FitSugar

Silver Lining of High Gas Prices: Smaller Waist Lines

FitSugar — Wed, 12 Sep 2007 02:30:00 -0700

I don't know about you, whenever I go to fill up my car with gas these days, I get mad because the cost of gas is so high and there doesn't seem to be an end in sight. I always say, nothing good can come out of this. Until now...

Leave it to science to find a silver lining to the ridiculously high gas prices. However, new findings are claiming that an increase of an additional $1 per gallon in gasoline prices will reduce U.S. obesity by 15 percent after five years. How so, you ask? Well the sky rocketing gas prices may reduce obesity by leading us to walk, bike or take public transportation (more walking) instead of driving. Furthermore, it may lead us to eat leaner at home instead of rich food at restaurants.

Interesting concept and one that I'm actually buying. I have always been a major proponent of walking, biking and taking public transportation for more reasons than just the high gas prices (more exercise during the day, better for the environment, etc.). Plus at the rate gas seems to be rising, it looks like obesity should be reduced way more than 15 percent in my town.

Think about it; how many times have you said, "Maybe I should just walk," after glancing at the per gallon price tag of gasoline? So maybe next time you really should just walk.

Source

Black Soy Beans Could Be the New Wonder Food

FitSugar — Tue, 27 Feb 2007 09:25:17 -0800

Thirty two rats in Korea agree, black soy beans are helping to prevent obesity, lower cholesterol levels and possibly even reduce your risk for Type 2 diabetes! Yes this new study on rodents seems to indicate that the gorging on black soy beans can significantly reduce help to control weight gain.

The study found several beneficial reason to eat these beans:

After two weeks, the rats getting 10 percent of their energy from black soya gained half as much weight as those in the control group, and their total blood cholesterol and LDL (so-called "bad") cholesterol fell by 25 percent and 10 percent, respectively.

It seems that the soy protein may affect how the liver metabolizes fat by preventing new fatty acids and cholesterol from forming together. Which in turn affects weight gain, especially in the abdominal area, which in turns affects the body's ability to create insulin. This is why some experts are interpreting this study as a possible means of fighting Type 2 diabetes.

Just as an interesting aside his metabolic effect may explain the traditional Asian use of black soy to treat Type 2 diabetes.

We have heard about wonder foods before and this study only involved less than three dozen rats. I really hope that we can soon all believe in the power of soy, but you don't need to start taking black soy supplements just yet. I am just dubious about miracle foods since garlic, considered a great dietary means for lowering cholesterol was recently found to have no real effect on it.

Why Exercise Won't Help You Lose Weight . . . Sort Of

FitSugar — Thu, 05 Nov 2009 03:00:36 -0800

There have been a lot of reports in the last year confirming that contrary to popular belief, not all exercise leads to significant weight loss. If you want to shed pounds, it mostly comes down to diet. It’s no surprise that changing your diet can help you lose weight, but for decades, many people believed that exercise was the best pathway to a slimmer, fitter you.

Today the New York Times added to the news that exercise doesn’t significantly aid in weight loss by reporting the results of an exercise and obesity study. The study followed a group of 58 obese individual who underwent three months of supervised aerobic activity but didn’t change their diets at all. And while the group lost an average of seven pounds, many participants barely lost three.

I admit that when all of these studies started coming up I was a little shocked, but it turns out that high intensity workouts mainly burn carbs, not just fat.

To hear what type of exercise may maximize fat loss, read more.

The article explains: "'The message of our work is really simple,' although not agreeable to hear, said Edward Melanson, PhD, the lead author of the study. 'It all comes down to energy balance,' or, as you might have guessed, calories in and calories out. People 'are only burning 200 or 300 calories' in a typical 30-minute exercise session, Melanson points out. 'You replace that with one bottle of Gatorade.'"

Fat loss can be maximized, but it’s a matter of how you approach your workout. To do this, work out at a lower intensity in your fat-burning zone, which is 60 to 70 percent of your maximum heart rate. For most people this zone falls between 105-134 beats per minute. Melanson’s study also found that once weight is lost from reduced calorie intake, exercise might prevent it from coming back by resetting metabolic pathways that stop the body from wanting to store fat.

The research is interesting, but should not dissuade any of us from our fitness goals. The benefits of exercise reach far beyond weight loss - it helps the brain function better, reduces stress, creates a toned body, and is important for healthy heart function.

Weight control and diet

FitSugar — Wed, 08 Oct 2008 17:34:58 -0700

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Cancer and Weight Control:

Cancer prevention guidelines from the American Cancer Society stress the importance of maintaining a healthy weight throughout life. A healthy weight is even more important than eating specific healthy foods, when it comes to cancer prevention.

Drug Warning:

The US Food and Drug Administration (FDA) is warning consumers not to buy a product known as the "Brazilian diet pill." This product is labeled as a dietary supplement, but contains several chemicals found in powerful prescription drugs. The products are also known as Emagrece Sim and Herbathin dietary supplements.

New Over-the-Counter Medication:

In February 2007, the FDA approved the first over-the-counter (OTC) weight-loss drug. Orlistat, previously available only by prescription as Xenical, will be available OTC at half its prescription strength. It will be sold under the name alli. Those eager to use the new pill should consider its cost and modest benefits compared with its side effects, most commonly oily diarrhea. This pill, which prevents fat absorption from food, also increases the risk of not absorbing important nutrients from food while using it. The FDA recommends taking a daily multivitamin supplement when using alli.

Research News:

A small study in Norway found that a diet low in fat and high in carbohydrates ("carbs") increases symptoms of psychological distress, such as depression and anger. The study compared three different diets with varying amounts of fat and carbohydrates.
A study released in March 2007 found that obesity in young girls results in early puberty -- as early as age 9.

Effects of Obesity on the Body:

Obesity is associated with certain problems related to infertility, such as uterine fibroids or menstrual irregularities. In men, obesity can contribute to reduced testosterone levels.
People who are obese are at higher risk for carpal tunnel syndrome and other problems involving nerves in their wrists and hands.
The Pickwickian syndrome, named for an overweight character in a Dickens novel, occurs in severe obesity when lack of oxygen produces intense and chronic sleepiness and, eventually, heart failure.

Introduction

A stable weight depends on a good balance between the energy you get from food and the energy you use. You use energy during the day in three ways:

As energy expended during rest (basal metabolism)
As energy used to break down food (thermogenesis)
As energy used during physical activity

Basal metabolism accounts for about two-thirds of spent energy. Your body generally uses this energy to keep your body temperature steady and keep the muscles of your heart and intestine working. Thermogenesis accounts for about 10% of spent energy.

When a person consumes more calories than the energy they use, the body stores the extra calories in fat cells. Fat cells function as energy reservoirs. They enlarge or shrink depending on how people use energy. If people do not balance energy input and output by eating right and exercising, fat can build up. This can lead to weight gain.

When energy input is equal to energy output, there is no expansion of fat cells (lipocytes) to accommodate excess. It is only when more calories are taken in than used that the extra fat is stored in the lipocytes and the person begins to accumulate fat.

Obesity is determined by measuring body fat, not just body weight. People might be over the weight limit for normal standards, but if they are very muscular with low body fat, they are not obese. Others might be normal or underweight, but still have excessive body fat. The following measurements and factors are used to determine whether or not a person is overweight to a degree that threatens their health:

Body mass index (BMI) (a measure of body fat)
Waist circumference (size around the waist)
Waist-hip ratio
Skin fold measurement (anthropometry)
The presence or absence of other disease risk factors (e.g., smoking, high blood pressure, unhealthy cholesterol levels, diabetes, relatives with heart disease)

A person's disease risk factors plus BMI may be the most important components in determining health risks with weight.

The Body Mass Index (BMI). The current standard measurement for obesity is the body mass index (BMI). In general, a BMI of 25 - 29.9 means you are overweight. Obesity is a BMI of 30 and above. Obesity is then classified into three categories:

Class 1: BMI of 30 - 34.9
Class II: BMI 35 - 39.9
Class III: BMI of 40 and greater

These guidelines are very important for people at risk for diabetes, heart disease, or certain cancers. It is also used to determine treatment approaches such as when surgery may be appropriate. The higher the BMI, the greater the risk for significant health problems.

Calculating Body Mass Index (BMI). One's body mass index (BMI) is calculated by multiplying a person's weight in pounds by 703, dividing by the height in inches, and then dividing that number by the height in inches. The steps are as follows:

Multiply one's weight in pounds by 703
Divide that answer by height in inches
Divide that answer again by height in inches

For example, a woman who weighs 150 pounds and is five feet eight inches (or 68 inches) tall has a BMI of 22.8.

Waist Circumference and Waist-Hip Ratio. The extent of abdominal fat can also be used in assessing risk of disease. Some studies suggest that:

Women whose waistlines are over 31.5 inches and men whose waists measure over 37 inches should watch their weight.
A waist size greater than 35 inches in women and 40 inches in men is associated with a higher risk for heart disease, diabetes, and impaired functioning.

Evidence strongly suggests that more body fat around the abdomen and hips (the apple-shape) is a more consistent predictor of heart problems and health risks than BMI.

The distribution of fat can be evaluated by dividing waist size by hip size. For example, a woman with a 30-inch waist and 40-inch hip circumference would have a ratio of 0.75; one with a 41-inch waist and 39-inch hips would have a ratio of 1.05. The lower the ratio the better. The risk of heart disease rises sharply for women with ratios above 0.8 and for men with ratios above 1.0.

Click the icon to see a depiction of the waist-to-hip ratio.

Anthropometry. Anthropometry is the measurement of skin fold thickness in different areas, particularly around the triceps, shoulder blades, and hips. This measurement is useful in determining how much weight is due to muscle or fat.

Biological and Medical Causes

Obesity results when a person consumes more calories than they need for the energy they use. Several different factors may influence weight gain.

About 90% of people who lose weight through dieting gain every pound back regardless of their weight-loss method.

Some evidence suggests that every person has an inherited weight. This range varies by only about 10% either up or down from some set point. For instance, a man whose "genetically-determined" weight is 200 pounds would tend to swing from 180 - 220 pounds. He would be unlikely to lose or gain more than this.

Genetic factors may play some part in 70 - 80% of obesity cases.

Appetite is determined by processes that occur both in the brain and gastrointestinal tract. Eating patterns are controlled by areas in the hypothalamus and pituitary glands (in the brain). The body produces a number of molecules that increases or decreases appetite. In some cases, the following factors may produce imbalances in this process:

Insulin. Insulin is a hormone that helps change blood sugar (glucose) into energy. During digestion, carbohydrates from our diet break down into different types of sugar molecules (including glucose). Proteins from our diet break down into smaller molecules called amino acids. Immediately after eating, blood glucose levels rise. This triggers the release of insulin, which pours into the bloodstream. Insulin pushes the glucose and amino acids into cells and muscles. Insulin and other hormones determine which nutrients will be burned for energy or stored for future use. The inability to use insulin efficiently (insulin resistance) has been associated with both obesity and diabetes.
Leptin. Leptin is a hormone that is released by fat cells. A number of scientists think this hormone may also be released by cells in the stomach. Leptin appears to play an important role in insulin resistance and fat storage in the body, but its role in obesity is unclear. The most likely scenario is that leptin levels rise as the cells store more fat. This increase in leptin levels decreases appetite. Falling levels of leptin make you feel hungry. In people who have genetically lower levels of leptin, however, the brain may be tricked into thinking that it is always starving because there is no leptin to decrease appetite. This can lead to weight gain.
Resistin. Resistin is a hormone produced by fat cells. It makes the body resistant to insulin activity. Some experts believe it may help explain the role of obesity in diabetes type 2.
Intestinal Chemicals. Ghrelin is a chemical produced in the stomach. It appears to be important in triggering the desire to eat. Peptide YY3–36 (PYY) is a substance secreted in the intestines after a meal. The level of PYY is proportionate to the number of calories a person eats. PYY tells the brain that you feel full. Deficiencies in ghrelin and PYY may contribute to some cases of obesity. Researchers are hoping that blocking ghrelin or infusing PYY may be possible treatments for obesity.
Other Chemicals. Many brain chemicals are being studied for their role in appetite stimulation and weight gain. Among them are neuropeptide Y, melanocortins, agouti-related protein, and melanocyte stimulating hormone. Pain-relieving chemicals called endorphins may be critical in reducing appetite and regulating energy use. Cholecystokinin, a hormone released in the upper intestine that stimulates digestive juices, may work to control meal size.

Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar.

Genetics may directly contribute to severe obesity in people with family histories of the problem. Genetic factors such as slow metabolisms may also make people more likely to be overweight. At least seven genetic mutations have been associated with specific and uncommon cases of severe obesity. Some are outlined below.

HOB1 (human obesity 1) is a gene that is linked to a high BMI in women.
Leptin gene variants have been linked to leptin deficiencies and obesity.
Melanocortin-4 receptor is a gene that helps turn off the urge to eat. It may not work properly in those with a family history of obesity.
Researchers have also identified a mutation in a gene for a protein called proopiomelanocortin, which results in a syndrome of obesity, red hair, and deficiencies in stress hormones.
A protein called agouti-related protein increases hunger. About 5% of severely obese people have mutations that over-respond to agouti-related protein.

Genetics also determine the number of fat cells a person has. Some people are simply born with more. It should be noted that even when genetic factors are present, a person can still control their diet.

The Thrifty Gene. Some experts think the existence of a so-called "thrifty" gene regulates changes in hormone levels, to accommodate seasonal changes. Theoretically, it works in the following manner:

In certain populations, hormones are released during seasons when food supplies have traditionally been low. This leads to insulin resistance and increased fat storage.
The process is reversed in seasons when food is readily available.
Because modern industrialization has made high carbohydrate and fatty foods available all year long, the gene no longer serves a useful function. Fat, originally stored for famine situations, is not used.

This theory could explain why the previously nomadic Native American tribes who now have Western dietary habits have such high rates of Type 2 diabetes and obesity. In the past, the traditional low-fat, high-fiber foods tribe members ate may have protected them from obesity and type 2 diabetes. Today, these tribes' diet consists of more Western foods, which are higher in fat. Furthermore, these foods are readily available year-round, and many members of the tribe are sedentary. The result is a very high incidence of Type 2 diabetes and obesity. Although genetic abnormalities may make it harder or easier to lose weight, the occurrence of obesity has dramatically increased over the past two decades, and genes cannot have changed within that short amount of time. Our ability to use the food that we eat evolved so that our body could conserve energy and store fat during times of famine. Most cases of obesity now occur in people with normal body function who live in industrialized nations, where there is more than enough food.

A number of medical conditions may contribute to being overweight, but rarely are they a primary cause of obesity.

Hypothyroidism is sometimes associated with weight gain. But, patients with an underactive thyroid generally show only a moderate weight increase of five to 10 pounds.
Very rare genetic disorders, including Froehlich's syndrome in boys, Laurence-Moon-Biedl, and the Prader-Willi syndromes, cause obesity.
Abnormalities or injury to the hypothalamus gland can cause hypothalamic obesity.
Cushing's disease is a rare condition caused by high levels of steroid hormones. It results in obesity, a moon-shaped face, and muscle wasting.
Obesity is also linked to polycystic ovarian syndrome, a hormonal disorder in women.

Click the icon to see an image of polycystic ovaries.

Some prescription medications contribute to weight gain, usually by increasing appetite. Such drugs include the following:

Corticosteroids
Female hormone treatments, including some oral birth control pills (effect is usually temporary), and certain progestins (such as Megestrol) used to treat cancer
Antidepressants and anti-psychotic drugs, including lithium and valproate
Insulin and insulin-stimulating drugs used to treat diabetes often lead to weight gain, a particularly unfortunate conflict of interest for obese individuals with type 2 diabetes

You should not stop taking any medications without your doctor's knowledge.

Cultural and Emotional Causes

Enough food is produced in the US to supply 3,800 calories every day to each man, woman, and child in the country, far more than the average person needs to sustain life. In a 2002 study, participants carefully recorded everything they ate and drank, and all activities and psychological factors surrounding the eating events. The people who gained weight ate more and their portions were larger than those who did not. This may be an obvious conclusion, but the public press often plays up biologic factors involved with obesity and overlooks the simple notion that Americans eat too much and exercise too little.

Obesity is dramatically increasing not only in American children and adults, but also in every country that has adopted similar cultural habits. The World Health Organization now considers obesity to be a global epidemic and a public health problem as more nations become "Westernized." In spite of the proven health risks of obesity, the government, insurance companies, and the medical profession do not spend nearly enough money to balance the commercial and cultural pressures that are producing millions of overweight people.

In 2007, the Robert Wood Johnson Foundation sounded a positive note with the announcement of a $500 million initiative, aimed at “reversing the childhood obesity epidemic by 2015.” The money will be used for research, education, and activities that promote healthy eating among America’s children.

Perhaps the primary reason for the dramatic rise in obesity is the sedentary (inactive) lives led by most Americans, including children and young people. In a 2003 study comparing modern life to the past, researchers found that labor saving devices had reduced a person's energy use by 111 calories a day -- adding up to an extra 11 pounds a year. Half the difference in energy use was due to less walking. At the same time, according to the U.S. Centers for Disease Control and Prevention, between 1970 and 2000 the typical American man increased his caloric intake by 168 calories a day (good for 17 pounds a year) while the average woman added 335 calories a day.

Regular television watching has been singled as the most hazardous pastime. According to a major 2003 study, for every 2 hours a person spends in front of the TV each day, the risk for obesity increases by 23% and for type 2 diabetes by 14%. In the study, TV watching produced the lowest metabolic rates compared to sewing, playing board games, reading, writing, and driving a car. Just the act of watching TV encourages unhealthy snacks and eating patterns. In addition, the advertising on the television complicates the problem by promoting fast foods, cereal, and snack products that are high in salt, fats, and carbohydrates. Even worse, much of these advertisements are directed at children -- the most vulnerable group.

People are not only eating more food than they did 20 years ago, they are also replacing home cooking with packaged foods, fast food, and dining out. This behavior, according to studies, places people at higher risk for obesity. Fast foods may be more harmful than restaurant cooking. These foods tend to be served in larger portions. They generally contain more calories and unhealthy fats, and less nutritious ingredients, than homemade or restaurant meals. Snack foods and sweet beverages, including juice and soft drinks, are specific problems that add to the increasing rates of obesity. Frequent small, healthy meals (instead of two or three large daily meals) have been associated with lower weights.

People react differently to stress. Some overeat and gain weight and others stop eating and lose weight. People who gain weight in response to stress often overeat foods high in sugar, fats, and salt. A 2003 study on rats suggested that stress hormones increase the pleasure of eating such so-called "comfort foods." Furthermore, the study supported previous research showing that stress-related eating was connected to the unhealthy accumulation of abdominal fat.

Risk Factors

Where you live plays a role in your risk for obesity. Simply living in the United States makes a person more susceptible to obesity. The prevalence of obesity in America has risen dramatically over the past few years and continues to increase.

According to the latest figures available, 32.2% of American adults (aged 20 and older) are obese (BMI over 30) -- up from about 23% in the early 1990s.
The number of Americans aged 20 - 74 who were overweight also increased -- from about 44.8% in 1960 to 65.2% in 2002.
The rate of extreme obesity (BMI > 40) increased from 0.8% in 1960 to 4.9% in 2002.
Obesity has increased in every state, in both men and women, across all age groups, and in every ethnic group, although some groups may face slightly higher risks than others.

Fat tends to settle in certain regions, depending on gender. Women gain fat predominantly in the stomach, hips and thighs, while men tend to gain fat in the belly and waist.

Risk by Age. People of any age are at risk for obesity. More children and adolescents are overweight in America than ever before. Gaining some weight is inevitable with age and adding about 10 pounds to a normal base weight over time is not harmful. The current weight gain in American adults over 50, however, is significant. By age 55, the average American has added nearly 40 pounds of fat during the course of adulthood. This condition is made worse by the fact that muscle and bone mass decrease with age.

Risk by Gender. In men, BMI tends to increase until age 50 and then it levels off. In women, weight tends to increase until age 70 before it plateaus. A 2000 study found that there are three high-risk periods for weight gain in women.

The first is at the onset of menstruation, particularly if it is early. In fact, a study released in March 2007 found that obesity in young girls results in early puberty -- as early as age 9. This, in turn, increases the risk for more weight gain as girls enter puberty.
The second is after pregnancy, with higher risk for women who are already overweight.
Finally, many women gain weight after menopause.

These findings are significant because they may allow women to target high-risk times, and consequently prevent unnecessary weight gain.

