranoia, urinary retention, restlessness, and labored or slow breathing. Unfortunately, opioid abuse among young people is a major concern.

When pain becomes a major problem and less potent pain relievers are ineffective, doctors may resort to corticosteroid (steroid) injections, usually by administering a shot into the affected joint every 3 months. Corticosteroid shots are useful only if inflammation is present in the joint. Relief from pain and inflammation is of short duration, and this treatment is rarely used for chronic osteoarthritis. These drugs may not be as effective for women as for men.

Corticosteroids mask pain, and the patient must be very careful to avoid over-use of the affected joints. Patients are usually advised not to have more than two or three injections a year, since there is some concern that repeated injections over the long term may be harmful. A reassuring study found no greater disease progression in people who had injections every 3 months for 2 years compared to those who were given sham injections on the same schedule. Because long-term use of corticosteroids has many potentially serious side effects, steroid medications are never given orally or systemically for the treatment of osteoarthritis.

Injections of hyaluronic acid (Hyalgan, Synvisc, Artzal, Nuflexxa) into the joint -- a procedure called viscosupplementation -- is now recommended as one of the treatments for osteoarthritis. Hyaluronic acid is a naturally occurring substance in joints that acts as a lubricant for slow movements and a shock absorber for fast motions. In high amounts, it also may have anti-inflammatory effects.

Patients receive a series of three to five injections once a week.
The drug is injected into the joint.
A health care worker will apply local anesthetic because these viscous (sticky) injections require a large needle.
Patients need to avoid weight-bearing activities for about 48 hours after each shot.

Hyaluronic injections appear to be about as effective as NSAIDs and corticosteroid injections for relieving pain, at least in men, and they have no adverse effects in the stomach or intestines. One study reported that between 39 - 56% of patients were at least nearly free of weight-bearing pain up to 24 weeks after the final injection. In another study, response was judged better or much better for 87% of knees after a second course, which was administered about 8 months later. Nevertheless, a number of studies on viscosupplementation have shown little or no benefits, particularly in women, and more research is needed to determine if they are useful. Injections are also expensive. Accurate placement of the needle directly into the knee joint space is important and may be difficult, even for experienced doctors, if there is no fluid build-up in the joint. Best success rates are with a specific approach into the kneecap called the lateral midpatellar.

Side Effects. Serious adverse reactions are rare. The most common side effects, pain at the injection site and knee pain and swelling, are usually mild and temporary. More research is needed to confirm benefits and long-term risks.

Researchers are studying various drugs that may provide pain relief or stop the disease process itself:

Bisphosphonates such as alendronate (Fosamax) and risedronate (Actonel) help prevent bone loss in people with osteoporosis. They are currently being investigated for osteoarthritis as well. A 2005 study reported that risedronate may delay joint destruction in patients with knee osteoarthritis.
Lidocaine, a local anesthetic, is available in patch form (Lidoderm) and has been used specifically for herpes zoster pain. Early studies indicate that it may provide significant pain relief for osteoarthritis.
Tetracycline antibiotics, such as doxycycline, may have a role to play in treating osteoarthritis. At low concentrations, the drug reduces the production of collagenases, which are enzymes critical to disease development and progression. Initial results from clinical trials suggest that doxycycline may help delay joint space narrowing.
Licofelone is a drug that inhibits both the COX enzyme plus an inflammatory substance called lipoxygenase 5. Early trials indicate it may be effective and safer than either NSAIDs or COX-2 inhibitors.
Diacerein inhibits an inflammatory substance in arthritic joints called interleukin-1b. It has shown promise in clinical trials. A 2006 review indicated that diacerein may be slightly better than NSAIDs for pain relief.
Botulinum toxin type A (Botox) injections may provide sustained pain relief for patients with knee osteoarthritis according to research presented at the 2006 American College of Rheumatology annual meeting.
Nitric oxide increases blood flow in the mucous lining and secretions of mucus and bicarbonate. Combining nitric oxide with NSAIDs may reduce the adverse effects on the gastrointestinal tract.
Trials of gene therapies that either fight joint degradation or strengthen cartilage are in very early stages.

Alternative and Complementary Medicine

Glucosamine hydrochloride and chondroitin sulfate are natural substances that are part of the building blocks found in and around cartilage. Extracts have been used in Europe for more than a decade to reduce pain and improve mobility in patients with osteoarthritis. For many years, researchers in the U.S. have been studying whether these dietary supplements really work for relieving osteoarthritis pain.

In 2006, the New England Journal of Medicine published the results from a major trial sponsored by the U.S. National Institutes of Health. Researchers compared the effects of glucosamine and chondroitin, alone and in combination, with the COX-2 inhibitor celecoxib (Celebrex) in nearly 1,600 patients with knee osteoarthritis. The dietary supplements were also compared with placebo (an inactive substance). Patients took the assigned substance once a day for 6 months.

The results indicated that, for most patients, neither glucosamine nor chondroitin were better than placebo in relieving knee pain. However, for patients with moderate-to-severe pain, a combination of glucosamine and chondroitin was significantly more effective than the other remedies. Celebrex worked best for patients with mild pain.

The next stage of the study will evaluate whether glucosamine and chondroitin, alone and in combination, can halt the progression of knee osteoarthritis.

Research presented at the 2006 American College of Rheumatology annual meeting suggested that chondroitin may prevent joint narrowing in patients with knee osteoarthritis.

Dosage. There are no current standard recommended dosages. Patients in the GAIT trial took 1,500 mg of glucosamine and 1,200 mg of chondroitin.

Side Effects. The safety records of both substances appear excellent. Long-term effects are still unknown, but studies of up to 3 years have reported no significant side effects. However, there are some concerns that glucosamine may affect insulin and blood sugar (glucose) metabolism. Patients with diabetes should not take glucosamine without first talking to their doctors.

Oral Enzymes. People in Europe have used natural enzymes -- including bromelain, trypsin, papain, and rutin -- to treat arthritic pain. Such enzymes have been marketed alone and in combinations (Wobenzym, Phlogenzym). They are not painkillers, and any benefits derived from them may take several weeks.

Ginger (Zingiberaceae). A 2001 study of patients with knee arthritis found that an extract of ginger reduced pain while standing and after walking. By using ginger, patients were able to reduce their pain medications after 6 weeks. Side effects included mild digestive upset.

S-adenosylmethionine (SAMe). S-adenosylmethionine (SAMe, pronounced "Sammy") is a synthetic form of a natural byproduct of the amino acid methionine. It has been marketed as a remedy for both depression and arthritis. Some research suggests that it may work as well as NSAIDs for short-term treatment of osteoarthritis. Other studies suggest that it may help rebuild damaged cartilage.

Generally, manufacturers of herbal remedies and dietary supplements do not need FDA approval to sell their products. Just like a drug, herbs and supplements can affect the body's chemistry, and therefore have the potential to produce side effects that may be harmful. There have been several reported cases of serious and even lethal side effects from herbal products. Always check with your doctor before using any herbal remedies or dietary supplements.

Acupuncture is being increasingly used to reduce osteoarthritis pain. The technique is painless and involves the insertion of small fine needles at select points in the body. Several study reviews have found that acupuncture provides at least short-term pain relief for osteoarthritis of the knee. Other studies have suggested that acupuncture’s benefits are mainly due to a strong placebo effect, or to the psychologically beneficial effects of close contact with health care providers.

In 2004, researchers published results from an important clinical trial that studied the effects of acupuncture on nearly 600 people with osteoarthritis of the knee. The results indicated that acupuncture can relieve pain and improve function. Several 2006 studies of thousands of patients with chronic osteoarthritis pain compared acupuncture to conventional treatment (physical therapy, anti-inflammatory drugs). These studies showed positive results and suggested that acupuncture’s benefits may be sustained for up to 6 months after treatment. In any case, acupuncture appears to be a safe and beneficial addition to standard therapy for certain patients, such as pregnant women, who cannot take most pain medications.

Acupuncture, hypnosis, and biofeedback are all alternative ways to control pain. Acupuncture involves the insertion of tiny sterile needles, slightly thicker than a human hair, at specific points on the body.

Transcutaneous electric nerve stimulation (TENS) uses low-level electrical pulses to suppress pain. Patients are barely aware of the sensation. According to one study, the optimal treatment length is 40 minutes. A variant (sometimes called percutaneous electrical nerve stimulation, or PENS) applies these pulses through a small needle to acupuncture points. A review of trials reported that both methods were better than placebo (sham treatments) in treating osteoarthritis of the knee, although additional well-designed studies are needed.

Low-level laser therapy (LLLT) generates extremely pure light in a single wavelength. It does not produce heat and is painless. Some researchers are combining LLLT with transcutaneous electric nerve stimulation (TENS). Studies report widely varying results, with some showing significant reductions in pain and others reporting no effect. The differences may be due to different approaches, and standardized methods are needed to determine any benefits.

Hydrotherapy, also called spa therapy or balneotherapy, is an ancient therapy that uses bathing in mineral baths for soothing pain. Although many studies report positive results, including improved quality of life, very few have been rigorously conducted. A major analysis reported weak evidence on any real effect on pain or quality of life, but some patients may find comfort from this pleasant therapy.

Surgery

Different surgical procedures are available as a final measure to relieve pain and increase function in patients with osteoarthritis. Certain surgical procedures can help relieve pain if medications fail. Even with these procedures, however, joint replacement may still be needed later on.

Arthroscopy is performed to clean out bone and cartilage fragments that, in theory at least, may cause pain and inflammation. More than 650,000 of these procedures are done on arthritic knees each year in the U.S., and about half of patients report less pain after the procedure.

A rigorous 2002 trial, however, found that arthroscopic knee surgery was no more effective than sham surgery, (in which surgeons only pretended to operate on the knee), for relief of osteoarthritic pain or stiffness. The study, which followed patients at a Veterans Affairs hospital for 2 years, has called into serious question whether the popular procedure has any real benefits for osteoarthritis beyond what might be achieved by a placebo response. Research and debate continues on whether arthroscopy provides true benefits for those with osteoarthritis and, if so, which patients it may most help.

Click the icon to see an illustrated series detailing knee arthroscopy surgery.

When osteoarthritis becomes so severe that pain and immobility make normal functioning impossible, many people become candidates for artificial (prosthetic) joint implants using a procedure called arthroplasty. Hip replacement is the most established and successful replacement procedure, followed by knee replacement. Knee replacement, in fact, has a slightly better long-term success rate than hip replacement. Other joint surgeries (shoulders, elbows, wrists, fingers) are less common, and some arthritic joints (in the spine, for instance) cannot yet be treated in this manner. When two joints, such as both knees, need to be replaced, having the operations done sequentially rather than at the same time may result in fewer complications.

Click the icon to see an illustrated series detailing knee joint replacement surgery.

Candidates. The primary indications for surgery are pain and significant limitations of movement, including walking, that cannot be treated by less invasive therapies. Some experts suggest, however, that joint replacement should be considered earlier rather than as a last resort. They argue that patients who wait until they are severely disabled do not recover as completely as those who have the procedure earlier.

Patients who may not be good candidates are those with the following conditions:

Severe neurologic, emotional, or mental disorders
Severe osteoporosis
Other chronic medical conditions
Obesity

Surgeons often prefer to delay prosthetic implantation in younger patients, because implants wear out and they will require at least one revision procedure later on. Newer, more long-lasting materials, however, may help reduce the rate of re-operations.

Procedure Description. Although the following is mostly a description of hip replacement surgery, the principles are similar for other arthroplasties.

The surgeon removes the ball and socket joint that joins the pelvis and thigh bone (femur) and replaces it with an artificial joint (a prosthesis). It is composed of two pieces:

A cup-like device fits in the hip socket (called the acetabula), which has been hollowed out. This ball-and-socket cup is positioned to form the new joint.
A metal shaft, or stem, with a polished metal ball at the top, is inserted into the narrow center of the femur.

The prosthesis is usually made of a metal alloy and plastic. A ceramic implant may prove to last longer than other materials and be a safe option for younger patients.

There are different options available for attaching it to the adjoining bones:

A cement made of polymethylmethacrylate (usually preferred for older patients who generally have thinner bones).
So-called cementless implants, in which the prosthesis is coated with a porous material that allows bone to grow into and eventually adhere to the device. These implants are usually used for patients younger than age 65, who are likely to need repeat surgery in their lifetime.

Click the icon to see an illustrated series detailing hip joint replacement surgery.

Complications. Complications can occur, and, although uncommon, some can be life-threatening. There is a 1% chance of death within 3 months of an initial procedure and a 2.6% risk after a repeat procedure. The risks are highest in the first 3 months. Those at highest risks for complications are elderly adults, men (compared to women), African-Americans, and those with serious medical conditions.

Specific complications include the following:

Deep blood clots (known as deep vein thrombosis) and pulmonary embolism. Deep blood clots can develop in the legs after this surgery. This poses a very small risk (0.9%) for pulmonary embolism -- a dangerous condition in which the clot travels to the lungs. Anticoagulants (blood thinners) are important for preventing blood clots. These drugs include warfarin and low-molecular weight heparin. Anticoagulant therapy is given during the hospital stay and continued for several weeks at home. The patient also wears specially fitted elastic stockings to help prevent clots. Patients who are overweight are at higher than average risk for post-operative blood clots
Infection. Wound infection occurs in about 0.2% of joint replacements and requires prompt removal of the implant to treat the infection. A new prosthesis must be re-implanted at a later time. Any pre-existing infection must be treated and cured before surgery is performed. (Older women should be aware of urinary tract infections, which may require postponing surgery.) After surgery, patients should take certain precautions. For example, they should take antibiotics before invasive dental procedures or other surgery because bacteria can be introduced into the bloodstream and infect the areas around the artificial joints.
Hip dislocation. Occurs in about 3.1% of first hip procedures. The rate is much higher (14.4%) in revision operations.