Risk by Economic Group. Obesity is more prevalent in lower economic groups. One 2002 study reported that women who reported that they did not have enough food were more likely to be overweight than those who said they had sufficient food. Researchers discovered that the low-income women tended to have fewer fruits and vegetables but were actually taking in more calories a day than higher-income women. However, obesity is increasing in young adults with college education as well as in other groups.

Ethnic Groups. Among ethnic groups in general, African-American women are more overweight than Caucasian women but African-American men are less obese than Caucasian men. (Currently, 80% of African-American women are overweight.) Hispanic men and women tend to weigh more than Caucasians.

US Regions. Regionally, the prevalence of obesity is lowest in the Western states and highest in the South.

A number of dietary habits put people at risk for becoming overweight:

Night-Eating Syndrome. Night-eating syndrome is defined as having no appetite in the morning, insomnia, and consuming more than half of daily food intake after 6:00 PM. It is associated with obesity and is difficult to treat. Stress reduction and relaxation techniques may be helpful.
Binge Eating and Eating Disorders. About 30% of people who are obese are binge eaters who typically consume 5,000 - 15,000 calories in one sitting. To be diagnosed as a binge eater, a person has to binge at least twice a week for 6 months. Many experts believe that binge-eating carbohydrates causes an increase in a natural opiate leading to dependence on carbohydrates. Therefore, this condition should be treated as an addiction. Other eating disorders are bulimia and anorexia. Bulimia is binge eating followed by purging in order to lose weight. Anorexia nervosa is a mental illness in which the person refuses to maintain weight at the normal level. The patient with anorexia has a terrible fear of getting fat, and an abnormal perception of what his or her body looks like. Both conditions pose risks for serious medical problems, and anorexia nervosa can be life-threatening. A combined approach using behavioral therapy and antidepressants may help these individuals. [See In-Depth Report #49: Eating disorders.]
Restrained Eating. Some people, mostly middle-aged women who have normal weight, have a pattern referred to as restrained eating. This pattern requires a high level of conscious control and usually maintains a lower weight. However, such restraint places these individuals at higher risk for loss of control and subsequent overeating.
Infrequent Eating. There is some evidence to suggest that eating small frequent meals uses more calories than infrequent large meals. It should be strongly noted, however, that packaged snack foods add calories and some do not produce a feeling of being full, so that people simply eat more than they should.

Anyone with Sedentary Lifestyles. Office workers, drivers, and anyone whose lifestyle involves sitting for long periods are at higher risk for obesity.

Ex-Smokers. The trend toward weight increase has followed the trend for quitting smoking. Nicotine increases the metabolic rate, and quitting, even without eating more, can cause weight gain, which may be considerable. It is important to note that weight control is not a valid reason to smoke. People in previous centuries did not smoke cigarettes, nor were they usually obese.

Shift-Workers. A recent study found that individuals who work late shifts (between 4 p.m. and 8 a.m.) tend to eat more and take longer naps than day workers and are more likely to gain excess weight.

People with Disabilities. Obesity rates are higher than average in people with physical or mental disabilities. Those with disabilities in the lower part of the body, such as the legs, are at highest risk.

Overweight in children and adolescents is rising at an alarming rate. In 2004, 19% of young children aged 6 - 11 were overweight, an increase of 8% from 1994. Among children aged 25, 13.9% were overweight in 2004, up from 7.2% 10 years earlier.

Definition of Overweight in Children

Children and adolescents are considered to be overweight if their BMI is above 95% of the children in their age and sex categories. Ethnic variations, timing of growth spurts, and higher normal fat levels around puberty can affect these measurements.

Causes and Risk Factors for Overweight in Children

Lifestyle Factors. Without educational or parental guidance, children are extremely vulnerable to the intense cultural pressures that are largely responsible for the obesity epidemic. The following are some specific problems created by the culture:

Excessive television watching plays a critical role in obesity in children. Not only is it a sedentary activity, but television also offers innumerable temptations with its advertisements for fast foods, sugar cereals, and unhealthy snacks. In one study obesity rates were lowest in children who watched television 1 hour or less a day and highest in those who watched 4 or more hours.
Sugar, particularly from soda, other sweetened beverages, and fruit juice, may be the major contributor to childhood obesity. One study reported that drinking soda regularly increases a child's risk for obesity by 60%. The average American adolescent consumes 15 - 20 extra teaspoons of sugar a day just from soda and sugary drinks. (Juice, while better than soda, is still filled with sugar.)
Less physical exercise and greater sedentary activities play another significant role in obesity in children. A high level of physical activity -- not just using up energy -- is important for weight control in young people. Unfortunately, according to one study, the annual distance walked by children has fallen by nearly 30% since 1972, partially because more parents are driving their children to school out of fear of abduction, molestation, and traffic accidents. Schools are also offering fewer opportunities for daily physical activities than in the past.

Neither the media nor the educational system has strong well-financed programs that encourage healthy alternatives, including exercise and healthy foods.

Family History. Parental obesity more than doubles the risk that a young child, whether thin or overweight, will become obese as an adult. In older children and teenagers, obesity in parents starts to count less as a predictor for body weight than their own weight. The risk for obesity may be due to environmental or genetic factors, or both.

Ethnic and Socioeconomic Factors. As in adult populations, children from lower socioeconomic groups and minority populations are at higher risk for obesity. For example, among young Mexican Americans and African-Americans, there has been an increase in overweight prevalence of about 13% to over 23%.

Factors Surrounding Birth. The following factors surrounding birth are associated with a child's weight:

Low birth weight is a risk factor for later obesity and diabetes. One theory is that humans have a "thrifty gene" that produces metabolic changes in infants with low birth weight. Such changes affect insulin and fat accumulation, in order to produce a "catch-up" weight in these young children as quickly as possible. This rapid weight gain in infancy increases the risk for obesity in children and young adults.
In a study of African-American children, having an overweight pregnant mother increased the risk for later weight gain, but low birth weight did not.

Although some small studies have reported protection against obesity from breastfeeding, evidence is weak. In a 2003 study, for example, children who were breast fed for 3 - 5 months had a lower risk for obesity, but prolonged breastfeeding had no effect. Nevertheless, given the healthful effects of breast feeding and the possibility that it may have even a slight impact on childhood obesity, it is highly recommended.

Biological Effect of Childhood Overweight on Adult Weight

Achieving a healthy weight becomes more difficult as children get older. The odds of obesity persisting into adulthood ranges from 20% in 4 year olds to 80% in teenagers. One reason for the persistence is biological. The fat cells change in number or mass depending on a person's age:

Fat cells themselves multiply during two growth periods: early childhood and adolescence. Overeating during those times increases the number of fat cells. Some people are also just born with more fat cells.
After adolescence, fat cells tend to increase in mass rather than quantity, so that adults who overeat and gain weight tend to have larger fat cells, not more of them. This growth in mass may be responsible for the greater risk of persistent obesity among teenagers compared to small children who are overweight. Losing weight after adolescence reduces the size of the fat cells but not their number, so weight loss becomes much more difficult.

Health Consequences of Childhood Overweight

Children and adolescents who are overweight have poorer health than other children. Studies are reporting unhealthy cholesterol levels and high blood pressure in overweight children and adolescents. Of great concern is the dramatic increase in type 2 diabetes in young people, which is largely due to the increase in overweight children. Overweight in children is also linked to asthma, gallbladder problems, sleep apnea, and liver abnormalities. Overweight girls are more likely to enter puberty early, according to a new study, and subsequently be at higher risk for breast cancer.

It is not clear yet how many of these childhood problems persist in people who achieve normal weight as adults. Staying overweight into adulthood certainly carries health risks.

Managing Overweight Children

Childhood obesity is best treated by a non-drug, multidisciplinary approach including diet, behavior modification, and exercise. Evidence suggests that reducing calories by only 200 - 260 per day would prevent weight gain in most overweight children. Here some tips for children who are overweight:

Limit (or avoid, if possible) take out, fast foods, high-sugar snacks, commercial packaged snacks, soda, and sugar-sweetened beverages (including too much juice).
Let children snack but make sure the snacks are healthy. Eating small frequent healthy meals (instead of two or three large ones) has been associated with being thinner and having a better cholesterol profile.
Let children choose their own food portions. One study indicated that children naturally ate 25% less when they chose their own portion size. When they were given larger portions their bite sizes were larger and they ate more.
Do not criticize a child for being overweight. It does not help and such attitudes could put children at risk for eating disorders, which are equal or even greater dangers to their health.
Limit television, video games, and computer use to a few hours a week. This can contribute significantly to weight control, regardless of diet and physical activity.
For young children, try the traffic-light diet. Food is designated with stoplight colors depending on their high caloric content: Green for go (low calories); yellow for "eat with caution" (medium calories); red for "stop" (high calories).
Try a low glycemic index diet. This may be as beneficial, and possibly more, than a standard reduced-fat diet in overweight children. Such a diet focuses on certain carbohydrates (for example, dried beans and soy), which raise blood sugar more slowly than other types of carbohydrates. This diet is sometimes used in diabetes, and as a dietary approach in overweight adults. [See In-Depth Report #42: Diabetes diet.]

Click the icon to see an image about TV watching.

Click the icon to see an image of childhood overweight.

Complications

General Adverse Effects of Obesity. Obesity, defined as a BMI of 30 or over, accounts for nearly 300,000 deaths in the U.S. each year. It is associated with more chronic health problems than smoking, heavy drinking, or poverty. Furthermore, given the current increase in obesity, it will surpass smoking as the most important preventable cause of death in America.

Some studies indicate the following health risks by body mass:

The lowest risks for heart disease, diabetes, and some cancers are in people with BMI values of 21 - 25.
The risks increase slightly when BMI values are between 25 - 27.
The risks are significant in BMIs between 27 - 30.
The same risks are dramatic at BMIs over 30.

Anyone with chronic health problems such as heart or lung disease, stroke, or arthritis, should be concerned about extra weight. This same concern also applies to people with known risk factors for such conditions.

Metabolic Changes. As fat stores increase, the fat cells themselves enlarge and produce chemicals that increase the risk for several diseases. Such diseases may include diabetes, high blood pressure, gallbladder disease, and some cancers.
Increased Mass. The increased body weight itself causes problems that result in injury and diseases, including osteoarthritis and sleep apnea.
Harmful Fat Cell Types. Weight concentrated around the abdomen and in the upper part of the body (the apple shape) poses a higher health risk than fat that settles around the hips and flank (the pear shape). Fat cells in the upper part of the body appear to have different qualities from those found in the lower parts. In fact, studies suggest a higher risk for diabetes in people with the "apple shape" and lower risk in those who are "pear shaped."

Weight gain in the area of and above the waist (apple type) is more dangerous than weight gained around the hips and flank area (pear type). Fat cells in the upper body have different qualities than those found in hips and thighs.

General Adverse Effects of Being Overweight (Not Obese). It is still not clear if being overweight (a BMI of 25 - 29.9) hurts healthy people with no risk factors for serious illnesses.

According to one 2001 study, just being overweight increased the risk for developing diabetes, gallstones, hypertension, heart disease, stroke, and colon cancer. The risk rose according to how much the individuals were overweight. In any case, adults who are overweight in middle age face a poor quality of life as they age, with the quality declining the greater the weight. One study suggested, however, that being over 65 and overweight (but not obese) is not associated with higher mortality rates.

Some experts argue, in fact, that in anyone who is not severely obese, it is the unhealthy diet and sedentary lifestyle that causes harm -- not weight per se. In support of this argument, a British study found that overweight fit individuals had half the death rate of unfit trim individuals.

Being somewhat overweight may also have some benefits under specific circumstances:

In older women, some excess fat may produce extra estrogen that helps slow down bone loss, and insulates bones from fall-related injuries. It should be strongly noted, however, that when older overweight women lose weight they report less pain, improved vitality, and improved physical function. The same positive effect of overweight does not appear to hold in older men.
Conditioned athletes may have high BMIs because of very dense muscle tissue. Being fit in general may protect many overweight people.
Some evidence suggests that Caucasians have the lowest mortality with BMIs of 24.3 - 24.7 while African-Americans are better off in the range of 26.8 - 27.1.
Children may have higher normal fat levels during growth spurts and around puberty.

Individuals with a BMI of at least 30 have a 10 - 50% increased rate of death from all causes, compared with individuals with a BMI of 20 - 25. Mortality rates from many causes are higher in obese people, but heart disease is the primary cause of death. People who are obese have almost three times the risk for heart disease as people with normal weights. Being physically unfit adds to the risk.

Weight concentrated around the abdomen and in the upper part of the body (apple shape) is particularly associated with insulin resistance and diabetes, heart disease, high blood pressure, stroke, and unhealthy cholesterol levels. Fat that settles in a pear shape around the hips and lower body appears to have a lower association with these conditions.

Obesity poses many dangers to the heart and circulatory system.

Damage in the Blood Vessels. As people age, changes in body fat (particularly increasing abdominal fat) seem to cause stiffness in the aorta, the major blood vessel leading from the heart. Studies are finding higher levels of a factor called C-reactive protein (CRP) in people with obesity and abdominal fat. CRP is now considered to be a marker for inflammation and damage in the arteries. (Losing weight reduces CRP levels.)

High Blood Pressure. High blood pressure is the health problem most commonly associated with obesity, and the greater the weight, the greater the risk. High blood pressure carries serious risks of stroke, heart attack, and heart failure. The link between obesity and high blood pressure is complex, and may be a combination of genetic, population, and biological factors. Many studies have reported that modest weight loss is beneficial for reducing existing high blood pressure. [See In-Depth Report #14: High blood pressure.]

Heart Failure. An important 2002 study reported that obesity might account for 11% of heart failure cases in men and 14% in women. This link existed independently of other risk factors, such as high blood pressure, sleep apnea, and diabetes, which are also associated with obesity. The biologic mechanisms involved in obesity that lead specifically to heart failure are not clear. [See In-Depth Report #13: Heart failure.]

Unhealthy Cholesterol Levels and Lipid Levels. The effect of obesity on cholesterol levels is complex. Although obesity does not appear to be strongly associated with overall cholesterol levels, among obese individuals triglyceride levels (the major form of fat storage in the body) are usually high, while HDL levels (the "good" cholesterol) tend to be low. Both conditions are risk factors for heart disease. [See In-Depth Report #23: Cholesterol.]

Click the icon to see an image of coronary artery disease.

Stroke. Obesity is also associated with a higher risk for stroke. [See In-Depth Report #45: Stroke.]

Type 2 Diabetes and Insulin Resistance. Most people with type 2 diabetes are obese and, in fact, studies strongly suggest that weight loss may be the key in controlling the current epidemic of type 2 diabetes. The common factor appears to be insulin resistance. Insulin is a critical hormone in the use of sugar. In type 2 diabetes, different factors cause the body to become insulin resistant -- that is, the body can no longer respond properly to insulin. This has the effect of increasing sugar levels in the blood, the hallmark of diabetes. Both obesity and insulin resistance, at different phases, are marked by high levels of certain chemicals. It is not known yet if the higher levels are simply a product of obesity, or play some role in causing diabetes.

Insulin resistance is also associated with high blood pressure and abnormalities in blood clotting. Some research indicates that obesity, in fact, is the one common element linking insulin resistance, diabetes type 2, and high blood pressure. [See In-Depth Report #60: Diabetes - type 2.]

Metabolic Syndrome. 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. A combination of weight loss and exercise is an effective treatment for this syndrome.

The American Cancer Society released new cancer prevention guidelines in September 2006. The guidelines stress the importance of keeping a healthy weight throughout life. The Society indicates that healthy weight is even more important than eating specific healthy foods, when it comes to cancer prevention.

Obesity has been associated with a higher risk for cancer in general and specific cancers in particular. Studies have also suggested that restricting calories reduces the risk for cancer. Some experts believe that effective weight control for children and adults could reduce cancer rates by 30 - 40%. One way obesity may increase the risk for cancer is its association with high levels of hormones called growth factors, which can trigger rapid cell production leading to cancer.

Uterine Cancers. The risk of uterine cancer in obese women appears to be two or three times higher than in thinner women.

Prostate Cancer. New studies from 2005 and 2006 report that obesity is associated with an increase in prostate cancer mortality, although not with the risk for less aggressive forms of prostate cancer.

Click the icon to see an image of prostate cancer.

Breast Cancer. Studies are mixed on the association between obesity and breast cancer. A number of studies have linked obesity to breast cancer in postmenopausal women, particularly in women who begin to gain weight after age 18.

Click the icon to see an illustrated series detailing a breast cancer surgery (mastectomy).

Gallbladder Cancer. Obese women are at higher risk for gallbladder cancer.

Gastrointestinal Cancers. A number of cancers in the gastrointestinal tract have been associated with obesity:

Cancer of the esophagus may be due to a higher incidence of gastroesophageal reflux disorder (heartburn) in people who are overweight.
Colon cancer has been linked to increased body mass in both men and women.
Pancreatic cancer and obesity have been weakly linked, with one study reporting a lower risk in overweight people who are physically active.

Click the icon to see an illustrated series detailing a colon cancer surgery.

Muscles and Bones

Obesity places stress on bones and muscles. Studies report that the incidence of osteoarthritis is significantly increased in people who are overweight. People who are obese are also at higher risk for carpal tunnel syndrome and other problems involving nerves in their wrists and hands. It should be noted that some weight may be protective against osteoporosis (loss of bone thickness).

Obesity increases the risk for the following mouth and eye disorders:

Gum disease
Cataracts
Maculopathy, an eye disease related to aging

Infertility. Abnormal amounts of body fat, either 10 - 15% too high or too low, can contribute to infertility in women. Obesity is specially related to certain infertility problems, such as uterine fibroids or menstrual irregularities. In men, obesity can contribute to reduced testosterone levels.

Effect on Pregnancy. Obesity has many dangerous effects on pregnancy. These include high blood pressure, gestational diabetes (diabetes, usually temporary, that occurs during pregnancy), urinary tract infections, blood clots, prolonged labor, and higher fetal death rate in late stages of pregnancy. Obesity is also associated with increased rates of cesarean delivery. Infants of women who are obese are also at higher risk for neural tube birth defects, which affect the brain or spine. Folic acid supplements, ordinarily effective in preventing these conditions, may not be as protective in overweight women.

Obesity is thought to be a risk factor for symptoms of adult-onset asthma. Though there is evidence that obesity causes wheezing and shortness of breath, it does not appear to be strongly associated with the disease mechanisms in the lungs that cause true asthma.

Obesity also puts people at risk for hypoxia, a condition in which there is not enough oxygen to meet the body's needs. Obese people need to work harder to breathe. They tend to have breathing muscles and lungs that do not work as well as those in thinner people.

The Pickwickian syndrome, named for an overweight character in a Dickens novel, occurs in severe obesity when lack of oxygen produces intense and chronic sleepiness and, eventually, heart failure.

Nonalcoholic Fatty Liver Disease. People with obesity, particularly if they also have type 2 diabetes, are at higher risk for a condition called nonalcoholic fatty liver disease, also called nonalcoholic steatohepatitis (NASH). This condition causes liver damage that is similar to liver injury seen in alcoholism. In some cases, it can be very serious and require liver transplantation. It occurs in about half of people with diabetes, and 20 - 50% of obese people, depending on how severe their obesity is. NASH can also occur in overweight children.

Gallstones. The incidence of gallstones is significantly higher in obese women and men. The risk for stone formation is also high if a person loses weight too quickly. In people on ultra-low calorie diets, gallstones may be prevented by taking ursodeoxycholic acid (Actigall).

Click the icon to see an image of gallstones.

People who are obese and nap tend to fall asleep faster and sleep longer during the day. At night, however, it takes them longer to fall asleep, and they sleep less than people with normal weights. In an apparent vicious circle, studies have suggested that obesity not only interferes with sleep but that sleep problems may actually contribute to obesity.

Sleep Apnea. Obesity, particularly the apple shape, is strongly associated with sleep apnea, which occurs when the upper throat relaxes and collapses from time to time during sleep. This collapse temporarily blocks the passage of air. Sleep apnea is increasingly being viewed as a potentially serious health problem, which may lead to complications such as heart disease and stroke. Some studies suggest that among overweight people, those who have sleep apnea have a greater risk of heart disease than those without it. In one study, the more obese a person with sleep apnea was, the higher the pressure on the airway, and therefore the greater the obstruction of the airway. Obstructive sleep apnea may also add to obesity, however, as sleepy people tend to be sedentary. Some studies indicate that treating sleep apnea may help people lose abdominal fat.

Narcolepsy. A small European study found a link between narcolepsy (a sleep disorder characterized by excessive daytime sleepiness with frequent daily sleep attacks) and high BMI.

Depression. A number of studies have reported an association between depression and obesity, particularly in obese women. There may be a number of factors to explain the link. In some cases of atypical depression, people overeat and may gain weight. Overweight people may also become depressed because of social problems and a poor self-image. In these cases, depression usually disappears when people lose weight.

There is evidence, however, that obesity itself may impair levels of tryptophan -- a chemical needed to make serotonin, a brain chemical associated with mental well-being. In one study, even after people lost weight, tryptophan levels were lower than normal.

There does not appear to be any association between depression and obesity in men.

Social Problems. One long-term study reported that overweight young women completed fewer years of school, were 20% less likely to be married, and had 10% higher rates of household poverty than their thinner peer. Obese young men were also less likely to be married, and their incomes were lower than their thinner peers. Nevertheless, studies consistently show that overweight males (both boys and men) are not as severely emotionally affected as females of any age. Women and girls tend to blame themselves for being heavy, while males tend to blame being overweight on outside factors.

Weight Loss and Maintenance

Even modest weight loss can reduce the risk factors for heart disease and diabetes. The simplest (but still difficult) approach to weight loss is reducing calories and exercising at least 150 minutes a week. Behavioral and mental changes in eating habits, physical activity, and attitudes about food and weight are also essential to weight management. For people who are very overweight and cannot lose weight through lifestyle changes, a number of effective weight-loss medications are available. For those with severe obesity, surgical procedures are proving to be very beneficial.

Some Tips for Losing Weight. The following are some general suggestions for dieters:

Start with realistic goals. Diet failure is extremely common, and the odds of significant weight loss are low, particularly in people with the highest weights. People who are able to restrict calories, engage in an exercise program, and get help in making behavioral changes can expect to lose between 5 - 10% of their current body weight. That is generally all that is needed to achieve meaningful health changes. Certainly, the distorted image of a super-thin female shape should not be anyone's goal.
Maintain a regular exercise program, assuming you have no health problems that will stop you. Choose a program that you enjoy. Check with your doctor about any health considerations. [See In-Depth Report #29: Exercise.]
Do not use hunger pangs as cues to eat. A stomach that has been stretched by large meals will continue to signal hunger for large amounts of food until its size reduces over time with smaller meals.
Be honest about how much you eat and start by recording all calories in writing. Studies suggest that when many people report their own calories intake they significantly underestimate their consumption of high-calorie and over-estimate the low-calorie foods. People who do not carefully note everything they eat tend to take in too many calories when they believe they are dieting.
Observe weekend eating. People tend to eat more on the weekends. If it is difficult to monitor all meals during the week, it be may be useful to at least track eating habits during the weekends.
Once the pounds are lost, do your best to keep the healthier weight. Make daily, even hourly, conscious decisions about eating and exercising activities. Such thinking, in many cases, can become automatic and not painful.
Don't give up, even after repeated weight loss failures. Most studies indicate that yo-yo dieting or weight cycling have no bad psychological or physical effects. Repeated dieting also does not harm the body's ability to burn calories efficiently.
Weight loss, in any case, should not be the only or even the primary goal for people concerned about their health. The success of weight loss efforts should be evaluated according to improvements in disease risk factors or symptoms, and by the adoption of healthy lifestyle habits, not just by the number of pounds lost.


Lifestyle	Reduce rate of eating. Keep food records. Eliminate environmental triggers to eating. Identify high-risk situations for overeating. Separate eating from other activities.
Exercise	Face up to emotional barriers to exercise. Understand the link between exercise and weight control. Establish reasonable exercise goals. Develop a plan for regular activity. Add increased activity into daily lifestyle.
Attitudes	Develop reasonable weight-loss goals. Avoid "all or none" thinking. Focus attention away from the scale and toward behavior. Uncouple weight from self-esteem. If you "fall off the wagon," take steps to ensure the situation does not repeat (recover from lapses with constructive action).
Relationships	Understand the key role of social support to health. Identify supportive others. Match personal style to support-seeking activities. Be specific in making support requests. Be assertive but reinforcing in drawing help from others.
Nutrition	Resist the temptation of popular fad diets. Eat with your health in mind; do not concentrate on what should be "off-limits." Eat with moderation in mind. Maximize fiber. Develop a tailored plan.
From Brownell KD. The LEARN Program for Weight Control. 7th ed. Dallas, Tex: American Health Publishing Company; 1998.

Weight Management

There are many approaches to dieting and many claims for great success with various fad diets. To date, although many diets achieve effective immediate weight loss, none has emerged as an effective tool for maintaining healthy weight. The only definite recommendation that can be made about any diet plan is to be sure it includes an exercise program, assuming there are no health problems to forbid it.

The original food pyramid, with four food groups, has been replaced with an updated food guide called "My Pyramid." This illustrates the relative proportions of different foods that make up a nutritious, well-balanced diet and includes exercise.

Calorie restriction has been the cornerstone of obesity treatment. The standard dietary recommendations for losing weight are the following:

As a rough rule of thumb, one pound of fat equals about 3,500 calories. A person could lose a pound a week by reducing daily caloric intake by about 500 calories a day. Naturally, the more severe the daily calorie restriction, the faster the weight loss. Very-low calorie diets have also been associated with better success, but extreme diets can have some serious health consequences.
To determine your daily calories requirements, multiply the number of pounds of ideal weight by 12 - 15 calories. The number of calories per pound depends on gender, age, and activity levels. For instance, a 50-year old woman who wants to maintain a weight of 135 pounds and is mildly active might require only 12 calories per pound (1,620 calories a day). A 25-year old female athlete who wants to maintain the same weight might require 25 calories per pound 2,025 (calories a day).
Fat intake should be no more than 30% of total calories. Most fats should be in the form of monounsaturated fats (such as olive oil). Saturated fats (found in animal products) should be avoided.

Extreme diets of less than 1,100 calories carry health risks. They are also often followed by bingeing or overeating, and a return to the obese state. Such diets often do not have enough vitamins and minerals, which must then be taken as supplements. Most of the initial weight loss is in fluids. Later, fat is lost, but so is muscle, which can account for more than 30% of the weight loss. No one should be on severe diets for longer than 16 weeks, or fast for more than 2 or 3 days. Severe dieting has unpleasant side effects including fatigue, intolerance to cold, hair loss, gallstone formation, and menstrual irregularities. There have been rare reports of death from heart arrhythmias when liquid formulas did not have sufficient nutrients. Pregnant women who excessively diet during the first trimester put their unborn children at risk for birth defects. Of note, those whose diets include a high intake of fluids and much reduced protein and sodium are at risk for hyponatremia, which can cause fatigue, confusion, dizziness, and in extreme cases, coma and death.

This dietary approach requires counting only grams of fat with the goal of achieving 30% or fewer calories from fat. One gram of fat contains nine calories, while one gram of carbohydrates or protein has only four calories. Fat in your diet converts more readily to fat in the body, compared with carbohydrates or proteins. Simply switching to low-fat or skimmed dairy products may be enough for some people.

There are possible drawbacks to this approach:

Some people who reduce their fat intake may not get enough basic nutrients, including vitamins A and E, folic acid, calcium, iron, and zinc. People on low-fat diets should eat a wide variety of foods and take a multivitamin supplement, if appropriate. Calcium deficiencies may be particularly harmful in women at risk for osteoporosis.
Many people start eating foods with too many carbohydrates, believing that they are not adding calories. No one should use a low-fat diet as an excuse for eating too many carbohydrates, particularly starchy foods and sugar. A high-calorie diet from any source will add pounds.
A small study in Norway found that a diet low in fat and high in carbohydrates ("carbs") increases symptoms of psychological distress, such as depression and anger. The study compared three different diets that had varying amounts of fat and carbohydrates in each. The diets contained the same amount of calories, but differed in the percentage and type of fat. People on the low-fat, high-carbohydrate diet reported more anger and depression compared with the other two diets.
Replacing fatty foods, such as cakes, cookies, and chips, with their commercial "low-fat" counterparts does not constitute a low-fat diet. These foods generally contain more sugar and hence calories, not to mention other ingredients, which have virtually no nutritional value. In fact, a 2002 study suggested that increasing sugar may, over time, reduce levels of HDL ("good") cholesterol.
Very low-fat diets may increase the risk for stroke from hemorrhage in the brain.

Some fat in a diet is essential. It should come from plant oils and fish, however, and not from animal products or hardened oils, such as margarine. Trans-fatty acids, found in hardened oils, are actually more of a risk factor for obesity than saturated fats from animal products, although both should be avoided.

Fiber and Complex Carbohydrates. In all cases, complex carbohydrates found in whole grains and vegetables are preferred over those found in starch-heavy foods, such as pastas, white-flour products, and potatoes. Fiber is an important component of many complex carbohydrates. Fiber is almost always found only in plants, particularly vegetables, fruits, whole grains, nuts, and legumes (beans and peas). One exception is chitosan, a dietary fiber made from shellfish skeletons. Fiber cannot be digested but passes through the intestines, drawing water with it, and is eliminated as part of feces content. The following are specific advantages from high-fiber diets (up to 55 grams a day):

Insoluble fiber (found in wheat bran, whole grains, seeds, nuts, and fruit and vegetable peels) has been associated with weight loss. Studies also suggest that diets rich in fiber from whole grains reduce the risk for type 2 diabetes.
Soluble fiber (found in dried beans, oat bran, barley, apples, citrus fruits, and potatoes) has important benefits for the heart, particularly for achieving healthy cholesterol levels and possibly benefiting blood pressure as well. Simply adding breakfast cereal to a diet appears to reduce cholesterol levels. People who increase their levels of soluble fiber should also increase water and fluid intake.

High-protein, low carbohydrate diets, such as the Atkins and South Beach diets, have been touted as effective ways to produce short-term weight loss. Because of their emphasis on fats and proteins, many experts are concerned about long-term health problems. A report in the March 2006 Lancet linked the Atkins diet to life-threatening complications that caused the death of one woman. The 40-year-old woman had a deadly buildup of acids called ketones in her blood, a condition called ketoacidosis. Ketoacidosis can cause coma and death. Ketones are a known by-product of high protein, low carbohydrate diets. At low levels they can cause nausea, lightheadedness, and bad breath.

The long-term effects of these diets are still unknown. For example, the Atkins diet restricts some vegetables and most fruits, which are known to protect against serious diseases such as heart problems and cancer. The diet may also cause too much calcium to build up in the urine. This can increase the risk for kidney stones and osteoporosis. In addition, high-protein intake, particularly from meat, can be harmful in people with kidney problems. Individuals at risk for kidney stones, or those who have other kidney problems, should not go on high-protein diets without talking to their doctor first. Unfortunately, many people with diabetes are at risk of kidney problems, which could reverse any possible benefits a high-protein diet may bring them. Eating a lot of meat has also been associated with certain common cancers, notably prostate and colon cancers. A 2002 study suggested that such diets during pregnancy may increase the risk for high blood pressure in the child.

Still, significant studies say that such diets improve cholesterol and blood sugar levels. Studies in 2002 and 2003 have indicated that these diets lower blood glucose levels, which can be important in people who are diabetic. The diets also reduce triglyceride levels (unhealthy fat molecules) and increases HDL (" good") cholesterol levels. High triglyceride and low HDL levels are important risk factors for heart disease, and are common in people with type 2 diabetes. Studies are mixed on whether this type of diet reduces overall cholesterol or LDL ("bad") cholesterol levels.

Experts that promote the low carbohydrate approach argue that heart problems from obesity are due to insulin disturbances from sugar imbalances. Therefore, they believe that restricting carbohydrates is the best approach for obesity -- especially for overweight people with diabetes. More research is needed, however, to determine the long-term impact of such diets on health.

High-protein, low-carbohydrate diets include Atkins, Protein Power, Sugar Busters, and Dr. Stillman. The Atkins diet is one of the most popular and has a four-phase program:

Induction. For the first 2 weeks, individuals consume no more than 20 grams of carbohydrates a day. The diet consists of pure protein and fats. There is no fruit, bread, grains, starchy vegetables, or dairy products other than cheese, cream, or butter. This phase is not suitable for children, pregnant women, or anyone with kidney disease.
On-going Weight Loss. After the first phase, individuals continue to lose weight while they increase carbohydrate levels by five grams each day.
Premaintenance. When individuals get close to their weight goal, they add another 10 grams of carbohydrates per day as long as they do not begin to gain weight. Weight loss is very slow at this time, but the individual is now getting used to maintenance.
Maintenance. Lifetime maintenance is usually between 40 and 100 grams of carbohydrates a day, depending on steady weight level.

Anyone who chooses this diet should prefer fish or soy products to meat as protein sources. Fish may reduce leptin, a hormone associated with fat storage and heart diseases, and would be the best protein source. People on this diet should also choose monounsaturated fats (as in olive oil) over saturated fats or trans-fatty acids fat. Patients often need supplements, at least a multivitamin and possibly calcium, chromium, omega-3 fatty acids (found in fish oil), and other supplements.

The South Beach and Zone diets encourage healthy fats. They also allow certain carbohydrates. For example the Zone uses healthy carbohydrates (vegetables and dried beans) and unsaturated fats. The South Beach diet uses carbohydrates that have a lower impact on blood sugar levels. This is called a low-glycemic index. Low-glycemic foods include barley, dried bean and peas, milk, strawberries, and apples. High-glycemic foods include refined grains, white bread, white potatoes, and bananas and other tropical fruits. The glycemic index was developed for use in diabetes -- not for weight loss. Nevertheless, there is some evidence that foods with low glycemic indexes may produce a feeling of fullness and so discourage further eating. As with any high-protein diets, people at risk for kidney stones, or those who have other kidney problems, should avoid these plans.

Replacing fats and sugars with substitutes may help many people who have trouble maintaining weight. In fact, in one 2003 study, people with type 2 diabetes used the artificial sweetener sucralose and a beta-glucan fat substitute (derived from oats) as part of a low-calorie diet. At the end of the 4 weeks, they achieved better weight, glucose control, and HDL levels than those on a standard diabetic diet.

Fat Substitutes. Fat substitutes added to commercial foods or used in baking deliver some of the desirable qualities of fat, but do not add as many calories. It should be stressed that eliminating all fats from a diet can be harmful to general health.

Fat substitutes include the following:

Stanols. Stanols are plant compounds used in margarines (Benecol, Take Control). Benecol is derived from pine bark and Take Control from soybeans. Two servings a day of either brand, as part of a low-fat, diet can lower LDL and total cholesterol by impairing its absorption in the intestinal tract. Some studies have reported that the use of stanols can allow lower doses of statins (cholesterol lowering medications). Stanols do not appear to block absorption of fat-soluble nutrients or vitamins, as olestra does.
Olestra (Olean) passes through the body without leaving behind any calories from fat. Studies suggest that it improves cholesterol levels and helps people lose weight when it is used to replace a third of normal dietary fats. (Note that simply adding snacks containing olestra does not appear to have any effect on cholesterol or weight loss.) Early reports of cramps and diarrhea after eating food containing olestra have not proven to be significant. Of greater concern is the fact that even small amounts of olestra deplete the body of certain vitamins and nutrients that may help protect against serious diseases, including cancer. The FDA requires that the missing vitamins be added back to olestra products, but not other nutrients. The side health effects, if any, are unknown.
Beta-glucan is a soluble fiber found in oats and barley. Products using this substance (e.g., Nu-Trim) may reduce cholesterol and have additional health benefits.

A number of other fat-substitutes are also available. Although studies to date are not showing any significant side effects, these products' effect on weight control is uncertain, since many of the products containing them may be high in sugar.

Artificial Sweeteners. Many artificial or low-calories sweeteners are available. A 2002 study confirmed that people who consumed artificial sweeteners and reduced their sugar intake weighed less over time than those who took in similar types and amounts of drinks and food containing sugar. It should be noted that using these artificial sweeteners should not give dieters a license to increase their fat intake. Studies indicate that consuming some sugar is not a significant contributor to weight gain, as long as the total amount of calories in the diet is under control. There is some public concern about chemicals used to produce many of these sweeteners, and the side effects seen in studies using rats. Natural low-calories sweeteners are available that may be more acceptable to many people.

Saccharin (Sugar Twin, Sweet n' Low, Sucaryl, and Featherweight). Saccharin has been used for years. Some studies found that large amounts of saccharin cause bladder cancer in rats. However, the rats were fed huge amounts that do not apply to human diets. Currently there is no evidence that saccharin causes cancer in humans.
Aspartame (Nutra-Sweet, Equal, NutraTase). Aspartame has come under scrutiny because of rare reports of nervous system disorders, including headaches or dizziness, associated with its use. People with phenylketonuria (PKU), a genetic condition, should not use it. Studies have not reported any serious health dangers, but some people may be sensitive to it.
Sucralose (Splenda). Sucralose has no bitter aftertaste and works well in baking, unlike other artificial sweeteners. It is made from real sugar by replacing part of the sugar with chlorine. Some people are concerned because chlorinated molecules used in major industrial chemicals have been associated with cancer and birth defects. Over 100 studies have been conducted on sucralose over a 20-year period, with no reports of such risks.
Acesulfame-potassium (Sweet One, SwissSweet, Sunette). It has been used in the U.S. since 1988 with no reported side effects.
Neotame (Neotame). Neotame is a synthetic variation of aspartame, but was developed to avoid its side effects. The association with aspartame has raised some concerns. Studies to date have reported no effects that would cause alarm, and it appears to be safe for general consumption.
D-tagatose (Tagatose). This reduced-calorie sweetener is made from lactose, which is the sugar found in dairy products and other foods. It may be especially beneficial for people with type 2 diabetes. It may also have additional benefits that help the intestinal tract.
Alitame (Aclame) is formed from amino acids, the building blocks of proteins. It has the potential to be used in all products that contain sugar, including baked goods.
Stevioside (Stevia). This is a natural sweetener derived from a South American plant. It is available in health food stores. People with diabetes should avoid alcohol-based forms. It has not been carefully tested.

Other sugar substitutes being investigated include glycyrrhizin (derived from licorice) and dihycrochalcone (derived from citrus fruits).

Some studies have reported good success with meal replacement beverages (Slim-Fast, Sweet Success). They contain major nutrients needed for daily requirements. Each serving typically contains between 200 - 250 calories and replaces one meal. (Note: Using them for all meals reduces calories to a severe extent and can be harmful.)

One study reported that most subjects who had undergone a 12-week weight loss program and then used Ultra Slim Fast supplements as directed for maintenance kept off more than half their weight loss after more than 3 years. A quarter of the subjects were still losing weight.

Medical evidence suggests that a diet rich in magnesium could reduce a person's risk of metabolic syndrome, a cluster of problems including obesity, high blood pressure, and high cholesterol. Metabolic syndrome can lead to diabetes and heart disease. A long-term study of thousands of Americans found that the risk for metabolic syndrome decreased in those who consumed the most magnesium from meals. The findings were published in the journal Circulation.

Commercial and Non-Profit Support Programs for Weight Loss. There are many different types of weight-loss program. (This report cannot address all of the many commercial and nonprofit weight-loss programs currently available, nor can it assess their claims.)

Taking off Pounds Sensibly (TOPS), a nonprofit support organization with many local chapters, is one of the least expensive programs, costing $20 a year.

Most of the commercial programs such as Weight Watchers, Jenny Craig, and NutriSystem offer individual or group support, lifestyle changes and packaged meals. These programs tend to be expensive. There are few well-conducted studies on these programs. One 2003 study reported modest weight loss over 2 years with Weight Watchers compared to a self-help program. There were no differences in heart risk factors.

Cognitive Behavioral Approaches. Most support programs use some form of cognitive-behavioral methods to change the daily patterns associated with eating. They are very useful for preventing relapse after initial weight loss. The following is a typical approach:

The patient first records in a diary all activity related to eating patterns, including the times of day, length of meal, emotional states, companions, and, of course, the kind and amounts of food eaten. Most people -- even professional dieticians, according to one study -- tend to underreport their daily calorie intake. However, writing it down is still a good method for increasing a person's awareness of eating patterns. (One patient said that recording circumstances surrounding relapses was a particularly valuable guide for understanding the stresses leading to her own eating behaviors.)
The patient reviews the diary with a therapist or group to set realistic goals and identify patterns that the patient can change. For instance, if food is normally eaten while watching television, then the patient may be advised to eat in another room instead.
Good eating habits are reinforced by rewards. These rewards are other pleasures that substitute the high calorie consumption and sedentary activities.

Behavioral modification has been shown to be helpful particularly for people who have an overly strong response to the taste, smell, and appearance of food. It also may be useful for binge eaters.