Click the icon to see an image of a dislocated hip.

Pain. Thigh pain can occur after hip replacement. Porous hip prostheses are more likely to produce thigh pain than cement implants, although advanced techniques using a tapered shaft are reducing this complication.
Failure. The primary reason for implant failure is osteolysis (bone destruction) caused by long-term wear. The main source of wear is from tiny particles released from the prosthesis.
Other complications. These include uneven leg lengths, nerve damage that can cause numbness or weakness, urinary tract infections, delayed healing, and allergic reactions to the metal. Long-term, there have been rare reports of a possible autoimmune response, in which loose particles released from the prosthetic device trick certain immune system factors into attacking healthy cells. Any incidence of unexplained weight loss and fatigue may be symptoms of this uncommon event.

Rehabilitation. Aside from the surgeon's skill and the patient's underlying condition, the success rate depends on the kind and degree of activity the joint receives following replacement surgery.

The patient is urged and aided into getting out of bed and walking the day after surgery. Most hip replacement patients leave the hospital within a week and can walk with crutches within 2 - 4 weeks, recovering fully in about 3 months.

Physical therapy takes about 6 weeks to rebuild adjoining muscle and strengthen surrounding ligaments. Studies suggest that an exercise program started before surgery and resumed afterward can improve recovery. Continuous passive motion (CPM) is an effective regimen for knee replacement patients. It uses a mechanical device that slowly moves the joint through an arc of motion for an extended period of time. It is used to prevent scar tissue from developing. In one review, a combination of physical therapy and CPM were more beneficial than physical therapy alone.

Limitations After Surgery. While many patients find that joint replacement provides remarkable pain relief and restores some mobility, they need time to adjust to the artificial joint.

Limitations after hip surgery include:

Usually patients with new hips are able to walk several miles a day and climb stairs, but they cannot run.
Prosthetic hips should not be flexed beyond 90 degrees, so patients must learn new ways to perform activities requiring bending down (like tying a shoe).

Limitations after knee surgery include:

Walking distance improves in 80% of patients after knee replacement surgery, but patients still cannot run.
Only slightly more than half of patients report improvement in stair climbing. (Artificial knee joints generally have a range of motion of just 110 degrees.)

Failure Rates. Infection is a major cause of early failure and always requires revision. Improper balancing of the ligaments and other tissues surrounding the joint and resulting poor joint stability is also a common reason for failure of arthroplasties. Surgical expertise is important for avoiding this complication.

Older cement prostheses have a particularly high rate of bone loss and loosening due to cement deterioration. In general, studies report reoperation rates of over 30% after 10 years. Fortunately, advances in cement and prosthetic implants are improving the implant survival rates and reducing the need for revision procedures.

Uncemented arthroplasty using porous material has shown good results for the hip, although it may be less successful for knee replacement. In spite of short-term success, longer experience with this method suggests it may not be superior to cement prostheses. Failure of bone to grow into the porous material is a relatively common event, a problem that does not occur with cement prostheses. Some experts recommend cement implants over cementless ones for total knee arthroplasty.

A repair procedure called arthroplasty revision may be used in cases where the original transplant fails. The specific procedure depends on whether the bone defects that occurred are contained or uncontained.

Contained defects can be repaired with small bone grafts, the use of cement, or oversized cementless implants as required.
Uncontained defects are more severe and may require a large bone graft or specially constructed implants to restore bone.

If a second arthroplasty is required, the potential for complications is magnified: more bone is cut, more blood is lost, and the operation takes longer. Patients are also generally older and more vulnerable to complications.

Resection Arthroplasty. In resection arthroplasty, a false joint of scar tissue is created. This procedure is used most often in treating arthritis of the foot.

Osteotomy. If only a certain section (the medial compartment) of the knee is damaged and deformed by osteoarthritis, the surgeon may choose to perform osteotomy:

A surgeon opens the knee.
The surgeon performs a debridement (removal of damaged tissue) in the joint to eliminate the loose or torn fragments that are causing pain and inflammation.
The bone is then reshaped to remove the deformity.
The procedure may ease symptoms and slow disease progression. It is best used in heavier adults who are under 60 years old.

Hemicallotasis. Hemicallotasis is a procedure for the knee that may be a less invasive alternative to osteotomy. The surgeon attaches the knee with pins to an external frame-like device that lengthens the deformed part of the knee over several weeks. The patient is mobile during this period. Infections at the pin site are the most common complications.

Arthrodesis. If the affected joint cannot be replaced, surgeons can perform a procedure called arthrodesis that eliminates pain by fusing the bones together. The patient must understand, however, that fusing the bones makes movement of the joint impossible. Bone fusion is most often done in the spine and in the small joints of the hands and feet.

Unicompartmental Knee Arthroplasty. Unicompartmental knee arthroplasty (also called unicondylar knee arthroplasty) may be a useful procedure in cases of limited knee damage. It is recommended for relatively sedentary patients who are 60 years or older and not obese. It may relieve pain and delay the need for a total knee replacement. The procedure involves a small incision and insertion of small implants. It retains important knee ligaments, which preserve more movement than a total knee replacement.

Cartilage Transplants. Autologous chondrocyte implantation, also called chondroplasty or the Carticel approach, is used for knees damaged by injuries. In this procedure, arthroscopy is used to first remove cartilage in eroded areas. The results have been good to excellent, although long-term benefits are questionable. Whether it has any benefit for older patients with osteoarthritis is not yet known. Other cartilage transplant procedures are also under study.

Hip Resurfacing. Hip resurfacing is a surgical alternative to total hip replacement. It involves scraping the surfaces of the hip joint and femur and placing a metal cap over the bone. The procedure preserves much of the bone, so that a standard hip replacement can be done years later if needed. It may provide more stability, a faster recovery, and greater range of motion, making it a potentially good option for young, physically active patients.

Resources

www.rheumatology.org -- American College of Rheumatology
www.arthritis.org -- Arthritis Foundation
www.niams.nih.gov -- National Institute of Arthritis and Musculoskeletal and Skin Diseases
www.aaos.org -- American Academy of Orthopaedic Surgeons
www.fda.gov/cder/drug/infopage/cox2 -- FDA NSAID and COX-2 Inhibitor Information

References

Bjordal JM, Klovning A, Ljunggren AE, Slordal L. Short-term efficacy of pharmacotherapeutic interventions in osteoarthritic knee pain: A meta-analysis of randomised placebo-controlled trials. Eur J Pain. 2007 Feb;11(2):125-38.

Cannon CP, Curtis SP, FitzGerald GA, Krum H, Kaur A, Bolognese JA, et al. Cardiovascular outcomes with etoricoxib and diclofenac in patients with osteoarthritis and rheumatoid arthritis in the Multinational Etoricoxib and Diclofenac Arthritis Long-term (MEDAL) programme: a randomised comparison. Lancet. 2006 Nov 18;368(9549):1771-81.

Chou R, Helfland M, Peterson K, Dana T, Roberts C. Comparative Effectiveness and Safety of Analgesics for Osteoarthritis. Comparative Effectiveness Review No. 4. (Prepared by the Oregon Evidence-based Practice Center under Contract No. 290-02-0024.) Rockville, MD: Agency for Healthcare Quality and Research. September 2006.

Felson DT, Niu J, Clancy M, Sack B, Aliabadi P, Zhang Y. Effect of recreational physical activities on the development of knee osteoarthritis in older adults of different weights: the Framingham Study. Arthritis Rheum. 2007 Feb 15;57(1):6-12.

Laine L, Curtis SP, Cryer B, Kaur A, Cannon CP; MEDAL Steering Committee. Assessment of upper gastrointestinal safety of etoricoxib and diclofenac in patients with osteoarthritis and rheumatoid arthritis in the Multinational Etoricoxib and Diclofenac Arthritis Long-term (MEDAL) programme: a randomized comparison. Lancet. 2007 Feb 10;369(9560):465-73.

Langford R, McKenna F, Ratcliffe S, Vojtassak J, Richarz U. Transdermal fentanyl for improvement of pain and functioning in osteoarthritis: a randomized, placebo-controlled trial. Arthritis Rheum. 2006 Jun;54(6):1829-37.

McGettigan P, Henry D. Cardiovascular risk and inhibition of cyclooxygenase: a systematic review of the observational studies of selective and nonselective inhibitors of cyclooxygenase2. JAMA. 2006 Oct 4;296(13):1633-44.

Rintelen B, Neumann K, Leeb BF. A meta-analysis of controlled clinical studies with diacerein in the treatment of osteoarthritis. Arch Intern Med. 2006 Sep 25;166(17):1899-906.

Scharf HP, Mansmann U, Streitberger K, Witte S, Kramer J, Maier C, et al. Acupuncture and knee osteoarthritis: a three-armed randomized trial. Ann Intern Med. 2006 Jul 4;145(1):12-20.

Witt CM, Jena S, Brinkhaus B, Liecker B, Wegscheider K, Willich SN. Acupuncture in patients with osteoarthritis of the knee or hip: a randomized, controlled trial with an additional nonrandomized arm. Arthritis Rheum. 2006 Nov;54(11):3485-93.

Review Date:
3/19/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com

Diabetes - type 2

FitSugar — Wed, 08 Oct 2008 17:34:58 -0700

In This Report

Highlights
Introduction
Causes
Risk Factors
Symptoms
Screening Tests
Treatment
Lifestyle Changes
Medications
Long-Term Complications
Emergency Complications
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Drug Approvals

Sitagliptin (Januvia), the first in a new class of diabetes drugs called DPP-4 inhibitors, was approved in 2006.
Janumet, a 2-in-1 pill that contains both sitagliptin and metformin, was approved in 2007.
These drugs are taken by mouth and may be more convenient for patients than exenatide (Byetta), a similar drug. DPP-4 inhibitors do not cause weight gain and may pose a lower risk for hypoglycemia than some other diabetes drugs.

Drug Safety Alert

Rosiglitazone (Avandia) may significantly increase the risk for heart attack, indicates a review published in the Journal of the American Medical Association. In 2007, a panel of experts from the Food and Drug Administration (FDA) agreed the drug increases the risk of heart attacks -- but concluded it should remain on the market. The panel did, however, recommend the FDA require rosiglitazone's maker to add warnings to the drug's label. Rosiglitazone and a similar drug, pioglitazone (Actos), are known to significantly increase the risks for heart failure. There is also evidence that these drugs increase the risk for bone fracture.

Anemia Drugs Warning

Patients with anemia associated with end-stage kidney disease, especially those on dialysis, should be aware of new warnings concerning dosing target levels of erythpoiesis-stimulating drugs. In 2007, the FDA warned that darbepoetin alfa (Aranesp) and epoetin alfa (Epogen and Procrit) can increase the risk for blood clots, stroke, and heart attacks when excessive doses are given. The FDA has defined target hemoglobin levels and recommends that patients who receive these drugs have frequent blood tests. Patients should also report to their doctors any unusual symptoms.

Genetics Research Breakthroughs

Scientists have now identified 10 genes that are associated with increased risk for type 2 diabetes. Six of these genes were discovered in 2006 and 2007.

Diabetes and Pre-Diabetes

About 20 million Americans have type 2 diabetes, and an additional 54 million have pre-diabetes. According to a 2007 study by the U.S. Centers for Disease Control, the prevalence of type 2 diabetes has been increasing by 5% each year since 1990. Rising rates of obesity may be one factor.
For people with pre-diabetes, lifestyle changes, such as losing weight, appear to work as well as drug treatment in delaying the progression to diabetes, according to a 2007 British Medical Journal study.

Introduction

The two major forms of diabetes are type 1 (previously called insulin-dependent diabetes mellitus, IDDM, or juvenile-onset diabetes) and type 2 (previously called noninsulin-dependent diabetes mellitus, NIDDM, or maturity-onset diabetes).

Both type 1 and type 2 diabetes share one central feature: elevated blood sugar (glucose) levels due to insufficiencies of insulin, a hormone produced by the pancreas. Insulin is a key regulator of the body's metabolism. It works in the following way:

During and immediately after a meal the process of digestion breaks down carbohydrates into sugar molecules (including glucose) and proteins into amino acids.
Right after the meal, glucose and amino acids are absorbed directly into the bloodstream, and blood glucose levels rise sharply.
The rise in blood glucose levels signals important cells in the pancreas, called beta cells, to secrete insulin, which pours into the bloodstream. Within 10 minutes after a meal, insulin rises to its peak level.
Insulin enables glucose and amino acids to enter cells in the body, particularly muscle and liver cells. Here, insulin and other hormones direct whether these nutrients will be burned for energy or stored for future use. (The brain and nervous system are not dependent on insulin; they regulate their glucose needs through other mechanisms.)
When insulin levels are high, the liver stops producing glucose and stores it in other forms until the body needs it again.
As blood glucose levels reach their peak, the pancreas reduces the production of insulin.
About 2 - 4 hours after a meal, both blood glucose and insulin are at low levels, with insulin being slightly higher. The blood glucose levels are then referred to as fasting blood glucose concentrations.