Stress-Reduction Techniques. Stress reduction and relaxation techniques may be helpful for some people with obesity, such as those whose weight is related to night-eating syndrome. [See In-Depth Report #31: Stress.]

Changing Sedentary Habits. Making even small changes in physical activity can expend energy. For example, simply getting up to turn the TV on and off instead of using the remote, and standing (instead of sitting) while talking on the phone may help a person lose up to five pounds a year. Other suggestions include cooking one's own food (instead of eating take-out or fast food), walking to as many places as possible, using stairs instead of escalators or elevators, and gardening. Even fidgeting may be helpful in keeping pounds off, and, in one study, chewing gum increased energy expenditure.

No one should rely on such mild activities, however, for serious weight loss. Only high levels of physical activity -- not just using up energy -- help prevent obesity.

Approach to Exercise. Exercise, which replaces fat with muscle, is the critical companion for any weight control program. In a one-year study, women who regularly averaged 3.5 days (176 minutes) of exercise each week lost significantly more weight than women who did not exercise regularly. Women who exercised more than 195 minutes a week lost nearly 7% of their abdominal fat.

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. Moreover, exercise improves overall health even with modest weight loss. In support of this, a British study found that overweight fit individuals had half the death rate of unfit trim individuals.

Be aware, however, that the pounds won't melt off magically. Losing significant weight requires both intensive exercise and calorie restriction. In addition, if a person exercises but doesn't diet, any actual pounds lost may be minimal, because denser and heavier muscle mass replaces fat. Nonetheless, regardless of weight loss, a fit body will look more toned and be healthier. In addition, exercise benefits the heart even with modest weight loss.

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

The more strenuous the exercise, the better the chances for short-term and long-term success. With intense exercise, the metabolism continues to burn calories before returning to its resting level. This state of elevated metabolism can last for as little as a few minutes after light exercise to as long as several hours after prolonged or heavy exercise.
Of the standard aerobic machines, the treadmill burns the most calories. It may be particularly effective when used in short multiple bouts during the day. In fact, frequent exercise sessions as short as 10 minutes in duration (about four times a day) may be the most successful exercise program for obese people.
Resistance, or strength, training is excellent for replacing fat with muscles. It should be performed two or three times a week.
As people slim down, their initial level of physical activity becomes easier and 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 phenomenon and keep adding to their daily exercise program.
As people age, they also need to exercise more to keep off the same amount of weight.
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. In one interesting study, women in aerobic and strength training programs lost fat in their arms and trunk, but did not gain muscle tissue in these regions.

Warning Note. Because obesity is one of the risk factors for heart disease and diabetes, anyone who is overweight must discuss their exercise program with a doctor before starting. Sudden demanding exercise, in such cases, can be very dangerous. [See In-Depth Report #29: Exercise.]

Medications

There are several different drugs used for weight loss. Unless specifically instructed by a doctor, people should use non-drug methods for losing weight. Except under rare circumstances, pregnant or nursing women should never take diet medications of any sort, including herbal and over-the-counter remedies.

A 2001 study reported that 7% of American adults use nonprescription weight-loss products. People must be cautious when using any weight-loss medications, including over-the counter diet pills and herbal or so-called natural remedies. Buying unverified products over the Internet can be particularly dangerous.

Green tea. Perhaps the best alternative advice for people who are overweight is to drink tea. Studies have indicated that regular tea drinking is associated with lower weight, particularly in people who drink it for years. Green tea specifically has been associated with increased energy expenditure. One study reported that people who took a green tea extract (Exolise) lost weight and reduced their waist size. Better evidence is needed to confirm the results on this supplement.

Thermogenic Approach to Weight Loss. An approach to weight loss called thermogenic (also hepatothermic) therapy is based on the idea that certain natural compounds have properties that enable the liver to increase energy in the cells and stimulate the metabolism. Theoretically, the result would be fat loss. Among the natural substances used in such products are EPA-rich fish oil, sesamin, hydroxycitrate, pantethine, L-carnitine, pyruvate, aloe vera, aspartate, chromium, coenzyme Q10, green tea polyphenols, aloe vera, DHEA derivatives, cilostazol, diazoxide, and fibrate drugs.

Nearly all the current over-the-counter dietary aids contain some combination of these ingredients. There is no evidence that any of these ingredients can produce weight loss, and some may even have harmful effects.

Chromium is a common ingredient in many diet supplements (e.g., Xenadrine, Dexatrim, Acutrim Natural, Twinlab Diet Fuel). It is claimed to specifically promote fat loss, rather than lean muscle loss. Some evidence suggests that niacin-bound chromium may improve insulin sensitivity. On the negative side, animal studies have suggested that chromium may have damaging effects on genetic materials in cells. This could cause sterility.

Ephedra, Ephedrine, and Ma Huang. The FDA does not allow the sale of drugs that contain ephedrine. In May 2004, the FDA banned the sale of dietary supplements that contain ephedra (also called Ma Huang). Ephedra has been linked to serious side effects, including strokes and heart attacks.

Brazilian Diet Pill. The US Food and Drug Administration (FDA) is warning consumers not to buy a product known as the "Brazilian diet pill." This product is labeled as a dietary supplement, but contains several chemicals found in powerful prescription drugs. The products are also known as Emagrece Sim and Herbathin dietary supplements.

Conjugated Linoleic Acid (CLA). Conjugated linoleic acid is found in many dietary products (e.g., Biosculpt Liquid, Body Success, GNC Optibolic Body Answers Dietary Formula). There is no evidence that it produces weight loss. Furthermore, there is some concern that CLA might increase insulin resistance and a dangerous inflammatory response in people with obesity.

Tiratricol. Over-the-counter products containing tiratricol, a thyroid hormone, have been sold for weight loss. Such products may increase the risk for thyroid disorders, heart attack, and stroke.

Laxative Actions in Natural Substances. Many dietary herbal teas contain laxatives, which can cause gastrointestinal distress, and, if overused, may lead to chronic pain, constipation, and dependency. In rare cases, dehydration and death have occurred. Some laxative substances found in teas include senna, aloe, buckthorn, rhubarb root, cascara, and castor oil.

Guar Gum. Some fiber supplements containing guar gum have also caused obstruction of the gastrointestinal tract.

Chitosan. Chitosan, a dietary fiber from shellfish, prevents a small amount of fat from being absorbed in the intestine. Well-conducted studies, however, have not found it to be effective. Products containing it include Cheat & Lean Fat Blocker, Natrol, Chroma Slim, and Enforma. People who are allergic to shellfish should not take these supplements.

Plantain. Dietary remedies that list the ingredient plantain may contain digitalis, a powerful chemical that affects the heart. NOTE: This substance should not be confused with the harmless banana-like plant also called plantain.

Orlistat (Xenical) can help about one-third of obese patients with modest weight loss, and can assist in long-term maintenance of weight loss. It works by slowing the absorption of fat (by about 30%) in the intestine. Studies indicate that between 50 - 80% of patients can achieve weight loss of 5% or greater, depending on other lifestyle changes. However, many people regain a significant portion of this weight back within 2 years. It does not work for all patients, however. In one survey of patients who took it, 10% gained weight or did not lose any, and 43% lost less than 5%. Nevertheless, orlistat may delay or even prevent the onset or progression of diabetes and improve cholesterol levels, regardless of weight loss.

The drug can cause gastrointestinal problems and may interfere with absorption of the fat-soluble vitamins A, D, and E and other important nutrients. The most unpleasant side effect is oily leakage of feces from the anus. Restricting fats can reduce this effect. People with bowel disease should probably avoid it. In spite of these side effects, most patients are able to tolerate this agent.

In February 2007, the FDA approved an over-the-counter (OTC) version of orlistat. It will be sold under the name alli, and will be available at half the prescription strength of Xenical. Those eager to use the new pill should consider its cost and modest benefits compared with its side effects, most commonly oily diarrhea. This pill, which prevents fat absorption from food, also increases the risk of not absorbing important nutrients from food while using it. The FDA recommends taking a daily multivitamin supplement when using alli.

Sibutramine (Meridia) helps balance the brain chemicals serotonin and norepinephrine. This helps increase metabolism, causes a feeling of fullness, and increases energy levels. It may be particularly useful for binge-eaters. Studies indicate that sibutramine is effective in achieving weight loss, although the weight loss slows considerably after the first 3 months. The drug also appears to improve cholesterol and lipid (fat) levels, and may have other effects that benefit the heart.

Side effects of sibutramine are common. They include dry mouth, constipation, and insomnia. In one study, almost half the patients dropped out as a result of these side effects. There have been reports of increases in heart rate and blood pressure while taking this medication, although a 2001 study indicates that blood pressure stabilizes over time.

At this time, people who have a history of high blood pressure, stroke, heart disease, or arrhythmias should not take this drug. People taking decongestants, bronchodilators (such as for asthma), monoamine oxidase inhibitors, or serotonin reuptake inhibitors should also avoid sibutramine.

Phentermine and Other Sympathomimetics. Sympathomimetics are drugs that act like the stress hormone (and chemical messenger) norepinephrine. These medications act as stimulants in the brain. Some are approved for treating obesity, but only for short-term use. They include:

Phentermine (Ionamin, Adipex-P, Fastin)
Benzphetamine (Didrex)
Phendimetrazine (Adipost, Bontril, Melfiat, Plegine, Prelu-2, Statobex)

Phentermine is the most commonly prescribed appetite suppressant, and is less expensive than orlistat or sibutramine. Its effects are not long lasting, however. It can also raise blood pressure. In addition, phentermine is associated with depression, which is already a problem in many cases of obesity. A combination (Phen-Pro) containing phentermine and the antidepressant fluoxetine (Prozac) is being investigated to help reduce this problem. Note: Neither phentermine nor such combinations are associated with the heart problems linked to the previous phentermine combination known as Fen-Phen (phentermine and fenfluramine).

Amphetamines. The amphetamines dextroamphetamine (Dexedrine), methamphetamine (Desoxyn), and phenmetrazine (Pleudin) are powerful stimulants. They were used most often in the past but are no longer prescribed for weight loss. These drugs improve mood and produce some modest weight loss over the short term, but carry serious risks of addiction, agitation, and insomnia.

Rimonabant. Rimonabant (Accompli) belongs to a new class of drugs called selective CB1 blockers. The drug is designed to block receptors in the brain associated with the regulation of eating. Rimonabant also targets receptors in fat tissue. The Rimonabant in Obesity-Lipids (RIO-Lipids) study looked at how rimonabant affected metabolic risk factors in high-risk overweight or obese patients with blood fat disorders. The study involved more than 1,000 participants. The findings, published in the November 2005 New England Journal of Medicine, said that people who took the drug significantly reduced their body weight and size of their waist.

Earlier studies involving the drug reported that obese patients treated with 20 mg of rimonabant lost significantly more weight and inches from their waist than patients who received placebo. The drug also appeared to have beneficial effects on raising HDL ("good") cholesterol levels.

Note: Fake rimonabant has been found for sale on several web sites. Patients should be aware that this drug is still experimental, and rimonabant is not available for sale. Buying and taking counterfeit drugs can have serious health consequences. In addition, an FDA advisory panel in April 2007 rejected the drug, citing fears it may cause psychiatric problems and seizures in some patients.

Axokine. Axokine is a type of drug called a ciliary neurotrophic factor. It signals the brain to suppress one's appetite. It is proving to be effective in achieving weight loss, and also improves cholesterol, lipid, and glucose levels regardless of food intake. It could be particularly helpful for people with type 2 diabetes. Early study results found that severely obese patient who took the drug lost more weight than those who took a dummy pill (placebo). Nearly half (46%) of patients who took the drug lost at least 10 pounds, compared to 5% of those who received the placebo. Study participants tolerated the drug well. There were no reports of serious side effects.

Zonisamide. Zonisamide (Zonegran) is an anti-seizure medication that is also being investigated for weight loss. In one study, patients who took it lost more weight than those on placebo. Zonisamide increases the risk for kidney stones, which can be reduced with increased fluid intake and citrate. It has also been associated with reduced sweating and a sudden rise in body temperature, especially in hot weather. Other side effects include dizziness, forgetfulness, headache, and nausea.

Topiramate. Topiramate (Topamax) is another anti-seizure medication being investigated for weight reduction. Three clinical trials have reported that patients given topiramate lost more weight than those receiving placebo. Weight loss was sustained for up to 1 year. The drug is also being studied for binge-eating disorders associated with obesity.

Other Treatments

Surgical procedures for obesity may be appropriate for some dangerously obese people, and may reduce heart problems and many of the risks associated with obesity. These risks include high blood pressure, sleep apnea, and diabetes. In fact, some evidence suggests that surgery may provide much greater control of weight and diabetes than nonsurgical weight-loss methods. Studies are reporting significant reductions in diabetes, and the need for diabetic medications, after surgery. Other medical conditions that often improve after surgery include heartburn, arthritis, and other joint and circulation problems.

Bariatric surgeries produce weight loss through one of two approaches:

Restrictive Banding Procedures. These procedures restrict the amount of food by closing off parts of the stomach with bands.
Malabsorptive Bypass Procedures. This approach restricts the amount of food and also reduces absorption by using a bypass of parts of the intestine.

The malabsorptive procedures are more successful in achieving weight loss than the banding approach, but they carry a greater risk for nutritional deficiencies.

Most people who have bariatric surgery lose about two-thirds of excess weight within 2 years. In addition, diseases associated with obesity (such as diabetes, high blood pressure, sleep apnea, joint pain, and incontinence) often improve.

Researchers at the Mayo Clinic looked at records from patients who had the surgery between 1990 and 2003. They found that those who had bariatric surgery reduced their risk of cardiovascular events such as a heart attack much more than those who lost weight without surgery. The findings were published in the September 2005 Mayo Clinic Proceedings.

Other studies have shown that even though most patients maintain significant weight loss, the majority regain about to 10% of their weight. Patients must still develop a healthy life style and be calorie conscious after the operation. Follow-up must be life-long.

Any surgical candidate must have failed consistently in losing weight through less invasive methods. Experts recommend bariatric surgery only for the following:

Those whose BMI is above 40 (about 100 pounds overweight)
Those with BMIs of over 35 who have type 2 diabetes or serious obesity-related medical problems
Those with severe obesity that interfered with employment, normal physical activity (e.g., walking), and important relationship

About a third of people who undergo these procedures achieve normal weight, and 80% experience some weigh loss. They are less successful than the bypass procedures, but carry a lower risk of nutritional deficiencies.

Vertical Banded Gastroplasty. Vertical banded gastroplasty (VBG) was the most common restrictive procedure. It involves creating a hole through both stomach walls and sealing the edges with a staple. This narrows the stomach, similar to a funnel, and allows only small amounts of food to pass through.

Laparoscopic Gastric Banding. Laparoscopic gastric banding (the Lap-Band) usually does not require a major incision and avoids some of the major complications of gastric bypass:

It employs an adjustable silicone band that is placed around the upper part of the stomach.
A small balloon-like reservoir attached to the band under the abdominal skin contains saline, which can be added or removed to tighten or loosen the band.
The procedure restricts the amount of food a person can eat and gives the feeling of fullness.

The band is removable, if necessary. Studies to date indicate that the intestinal tract returns to normal afterward. Studies, including those done in the elderly, have reported significant weight loss and improved quality of life with the procedure.

Malabsorptive procedures produce greater weight loss than restrictive procedures. Patients generally achieve about two-thirds of their weight loss within 2 years. Furthermore, in a 2003 study, after standard bypass surgery, 83% of patients with type 2 diabetes experienced normal blood glucose levels and the rest had significant reductions.

Roux-en-Y Gastric Bypass Procedure. This is the most common and successful malabsorptive surgery in the United States. It involves creating a small stomach pouch that serves as a reservoir and restricts food intake. The pouch eventually holds up to 3 ounces of food and has a small outlet that delays emptying and causes a feeling of fullness. Then the surgeon creates a Y-shaped section in the small intestine that attaches to the pouch. This section allows food to bypass the lower stomach and upper part of the intestine. One 2003 study reported that this procedure was associated with significant weight loss, and 80% of patients with type 2 diabetes were able to reduce their medications. A more recent study, published in the March 14, 2006, issue of Archives of Surgery, found that gastric bypass surgery also helps lower the blood pressure of very obese patients.

The procedure produces greater and more sustained weight loss than banding procedures, but it is also more complicated, and carries a higher risk of nutritional deficiencies. Laparoscopy techniques, which are less invasive, are now preferred over open surgery. They achieve equally good results with fewer complications.

Biliopancreatic Diversion. This procedure is more complicated and removes portions of the stomach. The pouch that is created attaches directly to the lower part of the small intestine. It poses a higher risk for nutritional deficiencies than other procedures and is not used as often.

Click the icon to see an image of gastric bypass surgery.

General Side Effects and Complications. Side effects and complications of bariatric procedures are common, and up to 25% of patients require corrective or repeat procedures. After any of these procedures people must chew all their food carefully, and they cannot eat large amounts of food at one time. If patients do not follow these guidelines, they will experience nausea, abdominal distress, or both.

Complications from any bariatric procedure includes the following:

Vomiting: This is the most common complication, and it is most common with banding procedures.
Nutritional deficiencies: There is a strong risk of nutritional deficiencies, particularly with malabsorptive operations. This complication can lead to anemia and increase the risk of bone loss and osteoporosis. Taking enough mineral and vitamin supplements is important after bariatric surgery.
Deep-vein thrombosis: There is a significant risk for deep-vein thrombosis (blood clots in the veins).
Abdominal hernia: This is another common complication. Newer, laparoscopic techniques do not carry this risk, but not all individuals are candidates for this less-invasive approach.
Rapid weight loss after surgery: This complication puts people at high risk for gallstones.
Women who wish to be pregnant should wait until their weight has stabilized. Rapid weight loss and nutritional deficiencies can harm the fetus.

People at highest risk for complications are those with heart or lung problems, severe obesity, and a history of abdominal surgeries. The mortality rate from bariatric surgeries is 0.2%, which is lower than the morality rates from severe obesity itself. Other surgical variations and less invasive techniques using laparoscopy have been developed.

Specific Complications of Restrictive Banding Procedures. Nausea, vomiting, or both occurs in half the patients, and severe heartburn occurs in a third. Device-related complications include band slippage, pouch dilation (widening), or both in nearly a quarter of patients, and obstruction in 12% of patients. Very serious complications are rare, but include blood clots, bleeding, infection, pneumonia, and perforation (tearing) of the stomach.

Specific Complications of Malabsorptive Bypass Procedures. Vomiting often occurs. Nutritional deficiencies occur more often in these procedures. The so-called dumping syndrome is a common unpleasant side effect, which occurs when food waste moves too quickly through the intestine. Symptoms include nausea, weakness, sweating, and faintness (particularly after eating sweets).

Spot Exercising. Anyone seeking to lose weight must expect that the results may not be as cosmetically satisfying as one would wish. Spot exercising (training particular areas of the body) is ineffective in reducing fat in specific locations because exercise draws on fat stores throughout the body. Gimmicky devices such as bust developers, vacuum pants, and exercise belts do absolutely nothing to reduce fat or add bulk in specific locations. Electrical pads wrapped around the waist, arms, or thighs were reported to cause burns and fires.

Cellulite-Removal Creams. Many women try to reduce fat in their thighs (cellulite) with creams that contain aminophylline (Skinny Dip, Thermojetics Body Toning Cream, Smooth Contours). Studies provide no evidence that these creams are effective. Their apparent effect on fat may simply be from narrowing blood vessels and forcing water from the skin, which could be dangerous for people with blood flow problems.

Endermologie. Endermologie uses motorized rollers and regulated suction to smooth out cellulite. In one study, about 28.6% of patients reported improved appearance after using it.

Liposuction. Liposuction eliminates fat in specific areas, such as the abdomen, thighs, buttocks, or knees. Special instruments are inserted through the skin into the pockets and suction is used to move the fat, break it up, and remove it. Small tubes may be used to drain blood and fluid during the first few days. The pain after the operation can be severe and often the skin does not contract, resulting in a flabby look. Complications can include burns from the vibrators, bruising, blood clots, and bleeding. Weight gain generally tends to develop in other locations after the operation. Some doctors are using this procedure in overweight people with diabetes to remove abdominal fat. Although there is no proof that it has an effect on diabetes, some experts believe the procedure deserves attention.

Liposuction is not recommended for major weight loss.

Resources

www.healthierus.gov/dietaryguidelines -- Dietary Guidelines for Americans 2005
www.naaso.org -- North American Association for the Study of Obesity
www.eatright.org -- American Dietetic Association
www.nutrition.gov. -- Nutrition.gov
www.asbs.org -- American Society for Bariatric Surgery
www.cnpp.usda.gov -- Center for Nutrition Policy and Promotion
http://fnic.nal.usda.gov -- Food and Nutrition Information Center
www.americanheart.org -- American Heart Association
www.nationaleatingdisorders.org -- National Eating Disorders Organization
www.aabt.org -- Association for Advancement of Behavior Therapy
www.fda.gov -- Food and Drug Administration
http://win.niddk.nih.gov -- Weight-Control Information Network

References

US Food and Drug Administration FDA Approves Orlistat for Over-the-Counter Use. Rockville, MD: National Press Office; February 7, 2007.

Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999-2004. Journal of the American Medical Association. 2006; 295:1549-1555.

National Center for Health Statistics. Chartbook on Trends in the Health of Americans. Health, United States, 2005. Hyattsville, MD: Public Health Service. 2005

National Institute of Diabetes and Digestive and Kidney Diseases - Weight-control Information Network. Statistics Related to Overweight and Obesity. Available online.

National Center for Health Statistics. Prevalence of Overweight Among Children and Adolescents: United States, 2003-2004.

Morino M, Toppino M, Bonnet G, Rosa R, et al. Laparoscopic vertical banded gastroplasty for morbid obesity. Assessment of efficacy. Surg Endosc. 2002 Nov;16(11):1566-72.

Brethauer SA, Schauer PR, Chand B. Risks and benefits of bariatric surgery: Current evidence. Cleveland Clinic Journal Of Medicine. 2006 Nov; 73(11): 993-1007.

Rosenthal RJ, Szomstein S, Kennedy CI, et al. Laparoscopic surgery for morbid obesity: 1,001 consecutive bariatric operations performed at The Bariatric Institute, Cleveland Clinic Florida. Obes Surg. 2006 Feb;16(2):119-24.

He K, Liu K, Daviglus ML, et al. Magnesium Intake and Incidence of Metabolic Syndrome Among Young Adults. Circulation. 2006: Published online before print. March 27, 2006.

Chen TY, Smith W, Rosenstock JL, Lessnau KD. A life-threatening complication of Atkins diet. Lancet. 2006 Mar 18;367(9514):958.

Lopez-Jimenez F, Bhatia S, Collazo-Clavell ML, Sarr MG, Somers VK. Safety and efficacy of bariatric surgery in patients with coronary artery disease. Mayo Clin Proc. 2005 Sep;80(9):1157-62.

Sidhaye A, Cheskin LJ. Pharmacologic treatment of obesity. Adv Psychosom Med. 2006;27:42-52.

Fernstrom JD, Courcoulas AP, Houck PR, Fernstrom MH. Long-term changes in blood pressure in extremely obese patients who have undergone bariatric surgery. Arch Surg. 2006 Mar;141(3):276-83.

Despres JP, Golay A, Sjostrom L; Rimonabant in Obesity-Lipids Study Group. Effects of rimonabant on metabolic risk factors in overweight patients with dyslipidemia. N Engl J Med. 2005 Nov 17;353(20):2121-34.

Lanningham-Foster L, Nysse LJ, Levine JA. Labor saved, calories lost: the energetic impact of domestic labor-saving devices. Obes Res. 2003 Oct;11(10):1178-81.

Review Date:
6/14/2007
Reviewed By:
A.D.A.M. Editorial Team: Greg Juhn, M.T.P.W., David R. Eltz, Kelli A. Stacy. Previously reviewed by Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital (4/30/2007).

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

Coke Launches New 90-Calorie Mini Can

FitSugar — Mon, 19 Oct 2009 09:00:35 -0700

Coca-Cola is giving consumers even more ways to manage their calories with the introduction of its new 7.5 oz. mini can. The 90-calorie can will be released in select East Coast cities this December, with a nationwide rollout set for 2010.

“As the world’s largest beverage company, we take seriously the need to help consumers balance calories consumed with calories expended,” said Sandy Douglas, president, Coca-Cola North America. “The Coca-Cola mini can innovation reinforces the Company’s support for healthy, active lifestyles.”

This announcement is coming on the heels of the company's move to put calorie information of the front of all its packaging. They've also partnered with Healthy Weight Commitment, a group of retailers and food manufacturers committed to reducing obesity in America.

By all accounts it sounds like the soda giant is becoming quite concerned over the nation's growing waistline and its contribution to it. But some argue the company is trying to skirt the impending soda tax. Don't be fooled by the small packaging, the recipe remains unchanged and is still filled with HFCS, but may be a good option for consumers who keep tabs on calories.

Coca-Cola will also be offering the mini cans in Sprite, Fanta Orange, Cherry Coca-Cola and Barq's Root Beer.

Obesity

FitSugar — Wed, 08 Oct 2008 17:35:32 -0700

Overview

Signs and Symptoms
What Causes It?
Risk Factors
Preventive Care
What to Expect at Your Provider's Office
Treatment Options
Other Considerations
Supporting Research

HEALTH GUIDE REFERENCE FROM A.D.A.M

Being overweight or obese puts you at risk for a number of diseases, including heart disease, diabetes, high blood pressure, stroke, gallbladder disease, osteoarthritis, and respiratory disorders. The risk of developing these diseases is even higher when weight is concentrated near the waist.

Obesity is an increasing problem. According to the National Institutes of Health, 60% of American adults are overweight and 25% are considered obese, while about 25% of American children are overweight or obese. And the numbers are rising. Taking weight off, and keeping it off, is difficult. Many people who lose weight later gain back some or all of the excess pounds.

Despite growing research on obesity, there are no medications, herbs, or supplements that can help you lose a significant amount of weight, and all have some side effects. The only way to lose weight is to reduce the amount of calories you eat and increase the time and intensity of your exercise. These actions have many health benefits in addition to helping you lose weight.

Signs and Symptoms

Obesity is usually determined by body mass index, or BMI, using a formula that calculates a ratio of your height to your weight.

BMI 25 - 29.9 (overweight)
BMI 30 and above (obese)

A high waist to hip ratio (indicating that fat is centered around the waist) increases the risk for developing serious, even life-threatening conditions associated with obesity. Generally, for men a ratio of .90 or less is considered safe. For women, .80 or less is considered safe.

Conditions that may accompany obesity include:

High cholesterol (including high triglyceride levels)
Diabetes
High blood pressure
Sleep apnea (episodes when a person stops breathing while asleep)
Osteoarthritis
Gallstones

What Causes It?

A number of factors contribute to obesity.

Diet: Eating high-fat, high-calorie foods causes weight gain.
Lack of exercise: Sedentary people don't burn as many calories as active people.
Genetics: Your genes may influence how much fat your body stores and where it store it, although genes alone do not mean you will be obese.
Age: People gain weight as they get older, because they tend to be less active and to lose muscle mass.
Psychological issues: Some people overeat when they are upset or stressed.
Medications: Some drugs, such as corticosteroids, blood pressure medication, and tricyclic antidepressants, can cause you to gain weight.
Medical problems: Rarely, obesity is due to a medical problem such as Cushing's syndrome (where the adrenal glands produce too much hormone) or hypothyroidism (where the thyroid gland doesn't produce enough hormone). Conditions such as osteoarthritis cause people to be less active, which can lead to weight gain.

Risk Factors

The following factors may increase an individual's risk for becoming obese:

Living in an industrialized country, especially the United States
Having family members who are overweight or obese
Not being physically active
Overeating
Eating a high-fat diet
Taking certain prescription medications (see "Causes")
Having a hormone disorder, such as Cushing's syndrome or hypothyroidism (underactive thyroid)
Being emotionally stressed (from the death of a loved one, for example), which may cause a person to overeat

Preventive Care

The best way to prevent obesity and maintain a normal weight is to eat a healthy diet and exercise daily. Keeping a food and exercise journal, where you record what you eat and how long you exercise, is an excellent way to get started.

Organizations such as the American Diabetes Association, the American Heart Association, and the American Dietetic Association have developed guidelines that promote weight loss and healthy eating. These guidelines recommend that no more than 30% of a person's total calorie intake should come from fats. Overall, you should eat a wide variety of foods, especially fruits and vegetables, in order to stay healthy and maintain proper weight.

Many studies show that exercise -- from moderate to intense -- helps prevent obesity. The Centers for Disease Control and Prevention and the American Academy of Sports Medicine recommend at least 30 minutes of moderate aerobic activity (such as a brisk walk) at least 5 days a week. You don't have to exercise for 30 minutes at a time; 10 minutes, done three times a day, is also effective. In fact, any exercise -- from taking the stairs to cleaning the house or working in the garden -- is beneficial.

What to Expect at Your Provider's Office

Health care practitioners use BMI to diagnose obesity. To determine BMI, weight in kilograms is divided by height in meters, squared. You can find online BMI calculators that do the math for you. As previously noted in the "Signs and Symptoms" section, the following BMI ranges are most often used as indications that a person is overweight or obese:

BMI 25 - 29.9 (overweight)
BMI 30 and above (obese)

Your doctor may also measure your blood pressure and percentage of body fat, and may order blood tests to check cholesterol levels and determine how well your thyroid is functioning.

Treatment Options

Losing weight -- and then maintaining a healthy weight -- involves a combination of diet, exercise, and other lifestyle modifications. Although some medications, herbs, and supplements may help you lose a little weight, you still must eat fewer calories and exercise more to see any real effect. For severe obesity, bariatric surgery (which physically restricts the amount of food a person can eat) may be an option.

Lifestyle

To lose weight, you must eat fewer calories and increase your physical activity to burn more calories. The key to losing and keeping off weight is to set realistic weight loss goals that are achievable. The changes you make to your eating and exercise habits will need to last throughout your life.

Exercise

Exercise can help you lose weight, especially in the first six months, and to maintain your desired weight in the long-term. Exercise not only contributes to weight loss, it also decreases abdominal fat and increases heart health, lowers blood pressure, and helps keep blood sugar in check.

If you are not used to exercising, start slowly and build up to the goal of 30 minutes a day for at least 5 days a week. An ideal exercise program includes aerobic activity (walking, swimming, biking), strength training (lifting weights), and flexibility (stretching). If you are severely obese or have other medical problems, talk to your doctor before starting a new exercise program.

You may be sore at first. Some muscle soreness is normal. However, if you experience pain that lasts more than 2 hours after your workout, see your doctor before continuing.

Drug Therapies

Some medications help promote weight loss, but there are no drugs to cure obesity. Weight loss medications should be used in addition to diet, exercise, and other lifestyle modifications. Many of these drugs are available by prescription only and some have serious side effects.

Over-the-counter Medications

Orlistat (Alli) -- The FDA has approved Alli as the only over-the-counter weight loss drug. It reduces the amount of fat your body can absorb from foods. Side effects include oily stools, flatulence, and diarrhea. Alli also blocks you body from absorbing some vitamins and nutrients, so you should take a multivitamin daily.

Prescription Medications

Sibutramine (Meridia) -- boosts metabolism, enhances energy level, and promotes a feeling of fullness. Side effects include dry mouth and insomnia; cannot be taken by people with a history of stroke, seizures, or heart, liver, or kidney diseases. Meridia is moderately effective; studies show that people who take Meridia lost about 10 pounds more than those who just followed a low-calorie diet.
Orlistat (Xenical) -- reduces the absorption of fat from foods; side effects include oily stools, flatulence, and diarrhea. Recently approved for over-the-counter sale in the U.S.
Phentermine -- suppresses appetite; serious potential side effects include pulmonary hypertension and heart valve defects. Phentermine is similar to an amphetamine and should not be taken by people with high blood pressure, heart disease, glaucoma, or those taking antidepressant medications

Surgical Procedures

Bariatric or weight-loss surgery may be considered in cases where people are severely obese and lifestyle changes have not worked. Physicians carefully select individuals for surgery, and patients must undergo psychological testing and counseling. Bariatric surgery reduces the amount of food that can be taken into the stomach. People who have had bariatric surgery must be monitored by their doctor afterward to make sure they get enough essential nutrients. Procedures include:

Roux-en Y procedure (gastric bypass) -- permanently reduces the size of the stomach; vomiting is the most common side effect
Gastric banding -- An adjustable silicone band is placed around the stomach, decreasing the amount of food that can be eaten. The band can be adjusted or removed.

Complementary and Alternative Therapies

Diet

Diet plans are enormously popular. They range from traditional low-fat, high-carbohydrate diets to high-protein, high-fat, low-carbohydrate diets. The truth is, no specific diet works for everyone, and no diet works without the other essential components of weight loss -- exercise and stress management.

The U.S. Department of Health and Human Services says a healthy diet

Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat dairy products
Includes lean meats, poultry, fish, beans, eggs, and nuts
Is low in saturated fats, trans fats, cholesterol, salt, and added sugar

Among many weight-loss plans available, the ones that generally result in a balanced diet include the Weight Watchers plan, the South Beach Diet, and the American Heart Association No Fad Diet. Beware of diets that promise quick, substantial weight loss; they often don't contain enough of the nutrients your body needs to stay healthy, and you're more likely to go off the diet and engage in binge eating, gaining the weight back. Weight loss of about 1 to 2 pounds per week is considered safe and sustainable. Before attempting any diet, it is important to consult a healthcare practitioner to determine which plan is right for you.

Nutrition and Supplements

Most evidence for using these supplements in weight loss is either scant or mixed. None of these supplements will work for significant weight loss without changes to diet and exercise habits. Talk to your healthcare provider before using these supplements.

5-Hydroxytryptophan (5-HTP) (600 - 900 mg per day) -- 5-HTP is thought to reduce hunger cravings by boosting serotonin levels in the central nervous system, which may reduce appetite and lessen food cravings. However, 5-HTP has been associated with eosinophilia myalgia syndrome (EMS), a rare and potentially fatal blood disorder, although it isn't clear whether 5-HTP actually contributes to developing the disorder. In addition, people who take antidepressants or herbs and supplements with antidepressant effects (such as St. John's wort and SAMe) should avoid 5-HTP. Talk to your doctor before taking 5-HTP.

Fiber -- may help lower insulin levels (insulin controls the amount of sugar in the blood) and help you feel fuller.

Conjugated linoleic acid (CLA) -- Preliminary human and animal studies suggest that CLA may help control weight by reducing body fat and enhancing lean body mass. However, the benefit appears to be slight, there is some question as to whether CLA can increase insulin resistance in overweight people (a precursor to developing diabetes), and studies show mixed results for weight loss.

Zinc (15 - 20 mg per day) -- may increase lean body mass and decrease or keep stable the amount of fat. The reason may be that zinc increases levels of leptin, a hormone in the body that helps you feel full.

Chitosan (1,500 mg three times per day) -- Chitosan is a fiber-like supplement made from the shells of crustaceans such as shrimp and crab. While some studies have found that chitosan (in addition to a low-calorie diet) reduces weight, it is unclear whether the supplement itself, the low-calorie diet, or a combination of both led to the weight loss. Other studies have shown mixed results.

Pyruvate (22 - 44 g per day) -- Pyruvate is a substance that occurs naturally in the body, where it is converted to lactic acid. There is some evidence that it may help reduce body fat, possibly by increasing the body's metabolic rate. Other studies show no effect.

Hydroxycitric acid (HCA) (2.5 g per day) -- This substance, extracted from the fruit Garcinia cambogia, is similar to citric acid (found in oranges and citrus fruits). In test tubes, HCA stops carbohydrates from being stored as fat, and some animal tests indicate HCA can suppress appetite. However, studies in humans show mixed results.

7-keto or 7-keto-DHEA (3-acetyl-7-oxo-dehydroeplandrosterone) (100 mg two times per day) -- 7-keto is a substance related to DHEA, a substance in the body that is the precursor to male and female hormones. DHEA has been studied as a weight-loss supplement, but results are mixed and there is some concern over DHEA's hormone-like effects on the body. One preliminary trial suggested that 7-keto may help enhance weight loss for people who are already dieting and exercising, without risk of the side effects of DHEA (7-keto is not converted to hormones in the body). However, more studies are needed to determine whether 7-keto has any real effect on weight loss. People who have had or are at risk of hormone-related cancers should not take 7-keto without their doctor's supervision.

Chromium (600 mcg per day) -- Chromium or chromium picolonate is a popular supplement among bodybuilders and those trying to lose weight and build more lean muscle mass. However, results from scientific studies have been mixed, and its effects are small compared to those of exercise and a well-balanced diet. Chromium may improve blood sugar (also a risk factor for heart disease), particularly in those with diabetes and glucose intolerance, but should not be taken for that purpose without a doctor's supervision. In addition, large doses of chromium can cause kidney damage.

Glucomannan (1 g three times per day, 1 hour before each meal) -- Glucomannan is a kind of insoluble fiber that appears to reduce blood sugar levels and may help to promote weigh loss. People with diabetes should not take glucomannan without their doctor's supervision.

Herbs

Psyllium (Plantaginis ovatae) -- Psyllium, a kind of soluble fiber, may reduce hunger cravings by making you feel full. For this reasons, incorporating psyllium and other sources of fiber into your diet may aid weight loss.

Green tea (Camellia sinensis) -- Researchers have theorized that polyphenols (chemical substances found in plants that have antioxidant properties, protecting cells in the body against damage) found in green tea extract may boost metabolism and help burn fat. However, studies have shown mixed results so far. In addition, the extracts used in the studies have contained caffeine, which could be responsible for increasing metabolism and promoting weight loss. If you are sensitive to caffeine or have anxiety or heart problems, you may want to limit how much green tea you consume.

Guggul (Commiphora mukal, 25 mg of guggulsterones three times per day) -- a common ingredient in several Ayurvedic medicines used to treat obesity. Studies suggest that overweight people who take these Ayurvedic remedies lose slightly more weight compared to those who do not take them. Guggul can cause mild diarrhea and nausea, and may interact with the following medications: blood-thinning drugs (anticoagulants), birth control pills, thyroid hormone, tamoxifen, and estrogens. People who take these medications should not take guggul. In addition, people who have or have had hormone-sensitive cancers (breast, ovarian, or prostate cancer) should not take guggul.

Cayenne or capsaicin (Capsicum frutescens, 6 - 10 g per meal) -- Preliminary evidence indicates that capsaicin (the substance that makes chili peppers taste hot) may reduce hunger and help the body burn fat, particularly when eating a high-fat diet. More research is needed to confirm these early findings, however.

Hoodia (Hoodia gordonii) -- A number of media reports on hoodia have suggested it could be an effective weight-loss supplement. However, the only evidence that exists is a single, unpublished study funded by the manufacturer of the supplement, so no one knows whether hoodia works or even whether it is safe. In addition, news reports now suggest that most hoodia supplements on the market today contain little if any of the actual herb. Until more research is done and trusted sources exist to provide the herb, hoodia is best avoided.

Homeopathy

Few studies have examined the effectiveness of specific homeopathic remedies, and there is no single or combination homeopathic remedy that will help all people lose weight. However, individualized homeopathic therapy can be designed to aid weight loss by addressing metabolism, digestion, and elimination. Before prescribing a remedy, homeopaths take into account a person's constitutional type -- your physical, emotional, and intellectual makeup. An experienced homeopath assesses all of these factors when determining the most appropriate remedy for an individual.

Acupuncture

Many studies have found both acupuncture and acupressure can improve weight loss slightly. Acupuncture is believed to promote weight loss by stimulating points on the body that boost serotonin levels. (Elevated serotonin levels are thought to suppress appetite.) One well-designed study found that people who received electrical acupuncture of the ear (auricular acupuncture) reduced their appetite.

Cognitive Behavioral Therapy

Besides changing diet and exercise habits, successful weight loss often requires additional behavioral adjustments to keep the weight off. That might include setting reasonable weekly or monthly goals -- how much exercise or how much weight loss is desired, for instance -- and finding ways to reward yourself for successes that don't involve food. Working with both a dietician and a behavioral specialist can help you put these practices into play.

It also helps to reduce the stress that leads to overeating by practicing relaxation exercises, such as yoga, meditation, or tai chi.

Finally, it is hard to lose weight without support. Support groups such as Overeaters Anonymous or Weight Watchers can help you stay focused on your goals and allow members to share success and encourage each other.

Hypnosis

Although studies are mixed, some evidence indicates that hypnosis (especially when used in combination with cognitive behavioral therapy, exercise, and a low-fat diet) may help overweight or obese people lose weight.

Other Considerations

Pregnancy

Pregnant women should not take any herbal remedies or over-the-counter or prescription medications for weight loss.