The pancreas is located behind the liver and is where the hormone insulin is produced. Insulin is used by the body to store and utilize glucose.

Type 2 diabetes is the most common form of diabetes, accounting for 90 - 95% of cases. The disease mechanisms in type 2 diabetes are not wholly known, but some experts suggest that it may involve the following three stages in most patients:

The first stage in type 2 diabetes is the condition called insulin resistance. Although insulin can attach normally to receptors on liver and muscle cells, certain mechanisms prevent insulin from moving glucose (blood sugar) into these cells where it can be used. Most patients with type 2 diabetes produce variable, even normal or high, amounts of insulin. In the beginning, this amount is usually sufficient to overcome such resistance.
Over time, the pancreas becomes unable to produce enough insulin to overcome resistance. In type 2 diabetes, the initial effect of this stage is usually an abnormal rise in blood sugar right after a meal (called postprandial hyperglycemia). This effect is now believed to be particularly damaging to the body.
Eventually, the cycle of elevated glucose further impairs and possibly destroys beta cells, thereby stopping insulin production completely and causing full-blown diabetes. This is made evident by fasting hyperglycemia, in which elevated glucose levels are present most of the time.

In type 1 diabetes, the disease process is more severe and onset is usually in childhood:

Beta cells in the pancreas that produce insulin are gradually destroyed. Eventually insulin deficiency is absolute.
Without insulin to move glucose into cells, blood glucose levels become excessively high, a condition known as hyperglycemia.
Because the body cannot utilize the sugar, it spills over into the urine and is lost.
Weakness, weight loss, and excessive hunger and thirst are among the consequences of this "starvation in the midst of plenty."
Patients become dependent on administered insulin for survival. [See In-Depth Report #9: Diabetes - type 1.]

Click the icon to see an image of the pancreas.

Conditions that damage or destroy the pancreas, such as pancreatitis, pancreatic surgery, or certain industrial chemicals can cause diabetes. Polycystic ovaries are highly associated with diabetes. Certain drugs can also cause temporary diabetes, including corticosteroids, beta-blockers, and phenytoin. Rare genetic disorders (Klinefelter's syndrome, Huntington's chorea, Wolfram's syndrome, leprechaunism, Rabson-Mendenhall syndrome, lipoatrophic diabetes) and hormonal disorders (acromegaly, Cushing syndrome, pheochromocytoma, hyperthyroidism, somatostatinoma, aldosteronoma) are associated with or increase the risk for diabetes.

Causes

Type 2 diabetes is caused by a complicated interplay of genes, environment, insulin abnormalities, increased glucose production in the liver, increased fat breakdown, and possibly defective hormonal secretions in the intestine. The recent dramatic increase indicates that lifestyle factors (obesity and sedentary lifestyle) may be particularly important in triggering the genetic elements that cause this type of diabetes.

The characteristic features of most patients with type 2 diabetes are:

Insulin resistance in muscle cells
Normal or even excessive levels of insulin (to compensate for this resistance), eventually followed by a drop in insulin production

In addition, researchers are trying to determine the factors that might promote insulin resistance:

Both obesity and insulin resistance at different phases are marked by elevated levels of free fatty acids and the hormones resistin and leptin. It is not known yet if elevated levels are simply a product of obesity or play some causal role in diabetes.
Insulin resistance is associated with a chronic low inflammatory response, which involves a number of immune factors, such as TGH-beta 1 and C-reactive protein. Such factors can cause damage over time and may be responsible for the association between insulin resistance and heart disease.

Type 2 diabetes has a genetic component. In 2006 and 2007, major breakthroughs in genetic research identified six new genes associated with type 2 diabetes. Ten genes have now been positively confirmed as increasing the risk for type 2 diabetes: TCF7L2, SLC30A8, HHEX, PPARG, KCNJ11, IGF2B2, CDKAL1, CDKN2A, CDKN2B, and FTO.

Most of these genes play a role in regulating insulin action, including the processes that occur in the pancreas’ insulin-producing beta cells. The FTO gene increases the risk for obesity, which itself is a risk factor for type 2 diabetes. These genes appear to cluster around three genetic regions that include a number of chromosomes. Scientists hope that future research will help uncover how genes influence the progression from pre-diabetes to diabetes, and how lifestyle and medical intervention may help delay or prevent this process.

Risk Factors

Nearly 21 million Americans have diabetes; up to 95% of these cases are type 2. In addition, 26% of Americans age 20 and older (and 40% of Americans age 65 and older) have impaired fasting glucose, a pre-diabetes condition that increases the risk for diabetes. According to the American Diabetes Association, 54 million people have pre-diabetes, bringing a total of 75 million Americans who either have diabetes or are at risk of developing it.

Historically, type 2 diabetes usually developed after the age of 40, but it is now also increasing in children. The prevalence of diabetes in the U.S. has increased by 5% each year since 1990, and experts believe that obesity is the major factor behind this dramatic growth rate. Given the current epidemic of obesity, experts estimate that over a third of all people born in 2002 will eventually develop diabetes. Furthermore, the dramatic increase in diabetes is occurring worldwide as American lifestyles become global. Evidence strongly suggests that healthy lifestyles can prevent most cases of type 2 diabetes. People with pre-diabetes can substantially lower their risk by losing weight through diet and exercise.

Healthy adults age 45 and older should get tested for diabetes. Patients who are younger than age 45 and who are overweight or have other risk factors should also ask their doctors about testing. According to the National Institutes of Health, the following are major risk factors for diabetes and pre-diabetes:

Age 45 or older
Family history of diabetes
Overweight
Inactive lifestyle (exercise less than 3 times a week)
African-American, Hispanic/Latin American, American Indian and Alaska Native, Asian-American, or Pacific Islander ethnicity
High blood pressure (140/90 mm/Hg or higher)
HDL (“good”) cholesterol less than 35 mg/dL or triglyceride level 250 mg/dL or higher
Have had diabetes during pregnancy (gestational diabetes) or have given birth to a baby that weighed more than 9 pounds
Polycystic ovary syndrome (metabolic disorder that affects female reproductive system
Acanthosis nigricans (dark, thickened skin around neck or armpits)
History of disease of blood vessels to the heart, brain, or legs
Diabetes test history of impaired fasting glucose (IFG) or impaired glucose tolerance (IGT)

Obesity is the number one risk factor for type 2 diabetes. It is estimated that 80 - 95% of the current dramatic increases in type 2 diabetes are due to obesity. Excess body fat appears to play a strong role in insulin resistance, but the way the fat is distributed is also significant. Weight concentrated around the abdomen and in the upper part of the body (apple-shaped) is associated with insulin resistance and diabetes, heart disease, high blood pressure, stroke, and unhealthy cholesterol levels. Waist circumferences greater than 35 inches in women and 40 inches in men have been specifically associated with a greater risk for heart disease and diabetes. (People with a "pear-shape" -- fat that settles around the hips and flank -- appear to have a lower risk for with these conditions.) However, obesity does not explain all cases of type 2 diabetes. It is also common among people in countries where weights tend to be low, such as Asia or India.

Metabolic Syndrome. A set of conditions referred to as metabolic syndrome (also called Syndrome X) is a pre-diabetic condition that is significantly associated with heart disease and higher mortality rates from all causes. The syndrome consists of obesity marked by abdominal fat, unhealthy cholesterol levels, high blood pressure, and insulin resistance. A 2002 study estimated that nearly a quarter of the U.S. population now has this condition. Even worse, according to a 2003 study, nearly a million American teenagers have this syndrome.

Between 25 - 33% of patients with type 2 diabetes have family members with diabetes. Having a first-degree relative with the disease poses a 40% risk of developing diabetes. One study reported that people with diabetic family histories have a higher risk for developing the disease at an earlier stage and with more severe features. Because families share many lifestyle features (eating and exercise habits) it is difficult to determine when genetics or environment play the major role. When clusters of type 1 and type 2 diabetes appear within families, genetic factors should be strongly suspected.

The risk for type 2 diabetes varies among population groups. Diabetes also seems to pose higher or lower risks for specific complications among ethnic groups. Genetic and socioeconomic factors, or both, seem to be involved in some ethnic differences, but in most cases the observed increase in ethnic groups in Americans is due to changes in traditional lifestyles.

African-Americans. African-American men have twice the risk of developing type 2 diabetes as Caucasian men. African-Americans with diabetes are also at higher risk for amputations than Caucasians. This is most likely due to a higher incidence of high blood pressure and smoking as well as poorer health care in African-Americans. Genetic factors may also play a role. For example, there is some evidence that African-Americans process insulin in the liver differently from Caucasians, which may make them more susceptible to diabetes when other risk factors are present.
Native Americans. The Pima tribe in Arizona has an incidence of type 2 diabetes that is 19 times higher than that of the white population. The risk for diabetic complications among young Pima adults is also very high. Other Native American tribes in North America are also at high risk for type 2 diabetes. The association between diet and diabetes among this population remains critical, however, in assessing the reason for their higher risk. For example, Pimas who live in Mexico exercise more and eat less fat (but consume more calories) than Pima tribes in Arizona. Mexican Pimas have a prevalence of diabetes of only 6%, while half of their Arizona Pima neighbors have diabetes.
Hispanic Americans. The rate of type 2 diabetes is also very high among Mexican-Americans, approximately double that for Caucasians. This group may also be at higher risk for heart problems than other ethnic groups with diabetes.
Asian-Americans. Overweight Asian-Americans and Pacific Islanders are at increased risk for developing type 2 diabetes. The risk for some Asian ethnic groups (such as Native Hawaiians and Filipinos) is twice that of Caucasians.

Smoking increases the risk for diabetes. According to a 2006 study, smokers are more than twice as likely to develop diabetes as people who have never smoked. Another 2006 study found that exposure to second-hand cigarette smoke also increases the risk for diabetes in non-smokers.

Low birth weight is now a recognized risk factor for type 2 diabetes and heart disease in adulthood. The reasons are unclear, although studies suggest it may represent a genetic factor. Studies have observed that babies of fathers with type 2 diabetes and of women who later developed type 2 diabetes tend to weigh less than babies of parents without diabetes. Such studies suggest that some parents may have some specific gene that affects insulin factors, putting both themselves and their children at risk for future diabetes. Theoretically, such a gene might also affect insulin factors in the developing fetus, causing low birth weight. (Of note, mothers of very high-weight babies are also at risk for diabetes -- although in these cases it is most often associated with gestational diabetes.)

Obesity-Related Type 2 Diabetes in Children. Until recent years, diabetes in children was almost always type 1 (an autoimmune disease). Between 1982 - 1994, however, the incidence of type 2 diabetes in children increased 10-fold. By 1996, a study reported that a third of all new diabetes cases in children were type 2. This increase parallels the rising epidemic in childhood obesity that has occurred both in the U.S. and worldwide, notably Europe and Japan. In some areas of Japan, type 2 diabetes has now become the dominant form of diabetes in children and adolescents. Obesity in children is also related to abnormalities in cholesterol, blood pressure, and insulin levels in adults. Administering glucose tolerance tests in overweight children may be helpful in identifying those at high risk for diabetes.

Maturity-Onset Diabetes in Caucasian Youth. Maturity-onset diabetes in youth (MODY) is a rare genetic form of type 2 diabetes that develops only in Caucasian teenagers. It accounts for 2 - 5% of type 2 cases. (This form of type 2 diabetes is not associated with obesity.)

An estimated 5% of pregnant women develop a form of type 2 diabetes, usually temporary, in their third trimester called gestational diabetes.

Gestational diabetes is diabetes that first appears during pregnancy. It usually develops during the third trimester of pregnancy. After delivery, blood sugar (glucose) levels generally return to normal, although 25% of these women develop type 2 diabetes within 15 years.

Who Gets Gestational Diabetes? Estimates for the prevalence of gestational diabetes are generally about 4%. Some studies, however, have suggested significantly higher rates. In one German study, 13% of pregnant women were diagnosed with this form of diabetes, including many who did not have any risk factors.

A pregnant woman's risk factors include:

Family history of diabetes
African-American, Hispanic, Asian, or Pacific Islander ethnicity
Overweight
Older than 25 years
Gestational diabetes with past pregnancy
Having given birth to a child weighing over 9 pounds
Diagnosis of pre-diabetes

Who Should Be Tested for Gestational Diabetes? A number of expert groups recommend that all pregnant women be tested for gestational diabetes between their 24th - 28th week. Pregnant women at high risk for diabetes should be tested earlier. The only women who do not need to be tested are those at very low risk. Generally they have the following characteristics:

Under 25 years old
Normal weight
No first-degree relatives with diabetes
Not belonging to high-risk ethnic groups

Effect of Diabetes on the Fetus. Because glucose crosses the placenta, a woman with diabetes can pass high levels of blood glucose to the fetus. In response, the fetus secretes high level of insulin. Studies indicate that such conditions may affect the developing fetus as soon as it is conceived, placing the unborn child at risk for:

Excessive fetal weight gain, which can lead to complications during delivery
Birth defects
Breathing problems and delayed lung development
Low blood sugar
Higher future risk for obesity and diabetes

Effect of Diabetes on the Pregnant Woman. In addition to endangering the fetus, diabetes also presents risks to the pregnant woman.