Obese women who become pregnant are at an increased risk for the following:

Gestational diabetes -- a diabetic condition that appears during pregnancy and usually goes away after the birth of the baby
High blood pressure
Preeclampsia -- a potentially fatal condition causing high blood pressure, fluid retention, and protein in the urine; may cause abdominal pain and vomiting
Caesarean sections
Fetal distress -- a condition in which the baby does not receive enough oxygen

Prognosis and Complications

People who are overweight or obese increase their risk for developing the following conditions:

Type 2 diabetes
High blood pressure
Coronary artery disease
High cholesterol
High levels of triglycerides (fat) in the blood
Heart failure
Respiratory problems (such as sleep apnea)
Circulatory problems (such as varicose veins)
Gallbladder disease
Breast cancer (after menopause) and endometrial cancer
Prostate cancer
Colorectal cancer
Osteoarthritis

Eating and exercise habits are hard to change. Many people are able to lose at least 20 pounds with diet and exercise plans, but only about 10 - 20% can maintain that weight loss for a long period of time. Losing just 15 - 20 pounds, however, can reduce the risk of serious complications, such as diabetes and heart failure, by 10 - 25%.

Supporting Research

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Barabasz M, Spiegel D. Hypnotizability and weight loss in obese subjects. Int J Eat Disord. 1989;8:335-341.

Bhattacharya A, Rahman MM, McCarter R, O'Shea M, Fernandes G. Conjugated linoleic acid and chromium lower body weight and visceral fat mass in high-fat-diet-fed mice. Lipids. 2006 May;41(5):437-44.

Birdsall TC. 5-hydroxytryptophan: a clinically-effective serotonin precursor. Alt Med Rev. 1998;3(4):271-280.

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Bray GA, Blackburn GL, Ferguson JM, et al. Sibutramine produces dose-related weight loss. Obes Res. 1999;7:189-198.

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Review Date:
3/24/2007
Reviewed By:
Steven D. Ehrlich, N.M.D., private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.

A.D.A.M. Copyright

adam.com

Cholesterol

FitSugar — Wed, 08 Oct 2008 17:34:59 -0700

In This Report

Highlights
Introduction
Cholesterol's Effect on the...
Cholesterol's Effect on the...
Risk Factors
Symptoms
Diagnosis
Lifestyle Changes
Treatment
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

New Guidelines for Children and Adolescents

In 2007, the American Heart Association (AHA) established new guidelines for assessing and treating high cholesterol in children and adolescents. According to the AHA’s scientific statement:

LDL (“bad") cholesterol goals for children should be 190 mg/dL or less for children without heart disease risk factors and 160 mg/dL or less for children with heart disease risk factors.
Children who are overweight or obese, as well as those with a family history of high cholesterol and heart disease, should get their cholesterol levels checked.
For overweight and obese children with cholesterol imbalances, diet changes and exercise should be tried before drug treatment. For children with cholesterol imbalances who have a family history of cholesterol and heart problems, statins are the best first-line drug therapy.

Herbs and Supplements

Garlic, whether raw or in supplement form, does not help lower LDL in patients with moderately high LDL levels, according to a 2007 Archives of Internal Medicine Study.
Policosanol, a dietary supplement derived from sugar cane, has no effect on cholesterol, indicates a 2006 Journal of the American Medical Association (JAMA) study.

Diet Plans

In a 2007 JAMA comparison study of four diet plans (Atkins, Ornish, Zone, and LEARN), the low-carbohydrate Atkins diet was best at raising HDL (“good cholesterol”) levels and lowering triglyceride levels, but did not affect LDL levels. The low-fat Ornish diet was best at lowering LDL levels.
The Mediterranean diet works better than a low-fat diet in quickly lowering cholesterol as well as blood pressure and blood sugar, suggests a 2006 Annals of Internal Medicine study.

Drug Research

In contrast to research findings released last year, rosuvastatin (Crestor) does not appear to reverse heart disease, according to a 2007 JAMA study. However, the statin drug did help slow the progression of arterial thickening.

Introduction

Lipids are the building blocks of the fats and fatty substances found in animals and plants. They are microscopic layered spheres of oil, which, in animals, are composed mainly of cholesterol, triglycerides, proteins (called lipoproteins), and phospholipids (molecules made up of phosphoric acid, fatty acids, and nitrogen). Lipids do not dissolve in water and are stored in the body to serve as sources of energy.

Cholesterol is a white, powdery substance that is found in all animal cells and in animal-based foods (not in plants). In spite of its bad press, cholesterol is an essential nutrient necessary for many functions, including:

Repairing cell membranes
Manufacturing vitamin D on the skin's surface
Producing hormones, such as estrogen and testosterone
Possibly helping cell connections in the brain that are important for learning and memory

Regardless of these benefits, when cholesterol levels rise in the blood, they can have dangerous consequences, depending on the type of cholesterol. Although the body acquires some cholesterol through diet, about two-thirds is manufactured in the liver, its production stimulated by saturated fat. Saturated fats are found in animal products, meat, and dairy products.

Saturated fats are found predominantly in animal products, such as meat and dairy products, and are strongly associated with higher cholesterol levels. Tropical oils -- such as palm, coconut, and coconut butter -- are also high in saturated fats.

Triglycerides are composed of fatty acid molecules. They are the basic chemicals contained in fats in both animals and plants.

Lipoproteins are protein spheres that transport cholesterol, triglyceride, or other lipid molecules through the bloodstream. Most of the information about the effects of cholesterol and triglyceride actually concerns lipoproteins.

Lipoproteins are categorized into five types according to size and density. They can be further defined by whether they carry cholesterol or triglycerides.

Cholesterol-Carrying Lipoproteins. These are the lipoproteins commonly referred to as cholesterol.

Low density lipoproteins (LDL). (Often called the "bad" cholesterol.)
High-density lipoproteins (HDL), the smallest and most dense. (Referred to as the "good" cholesterol.)

Triglyceride-Carrying Lipoproteins.

Intermediate density lipoproteins (IDL). They tend to carry triglycerides.
Very low density lipoproteins (VLDL). These tend to carry triglycerides.
Chylomicrons (largest in size and lowest in density).

Lipoprotein(a). Lipoprotein(a), or lp(a) has a size and density somewhere between LDL and HDL. The molecules carry a protein that may interfere with the body's ability to dissolve blood clots. Lipoprotein(a) is being investigated as a possible marker or cause of heart disease.

Remnant Lipoproteins. Remnant lipoproteins are byproducts of chylomicrons, very low-density lipoproteins (VLDL), or both. Some research indicates that high levels may be an important risk factor for coronary artery disease, particularly in patients who have otherwise normal cholesterol levels.

Reducing LDL and total cholesterol levels, while at the same time boosting HDL levels, can prevent heart attacks and death in all people (with or without heart disease). Reducing LDL is the primary goal of most cholesterol therapy.

Blood tests can easily measure both HDL and overall cholesterol levels. It is very difficult to measure LDL levels by themselves, but LDL levels can be reliably calculated by subtracting HDL and triglyceride levels from total cholesterol. The exact formula is:

LDL = TOTAL CHOLESTEROL - HDL - TRIGLYCERIDES/5.

In 2004, the National Cholesterol Education Program updated its clinical practice guidelines. The new recommendations set lower treatment goals for LDL levels based on a patient's risk factors for heart disease.

The risk factors include:

Having a first-degree female relative diagnosed with heart disease before age 65 or a first-degree male relative diagnosed before age 55
Being male and over age 45 or female and over age 55
Cigarette smoking
Diabetes
High blood pressure
Metabolic syndrome (risk factors associated with obesity such as low HDL levels and high triglycerides)

Two or more of these risk factors increases by 20% the chance of having a heart attack within 10 years.

The LDL cholesterol level is one of the most important factors in determining whether a patient needs cholesterol therapy and whether the treatment is working properly. In particular, the new guidelines emphasize lower LDL levels and earlier treatment for people with coronary artery disease, or other forms of atherosclerosis, and diabetes.


Risk Level	Goal (d/L)	OptimalGoal(d/L)
Very High Risk	70	70
High Risk	100	70
Moderate Risk	130	100
Low Risk	160	130

The following chart summarizes all goals.


Total Cholesterol Goals	LDL Goals	HDL Goals	Triglyceride Goals
Less than 200 mg/dL is desirable. Between 200 and 239 is borderline. Over 240 is high.	70 mg/dL is the new goal for very high-risk patients (recent heart attack; current active or unstable cardiovascular or cerebrovascular disease; or two multiple risk factors as defined above.) Below 100 mg/dL is optimal for everyone. It should be the goal for high-risk people including those with existing heart disease, diabetes, or two or more risk factors for heart disease; 70 mg/dL is an optimal goal for these individuals. 130 mg/dL or below for people with two or more risk factors; 100 mg/dL is an optimal goal. 160 mg/dL or below for people at less risk (one or zero risk factors); 130 mg/dL is an optimal goal. Anything above 160 is high, with levels above 190 being very high. LDL levels over 190 require medication even with no other cardiac risk factors present.	Levels above 40 mg/dL are desirable; levels above 60 mg/dL are optimal.	Below 150 mg/dL is normal. 150 - 199 is borderline high. 200 - 499 is high. Over 500 is very high.
*Risk factors for heart disease include a family history of early heart problems before age 55 for men (before age 65 for women), smoking, high blood pressure, diabetes, being older (over 45 for men and 55 for women), and having HDL levels below 35 mg/dL. People with two or more of these risk factors may have a 10-year risk of heart attack that exceeds 20%, and may therefore need to aim for LDL levels of 100 mg/dL or below.

Although current guidelines as described in the table are extremely useful, they do have pitfalls. For example, the following cholesterol levels pose some dilemmas:

Low LDL levels (protective) accompanied by low HDL, high triglycerides, or both (harmful)
High total cholesterol (harmful) accompanied by high HDL (protective)

Would individuals with these cholesterol balances be at high risk or low risk for developing heart disease? To resolve this dilemma, experts have devised a calculation for a risk ratio by dividing the total cholesterol by either total HDL or LDL. It is not clear at this point which ratio is a better predictor of heart disease, although the HDL ratio may be superior. Using this ratio, the following results indicate better to worse outlook:

The ideal ratio is 3.5 or below.
A ratio of 4.5 carries an average risk.
Ratios of 5 or higher are potentially dangerous.

For example, if a person has a high total cholesterol of 280 mg/dL but a high HDL level of 70 mg/dL, the risk ratio is 4, which actually carries a lower than average risk. The use of this ratio may predict coronary artery disease more accurately than using total cholesterol levels alone. Still, the primary goal of lipid-lowering therapy is reducing LDL levels. Evidence strongly suggests that the lower the LDL levels, the lower the risk for heart disease.

Cholesterol's Effect on the Heart

Coronary artery disease, commonly known as heart disease, is the leading cause of death in the U.S. and was responsible for nearly 500,000 deaths in 2003.

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.

As many as half of these deaths were probably due to unhealthy cholesterol and lipid levels. Strong evidence points to LDL as the villain and HDL as a hero in the process. The role of other lipids, notably triglycerides, is not entirely clear.

Unhealthy cholesterol, particularly low-density lipoprotein (LDL), forms a fatty substance called plaque, which builds up on the arterial walls. Smaller plaques remain soft, but older, larger plaques tend to develop fibrous caps with calcium deposits.

Click the icon to see an image of the developmental process of atherosclerosis.

The long-term result is atherosclerosis, commonly called hardening of the arteries. The heart is endangered in two ways by this process:

Eventually these calcified and inelastic arteries become narrower (a condition known as stenosis). As this process continues, blood flow slows and prevents sufficient oxygen-rich blood from reaching the heart. This condition leads to angina (chest pain) and, in severe cases, to heart attack.

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

Smaller unstable plaques may rupture, triggering the formation blood clots on their surface. The blood clots block the arteries and are important causes of heart attack.

This process is accelerated and enhanced by other risk factors, including high blood pressure, smoking, obesity, diabetes, and a sedentary life style. When more than one of these risk factors is present, the risk is compounded.

The effects of cholesterol on the heart may involve more than just the arteries. There is some evidence that unhealthy levels may affect the heart muscles and increase the risk for heart failure. High cholesterol levels may even reduce the protection that aspirin provides for people with heart disease.

On an encouraging note, mortality rates associated with coronary artery disease have declined dramatically during the past 30 years. Some experts estimate that about 30% of the decline is due to better cholesterol management and statin drugs.

Studies consistently report a higher risk for death from heart disease with high total cholesterol levels (200 mg/dL and higher). The higher the cholesterol, the greater the risk. One study reported that men with total cholesterol levels higher than 240 mg/dL had a risk nearly two to four times that of men whose cholesterol was below 200 mg/dL. On average, every time a person's cholesterol level drops by a point, the risk of heart disease drops by 2%.

The primary villain in the cholesterol story is low-density lipoprotein (LDL). In a major study, the lowest incidence in heart disease was found among people with the lowest LDL levels. Lowering LDL is the primary goal of cholesterol drug and lifestyle therapy.

Low-density lipoprotein (LDL) transports about 75% of the blood's cholesterol to the body's cells. It is normally harmless. However, if it is exposed to a process called oxidation, LDL can penetrate and interact dangerously with the walls of the artery, producing a harmful inflammatory response. Oxidation is a natural process in the body that occurs from chemical combinations with unstable molecules. These molecules are known as oxygen-free radicals or oxidants.

When LDL collects on arterial walls these oxidants are released from the wall membranes.
Oxidants are missing an electron and tend to bind with other molecules in the body, a process called oxidation.
When the oxidation process modifies LDL, it signals the immune system that a harmful molecule has appeared.

Inflammation and Plaque. In response to oxidized LDL, the body releases various immune factors aimed at protecting the damaged walls. Unfortunately, in excessive quantities they cause inflammation and promote further injury to the areas they target:

White blood cells and other factors gather and form a fatty substance called plaque. (Of interest in this process is an enzyme called lipoprotein-associated phospholipase A2, which binds to oxidized LDL. Studies report that this enzyme may play a major role in the release of plaque-forming inflammatory factors.)
Other immune factors also cause inflammation and injure the endothelium, the layer of cells that line blood vessels.

Click the icon to see an image of the cut section of an artery.

Immune factors that increase the risk for blood clots are also mobilized.
Oxidized LDL plays another dangerous role by reducing levels of nitric oxide, a chemical that helps relax the blood vessels and allow blood to flow freely.

High density lipoprotein (HDL) appears to benefit the body in two ways:

It removes cholesterol from the walls of the arteries and returns it to the liver.

Click the icon to see an image of the liver.

It helps prevent oxidation of LDL. HDL actually appears to have its own antioxidant properties.

HDL helps keep arteries open and reduces the risk for heart attack. High levels of high HDL (above 60 mg/dL) may be nearly as important for the heart as low levels of LDL. HDL levels below 40 mg/dL are considered to be harmful. In one study, for each 4 mg/dL decline in HDL levels there was a 10% increase in coronary artery disease.

Triglycerides are major troublemakers for the heart. They appear to interact with HDL cholesterol in such a way that HDL levels fall as triglyceride levels rise. Low HDL is known to be harmful to the heart.

The harmful imbalance of high triglycerides with low HDL levels is also associated with obesity (particularly around the abdomen), insulin resistance, and diabetes. Insulin is a hormone essential for regulating the storage and use of glucose (sugar) and amino acids (proteins) in the body. Insulin resistance occurs when there are normal levels of insulin but the body cannot use it. Insulin resistance increases the risk for developing type 2 diabetes, and it is also associated with metabolic syndrome. Both of these conditions increase the risk for heart disease.

Some evidence also suggests that high triglycerides pose other dangers, regardless of cholesterol levels. Triglycerides, for example, may be responsible for blood clots that form and block the arteries. High triglyceride levels are also associated with the inflammatory response -- the harmful effect of an overactive immune system that can cause considerable damage to cells and tissues, including the arteries.

Studies are finding an elevated risk for angina and first heart attacks in people with elevated levels of lipoprotein(a), also known as or lp(a). This lipoprotein falls somewhere between HDL and LDL in density and may have some properties that increase the risk for blood clots. Some experts suggest, however, that high levels of lp(a) may merely be markers of late-stage atherosclerosis, not a cause. Because concentrations of lipoprotein(a) are usually inherited, they do not respond to dietary or lifestyle changes. At this time, few experts recommend drug treatments to reduce lp(a) levels. Older women, but not men, appear to be at greater risk for high lp(a) levels and their consequences.

Cholesterol's Effect on the Brain

Having adequate levels of HDL may be the most important lipid-related factor for preventing ischemic stroke, a type of stroke caused by blockage of the carotid arteries that carry blood to the brain. HDL may even reduce the risk for hemorrhagic stroke, a less common type of stroke caused by bleeding in the brain that is associated with low overall cholesterol levels.

The build-up of plaque in the internal carotid artery may lead to narrowing and irregularity of the artery's lumen, preventing proper blood flow to the brain. More commonly, as the narrowing worsens, pieces of plaque in the internal carotid artery can break free, travel to the brain, and block blood vessels that supply blood to the brain. This leads to stroke, with possible paralysis or other deficits.

The effects of high total cholesterol and LDL levels on ischemic stroke are less clear. One study suggested that the risk for ischemic stroke increases when total cholesterol is above 280 mg/dL. A 2002 study suggested that high cholesterol poses a risk for stroke only when specific proteins associated with inflammation are present.

Evidence points to high cholesterol levels, along with high blood pressure and a family history of the disease, as independent risk factors for AD. A major research target for common factors between cholesterol levels and AD has been apolipoprotein E (ApoE). ApoE plays a role in the movement and distribution of cholesterol for repairing nerve cells during development and after injury. People who carry a variant of this gene (ApoE4) are at significantly higher risk for AD.

High cholesterol may pose a risk for Alzheimer's regardless of this genetic factor, however. Some studies report that cholesterol is important within the brain for cell communication and memory.

Risk Factors

About half of all American adults have total cholesterol levels over 200 mg/dL. Over 25% have been told by doctors that they have unhealthy levels. Total cholesterol levels have been declining over the last several decades, at least among middle-aged and older adults. This decline may be partly due to the increased use of statins and other lipid-lowering medications. However, total cholesterol levels are getting higher among younger adults (ages 25 – 34 years). The major risk factor for these high rates may be the Western lifestyle. The typical high-fat/low-fiber American diet coupled with sedentary habits is largely responsible for this unfortunate trend.

Men. Heart disease is the major cause of death in men. On average, men develop coronary artery disease 10 - 15 years earlier than women do and have a greater risk for dying of heart disease at a younger age. A 2006 study suggested that high total cholesterol may also contribute to the development of high blood pressure in men.

Women. Coronary artery disease is also the number one killer of women. Women between the ages of 20 and 34, and after menopause (around age 55), have higher cholesterol levels than men. Some evidence suggests that HDL levels may be more significant in women than in men. In one study, at total cholesterol levels above 200, women with HDL levels below 50 had a higher death rate than those with levels above 50, regardless of their LDL cholesterol levels. Women also appear to be more susceptible to the high-triglyceride low-HDL syndrome, which may be a particular risk factor for heart disease.

Children and Adolescents. Children who have abnormal cholesterol levels are at increased risk of developing heart disease later in life. However, it is difficult to distinguish “normal” cholesterol levels in children. Changes in cholesterol levels occur between the ages of 8 - 18, and vary between genders and population groups. Cholesterol levels tend to naturally rise sharply until puberty, then decrease sharply, and then rise again.

In 2007, the American Heart Association established general LDL goals for children that take into account these fluctuations. The association’s LDL goals are 190 mg/dL or less for children with no additional heart disease risk factors and 160 mg/dL or less for children with additional risk factors (such as family history of high cholesterol, heart disease, and diabetes).

It is also clear that children who are overweight are at higher risk for high triglycerides and low HDL, which may be directly related to later unhealthy cholesterol levels. Studies have confirmed that childhood LDL levels and body-mass index (BMI) are strongly associated with cardiovascular risk during adulthood. The American Heart Association recommends that children who are overweight and obese, as well as those with a family history of high cholesterol, undergo cholesterol screening. Overweight and obese children who have high cholesterol should also get tested for high blood pressure, diabetes, and other conditions associated with metabolic syndrome.

As in adults, the primary source of unhealthy cholesterol levels in children comes from diets high in unhealthy fats: Saturated fats (found mainly in animal and dairy products) and trans fatty acids (found in commercial food products). Over-consumption of unhealthy fats increases the risk for both obesity and heart disease.