The most serious potential complications from gestational diabetes are high blood pressure during pregnancy, a condition called preeclampsia that is potentially dangerous. Because gestational diabetes increases the size of the fetus, it is also increases the likelihood that a woman will require a Cesarean delivery. Gestational diabetes also increases the risk that a woman will later develop type 2 diabetes.

How Is Gestational Diabetes Managed? Some suggestions for preventing complications include:

In most cases, increases in glucose levels can be managed with diet and exercise. Aerobic exercise before and during pregnancy may lower glucose levels and help protect women at risk or those who have gestational diabetes. (Any pregnant woman should check with her doctor before embarking on a vigorous exercise regimen.)
If a woman with gestational diabetes cannot control her glucose with lifestyle measures, she is usually given insulin.

The placenta provides the fetus with oxygen and nutrients and takes away waste, such as carbon dioxide, via the umbilical cord.

Polycystic Ovary Syndrome. Polycystic ovary syndrome (PCOS) is a condition that affects about 6% of women and results in the ovarian production of high amounts of androgens (male hormones), particularly testosterone. It appears to be an important cause of many menstrual disorders. Women with PCOS are at higher risk for insulin resistance, and about half of PCOS patients also have diabetes.

Click the icon to see an image of polycystic ovary syndrome.

Schizophrenia. While no definitive association has been established, research has suggested an increased background risk of diabetes among people with schizophrenia. In addition, many of the new generation of antipsychotic medications may elevate blood glucose levels. Patients taking antipsychotic medications (such as clozapine, olanzapine, risperidone, aripiprazole, quetiapine fumarate, ziprasidone) should receive a baseline blood glucose level test and be monitored for any increases during therapy.

Depression. According to a 2007 study, adults who have severe clinical depression may have a greater risk of developing type 2 diabetes than those who have never experienced depressive symptoms.

Hepatitis C. Patients with hepatitis C have a higher incidence of type 2 diabetes. The reasons for this are unclear.

Symptoms

Type 2 diabetes usually begins gradually and progresses slowly. Symptoms in adults include:

Excessive thirst
Increased urination
Fatigue
Blurred vision
Weight loss
In women, vaginal yeast infections or fungal infections under the breasts or in the groin
Severe gum problems
Itching
Erectile dysfunction in men
Unusual sensations, such as tingling or burning, in the extremities

Symptoms in children are often different:

Most children are obese or overweight
Increased urination is mild or even absent
Many children develop a skin problem called acanthosis, which is characterized by velvety, dark colored patches of skin

Screening Tests

There are no clear-cut guidelines for when to screen for diabetes. Some experts recommend that everyone over age 45 be tested regularly for diabetes, although others do not feel this necessary in people without symptoms or risk factors. In fact, early screening may identify some people with impaired glucose levels that would eventually normalize. Such people might be treated unnecessarily with medications that pose a risk for high blood sugar (hypoglycemia).

Still, given the risk for serious complications with diabetes and the potential value of early treatments, most experts recommend that all adults over 45 be screened and that younger adults be screened if they have one or more of the following conditions:

A weight that is 20% more than ideal body weight
Risk factors for heart disease (high blood pressure, unhealthy cholesterol levels -- especially for patients with low HDL cholesterol and high triglyceride levels
A close relative with diabetes
A high-risk ethnic group background
In women, having delivered a baby weighing over 9 pounds or having a history of gestational diabetes

Some experts recommend that children over age 10 should be tested for type 2 diabetes (even if they have no symptoms), if they are overweight and have at least two of the above mentioned risk factors.

Fasting Plasma Glucose. The fasting plasma glucose (FPG) test is the standard test for diabetes. It is a simple blood test taken after 8 hours of fasting. Results indicate:

FPG levels are considered normal up to 100 mg/dL (or 5.5 mmol/L).
Levels between 100 - 125 mg/dL (5.5 - 7.0 mmol/L) are referred to as impaired fasting glucose or pre-diabetes. These levels are considered to be risk factors for type 2 diabetes and its complications.
Diabetes is diagnosed when FPG levels are 126 mg/dL (7.0 mmol/L) or higher.

The FPG test is not always reliable, so a repeat test is recommended if the initial test suggests the presence of diabetes, or if the test is normal in people who have symptoms or risk factors for diabetes. For example, people who take the test in the afternoon and show normal results may actually have abnormal levels that would be revealed if they were tested in the morning.

A 2005 study suggested that even people with FPG levels in the high end of the normal range (high 90s) may be at increased risk for developing type 2 diabetes. Obesity further increases this risk. Patients with FPG levels in the upper 90s should strive to exercise and lose weight to help lower their FPG levels.

It first uses an FPG test.
A blood test is then taken 2 hours later after drinking a special glucose solution.

The following results suggest different conditions:

OGTT levels are considered normal up to 140 mg/dL.
Levels between 140 - 199 mg/dL are referred to as impaired glucose tolerance or pre-diabetes.
Diabetes is diagnosed when OGTT levels are 200 mg/dL or higher.

Both the FPG and OGTT require that the patient not eat for at least 8 hours prior to the test.

Test for Glycated Hemoglobin. Tests for blood levels of glycated hemoglobin, also known as hemoglobin A1c (HbA1c), are not currently used for an initial diagnosis, but they are useful for determining the severity of diabetes. Some experts think this test can help predict complications in people who have FPG levels between 110 - 139, which are above normal but do not indicate full-blown diabetes.

The basis for its use as a diagnostic measurement in diabetes is as follows:

Hemoglobin is a protein molecule found in red blood cells. When glucose binds to it, the hemoglobin becomes modified, a process called glycosylation.
Glycosylation affects a number of proteins, and elevated levels of glycolated hemoglobin are strongly associated with complications of diabetes.
A glycated hemoglobin level of 1% above normal range identifies diabetes in 98% of patients. Normal HbA1c levels do not necessarily rule out diabetes, but if diabetes is present and levels are normal, the risk for complications is low.

The test is not affected by food intake so it can be taken at any time. A home test has been developed that might make it easier to measure HbA1c. In general, measurements suggest the following:

Normal HbA1c levels should be below 7%.
Levels of 11 - 12% glycolated hemoglobin indicate poor control of carbohydrates. High levels are also markers for kidney trouble.

Screening for Heart Disease. All patients with diabetes should be tested for hypertension and unhealthy cholesterol and lipid levels and given an electrocardiogram. For cholesterol, people with diabetes should aim for LDL levels below 100 mg/dL, HDL levels over 50 mg/dL, and triglyceride levels below 150 mg/dL. Blood pressure goals should be 130/80 mmHg or lower. Other tests may be needed in patients with signs of heart disease.

The electrocardiogram (ECG, EKG) is used extensively in the diagnosis of heart disease, from congenital heart disease in infants to myocardial infarction and myocarditis in adults. Several different types of electrocardiogram exist.

Screening for Kidney Damage. The earliest manifestation of kidney damage is microalbuminuria, in which tiny amounts (30 - 300 mg per day) of protein called albumin are found in the urine. About 20% of type 2 patients show evidence of microalbuminuria upon diagnosis of diabetes. (However, not all people with type 2 diabetes eventually develop kidney disease.) Microalbuminuria typically shows up in patients with type 2 diabetes who have high blood pressure.

Screening for Retinopathy. The American Diabetes Association recommends that patients with type 2 diabetes get an initial comprehensive eye exam by an ophthalmologist or optometrist shortly after they are diagnosed with diabetes, and once a year thereafter. (People at low risk may need follow-up exams only every 2 - 3 years.) The eye exam should include dilation to check for signs of retinal disease (retinopathy).

Screening for Neuropathy. All patients should be screened for nerve damage (neuropathy), including a comprehensive foot exam. Patients who have loss of sensation in their feet should be sure to have a foot exam every 3 - 6 months to check for ulcers or infections.

Screening for Thyroid Abnormalities. Thyroid function tests should be administered.

Treatment

Pre-diabetes precedes the onset of type 2 diabetes. People who have pre-diabetes have fasting blood glucose levels that are 100 - 125 mg/dL -- higher than normal, but not yet high enough to be classified as diabetes. (Pre-diabetes used to be referred to as “impaired glucose tolerance.”) Pre-diabetes greatly increases the risk for diabetes.

Treatment of pre-diabetes is very important. Research shows that lifestyle and medical interventions can help prevent, or at least delay, the progression to diabetes. While insulin-regulating drugs such as metformin (Glucophage) and acarbose (Precose) are sometimes prescribed, evidence indicates that lifestyle changes can be at least as effective as drug therapy. The most important lifestyle treatment for people with pre-diabetes is to lose weight through diet and regular exercise. Even a modest weight loss of 10 - 15 pounds can significantly reduce the risk of progressing to diabetes.

Because people with pre-diabetes have a higher risk for heart disease and stroke, diet and exercise are also very important for heart health, as is quitting smoking. It is also important to have your doctor check your cholesterol and blood pressure levels on a regular basis. Your doctor should also check your fasting blood glucose levels every 1 - 2 years.

The major treatment goals for people with type 2 diabetes are:

Treat all conditions that place the patients at risk for heart disease and stroke, which are the major killers of people with type 2 diabetes.
Control blood glucose levels. The goal is to achieve fasting blood glucose levels of less than 110 mg/dL and glycolated hemoglobin (HbA1c) levels of less than 7%. The objective is to reduce complications in small blood vessels and the nerve damage associated with diabetes.

An intensive multi-pronged approach is critical for reducing complications and improving survival rates in patients with diabetes. Intensive therapy includes:

Healthy lifestyle changes: Regular exercise; heart-healthy diet; quitting smoking.
Controlling blood sugar levels. Monitor blood sugar and hemoglobin HbA1C levels. Oral anti-hyperglycemic drugs such as metformin are first-line drug treatments. Insulin may eventually be needed.
Heart-protective drugs. These medications include various drugs to control high blood pressure (ACE inhibitors, diuretics, others) and cholesterol (statins, fibrates). Controlling high blood pressure is a proven factor in reducing mortality rates. Aspirin may help prevent blood clots and heart attack.

Different goals may be required for specific individuals, including pregnant women, very old and very young people, and those with accompanying serious medical conditions. Treating children with type 2 diabetes depends on the severity of the condition at diagnosis. Metformin is approved for children. Formerly, only insulin was approved for treating children with diabetes.

Lifestyle Changes

A simple heart-healthy diet with weight control and exercise is important for people with pre-diabetes and may be sufficient for some people with type 2 diabetes. Some patients may be able to control their blood sugar with lifestyle measures and not need medication. Even for patients who do need to take drugs, lifestyle plays an essential role in controlling diabetes. Lifestyle changes can be difficult to initiate and sustain, however. Patients should surround themselves with a solid network of doctors, dietitians, family, and friends who understand both their condition and their needs.

Although there are many major dietary approaches for protecting health, experts generally agree on the following recommendations for heart protection:

Choose fiber-rich food (whole grains, legumes, nuts) as the main source of carbohydrates, along with a high intake of fresh fruits and vegetables. High fiber foods help improve blood glucose levels. Whole grain cereals, which are rich in both fiber and magnesium, may also help reduce the risk for diabetes.
Limit saturated fats (found mostly in animal products) to less than 7% of total daily calories and avoid trans fatty acids (found in hydrogenated fats and many commercial products and fast foods). Choose unsaturated fats (particularly omega-3 fatty acids found in vegetable and fish oils).
In selecting proteins, choose soy protein, poultry, and fish over meat. A 2006 study found that soy does not help improve cholesterol. However, experts still recommend it as a heart-healthy food choice.
Weight control, quitting smoking, and exercise are essential components of any diet program.

[See In-Depth Report #43: Heart-healthy diet.]

There is no such thing as a single diabetes diet. Patients should meet with a professional dietitian to plan an individualized diet within the general guidelines that takes into consideration their own health needs.

Healthy eating habits along with good control of blood glucose are the basic goals, and several good dietary methods are available to meet them. General dietary guidelines for diabetes recommend:

Carbohydrates should provide 45 - 65% of total daily calories. The type and amount of carbohydrate are both important. Best choices are vegetables, fruits, beans, and whole grains. These foods are also high in fiber. Patients with diabetes should monitor their carbohydrate intake either through carbohydrate counting or meal planning exchange lists.
Fats should provide 25 - 35% of daily calories. Monounsaturated (olive, peanut, canola oils; avocados; nuts) and omega-3 polyunsaturated (fish, flaxseed oil, walnuts) fats are the best types. Limit saturated fat (red meat, butter) to less than 7% of daily calories. Choose nonfat or low-fat dairy instead of whole milk products. Limit trans-fats (hydrogenated fat found in snack foods, fried foods, commercially baked goods) to less than 1% of total calories.
Protein should provide 12 - 20% of daily calories, although this may vary depending on a patient’s individual health requirements. Patients with kidney disease should limit protein intake to less than 10% of calories. Fish, soy, and poultry are better protein choices than red meat.

[For detailed information, including diabetic exchange lists and carbohydrate counting, see In-Depth Report #42: Diabetes diet.]

Being overweight is the number one risk factor for type 2 diabetes. Even modest weight loss can help prevent type 2 diabetes from developing. It can also help control or even stop progression of type 2 diabetes in people with the condition and reduce risk factors for heart disease. Patients should aim to lose weight if their body mass index (BMI) is 25 - 29 (overweight) or higher (obese).