Less common causes of unhealthy cholesterol levels in children include:

Low-birth weight (associated with low HDL levels)
Low thyroid levels (hypothyroidism)
Kidney or liver diseases
Homozygous familial hypercholesterolemia. This is an uncommon inherited condition that causes severe cholesterol imbalances and can result in very early heart disease.
Certain medications such as specific antiseizure drugs, corticosteroids, and isotretinoin (Accutane)

Young and Middle-Aged Adults. The strongest evidence of unhealthy cholesterol levels and heart disease is in adults over age 45. However, a 2006 analysis found that while total cholesterol levels are decreasing among older adults, they are increasing in those age 25 - 34 years. Research strongly suggests that the younger a person is when unhealthy cholesterol levels develop, the greater the chance for serious heart and blood vessel problems in the future. A 2006 study in the New England Journal of Medicine indicated that keeping LDL levels low from an early age can help prevent heart disease later in life. In one important study, young men (ages 16 - 34) who had cholesterol levels at or above 240 mg/dL had two to four times the risk of dying from heart attack or other cardiac problems than did men whose cholesterol was lower than 200 mg/dL. Young men without cholesterol problems had a higher life expectancy, by up to 8 years. Other studies have suggested similar risks from unhealthy cholesterol in young women as well.

Elderly Adults. About 85% of people who die from coronary artery disease are over the age of 65. Because high cholesterol is an important risk factor for heart disease, experts strongly recommend statin or other lipid-lowering therapy for elderly people with high cholesterol levels. Surveys indicate that total cholesterol levels have been declining in older people over the last few decades. Many experts believe this is due in part to increased use of statin drugs.

In the U.S., obesity is at epidemic levels in all age groups. The effect of obesity on cholesterol levels is complex. Although obesity does not appear to be strongly associated with overall cholesterol levels, obese individuals tend to have high triglyceride levels and low HDL levels. This combination is a risk factor for heart disease. Obesity also causes other effects (high blood pressure, increase in inflammation) that pose major risks to the heart.

Obesity is a particularly hazard when it is one of the components of the metabolic syndrome, formerly known as syndrome X. This syndrome consists of obesity marked by abdominal fat, unhealthy cholesterol levels, high blood pressure, and insulin resistance. Metabolic syndrome is a pre-diabetic condition that is significantly associated with heart disease and higher mortality rates from all causes. A 2002 study estimated that 24% of the population now has this condition. Many experts recommend that patients with metabolic syndrome should be aggressively treated with high-dose statin therapy to lower LDL levels.

Obesity is also strongly associated with type 2 diabetes, which itself poses a significant risk for high cholesterol levels and heart disease.

Low thyroid levels (hypothyroidism) are associated with unhealthy lipid levels. (Lipids are fat molecules). Specifically, people with hypothyroidism are at higher risk for high total and LDL cholesterol, triglycerides, and other lipids associated with heart disease. Treating the thyroid condition can significantly reduce cholesterol levels. Some experts suggest that patients with high cholesterol should be evaluated for thyroid function before they are given cholesterol-lowering drugs. Research is mixed on whether mild hypothyroidism (subclinical hypothyroidism) is associated with unhealthy cholesterol levels. [See In-Depth Report #38: Hypothyroidism.]

Hypothyroidism is a decreased activity of the thyroid gland which may affect all body functions. In this condition, the rate of metabolism slows, causing mental and physical sluggishness. The most severe form of hypothyroidism is myxedema, which is a medical emergency.

Genetics play a major role in determining a person's blood cholesterol levels. Children from families with a history of premature heart disease should be tested for cholesterol levels after they are 2 years old. Genes may influence whether a person has low HDL levels, high LDL levels, high triglycerides, or high levels of other lipoproteins, such as lipoprotein(a).

Some inherited disorders and genetic abnormalities have been identified:

Familial hypercholesterolemia causes dangerous increases in cholesterol. It may be more common than previously thought. One European study reported familial hypercholesterolemia in 1 out of every 400 people.
Familial lipoprotein lipase deficiency is a very rare disorder that causes depletion of lipoprotein lipase. This is an enzyme that appears to be important in the removal of lipoproteins that are rich in triglycerides. People who are deficient in it have high levels of cholesterol and fat in their blood. A very low-fat diet is essential and is an effective treatment for these individuals.
Several studies have found a genetic mutation affecting neuropeptide Y in people with high total cholesterol and LDL levels. Neuropeptide Y is a compound in the brain that regulates appetite.
Researchers have identified a gene called APOAV, which may help detect patients at risk for elevated levels of triglycerides.

Other medical conditions strongly associated with unhealthy cholesterol levels include:

Polycystic ovarian syndrome. Women with this disorder, particularly those who are obese, appear to be at increased risk for high triglyceride and low HDL levels. This risk may be due to higher levels of the male hormone testosterone in these women.

Click the icon to see an image of a polycystic ovary.

Kidney disease

Symptoms

There are no warning signs for high LDL cholesterol levels. When symptoms finally occur, they usually take the form of angina or heart attack in response to the buildup of atherosclerotic plaque in the patient's arteries. This is definitely a condition where it pays to invest in preventive medicine before dangerous complications occur.

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.

Diagnosis

A blood test for cholesterol should include the entire lipoprotein profile: LDL, total cholesterol, HDL, and triglycerides. It is very difficult to measure LDL levels by themselves, but LDL levels can be reliably calculated using total cholesterol and HDL levels.

To obtain a reliable cholesterol reading, experts advise:

Avoid strenuous exercise for 24 hours before the test.
Do not eat or drink anything but water for 12 hours beforehand.
If the test results are abnormal, a second test should be performed between 1 week and 2 months after the first test.

Home Tests. Tests are available for home use and in public locations, such as shopping malls and pharmacies. For example, the CholesTrak Test can be taken at home with results in 10 minutes, but it measures only total cholesterol. The BioSafe Cholesterol Panel Test is also a home test, but it needs to be sent to a laboratory. This test, however, is very accurate and provides a full lipid profile.

Certain blood tests for factors associated with inflammation in the arteries indicate a higher risk for heart disease, even in people without unhealthy lipids:

C-reactive protein (CRP). CRP is regulated by a very potent immune factor called interleukin-6. Elevated levels have been strongly associated with the inflammatory response and a higher risk for heart attack, even in people with normal cholesterol levels. CRP is also associated with high blood pressure, insulin resistance (the primary problem in type 2 diabetes), and obesity.
A high white blood cell count.
Elevated fibrinogen (a factor responsible for blood clotting).
Lipoprotein-associated phospholipase A2 may prove to be another marker for inflammation and heart disease. Studies suggest that it may play some causal role in coronary artery disease.

A new type of test measures cholesterol levels in the skin. High skin levels may indicate an increased risk for atherosclerosis and serious heart disease.

General Screening Recommendations. Experts groups differ slightly on when screening should start, but the following are generally accepted recommendations:

Periodic cholesterol testing in all adults starting at age 20. Adults with normal cholesterol levels do not need to have the test repeated for 5 years unless changes occur in lifestyle (including weight gain and diet). Adults with risk factors for heart disease or stroke should be rechecked every 2 years.
Selective screening of children who are at risk for high cholesterol and heart disease or familial hypercholesterolemia, which is genetically elevated cholesterol. Risk factors include having parents with total cholesterol levels greater than 240, or having a parent or grandparent who had symptomatic heart disease at age 55 or younger.
Patients already being treated for high cholesterol should be checked every 2 - 6 months.

Lifestyle Changes

Although most studies that prove that lowering cholesterol saves lives are done using drug therapy, the absolute mandate for improving cholesterol levels is to first make changes in lifestyle (both diet and exercise). Even when drugs are used, healthy diet and physical activity are critical companions.

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. Walnuts in particular have cholesterol-lowering properties and are a good source of antioxidants and alpha-linolenic acid.
Avoid saturated fats (found mostly in animal products) and 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.
Controlling weight, quitting smoking, and exercising are essential companions of any diet program.

After embarking on any heart healthy diet, it generally takes an average of 3 - 6 months before any noticeable reduction in cholesterol occurs. However, some people see improved levels in as few as 4 weeks. An intensive program may be necessary to achieve significant improvements in cholesterol levels and to reduce heart risk factors.

Therapeutic Lifestyle Changes (TLC) from the National Cholesterol Education Program. Guidelines from the National Cholesterol Education Program include these recommendations for preventing and managing high cholesterol levels in adults:

Choose five or more servings of fresh fruits and vegetables and six or more servings of whole grains, legumes. Soluble fiber is preferred (from cereal grains, beans, peas, legumes, and many fruits and vegetables).
Fats can be up to 35% of daily calories, but no more than 7% should be from saturated fat. (People with high triglycerides, low HDL, or both may need a higher fat intake.) Choose fats containing unsaturated fatty acids (from vegetables, fish, legumes, and nuts). Choose margarines containing sterols or stanols (Benecol, Take Control). Avoid trans fatty acids found in commercial baked products.
Protein choices should be fat-free and low-fat milk products, fish, legumes, skinless poultry, and lean meats.
Limit dietary cholesterol intake to less than 200 mg per day.
Maintain healthy body weight and a healthy level of physical fitness.

Mediterranean Diet. The Mediterranean diet is rich in heart-healthy fiber and nutrients, including omega-3 fatty acids and antioxidants. The diet consists of fruits, vegetables, and unsaturated “good” fats, particularly olive oil. Olive oil has been associated with lower blood pressure, a lower risk for heart disease, and possible benefits for people with type 2 diabetes. Olive oil also contains polyphenol, which are phytochemicals that may help boost HDL levels.

A 2006 study that compared several types of Mediterranean diets to a low-fat diet found that Mediterranean diets were better at lowering blood pressure, cholesterol levels, and blood sugar levels after only 3 months. And, in research presented at the 2007 American College of Cardiology annual conference, the Mediterranean diet proved just as good as the American Heart Association low-fat diet for preventing recurrence of heart attack, stroke, or other heart events.

There are several variations to the Mediterranean diet but general recommendations include:

Limit red meats.
Drink one or two glasses of wine each day if alcohol is enjoyable and there are no reasons to restrict its use.
Limit dairy products.
Eat moderate amounts of fish and poultry. Fish is the diet’s main protein source. Some studies suggest that fish is the primary heart-protective ingredient in this diet.
Eat plenty of fresh fruits and vegetables, nuts, legumes, beans, and whole grains.
Season with garlic, onions, and herbs. Unfortunately, garlic does not appear to help lower cholesterol, but it may have other heart benefits. [See Herbs and Supplements in this section.]

Low-Carbohydrate Diets. The Atkins, South Beach, The Zone, and other diet restrict carbohydrate intake include. A 2006 review of low-carbohydrate diets found that they did help weight loss in the short term. However, while these diets appeared to lower triglyceride and raise HDL (“good”) cholesterol levels, they also raised overall and LDL (“bad”) cholesterol levels.

In contrast, a 2007 Journal of the American Medical Association study that compared four different low-carbohydrate and low-fat diet plans (Atkins, Zone, Ornish, and LEARN) found that the Atkins diet was best at raising HDL levels and reducing triglyciderides. In terms of LDL reduction, the low-fat Ornish diet produced the best improvements while the Atkins diet had no effect on LDL. The Atkins diet did result in better moderate weight loss (an average of 10 pounds over the course of a year versus 4 - 6 pounds for the other diet plans), which in itself may have accounted for the improved heart risk factors.

Glycemic Index. Low-carb diets -- such as South Beach, The Zone, and Sugar Busters -- rely on a concept called the "glycemic index," or GI, which ranks foods by how fast and how high they cause blood sugar levels to rise. Foods on the lowest end of the index take longer to digest. Slow digestion wards off hunger pains. It also helps stabilize insulin levels. Foods high on the glycemic index include bread, white potatoes, and pasta while low-glycemic foods include whole grains, fruit, lentils, and soybeans. (These low-glycemic foods are also important components of low-fat diet plans.) A 2006 study indicated that a high-protein, low-glycemic index diet can help produce better reductions in total and LDL cholesterol than a high-protein, high-glycemic index diet. Reducing glycemic load may also help to promote weight loss, especially for women.

Low Fat Diets. Dietary guidelines recommend keeping total fat intake to 20 - 30% of total daily calories, with saturated fat less than 10% of calories. Low-fat diets generally restrict fat intake to 20% or less of total daily calories. The Ornish program, which is recommended for some heart disease patients, limits fats even more drastically. It aims at reducing saturated fats as much as possible, restricting total fat to 10%, and increasing carbohydrates to 75% of calories. In 2006, the largest study to date on low-fat diets found that they did not help prevent heart disease or cancer. Women in the study reduced their fat consumption to 24 - 29% of total daily calories. Some critics say that the study did not do enough to distinguish between good types of fats (monounsaturated omega-3 polyunsaturated) and bad fats (saturated and trans fats).

The DASH Diet. 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).

The DASH diet recommends:

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. Many of these foods are rich in potassium, fiber, or both which may help 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 lower blood pressure even more, 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 mostly plant sources) or monounsaturated fats may help reduce heart disease risk factors.

Calorie Restriction. Calorie restriction has been the cornerstone of weight-loss programs. Restricting calories in such cases also appears to have beneficial effects on cholesterol levels, including reducing LDL and triglycerides and increasing HDL levels. At this point, reducing calories and increasing exercise is still the best method for maintaining weight loss and preventing serious conditions, notably diabetes. A 2006 study reported that a low-calorie, but nutritionally balanced diet can help prevent an aging-associated change in heart function. Patients in the small study took in 1,400 - 2,000 calories a day for an average of 6 years.

The standard dietary recommendations for losing weight are the following:

As a rough rule of thumb, one pound of fat equals about 3,500 calories, so one could lose a pound a week by reducing daily caloric intake by about 500 calories a day. Naturally, the more severe the daily calorie restriction, the faster the weight loss.
To determine the daily calorie requirements for specific individuals, multiply the number of pounds of ideal weight by 12 - 15 calories. The number of calories per pound depends on gender, age, and activity levels. For instance, a 50-year-old moderately active woman who wants to maintain a weight of 135 pounds might require only 12 calories per pound (1,620 calories a day). A 25-year-old female athlete who wants to maintain the same weight might require 25 calories per pound 2,025 (calories a day).

Fat intake should be no more than 30% of total calories. Most fats should be in the form of monounsaturated fats (such as olive oil). Saturated fats (found in animal products) should be avoided.

Inactivity is one of the four major risk factors for coronary artery disease, on par with smoking, unhealthy cholesterol, and high blood pressure. In fact, studies suggest that people who change their diet in order to control cholesterol only achieve a lower risk for heart disease when they also follow a regular aerobic exercise program.

People who maintain an active lifestyle have a 45% lower risk of developing heart disease than sedentary people. Even moderate exercise reduces the risk of heart attack. One study of women found that just 1 hour of walking a week was associated with a lower risk for heart disease. The effects were similar even in women at high risk for developing heart disease.
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.
Burning at least 250 calories a day (the equivalent of about 45 minutes of brisk walking or 25 minutes of jogging) seems to offer the greatest protection against coronary artery disease, most likely because it raises HDL ("good cholesterol") levels. Moderate exercise has little effect on HDL.
Aerobic exercise helps to open up blood vessels and, in combination with a healthy diet, may improve blood-clotting factors.
Resistance (weight) training offers a complementary benefit to aerobics by reducing LDL ("bad cholesterol") levels.
Exercises that train and strengthen the chest muscles may prove to be very important for patients with angina.

Cigarette smoking lowers HDL and is directly responsible for approximately 20% of all deaths from heart disease. The importance of breaking this habit cannot be emphasized enough. Once a person quits smoking, HDL cholesterol levels rise within weeks or months to levels that are equal to their nonsmoking peers. Passive smoking also reduces HDL levels in people exposed to cigarette smoke.

A number of studies have found heart protection from moderate intake of alcohol (one or two glasses a day). Moderate amounts of alcohol help raise HDL levels. Although red wine is most often cited for healthful properties, any type of alcoholic beverage appears to have similar benefit. Pregnant women, anyone who cannot drink moderately, and people with liver disease should not drink at all.

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 a number of 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.

The following natural remedies are of interest for cholesterol control:

Garlic. Contrary to popular belief, garlic does not significantly reduce cholesterol, according to a 2007 Archives of Internal Medicine study. Researchers tested raw garlic and two types of garlic supplements in 192 patients with moderately high LDL levels. None of the forms of garlic had any effect on LDL levels. However, the researchers note that garlic may still help people with very high LDL levels and it may contain other heart-protective properties.

Policosonol. Policosanol is a nutritional supplement derived from sugar cane that has been promoted as having lipid-lowering benefits. In a randomized, placebo-controlled trial published in 2007 in the Archives of Internal Medicine, policosanol was no better than placebo in reducing LDL levels.

Treatment

In 2004, the National Cholesterol Education Program issued its latest recommendations for cholesterol control and management. These guidelines increase the number of Americans who should be taking LDL-lowering medication.

Starting Medications. Even modest lowering of high cholesterol levels, whether through drug therapy or lifestyle changes, reduces the risk of disability and death from heart disease. Most experts now focus on lowering LDL ("bad") cholesterol. Reducing LDL levels is particularly critical for patients with diabetes.

The doctor will start or consider medication when:

LDL cholesterol is 190 mg/dL or higher.
LDL cholesterol is 160 mg/dL or higher AND patient has one risk factor for heart disease.
LDL cholesterol is 130 mg/dL or higher AND patient has either diabetes or two other risk factors for heart disease.
LDL cholesterol is 100 mg/dL or higher AND patient has heart disease. (If patient has diabetes, even without heart disease, medication may be considered for an LDL cholesterol of 100 mg/dL.)
LDL cholesterol is greater than 70 mg/dL AND patient has had a recent heart attack or has known heart disease along with diabetes, current cigarette smoking, poorly controlled high blood pressure, or the metabolic syndrome (high triglycerides, low HDL, and obesity).

Risk factors for heart disease include:

Having a first-degree female relative diagnosed with heart disease before age 65 or a first-degree male relative diagnosed before age 55
Being male and over age 45 or female and over age 55
Cigarette smoking
Diabetes
High blood pressure
Metabolic syndrome (risk factors associated with obesity such as low HDL levels and high triglycerides)

Recent studies have found that aggressive lipid lowering with high-dose statin therapy is more beneficial than standard statin therapy in patients with existing heart disease. The Pravastatin or Atorvastatin Evaluation and Infection Trial (PROVE-IT) and the Reversal of Atherosclerosis with Aggressive Lipid-Lowering trial (REVERSAL) compared the benefits of standard statin therapy (pravastatin, 40 mg) with intensive statin therapy (atorvastatin, 80 mg) in treating patients with heart disease.

Results from PROVE-IT demonstrated that for high-risk patients, intensive statin therapy is more effective than standard therapy in lowering LDL cholesterol and C-reactive protein (CRP) levels, and that CRP levels predict risk even when LDL cholesterol has been lowered substantially. The REVERSAL data suggest that intensive statin therapy produces greater reductions in LDL and CRP levels, and that the more that statins can lower LDL, the more effective they are in reducing the progression of atherosclerosis.

An important 2006 study found that aggressive treatment with rosuvastatin (Crestor):

Helped lower LDL to below guideline levels
Moderately increased HDL levels
Reduced fatty plaque in the arteries

Experts hoped that these results suggested that statin therapy might have the potential to reverse coronary atherosclerosis. However, a follow-up 2007 study of rosuvastatin indicated that while the drug slowed the rate of atherosclerotic progression, it did not reverse heart disease. Future studies will continue to investigate this issue and to explore whether other statins have a similar positive effect on coronary artery disease. Rosuvastatin lowers LDL more than other statins, but it also carries greater risks for more serious side effects (see Adverse Effects section). Many experts believe that the more that LDL is reduced through statin therapy, the greater the reduction in risk for heart disease, heart attack, and stroke.

It is important to emphasize that cholesterol-lowering medications are used along with healthy lifestyle habits, not in place of them.

Choosing the Correct Lipid-Lowering Medication. Experts now recommend that drug treatments be tailored for raising or lowering specific lipids, depending on the patient's blood lipid picture:

Statins are now the standard drugs for most people who require LDL-lowering therapy. Bile-acid binding resins or niacin may be considered. If LDL goals are not achieved, combinations of a statin with a bile-acid resin or niacin should be considered.
Fibrates or niacin are beneficial for people who need to lower triglycerides and increase HDL.

Considerations for Children and Adolescents. In 2007, the American Heart Association (AHA) issued a scientific statement addressing the use of cholesterol drugs in children and adolescents. The AHA recommends that for children who are overweight or obese, lifestyle modifications (diet, exercise) are preferred over drug therapy and should be the first step in lowering cholesterol.

For children and adolescents who have high-risk cholesterol imbalances -- and have a family history of high cholesterol, heart attack, stroke, and diabetes -- the AHA now recommends statins as the first-line drug therapy.