The American Diabetes Association recommends that patients aim for a small but consistent weight loss of ½ - 1 pound per week. Most patients should follow a diet that supplies at least 1,000 - 1,200 kcal/day for women and 1,200 - 1,600 kcal/day for men.

Unfortunately, not only is weight loss difficult to sustain, but many of the oral medications used in type 2 diabetes cause weight gain as a side effect. For obese patients who cannot control weight using dietary measures alone, weight-loss drugs, such as orlistat (Xenical) or sibutramine (Meridia), may be helpful. Orlistat may have specific benefits for people with diabetes. It may not only help achieve weight but also improve glucose, cholesterol, and lipid levels. In 2007, the FDA approved a non-prescription form of orlistat (alli). [See In-Depth Report #53: Obesity.]

Sedentary habits, especially TV watching, are associated with significantly higher risks for obesity and type 2 diabetes. Regular exercise, even of moderate intensity (such as brisk walking), improves insulin sensitivity and may play a significant role in preventing type 2 diabetes -- regardless of weight loss. An important study reported a 58% lower risk for type 2 diabetes in adults who performed moderate exercise for as little as 2.5 hours a week.

Aerobic Exercise. Aerobic exercise has significant and particular benefits for people with diabetes. Regular aerobic exercise, even of moderate intensity, improves insulin sensitivity. People with diabetes are at particular risk for heart disease, so the heart-protective effects of aerobic exercise are especially important. Moderate exercise protects the heart in people with type 2 diabetes, even if they have no risk factors for heart disease other than diabetes itself.

For improving glycemic control, the American Diabetes Association recommends at least 150 minutes per week of moderate-intensity physical activity (50 - 70% of maximum heart rate) or at least 90 minutes per week of vigorous aerobic exercise (more than 70% of maximum heart rate). Exercise at least 3 days a week, and do not go more than 2 consecutive days without physical activity.

Strength Training. Strength training, which increases muscle and reduces fat, is also helpful for people with diabetes who are able to do this type of exercise. The American Diabetes Association recommends performing resistance exercise three times a week. Build up to three sets of 8 - 10 repetitions using weight that you cannot lift more than 8 - 10 times without developing fatigue. Be sure that your strength training targets all of the major muscle groups.

Exercise Precautions. The following are precautions for all people with diabetes, both type 1 and type 2:

Because people with diabetes are at higher than average risk for heart disease, they should always check with their doctors before undertaking vigorous exercise. For fastest results, frequent high-intensity (not high-impact) exercises are best for people who are cleared by their doctors. For people who have been sedentary or have other medical problems, lower-intensity exercises are recommended.
Strenuous strength training or high-impact exercise is not recommended for people with uncontrolled diabetes. Such exercises can strain weakened blood vessels in the eyes of patients with retinopathy. High-impact exercise may also injure blood vessels in the feet.

Patients who are taking medications that lower blood glucose, particularly insulin, should take special precautions before embarking on a workout program:

Monitor glucose levels before, during, and after workouts (glucose levels swing dramatically during exercise).
Avoid exercise if glucose levels are above 300 mg/dL or under 100 mg/dL.
Inject insulin in sites away from the muscles used during exercise; this can help avoid hypoglycemia.
Drink plenty of fluids before and during exercise; avoid alcohol, which increases the risk of hypoglycemia.
Insulin-dependent athletes may need to decrease insulin doses or take in more carbohydrates prior to exercise, but may need to take an extra dose of insulin after exercise (stress hormones released during exercise may increase blood glucose levels).
Wear good, protective footwear to help avoid injuries and wounds to the feet.
Some blood pressure drugs can interfere with exercise capacity. Patients who use blood pressure medication should consult their doctors on how to balance medications and exercise. Patients with high blood pressure should also aim to breathe as normally as possible during exercise. Holding the breath can increase blood pressure.

[See In-Depth Report #29: Exercise.]

According to the American Diabetes Association, people with diabetes should aim for preprandial (before eating) plasma glucose levels of 90 - 130 mg/dL and postprandial (after eating) plasma glucose levels less than 180 mg/dL. Hemoglobin A1C levels should be less than 7%.

Measuring Blood Glucose. In patients being treated with insulin or insulin-producing or sensitizing drugs, it is important to monitor blood glucose levels carefully to avoid hypoglycemia. Different goals may be required for specific individuals, including pregnant women, very old and very young people, and those with accompanying serious medical conditions.

Blood glucose levels are generally more stable in type 2 diabetes than in type 1, so experts usually recommend measuring blood levels only once or twice a day. For patients who have become insulin-dependent, more intensive monitoring is necessary. Usually, a drop of blood obtained by pricking the finger is applied to a chemically treated strip. The glucose level is read on a standard meter or a small, portable digital display device. For patients who have trouble controlling hypoglycemia (low blood sugar) or fluctuating blood sugar levels, continuous glucose sensor monitors are also available. In 2007, the FDA approved the STS-7 System, which continuously measures glucose levels for up to 7 days through a sensor inserted beneath the skin of the abdomen. Continuous glucose sensor monitors do not replace fingerstick glucose meters and test strips, but are used in combination with them. [See In-Depth Report #9: Diabetes - type 1.]

Measuring Hemoglobin A1C. Hemoglobin A1c (also called HbA1c , HA1c, or A1C) is measured periodically every 2 - 3 months to determine the average blood-sugar level over the lifespan of the red blood cell. Normal A1C levels should be below 7%. Home tests are also available for measuring A1C.

To monitor the amount of glucose within the blood a person with diabetes should test their blood regularly. The procedure is quite simple and can often be done at home.

Some research suggests that not getting enough sleep may impair insulin use and increase the risk for obesity. More research is needed, but it is always wise to improve sleep habits.

Medications

The American Heart Association now recommends that patients should aim for the following test results for intensive control of glucose levels:

Fasting plasma glucose concentrations below 110 mg/dL.
Glycolated hemoglobin (HbA1c) levels of less than 7%. Controlling HbA1c is the most important factor for reducing the risk of complications in patients with diabetes. According to one 2000 study, a 1% reduction in people with elevated glycolated hemoglobin levels lowers the risk for complications by 21%.

Evidence clearly supports strict glycemic control for reducing complications in the nervous system and blood vessels that occur in both type 1 and type 2 diabetes. Research shows that tight glucose control can help prevent heart disease and complications.

Managing risk factors for heart disease and stroke, particularly strict control of blood pressure, may be more important for improving survival than strict control of blood glucose levels for some patients. Such goals also seem to be more attainable for many patients with type 2 diabetes.

Oral Anti-Hyperglycemic Drugs. Many oral anti-hyperglycemic drugs are available to help patients with type 2 diabetes control their blood sugar levels. Most of these drugs are aimed at using or increasing sensitivity to the patient's own natural stores of insulin. Metformin is the only drug to date that achieves lower mortality rates. Oral type 2 diabetes drugs include:

Biguanides (metformin). Metformin increases tissue sensitivity to available insulin. Metformin also has beneficial effects on cholesterol, blood pressure, and clotting factors. It does not cause weight gain or hypoglycemia. Diarrhea and digestive problems are the most common side effects. Metformin produces lower mortality rates than other drugs, including insulin, and should be considered as first-line therapy for most patients with type 2 diabetes.
Sulfonylureas (glyburide, glipizide, glimepiride, repaglinide). Stimulate insulin secretion but can cause hypoglycemia more than other drugs.
DPP-4 inhibitors (sitagliptin). Also called gliptins, DPP-4 inhibitors were first approved in 2006 and are the newest class of oral diabetes drugs. Like metformin, they do not cause weight gain and have low risks for hypoglycemia.
Meglitinides (repaglinide, nateglinide). Stimulate insulin secretion. These newer drugs are better than sulfonylureas in controlling glucose spikes after meals.
Thiazolidinediones (pioglitazone and rosiglitazone). Reduce insulin resistance. These drugs improve cholesterol levels and may reduce the risk for blood clots. However, they can cause swelling from fluid build-up, which can worsen heart failure or even precipitate it. They may also injure the liver.
Alpha-glucosidase inhibitors (acarbose and miglitol). Slow intestinal absorption of carbohydrates. Have only modest effects on diabetes and have gastrointestinal side effects. Can slightly raise HDL (“good”) cholesterol levels.
Combinations of these drugs, particularly with metformin, are often used to increase effectiveness.

A 2007 review in the Annals of Internal Medicine compared these various classes of medications. The review found that older drugs -- such as metformin and sulfonylureas -- are less expensive than and work as well as newer diabetes drugs. In particular, the review cited metformin as a safe and effective drug because it does not cause weight gain or too-low blood sugar. Metformin can also help lower LDL (“bad”) cholesterol.

Injectable Anti-Hyperglycemic Drugs. In 2005, the FDA approved two new injectable drugs to help patients improve blood sugar control:

Exenatide (Byetta). Exenatide is the first drug in a new class of drugs called incretin mimetics. It lowers blood glucose levels by increasing insulin secretion. Exenatide is used in combination with oral antihyperglycemics, such as metformin or a sulfonylurea drug.
Pramlintide (Symlin). Pramlintide is a first-in-class drug that is a synthetic form of the hormone amylin. The drug is meant for patients who take insulin but still have difficulty controlling their glucose levels.

Insulin Replacement. Insulin replacement may be required when natural insulin reserves are depleted. It is typically started in combination with an oral drug. Eventually, some patients may need to go on full insulin replacement. In addition to injectable forms of insulin, an inhaled insulin product (Exubera) is now available.

Metformin (Glucophage) is a biguanide, which works by reducing glucose production in the liver and by making tissues more sensitive to insulin. Many experts recommend it as a first choice for most patients with type 2 diabetes who are insulin resistant, particularly if they are overweight. Metformin achieves lower mortality rates from diabetes and all causes than other drugs. In one comparison study, it achieved the lowest mortality rates (8%) compared to insulin (28%), a sulfonylurea (16%), and a thiazolidinedione (14%). Combinations with insulin-secreting drugs, other insulin-sensitizing drugs, or insulin itself are particularly effective.

Metformin does not cause hypoglycemia or add weight, so it is particularly well-suited for obese patients with type 2 diabetes. (In some studies, in fact, patients lost weight.) Metformin also appears to have beneficial effects on cholesterol and lipid levels and may help protect the heart. Some research has suggested that it significantly reduces the risk for heart attack. It is also the first choice for children who need oral drugs and is proving to be very effective for women with polycystic ovary syndrome and insulin resistance.

Side Effects. Side effects include:

A metallic taste
Gastrointestinal problems, including nausea, and diarrhea
Interference with absorption of vitamin B12 and folic acid, (which are important for protection against heart disease)
Rare reports of lactic acidosis, a potentially life-threatening condition, particularly in people with risk factors for it. Major studies, however, found no greater risk with metformin than with any of the other drugs used for type 2 diabetes.

Certain people should not use this drug, including anyone with heart failure or kidney or liver disease. It is rarely suitable for adults over age 80.

Sulfonylureas are oral drugs that stimulate the pancreas to release insulin. They are also first-line oral drugs. For adequate control of blood glucose levels, the drugs should be taken only 20 - 30 minutes before a meal. A number of brands are available, including chlorpropamide (Diabinese), tolazamide (Tolinase), acetohexamide (Dymelor), glipizide (Glucotrol), tolbutamide (Orinase), glyburide (Micronase), glimepiride (Amaryl), and repaglinide (Prandin).

Most patients can take sulfonylureas for 7 - 10 years before they lose effectiveness. Combinations with small amounts of insulin or with other oral anti-hyperglycemic drugs (such as metformin or a thiazolidinedione) may extend their benefits. A combination of glyburide and metformin in one pill (Glucovance) is available. Glucovance may be particularly beneficial for patients with unhealthy cholesterol levels and poor control of their blood sugar levels. Some doctors recommend the combination as first-line treatment.

An encouraging 2000 study of patients with severe type 2 diabetes reporting that combinations of insulin with either chlorpropamide or glipizide achieved better glucose control over the long term than insulin alone.

Side Effects and Complications. In general, sulfonylureas should not be used by women who are pregnant or nursing or by individuals who are allergic to sulfa drugs. Side effects may include:

Weight gain (some sulfonylureas, such as glimepiride, may produce less weight gain than others)
Water retention
Although sulfonylureas pose a lower risk for hypoglycemia than insulin does, the hypoglycemia produced by sulfonylureas may be especially prolonged and dangerous. The newer sulfonylureas, such as glimipiride, have much less risk of hypoglycemia than older sulfonylureas.
Some sulfonylureas may pose a slight risk for cardiac events.

Sulfonylureas interact with many other drugs, and patients should be sure to inform their doctor of any medications they are taking, including alternative or over-the-counter drugs.

Meglitinides stimulate beta cells to produce insulin. They include repaglinide (Prandin), nateglinide (Starlix), and mitiglinide. These drugs are rapidly metabolized and short-acting. If taken before every meal, they actually mimic the normal effects of insulin after eating. Patients, then, can vary their meal times with this drug. (Nateglinide appears to work more quickly and is shorter-acting than repaglinide). These drugs may be particularly helpful in combination with metformin or other drugs. They may also be a good choice for people with potential kidney problems.

Side Effects. Side effects include diarrhea and headache. As with the sulfonylureas, repaglinide poses a slightly increased risk for cardiac events. (Newer drugs, such as nateglinide, may pose less of a risk.) People with heart failure or liver disease should use them with caution and be monitored.

Thiazolidinediones, also known as peroxisome proliferator-activated receptor (PPAR) agonists, include rosiglitazone (Avandia) and pioglitazone (Actos). They improve insulin sensitivity by activating certain genes involved in fat synthesis and carbohydrate metabolism. These drugs are usually taken once or twice per day; however, it may take several days before the patient notices any results from them and several weeks before they take full effect. Thiazolidinediones are usually taken in combination with other oral drugs or insulin.

Side Effects. Thiazolidinediones can have serious side effects. They tend to increase fluid-build up, which can cause or worsen heart failure in some patients. Combinations with insulin increase the risk. They should not be used by patients with existing heart failure and should be used cautiously in those with risk factors for heart failure.

In 2007, a study published in the New England Journal of Medicine (NEJM) raised serious concerns that rosiglitazone may increase the risk of heart attack. The study reviewed 42 clinical trials of rosiglitazone. Results suggested that patients who took rosiglitazone were 43% more likely to have a heart attack, and 64% more likely to die from overall heart causes, than patients with diabetes who did not take the drug. A subsequent interim analysis in the NEJM found that while rosiglitazone was definitely associated with increased risk of heart failure, the data were insufficient to determine if the drug increases heart attack risk. The FDA has concluded that rosiglitazone may increase the risk of heart attack and will likely restrict its use. In 2007, a panel of experts from the Food and Drug Administration (FDA) agreed the drug increases the risk of heart attacks -- but concluded it should remain on the market. The panel did, however, recommend the FDA require rosiglitazone's maker to add warnings to the drug's label. Patients who take rosiglitazone, especially those who have heart disease or who are at high risk for heart attack, should discuss their treatment options with their doctors.

Thiazolidinediones may cause more weight gain than other diabetes medications or insulin. Any patient who experiences sudden weight gain, water retention, or shortness of breath should immediately call their doctor. These drugs have also been linked to increased risks for bone fracture.

There have been rare reports of rosiglitazone causing or worsening diabetic macular edema. This is an eye condition associated with diabetic retinopathy that causes swelling in the macular area of the retina. Symptoms include blurred vision and decreased color sensitivity. Most patients who had this side effect also had swelling in the feet and legs (peripheral edema). The condition resolved or improved when patients stopped taking the drug.

Thiazolidinediones can also cause liver damage. Patients who take these drugs should have their liver enzymes checked regularly.

Alpha-glucosidase inhibitors, including acarbose (Precose, Glucobay) and miglitol (Glyset), reduce glucose levels by interfering with the absorption of starch in the small intestine. Acarbose tends to lower insulin levels after meals, a particular advantage, since higher levels of insulin after meals are associated with an increased risk for heart disease. Some evidence suggests that early use of these drugs may reduce heart risk factors, including high blood pressure. A 2002 study of acarbose suggested that these drugs may possibly delay the development of type 2 diabetes in high-risk individuals. Alpha-glucosidase inhibitors are not as effective alone as other single oral drugs, but combinations, such as with metformin, insulin, or a sulfonylurea, increase their effectiveness.

Side Effects. These medications need to be taken with meals. Unfortunately, about a third of patients stop taking the drug because of flatulence and diarrhea, particularly after high-carbohydrate meals. The drug may also interfere with iron absorption.

Alpha-glucosidase inhibitors do not cause hypoglycemia when used alone, but combinations with other drugs do. In such cases, it is important that the patient receive a solution that contains glucose or lactose, not table sugar. This is because acarbose inhibits the breakdown of complex sugar and starches, which includes table sugar.

Incretin mimetics belong to a new class of drugs that help improve blood sugar control. Incretins include glucagon-like peptide-1 (GLP-1) inhibitors and DDP-4 inhibitors.

In 2005, the FDA approved exenatide (Byetta), the first GLP-1 inhibitor drug. Exenatide is an injectable drug that is a synthetic version of the hormone found in the saliva of the Gila monster, a venomous desert lizard. Exenatide is injected twice a day, 1 hour before morning and evening meals. It is prescribed for patients with type 2 diabetes who have not been able to control their glucose with metformin or a sulfonylurea drug. It can be taken in combination with these drugs or alone.

Side Effects. Exenatide stimulates insulin secretion only when blood sugar levels are high and so has less risk for causing low blood sugar (hypoglycemia) when it is taken alone. However, the risk for hypoglycemia increases when exenatide is taken along with a sulfonylurea drug. There does not appear to be a risk for hypoglycemia when exenatide is used along with metformin. Other side effects may include nausea, vomiting, and diarrhea.

A 2005 study compared exenatide to insulin for improving glucose control in patients taking metformin and a sulfonylurea. Both insulin and exenatide worked well for glucose control. Patients lost weight with exenatide and gained weight with insulin. However, patients who received exenatide had significantly more problems with nausea, vomiting, and diarrhea than those who received insulin.

Dipeptidyl peptidase-4 (DPP-4) inhibitors, also called gliptins, are the second class of incretin drugs. In October 2006, the FDA approved the first DPP-4 inhibitor -- sitagliptin (Januvia). It can be used alone or in combination with metformin or a thiazolidinedione drug. In April 2007, the FDA approved Janumet, which combines sitagliptin with metformin in one pill. Other DPP-4 drugs being studied include vildagliptin (Galvus) and saxagliptin.

DPP-4 inhibitors work in a similar way to GLP-1 inhibitors. However, unlike exenatide, which is given by injection, DPP-4 inhibitor drugs are taken as pills by mouth.

Like exenatide, DPP-4 inhibitors do not cause weight gain, have low risks for hypoglycemia, and have few severe side effects. The most common side effects include upper respiratory tract infection, sore throat, and diarrhea.

Insulin replacement is the best treatment for strict control of blood glucose and is required once natural insulin reserves are depleted. Because type 2 diabetes is progressive, most patients eventually require insulin, typically starting it in combination with an oral anti-hyperglycemic drug. However, when a single oral drug fails to control blood sugar it is not clear whether it is better to add insulin replacement or to add a second or third oral drug.

Some experts advocate using insulin as early as possible for optimal control. However, in patients who still have insulin reserves, there is concern that extra natural insulin will have adverse effects. Low blood sugar (hypoglycemia) and weight gain are the main side effects of insulin therapy. Some research suggests that insulin may also cause heart complications. A 2006 study reported that insulin therapy increases the risk of developing high blood pressure (hypertension). It is still not clear if insulin replacement improves survival rates compared to oral drugs, notably metformin.

One approach is to combine insulin with metformin, which achieves blood glucose control without added weight gain. Newer forms of insulin analogues, such as glargine, may be especially helpful for people with type 2 diabetes and reduce the risk for hypoglycemia.

Fortunately, studies to date have not reported any adverse cardiac effects in patients with type 2 diabetes who take insulin. In fact, insulin has been associated, in some cases, with improvement in heart risk factors. More research is needed to clarify these important issues.

Forms of Insulin. Experts are working toward administering insulin so that it closely mimics the daily pattern of insulin, which responds to blood sugar levels by surging after meals and then falling to a steady base level afterward. To achieve this, doctors may use two insulin types:

Fast-Acting Insulins for Surges. Insulin lispro and aspart are fast-acting insulins. They mimic insulin's response to food intake. They are taken before meals, and their short action reduces the risk for hypoglycemia afterward.
Slower Insulins for Base Levels. Intermediate forms (including NPH and lente) and long-acting forms (glargine, ultralente) were developed to provide a steady level of insulin throughout the day. To date, glargine (Lantus) seems to be the most successful in achieving this goal in type 2 diabetes.

In 2006, the FDA approved the first non-injected form of insulin. Exubera is an inhaled form of insulin. It is approved for adults but should not be used by patients who smoke or have quit smoking within the past 6 months. Patients with asthma, bronchitis, or emphysema should also not use inhaled insulin. Clinical trials indicate that Exubera can provide sustained blood sugar control over a 2-year period. Patients in the trials who took Exubera experienced half as much weight gain as those who took injected insulin. Scientists are also developing other types of non-injected insulin, including spray formulas.

In a 2005 trial, Exubera improved blood sugar control when it was added to or substituted for combination oral drug therapy (sulphonylurea and thiazolidenedione). However, as with other forms of insulin, Exubera caused more hypoglycemia and weight gain than the oral anti-hyperglycemic drugs.

Pramlintide (Symlin) is a new type of injectable drug that may help patients who take insulin but still need better blood sugar control. The FDA approved this drug in 2005. Pramlintide is a synthetic form of amylin, a hormone that is related to insulin. Pramlintide is used in combination with insulin to lower blood sugar levels in the 3 hours after meals.

[See In-Depth Report #9: Diabetes - type 1.]

Sodium Glucose Uptake Transporter 2 (SGLT-2) Inhibitors. SGLT-2 inhibitors are a new class of drug being investigated for treatment of type 2 diabetes. Preliminary trials for two of these drugs, dapagliflozin and serglifozin, have shown promising results in helping improve blood glucose control. The drugs are being tested in combination with metformin.

Long-Term Complications

Patients with diabetes have higher mortality rates than people who do not have diabetes regardless of sex, age, or other factors. Heart disease and stroke are the leading causes of death in these patients. All lifestyle and medical efforts should be made to reduce the risk for these conditions.

People with type 2 diabetes are also at risk for nerve damage (neuropathy) and abnormalities in both small and large blood vessels (vascular injuries) that occur as part of the diabetic disease process. Such abnormalities produce complications over time in many organs and structures in the body. Although these complications tend to be more serious in type 1 diabetes, they still are of concern in type 2 diabetes. All people with diabetes should aim for fasting blood glucose levels of less than 110 mg/dL and hemoglobin HbA1C of less than 7%.

There are two important approaches to preventing complications from diabetes:

Intensive control of blood glucose and keeping glycosylated hemoglobin (HbA1c) levels below 7%. Tight blood glucose and HbA1c control can prevent complications due to vascular (blood vessel) abnormalities and nerve damage (neuropathy) that can cause major damage to organs, including the eyes, kidneys, and heart.
Managing risk factors for heart disease. Control of blood glucose also helps the heart, but its benefits occur over time. It is very important that people with diabetes control blood pressure, cholesterol levels, and other factors associated with heart disease.

Heart attacks account for 60% and strokes for 25% of deaths in patients with diabetes. Diabetes affects the heart in many ways:

Both type 1 and 2 diabetes speed the progression of atherosclerosis (hardening of the arteries). Diabetes can adversely affect blood lipid levels by lowering HDL ("good cholesterol") and increasing triglycerides. This can lead to coronary artery disease, heart attack, or stroke. According to a 2007 study, the risk of stroke doubles within 5 years of type 2 diabetes diagnosis.
Impaired nerve function (neuropathy) associated with diabetes also causes heart abnormalities. Some experts estimate that the mortality rates from neuropathy-related heart conditions range between 15 - 53%.
Women with diabetes are at particularly high risk for heart problems. A 2007 study indicated that while progress has been made in reducing mortality rates among men with diabetes, women with diabetes continue to face a high risk of death from heart disease and overall causes.

Tight blood sugar control may help protect blood vessels and reduce the risk for blood clotting. It is still not known whether intensive control will have a major protective effect on the heart, however. People with diabetes must be sure to use other measures as well to protect the heart.

Aspirin for Reducing the Risk for Blood Clots. Taking a daily aspirin (75 - 162 mg/day) reduces the risk for blood clotting and may help protect against heart attacks and heart disease. In a 2000 study, low-dose aspirin was associated with a 30% lower risk for death from heart disease in adults with type 2 diabetes.

Controlling Blood Pressure. Strict control of blood pressure is critical for preventing complications of diabetes and has proven to improve survival rates. Patients should strive for blood pressure levels of less than 130/80 mm Hg (systolic/diastolic). (Controlling systolic pressure may be especially important for reducing the risk for kidney complications.)

Dozens of anti-hypertensive drugs are available. Most fall into the following categories:

Diuretics rid the body of extra sodium (salt) and water. There are three main types of diuretics: Potassium-sparing, thiazide, and loop.
Angiotensin-converting enzyme (ACE) inhibitors reduce the production of angiotensin, a chemical that causes arteries to narrow.
Angiotensin-receptor blockers (ARBs) block angiotensin.
Beta-blockers block the effects of adrenaline and ease the heart’s pumping action.
Calcium-channel blockers (CCBs) decrease the contractions of the heart and widen blood vessels.

The American Diabetes Association (ADA) recommends any of these classes of drugs as first-line treatment for hypertension. New research suggests, however, that beta-blockers are less effective at preventing strokes and heart attacks than other types of blood pressure medications. Many patients require more than one type of drug to control blood pressure. For patients with diabetes who have microalbuminuria, the ADA strongly recommends ACE inhibitors or ARBs. Microalbuminuria is an accumulation of protein in the blood, which can signal the onset of kidney disease (nephropathy).

The 2005 landmark Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicated that a thiazide-type diuretic works as well as an ACE inhibitor or CCB for patients with diabetes and high blood pressure. Compared with ACE inhibitors or CCBs, diuretics appeared to be better at lowering systolic blood pressure and preventing heart failure. In addition, the trial suggested that diuretics are especially helpful for African-Americans, by offering greater protection than ACE inhibitors or CCBS in preventing strokes.

Several 2006 studies suggested that anti-hypertensive drugs may increase the risk of developing diabetes. One study found more risk for thiazide diuretics and beta-blockers than ACE inhibitors and CCBs. Another study indicated that the ACE inhibitor ramipril had a lower risk of causing diabetes in African-Americans than a CCB or beta-blocker. A 2007 review in the Lancet also found a higher risk for new-onset diabetes with beta-blockers and diuretics, a medium risk with CCBs, and the lowest risk with ARBs and ACE inhibitors.

Research in this subject is important for patients with pre-diabetes who have high blood pressure. Results of future research may help doctors decide which treatment is most appropriate for patients with high blood pressure who are at high risk for diabetes. [See In-Depth Report #14: High blood pressure.]

Improving Cholesterol and Lipid Levels. Abnormal cholesterol and lipid levels are common in diabetes. High LDL (“bad”) cholesterol should always be lowered, but people with diabetes also often have additional harmful imbalances including low HDL (“good”) cholesterol and high triglycerides. Patients should aim for LDL levels below 100 mg/dL, HDL levels over 50 mg/dL and triglyceride levels below 150 mg/dL. Patients with diabetes and existing heart disease should strive for even lower LDL levels; the American Diabetes Association recommends LDL levels below 70 mg/dL for these patients.

Statins are the best cholesterol-lowering drugs. They include atorvastatin (Lipitor), lovastatin (Mevacor, generics), pravastatin (Pravachol), simvastatin (Zocor, generics), fluvastatin (Lescol), and rosuvastatin (Crestor). These drugs are very effective for lowering LDL cholesterol levels. Recent studies indicate that aggressive high-dose statin therapy may be an important treatment approach for high-risk patients who need to substantially lower their LDL levels. A 2006 study found that patients with diabetes and heart disease who were treated with 80 mg daily of atorvastatin had a 25% lower risk of heart attack and stroke than patients who received the standard 10 mg daily dose.

Although lowering LDL is beneficial, statins are not as effective as other medications -- such as fibrates, niacin, ezetimbe, or bile acid sequesters -- in addressing HDL and triglyceride imbalances. This is a common problem in type 2 diabetes. Combinations of statins with one of these drugs may be helpful for people with diabetes who have heart disease, low HDL, and near-normal LDL levels. Although combinations of statins and fibrates or niacin increase the risk of myopathy, both combinations are considered safe if used with extra care. Research presented at the 2007 annual meeting of the American Diabetes Association suggested that statins and fibrates may also help reduce the risk of developing peripheral neuropathy, the diabetes-associated nerve damage that can lead to loss of sensation in the feet.

Gemfibrozil (Lopid) and fenofibrate (Tricor) are usually the first choice for fibrate drugs. Niacin has the most favorable effect on raising HDL and lowering triglycerides of all the cholesterol drugs. However, about 30% of patients who take high-dose niacin experience increased blood glucose levels. Moderate doses of niacin can achieve lipid control without causing serious blood glucose problems. [See In-Depth Report #23: Cholesterol.]

Prevention and Treatment of Nephropathy. Tight control of blood sugar and blood pressure is essential for preventing the onset of kidney disease. Long-term studies report that strict control of these two conditions produces a 60% reduction in new cases of nephropathy and a delay in progression of the disease. ACE inhibitors and ARBs, two classes of blood pressure medications, are very helpful for preventing or slowing the progression of diabetic kidney disease.

Diabetic nephropathy occurs in about 20 - 40% of patients with diabetes and is the leading cause of end-stage renal disease. If the kidneys fail, dialysis is required. Symptoms of kidney failure may include swelling in the feet and ankles, itching, fatigue, and pale skin color.

Anemia is a common complication of end-stage kidney disease. Patients on dialysis usually require injections of erythropoiesis-stimulating drugs to increase red blood cell counts and control anemia. Dosing target levels of erythropoiesis-stimulating drugs are controversial, especially for patients with chronic kidney disease. In 2006, two important New England Journal of Medicine studies indicated that aggressive dosing to completely normalize hemoglobin levels does not work better than standard dosing that only partially corrects anemia.

In 2007, the FDA issued new warnings on darbepoetin alfa (Aranesp) and epoetin alfa (Epogen and Procrit). The warnings describe an increased risk with blood clots, strokes, and heart attacks in patients with end-stage kidney disease when these drugs were given at higher than recommended doses. The FDA has set new dosing and hemoglobin target levels for these drugs.

Another controversy surrounding erythropoiesis-stimulating drugs concerns their overuse at dialysis centers. A 2007 study in the Journal of the American Medical Association suggested that large, for-profit dialysis centers tend to administer higher-than-appropriate doses of these drugs compared to nonprofit facilities. The study suggested that for-profit centers are giving higher doses for financial, not medical, reasons.

The FDA recommends that patients with end-stage kidney disease who receive erythropoiesis-stimulating drugs should:

Maintain hemoglobin levels that do not exceed 12 g/dL
Receive frequent blood tests to monitor hemoglobin levels
Contact their doctors if they experience such symptoms as shortness of breath, pain, swelling in the legs, or increases in blood pressure

[See In-Depth Report #57: Anemia.]

Click the icon to see an image of the pancreas and kidneys.

Diabetes reduces or distorts nerve function, causing a condition called neuropathy. Neuropathy refers to a group of disorders that affect nerves. The two main types of neuropathy are:

Peripheral (affects nerves in the toes, feet, legs, hand, and arms)
Autonomic (affects nerves that help regulate digestive, bowel, bladder, heart, and sexual function)

Tingling
Weakness
Burning sensations
Loss of the sense of warm or cold
Numbness (if the nerves are severely damaged, the patient may be unaware that a blister or minor wound has become infected)
Deep pain

Autonomic neuropathy can cause digestive problems (constipation, diarrhea, nausea, vomiting), bladder infections, and erectile dysfunction. In some cases, neuropathy may mask angina, the chest pain warning for heart disease and heart attack. Patients with diabetes should be aware of other warning signs of a heart attack, including sudden fatigue, sweating, shortness of breath, nausea, and vomiting.

Prevention of Neuropathy. Patients with type 2 diabetes should receive regular screenings for loss of sensation in feet and other signs of neuropathy. A 2007 study suggested that statin and fibrate drugs, which are used to control cholesterol, may help protect against diabetic peripheral neuropathy.

Pain Relief for Peripheral Neuropathy. A number of different drugs are used for peripheral neuropathy pain relief. They include:

Nonprescription analgesics such as aspirin, acetaminophen, and non-steroidal anti-inflammatory drugs (NSAIDs). (Patients with stomach or kidney problems should check with their doctors before using these drugs.)
Prescription painkillers, such as tramadol (Ultram). Tramadol is a drug that is similar to opioids. It can help relieve pain but has significant side effects, including nausea, constipation, and headache.
Topical medications, particularly capsaicin (the active ingredient in hot peppers), are applied to the skin to relieve minor local pain. A 5% lidocaine patch has also shown good results in clinical trials.
Tricyclic antidepressants, such as amitriptyline (Elavil) or doxepin (Sinequan), are effective in reducing pain from neuropathy in up to 75% of patients. A combination of doxepin and capsaicin (applied to the skin) may be particularly beneficial. Unfortunately, tricyclics may cause heart rhythm problems.
Duloxetine (Cymbalta) is a serotonin and norepinephrine reuptake inhibitor, a newer type of antidepressant, which was approved in 2004 for treatment of pain associated with diabetic peripheral neuropathy.
The anti-convulsant drug pregabalin (Lyrica) was approved in 2004 for neuropathic pain management. It is classified as a controlled substance (like narcotics), which indicates a potential risk for abuse. Other anti-seizure drugs used for peripheral neuropathy pain relief include gabapentin (Neurontin) and valproate (Depakote).

Erectile dysfunction is also associated with neuropathy. Evidence shows that phosphodiesterase type 5 (PDE-5) drugs, such as sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis), are safe and effective, at least in the short term, for patients with diabetes. Typical side effects are minimal but may include headache, flushing, and upper respiratory tract and flu-like symptoms.

Diabetes is responsible for more than half of all lower limb amputations performed in the U.S. Each year there are about 88,000 non-injury amputations, 50 - 75% of them due to diabetes. The number is increasing as the prevalence in diabetes type 2 rises. According to a 2005 study in the Lancet, every 30 seconds someone in the world receives a lower limb amputation due to diabetes. About 85% of amputations start with foot ulcers, which develop in about 12% of people with diabetes.

Charcot Foot. Charcot foot or Charcot joint (medically referred to as neuropathic arthropathy) occurs in about 2.5% of people with diabetes. Early changes appear like an infection, with the foot becoming swollen, red, and warm. A seriously affected foot can become deformed. The bones may crack, splinter, and erode, and the joints may shift, change shape, and become unstable. It typically develops in people who have neuropathy to the extent that they cannot feel sensation in the foot and are not aware of an existing injury. Instead of resting an injured foot or seeking medical help, the patient often continues normal activity, causing further damage.

Measures to Prevent Foot Ulcers. Preventive foot care can significantly reduce the risk of ulcers and amputation. Some tips for preventing problems include:

Patients should inspect their feet daily and watch for changes in color or texture, odor, and firm or hardened areas, which may indicate infection and potential ulcers.
When washing the feet, the water should be warm (not hot), and the feet and areas between the toes should be thoroughly dried afterward. Check water temperature with the hand or a thermometer before stepping in.
Moisturizers should be applied, but not between the toes.
Corns and calluses should be gently pumiced and toenails trimmed short and the edges filed to avoid cutting adjacent toes.
Patients should not use medicated pads or try to shave the corns or calluses themselves.
Well-fitting footwear is very important. People should be sure the shoe is wide enough; according to a 2001 study, 30% of patients with diabetes wear shoes that are too narrow. Patients should also avoid high heels, sandals, thongs, and going barefoot. Shoes with a rocker sole reduce pressure under the heel and front of the foot by 35 - 65% and may be particularly helpful. Custom-molded boots increase the surface area over which foot pressure is distributed. This reduces stress on the ulcers and allows them to heal.
Shoes should be changed often during the day.
Wear socks, particularly with extra padding (which can be specially purchased).
Patients should avoid tight stockings or any clothing that constricts the legs and feet.
Foot pain, numbness, or tingling is worse at night; diphenhydramine (Benadryl) may help.
A specialist in foot care should be consulted for any problems.

People with diabetes are prone to foot problems because the disease can cause damage to the blood vessels and nerves, which may result in decreased ability to sense trauma to the foot. The immune system is also altered, so that the patient cannot efficiently fight infection.

Treating Foot Ulcers in Diabetes. About one-third of foot ulcers will heal within 20 weeks with good wound care treatments. Treatments include:

Antibiotics are generally given. In some cases, hospitalization and intravenous antibiotics for up to 28 days may be needed for severe foot ulcers.
In virtually all cases, wound care requires debridement, which is the removal of injured tissue until only healthy tissue remains. Debridement may be accomplished using chemical (enzymes), surgical, or mechanical (irrigation) means.
Hydrogels (Nu-Gel, Intrasite Gel, Scherisorb, Clearsite, Duoderm, Geliperm) are helpful in healing ulcers and are noninvasive and soothing.
Felted foam may be helpful in healing ulcers on the sole of the foot. Felted foam uses a multi-layered foam pad over the bottom of the foot with an opening over the ulcer.

Other Treatments for Foot Ulcers. Doctors are also using or investigating other treatments to heal ulcers. These include:

Administering hyperbaric oxygen (oxygen given at high pressure) is showing promise in promoting healing. In one study, patients who had had ulcers that had not responded to treatment for over 3 months received daily treatments that lasted 90 minutes for 2 weeks. About 15 days after completion, patients who received oxygen had significant reduction in ulcers, sometimes with complete healing. Other studies are also demonstrating good results.
Monochromatic near-infrared photo energy (MIRE) uses light therapy to improve sensation in the feet of patients with peripheral neuropathy.
Total-contact casting (TCC) uses a cast that is designed to match the exact contour of the foot and to distribute weight along the entire length of the foot. It is usually changed weekly. It may be helpful for ulcer healing and for Charcot foot. Although it is very effective in healing ulcers, recurrence is common.

Diabetes accounts for 12,000 - 24,000 of new cases of blindness annually and is the leading cause of new cases of blindness in adults age 20 - 74. The most common eye disorder in diabetes is retinopathy. People with diabetes are also at higher risk for developing cataracts and certain types of glaucoma, such as primary-open angle glaucoma (POAG). The risk for POAG is especially high for women with type 2 diabetes. [See In-Depth Report #26: Cataracts and In-Depth Report #25: Glaucoma.]

Description of Retinopathy. Retinopathy is a condition in which the retina in the eye becomes damaged. The two primary abnormalities that occur are a weakening of the blood vessels in the retina and the obstruction in the capillaries -- probably from very tiny blood clots. Retinopathy generally occurs in one or two phases:

Click the icon to see an image of diabetic retinopathy.

The early and more common type of this disorder is called nonproliferative or background retinopathy. The blood vessels in the retina are abnormally weakened. They rupture and leak, and waxy areas may form. If these processes affect the central portion of the retina, swelling may occur, causing reduced or blurred vision.
If the capillaries become blocked and blood flow is cut off, soft, "woolly" areas may develop in the retina's nerve layer. These woolly areas may signal the development of proliferative retinopathy. Often there are no symptoms of progressing retinopathy. In this more severe condition, new abnormal blood vessels form and grow on the surface of the retina. They may spread into the cavity of the eye or bleed into the back of the eye. Major hemorrhage or retinal detachment can result, causing severe visual loss or blindness. The sensation of seeing flashing lights may indicate retinal detachment.

Click the icon to see an animation on diabetic retinopathy.

According to a 2003 study, about 40% of young adults with type 1 diabetes had developed retinopathy within 10 years of diagnosis. (Although this rate is high, it is significantly lower than in previous years when blood glucose control was not as strict.) The risk is lower in patients with type 2 diabetes, although in one study over 20% had signs of retinopathy 6 years after diagnosis. Patients who are newly diagnosed with type 2 diabetes should get a comprehensive eye examination, including dilation. In general, all patients with diabetes should have a yearly eye examination. Patients with no signs of retinal damage or low risk factors for retinopathy may only require screening every 2 - 3 years.

Diabetes doubles the risk for depression. Furthermore, according to one study, depression, in turn, increases the risk for hyperglycemia and complications of diabetes. Restoring mental health, both through medication and psychotherapy, not only improves quality of life but may help patients control their blood sugar levels.

Diabetes changes bone quality and density, but the effects differ, depending on type:

Type 1 diabetes is associated with a slightly reduced bone density, putting patients at risk for osteoporosis and possibly fractures. The best medications for bone loss in patients with diabetes are bisphosphonates, such as alendronate (Fosamax) and risedronate (Actonel). They not only help prevent bone loss but may even reduce daily insulin requirements in patients taking insulin. [See In-Depth Report #18: Osteoporosis.]
Type 2 diabetes, on the other hand, is associated with an increased bone density but is also associated with fractures. In such cases, the bone quality itself may be impaired.

Older patients with either type of diabetes are at risk for falling, which compounds the risk for fracture.

Diabetes increases the risk for other conditions, including:

Hearing loss
Periodontal disease
Carpal tunnel syndrome
Nonalcoholic fatty liver disease, also called nonalcoholic steatohepatitis (NASH), a particular danger for people who are obese
Colorectal cancer
Uterine cancer

Emergency Complications

People with diabetes who need to intensively control glucose levels are at risk for low blood sugar (hypoglycemia). Hypoglycemia, also called insulin shock, develops if blood sugar levels fall below normal. It may also be caused by insufficient intake of food, excess exercise, or alcohol intake. The condition is usually manageable, but occasionally it can be severe or even life threatening, particularly if the patient fails to recognize the symptoms. Mild hypoglycemia is common among people with type 2 diabetes, but severe episodes are rare, even among those who are taking insulin. Still, all patients who intensively control blood sugar (glucose) levels should be aware of warning symptoms.

Risk Factors for Severe Hypoglycemia. People at highest risk for severe hypoglycemia are those who intensively control blood glucose and also have one or more of the following conditions:

Long-term diabetes
Less education on their condition
A previous history of severe hypoglycemia
Hypoglycemia unawareness

Hypoglycemia unawareness is a condition in which people become insensitive to hypoglycemic symptoms. It affects about 25% of patients who use insulin, nearly always people with type 1 diabetes. In such cases, hypoglycemia appears suddenly, without warning, and can escalate to a severe level. Even a single recent episode of hypoglycemia may make it more difficult to detect the next episode. With vigilant monitoring and by rigorously avoiding low blood glucose levels, patients can often regain the ability to sense the symptoms. However, even very careful testing may fail to detect a problem, particularly one that occurs during sleep.

Symptoms. Mild hypoglycemia symptoms usually occur at moderately low and easily correctable levels of blood glucose. They include:

Sweating
Trembling
Hunger
Rapid heartbeat

Severely low blood glucose levels can cause neurologic symptoms, such as:

Confusion
Weakness
Disorientation
Combativeness
In rare and worst cases, coma, seizure, and death

Preventive Measures. The following tips may help avoid hypoglycemia or prepare for attacks:

Patients are at highest risk for hypoglycemia at night. Bedtime snacks may be helpful.
Patients who intensively control their blood sugar should monitor blood levels as often as possible, four times or more per day. This is particularly important for patients with hypoglycemia unawareness.
In adults, it is also particularly critical to monitor blood glucose levels before driving, when hypoglycemia can be very hazardous.
Patients who use medications that put them at risk for hypoglycemia should always carry hard candy, juice, sugar packets, or commercially available glucose substitutes designed for individuals with diabetes.

Family and friends should be aware of the symptoms and be prepared:

If the patient is helpless (but not unconscious), family or friends should administer three to five pieces of hard candy, two to three packets of sugar, half a cup (four ounces) of fruit juice, or a commercially available glucose solution.
If there is inadequate response within 15 minutes, additional oral sugar should be provided or the patient should receive emergency medical treatment, including intravenous administration of glucose.
Family members and friends can learn to inject glucagon, a hormone, which, in contrast to insulin, raises blood glucose.

Click the icon to see a glucagon kit.

Diabetic ketoacidosis (DKA) is a life-threatening complication caused by insulin depletion. Until recently, it was a complication almost exclusively of type 1 diabetes. In such cases, it is nearly always due to noncompliance with insulin treatments. However, DKA is being reported increasingly in type 2 diabetes, especially among Hispanic- and African-Americans. It is not clear what causes total insulin depletion in these patients. Researchers are trying to learn which individuals are at particular risk.

Diabetic ketoacidosis often develop as follows:

The process is usually triggered in insulin-deficient patients by a stressful event, most often pneumonia or urinary tract infections. Other triggers include alcohol abuse, physical injury, pulmonary embolism, heart attacks, or other illnesses.
Severely low insulin levels cause excessive amounts of glucose in the bloodstream (hyperglycemia).
Fat breakdown then accelerates and increases the production of fatty acids.
These fatty acids are converted into chemicals called ketone bodies, which are toxic at high levels.

Symptoms and complications may include:

Nausea and vomiting
Abnormally deep and rapid breathing with frequent sighing
Rapid heartbeat
If the condition persists, coma and, eventually, death, may occur; however, over the past 20 years, death from DKA has decreased to about 2% of all cases.
Other serious complications from DKA include aspiration pneumonia and adult respiratory distress syndrome.

Life-saving treatment uses rapid rehydration with a saline solution followed by low-dose insulin and potassium replacement.

Resources

www.diabetes.org -- American Diabetes Association
www.niddk.nih.gov -- National Institute of Diabetes and Digestive and Kidney Diseases
www.americanheart.org -- American Heart Association
www.kidney.org -- National Kidney Foundation
www.nei.nih.gov -- National Eye Institute
www.medicalert.org -- Medic Alert
www.eatright.org -- American Dietetic Association
http://limaye.ecri.org -- Limaye Center

References

American Diabetes Association (ADA). Standards of medical care in diabetes. IV. Prevention/delay of type 2 diabetes. Diabetes Care. 2007 Jan;30(Suppl 1):S7-8.

American Diabetes Association (ADA). Standards of medical care in diabetes. V. Diabetes care. Diabetes Care. 2007 Jan;30(Suppl 1):S8-15.

American Diabetes Association (ADA). Standards of medical care in diabetes. VI. Prevention and management of diabetes complications. Diabetes Care. 2007 Jan;30(Suppl 1):S15-24.

Amori RE, Lau J, Pittas AG. Efficacy and safety of incretin therapy in type 2 diabetes: systematic review and meta-analysis. JAMA. 2007 July 11;298:194-206.

Aschner P, Kipnes MS, Lunceford JK, Sanchez M, Mickel C, Williams-Herman DE, et al. Effect of the dipeptidyl peptidase-4 inhibitor sitagliptin as monotherapy on glycemic control in patients with type 2 diabetes. Diabetes Care. 2006 Dec;29(12):2632-7.

Bolen S, Feldman L, Vassy J, Wilson L, Yeh H-C, Marinopoulos S, et al. Systematic review: comparative effectiveness and safety of oral medications for type 2 diabetes mellitus. Ann Intern Med. 2007 Jul 17; 147(6). [Epub ahead of print]

Carnethon MR, Biggs ML, Barzilay JI, Smith NL, Vaccarino V, Bertoni AG, et al. Longitudinal association between depressive symptoms and incident type 2 diabetes mellitus in older adults: the cardiovascular health study. Arch Intern Med. 2007 Apr 23;167(:802-7.

Charbonnel B, Karasik A, Liu J, Wu M, Meininger G; Sitagliptin Study 020 Group. Efficacy and safety of the dipeptidyl peptidase-4 inhibitor sitagliptin added to ongoing metformin therapy in patients with type 2 diabetes inadequately controlled with metformin alone. Diabetes Care. 2006 Dec;29(12):2638-43.

Elliott WJ, Meyer PM. Incident diabetes in clinical trials of antihypertensive drugs: a network meta-analysis. Lancet. 2007 Jan 20;369(9557):201-7.

Florez JC, Jablonski KA, Bayley N, Pollin TI, de Bakker PI, Shuldiner AR, et al. TCF7L2 polymorphisms and progression to diabetes in the Diabetes Prevention Program. N Engl J Med. 2006 Jul 20;355(3):241-50.

Frayling TM, Timpson NJ, Weedon MN, Zeggini E, Freathy RM, Lindgren CM, et al. A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity. Science. 2007 May 11;316(5826):889-94. Epub 2007 Apr 12.

Gillies CL, Abrams KR, Lambert PC, Cooper NJ, Sutton AJ, Hsu RT, et al. Pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance: systematic review and meta-analysis. BMJ. 2007 Feb 10;334(7588):299. Epub 2007 Jan 19.

Grant SF, Thorleifsson G, Reynisdottir I, Benediktsson R, Manolescu A, Sainz J, et al. Variant of transcription factor 7-like 2 (TCF7L2) gene confers risk of type 2 diabetes. Nat Genet. 2006 Mar;38(3):320-3. Epub 2006 Jan 15.

Gregg EW, Gu Q, Cheng YJ, Narayan KM, Cowie CC. Mortality trends in men and women with diabetes, 1971-2000. Ann Intern Med. 2007 Jun 18; [Epub ahead of print]

Home PD, Pocock SJ, Beck-Nielsen H, Gomis R, Hanefeld M, Jones NP, et al. Rosiglitazone evaluated for cardiovascular outcomes--an interim analysis. N Engl J Med. 2007 Jul 5;357(1):28-38. Epub 2007 Jun 5.

Jeerakathil T, Johnson JA, Simpson SH, Majumdar SR. Short-term risk for stroke is doubled in persons with newly treated type 2 diabetes compared with persons without diabetes: a population-based cohort study. Stroke. 2007 Jun;38(6):1739-43. Epub 2007 May 3.

Lee AJ, Hiscock RJ, Wein P, Walker SP, Permezel M. Gestational diabetes mellitus: clinical predictors and long-term risk of developing type 2 diabetes: a retrospective cohort study using survival analysis. Diabetes Care. 2007 Apr;30(4):878-83.

Pasquale LR, Kang JH, Manson JE, Willett WC, Rosner BA, Hankinson SE. Prospective study of type 2 diabetes mellitus and risk of primary open-angle glaucoma in women. Ophthalmology. 2006 Jul;113(7):1081-6. Epub 2006 Jun 6.

Nissen SE, Wolski K. Effect of rosiglitazone on the risk of myocardial infarction and death from cardiovascular causes. N Engl J Med. 2007 Jun 14;356(24):2457-71. Epub 2007 May 21.

Psaty BM, Furberg CD. Rosiglitazone and cardiovascular risk. N Engl J Med. 2007 Jun 14;356(24):2522-4. Epub 2007 May 21.

Schulze MB, Schulz M, Heidemann C, Schienkiewitz A, Hoffmann K, Boeing H. Fiber and magnesium intake and incidence of type 2 diabetes: a prospective study and meta-analysis. Arch Intern Med. 2007 May 14;167(9):956-65.

Scott LJ, Mohlke KL, Bonnycastle LL, Willer CJ, Li Y, Duren WL, et al. A genome-wide association study of type 2 diabetes in Finns detects multiple susceptibility variants. Science. 2007 Jun 1;316(5829):1341-5. Epub 2007 Apr 26.

Singh AK, Szczech L, Tang KL, Barnhart H, Sapp S, Wolfson M, et al. Correction of anemia with epoetin alfa in chronic kidney disease. N Engl J Med. 2006 Nov 16;355(20):2085-98.

Thamer M, Zhang Y, Kaufman J, Cotter D, Dong F, Hernen MA. Dialysis facility ownership and epoetin dosing in patients receiving hemodialysis. JAMA. 2007 Apr 18;297(15):1667-74.

Vardi M, Nini A. Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus. Cochrane Database Syst Rev. 2007 Jan 24(1):CD002187.

Zeggini E, Weedon MN, Lindgren CM, Frayling TM, Elliott KS, Lango H, et al. Replication of genome-wide association signals in UK samples reveals risk loci for type 2 diabetes. Science. 2007 Jun 1;316(5829):1336-41. Epub 2007 Apr 26.

Review Date:
7/31/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com