Considerations for People with Diabetes. At this time, statins are recommended as the best drugs for improving cholesterol and lipid levels in people with diabetes. Studies suggest that they can reduce the risk for adverse heart events in people with diabetes, even if their cholesterol levels are normal or if their diabetes is mild. Furthermore, in one study, a statin was shown to reduce the risk of developing diabetes by 30% in people with high cholesterol. Fibrates may also be useful for people with type 2 diabetes. Niacin (nicotinic acid) has the best effect on the cholesterol profile of people with diabetes but it also increases blood sugar levels. One well-controlled study, however, found that people with diabetes who used niacin had little trouble with glucose control, and some experts believe it now may be used as an alternative to or in combination with statins.


	Effect on High LDL	Effect on Low HDL	Effect on High Triglycerides	Effect on Lp(a)
Statins	Decrease (18 - 55%)	Modest increase (5 - 15%)	Decrease (7 - 30%)	No change
Nicotinic acid (Niacin)	Modest decrease (5 - 25%) In combination with statins, may convert more dangerous LDL type to less dangerous.	Increase (15 - 35%) Drugs of choice for improving HDL levels	Decrease (20 - 50%) Drug of choice for lowering triglycerides	Decrease
Fibrates	Effect varies, but in general has little effect or modest decrease (5 - 20%)	Modest increase (6 - 20%)	Decrease (20 - 50%)	No change
Bile acid-binding resins	Decrease (15 - 30%)	Very modest increase (3 - 5%)	No change	No change

Statins are the most effective drugs for the treatment of high cholesterol, and may even prove important drugs for many people at risk for heart disease who have normal cholesterol levels. Statins inhibit the liver enzyme HMG-CoA reductase, which is used in the manufacturing of cholesterol. These drugs effectively reduce the risk of major coronary events, including first and second heart attacks, in both adult women and men of any age with unhealthy cholesterol levels. Experts estimate a 25 - 30% reduction in mortality rates when patients take statins after a heart attack. (Some believe the decrease may even be greater.) These drugs may also help improve the outcome in patients with heart disease who have had angioplasty.

Important studies have reported lower rates of heart attack, stroke, and mortality rates from all causes in statin users who were at high risk for heart disease, even if they had normal or low cholesterol levels. Benefits were similar in these people regardless of gender, age, or the presence of specific heart risk factors, such as diabetes or peripheral artery disease.

Brands. Statins are currently categorized into four groups:

So-called natural statins, including lovastatin (Mevacor, generics), pravastatin (Pravachol), and simvastatin (Zocor, generics). These are the most studied statins and have proven effectiveness and good safety record.
Synthetic statins include fluvastatin (Lescol) and atorvastatin (Lipitor). Studies using atorvastatin suggest they may reduce LDL more effectively than natural statins. In 2007, Lipitor was approved for additional indications to reduce the risk of heart attacks, strokes, certain types of heart surgery, hospitalization for heart failure, and chest pain in patients with heart disease. Lipitor is also approved for children.
The newer statins include rosuvastatin (Crestor), which was approved in 2003. Trial results have suggested that rosuvastatin is more effective in improving lipid profiles than atorvastatin, simvastatin, or pravastatin. However, like all statin drugs, rosuvastatin can cause serious side effects (see the Adverse Effects section in this report). The risks may be higher for Asian patients; this population should be started on the lowest rosuvastatin dose (5 mg).
Fixed-dose combination statins, which combine two drugs in one pill, first appeared on the market in 2004. Ezetimibe/simvastatin (Vytorin) combines two cholesterol medications that work in different ways. Simvastatin blocks cholesterol production in the liver, while ezetimibe (a non-statin cholesterol medication) blocks cholesterol absorption in the digestive tract. A 2005 study found that Vytorin was more effective than atorvastatin in lowering LDL and increasing HDL levels. Amlodipine/atorvastatin (Caduet) is a dual-therapy medication that combines the antihypertensive calcium channel blocker amlodipine with atorvastatin. It is used to treat simultaneously high blood pressure and high cholesterol.

Statins are generally administered once a day, typically in the evening because most cholesterol synthesis occurs between midnight and 3 a.m. (Atorvastatin and rosuvastatin, however, can be taken in the morning.) Statins are often prescribed along with other cholesterol-lowering drugs such as bile acid-binding resins, nicotinic acid (niacin), and fibrates.

Beneficial Effects on the Heart and Circulation.

Statins are particularly effective for lowering LDL levels. They also reduce triglycerides, apparently in direct proportion to their LDL-lowering effects. Statins also raise HDL levels, but to a lesser extent than other anti-cholesterol drugs. (The newer statins appear to produce more significant increases in HDL.) Evidence now strongly suggests that statins may offer other health benefits beyond lowering cholesterol:

Statins may improve the function of the endothelium (the lining of blood vessels), thereby improving blood flow. (This benefit apparently does not extend to people with diabetes.)
Statins appear to reduce inflammation in the arteries, which is now believed to be a major factor in blood vessel injury.
Some evidence suggests that statins may help prevent blood clotting, a major factor in heart attacks.

Beneficial Effects Outside the Heart. Studies also suggest that the benefits of statins go beyond the heart. At this time, nearly all studies on the following conditions have used natural statins:

Stroke. Statins may reduce the risk for ischemic stroke in high-risk patients with a wide range of cholesterol and lipid levels. (Ischemic strokes occur from blockage in the blood vessels that lead to the brain.) In 2003, statin therapy was shown to reduce both fatal and non-fatal stroke in patients with hypertension and at least three additional cardiovascular risk factors. A 2004 study of stroke patients found that those who were receiving statin therapy at the time of their stroke had more favorable long-term outcomes than patients who were not on statin therapy, suggesting that statin therapy may provide additional benefits to patients who develop stroke.
Diabetes. Statins may have a number of effects that are helpful for patients with diabetes, and may even prevent diabetes in some people with high cholesterol. Statins, however, do not appear to have any effect on blood vessel inflexibility in diabetes, which is an important risk factor for heart disease in these patients. A major 2003 study found that statin therapy helped prevent cardiovascular events including coronary death, heart attack, stroke, and the need for revascularization therapy in patients with diabetes, even in those who did not have high cholesterol levels or established coronary disease.
High Blood Pressure. In an important 2002 study, patients with high blood pressure but normal hMG-CoA reductase or slightly high cholesterol levels had fewer heart attacks and strokes when they took the statin atorvastatin. The study was stopped so all subjects could take statins. An earlier study showed similar benefits with the statin simvastatin.
Alzheimer's Disease. A number of studies have reported a significantly lower risk for Alzheimer's disease in people who take specific statins. Some evidence suggests they may even improve mental function in people without unhealthy cholesterol levels. Statins showing the greatest promise include lovastatin (Mevacor), pravastatin (Pravachol), and atorvastatin (Lipitor.) These statins appear to reduce levels of beta-amyloid. Other statins have not been associated with a lower risk for Alzheimer's. In fact, some researchers are concerned that certain statins that cross the blood-brain barrier may actually worsen Alzheimer's in people who already have it.
Kidney Disease. Statins may prove to protect against heart disease development in patients with mild kidney disorders. According to a 2004 study, statins may also help slow the progression of existing kidney disease.
Eye Disease. Studies are investigating whether statins can help prevent macular degeneration, an age-related eye disease that can lead to blindness. Research is still preliminary, and results have been mixed.

Macular degeneration is a disease of the retina that affects the macula in the back of the eye. The macula is important for clear central vision, allowing an individual to see fine details. There are two types of macular degeneration, dry and wet. Dry macular degeneration is more common and is characterized by the thinning of the retina and drusen, small white deposits that form within the retina. The dry form of macular degeneration is usually mild. Wet macular degeneration can happen more quickly and be more serious. It occurs when vessels under the retinal layer hemorrhage and cause the retinal cells to die, creating blind spots or distorted vision in the central vision. The disease becomes increasingly common among people in each succeeding decade over 50.

Adverse Effects. The statins tend to be better tolerated than other cholesterol-lowering drugs. In many studies the side effects reported were nearly the same as those taking placebo. Side effects may include gastrointestinal discomfort, headaches, skin rashes, muscle aches, sexual dysfunction, drowsiness, dizziness, nausea, constipation, and peripheral neuropathy (numbness or tingling in the hands and feet).

The primary safety concern with statins has involved an uncommon condition called myopathy, which can cause muscle damage and in some cases, muscle and joint pain. A specific myopathy, called rhabdomyolysis, can lead to kidney failure. Reports of rhabdomyolysis prompted the recall of cerivastatin (Baycol) in 2001. The risk for myopathy/rhabdomyolysis is highest at higher doses and in older people (over 65 years), those with hyperthyroidism, and those with renal insufficiency (kidney disease). Both statins and fibrates carry a risk for myopathy. The combination of the two drugs increases this side effect. Some people who use a statin-fibrate combination withdraw from the regimen because of muscle discomfort.

In 2005, the FDA issued a public health advisory for rosuvastatin (Crestor), noting that this drug, like other statins, increased the risk for myopathy and rhabdomyolysis. The risks were greatest at the highest dose level (40 mg). The FDA advises that patients should not start therapy at this dose. In addition, the FDA reported the results of a post-marketing study that found that people of Asian heritage had twice the blood levels of the drug as Caucasians who had taken the same dose. Because of this difference in drug metabolism, the FDA advises that Asian Americans should start treatment at the lowest rosuvastatin dose (5 mg). In general, all statin therapy should start at a lower dose and be raised incrementally until healthy cholesterol levels are maintained. Patients should immediately tell their doctor about any unusual muscle discomfort or weakness, fever, nausea or vomiting, or darkening of urine color.

Statins can also affect the liver, particularly at higher doses, so patients should have periodic liver function tests. Statins should not be taken by anyone with liver problems or by women during pregnancy or breast-feeding. Similarly, high statin doses increase the risk for kidney failure, particularly for patients with other existing risk factors (diabetes, hypertension, atherosclerosis, history of heart failure).

Interactions with Drugs and Food. Statins may have some adverse interactions with other drugs, including other cholesterol-lowering medications. Among the drugs that increase the risk for adverse effects are cyclosporine, macrolide antibiotics, and certain antifungals. Patients should tell their doctors about any other medications they are taking. Grapefruit juice and Seville oranges may increase statin potency.

Brands. Nicotinic acid is the active compound found in niacin, or vitamin B3. It is the first choice for patients with low HDL levels. Brands include Niacor, Nicolar, and Slo-Niacin. An extended-release form (Niaspan), administered at bedtime, may have fewer side effects, including headaches and flushing, than rapidly-acting niacin drugs. Although niacin is available over the counter, the active form used for cholesterol is given in much higher doses and is available only by prescription. It is important to take this medication under a doctor's direction in order to ensure its safety and effectiveness.

Benefits. When used in high doses, it has the following benefits:

Raises HDL levels higher than other anti-cholesterol drugs
Reducing triglyceride levels very effectively
Lowers LDL-cholesterol and lipoprotein(a)
Costs less than other anti-cholesterol drugs

Combinations with other drugs, particularly statins, may add significant benefits.

Side Effects. Many patients do not like the side effects of the rapidly-absorbed form of nicotinic acid. About a quarter of patients who use rapid-acting forms of nicotinic acid stop taking them. The most common side effects are flushing of the face and neck, itching, headache, blurred vision, and dizziness. They usually occur between 5 minutes to hours after taking the drug and can last for minutes to, uncommonly, hours. The body does eventually become tolerant to these effects, and they generally subside.

The following may reduce flushing and itching:

Starting with low doses taken at mealtime and gradually working up to the prescribed dose.
Taking low-dose aspirin about 30 minutes before taking nicotinic acid. This may help prevent flushing.
Avoiding hot drinks.
Choosing an extended release form. (Even with this form, it is wise to gradually increase the bedtime dose over time and take a low-dose aspirin a half-hour beforehand.)

Stomach problems are common. Other side effects include dry skin and mucous membranes and darkening of the skin.

About 30% of patients who take niacin experience elevated levels in blood glucose, which can be a problem for people with diabetes. Niacin's effects on HDL and triglycerides, however, are especially suited for the lipid imbalances that are common in diabetes. And, some studies report that people with diabetes who use niacin have little trouble with blood sugar control.

Potentially Serious Complications. About 3 - 5% of people taking nicotinic acid develop liver problems, which disappear after the medication is discontinued. The extended form (Niaspan) appears to be safe for the liver, but people with chronic liver disease should not use any form of nicotinic acid. People with gout should also avoid nicotinic acid because it elevates uric acid.

Bile-acid binding resins work, as their name suggests, by binding to bile in the digestive tract. This reduces cholesterol in the following way:

Bile is made in the liver and is used as one of the body's primary manufacturing components.

Click the icon to see an image of the gallbladder.

Once the resins bind to bile in the digestive tract, the bile is excreted in feces.
As the resins eliminate bile from the body, the liver takes more cholesterol from the bloodstream in order to produce more bile.
As cholesterol is taken out of the bloodstream, LDL levels drop.

When used in combination with dietary control, LDL levels are reduced by 15 - 20%. Combinations with nicotinic acid are even more effective, with reductions of 40 - 60% observed.

Brands. The bile-acid binding resins and similar drugs include cholestyramine (Questran, Questran Light). They are commonly used in a powder that is dissolved in liquid. Colesevelam (Welchol) is available in tablet form.

Side Effects. None of these drugs poses major risks. Most, however, cause constipation, heartburn, gas, and other gastrointestinal problems, side effects that many people cannot tolerate. One study found that only half the standard dose of colestipol was needed when psyllium, (a soluble fiber supplement found in Metamucil, Fiberall, and Perdiem), was added to the drink. In addition, bloating and constipation were reduced. Colesevelam, a newer resin, appears to have significantly fewer of these side effects.

Bile-acting drugs may contribute to calcium loss and therefore increase the risk for osteoporosis. Over time, deficiencies of vitamins A, D, E, and K may occur, and vitamin supplements may be necessary.

Rarely, toxic effects on the liver have been reported. Patients with liver disorders should be monitored.

Drug Interactions. Bile-acid binding resins may also interfere with other medications, including digoxin (Lanoxin), warfarin, beta-blocker drugs, and a number of medications used to treat low blood sugar. In order to prevent drug interactions, other drugs should be taken 1 hour before or 4 - 6 hours after taking the bile acid-binding resins.

Brands. Fibrates (sometimes called fibric acid derivatives) break down the particles that make triglycerides. Gemfibrozil is the standard fibrate. It is usually taken twice a day, 30 minutes before breakfast and before the evening meal. Newer fibrates, including fenofibrate (Lofibra, Tricor, Triglide), may be more effective in lowering cholesterol than gemfibrozil.

Benefits. Most fibrates have been shown to lower the risk of heart attack. In a 2001 study, men with both low HDL and LDL levels had a slightly lower risk of stroke after taking gemfibrozil. Fibric acid derivatives, or fibrates, have the following effects on cholesterol, lipids, and other factors:

They are good choices for many patients who need to lower triglyceride levels and increase HDL but who cannot take drugs ordinarily used for these purposes, such as nicotinic acid. In one study gemfibrozil, the standard fibrate, reduced the risk for adverse heart events by 22%.
Fibrates can produce modest reductions in LDL levels, although not as effectively as statins or other drugs. LDL may actually increase in patients with very high triglycerides who take these drugs. (The newer fibrates are much more effective in lowering LDL than gemfibrozil.)
A study on bezafibrate suggested it might have anti-inflammatory effects in patients with high triglyceride levels. Inflammation in the blood vessels is now recognized as a major contributor to the process leading to heart disease. However, according to a 2004 study, patients with diabetes or impaired fasting glucose levels were less likely to benefit from bezafibrate.
A study on fenofibrate further suggested that it reduced certain clotting factors (another risk factor for heart disease) and also uric acid (a risk factor for gout). Another study, published in 2004, demonstrated that like bezafibrate, fenofibrate has significant anti-inflammatory properties in patients with high triglyceride levels.

Concerns. Fibrates do not appear to reduce mortality rates. In one study, people who took gemfibrozil had higher rates of death from other causes, including cancer. Some evidence suggests that fibrates may affect receptors involved in cancer development. However, a number of studies have found no higher incidence of cancer.

Side Effects. Side effects may include gastrointestinal discomfort, aching muscles, sensitivity to sunlight, and skin rashes. Fibrates have been known to cause gallstones, so people with gallbladder problems should not use these drugs.

Click the icon to see an image of gallstones in the gallbladder.

The drugs may cause abnormal heart rhythms and can affect the liver and kidney.

Drug Interactions. Fibrates interact with a number of drugs and substances including warfarin, some oral drugs used for diabetes, certain antibiotics, and grapefruit juice.

Ezetimibe (Zetia) blocks absorption of cholesterol that comes from food. Ezetimibe is usually prescribed alone or in combination with a statin. In 2004, the FDA approved Vytorin, which combines ezetimbe and the statin simvastatin into a single pill.

In 2006, the FDA approved the use of ezetimbe in combination with fenofibrate (Tricor) for reduction of total cholesterol and LDL in patients with mixed hyperglycemia (high LDL levels, high triglycerides, low HDL levels) whose cholesterol has not been adequately controlled through diet alone. Fenofibrate is a cholesterol drug that is used along with diet to reduce LDL and triglycerides.

CETP Inhibitors. Cholesteryl ester transfer protein (CETP) inhibitors, such as the experimental drug torcetrapib, are a new drug class that is being investigated for its effect on raising HDL ("good" cholesterol) levels while lowering LDL ("bad") cholesterol levels. Torcetrapib was the most widely studied of these drugs. However, in December 2006, the drug’s manufacturer abruptly stopped late-stage clinical trials after discovering that torcetrapib significantly increased blood pressure and risk of death.

Several studies published in 2007 in the New England Journal of Medicine revealed that while torcetrapib does greatly boost HDL levels (by 61% in one study) and lower LDL, it has no effect on arterial plaque. Scientists are trying to understand why this drug did not work. One theory is that torcetrapib may have increased the quantity of HDL, but not the quality. It is still not clear whether the failure of trocetrapib is specific to this drug or the entire CETP drug class. Given the current findings, it is also unclear whether research will continue on other CETP drugs.

Selective Estrogen-Receptor Modulators(SERMs). Selective estrogen-receptor modulators (SERMs) have been designed to produce the benefits of estrogen without its risks. They are thought to act like estrogen in some tissues but behave like estrogen blockers (antiestrogens) in others. They include tamoxifen (Nolvadex), raloxifene (Evista), and droloxifene. Any beneficial effects of the SERMs on cholesterol and the heart are still unclear. SERMs pose a risk for deep vein blood clots, which may have implications for people with heart problems. Longer studies are needed on possible risks and benefits.

Recombinant ApoA-I Milano. ApoA-I Milano is a type of HDL protein that is found in people with very low levels of HDL. A 2003 study showed that treating patients with a synthetic form of HDL, derived from ApoA-I Milano, caused a significant regression of atherosclerosis. Ongoing trials will evaluate whether this drug can prevent cardiovascular events such as heart attack or death.

Plasmapheresis and Familial Hypercholesterolemia. Plasmapheresis is a blood-filtering procedure that is used to dramatically reduce triglycerides and may also be used to remove LDL. The procedure may be beneficial for patients with severe hereditary forms of high cholesterol who do not respond to other therapies. Studies suggest, for example, that plasmapheresis is particularly useful for patients with familial hypercholesterolemia. The process takes about 3 hours. If not performed regularly, its benefits last only about 2 weeks. People using this procedure are still advised to maintain a healthy diet and continue to take any prescribed medications to control cholesterol.

Resources

www.nhlbi.nih.gov/about/ncep -- National Cholesterol Education Program
www.nhlbi.nih.gov -- National Heart, Lung, and Blood Institute
www.acc.org -- American College of Cardiology
www.americanheart.org -- American Heart Association
www.eatright.org -- American Dietetic Association

References

Berthold HK, Unverdorben S, Degenhardt R, Bulitta M, Gouni-Berthold I. Effect of policosanol on lipid levels among patients with hypercholesterolemiaor combined hyperlipidemia: a randomized controlled trial. JAMA. 2006 May 17;295(19):2262-9.

Covas MI, Nyyssonen K, Poulsen HE, Kaikkonen J, Zunft HJ, Kiesewetter H, et al. The effect of polyphenols in olive oil on heart disease risk factors: a randomized trial. Ann Intern Med. 2006 Sep 5;145(5):333-41.

Crouse JR 3rd, Raichlen JS, Riley WA, Evans GW, Palmer MK, O'Leary DH, et al. Effect of rosuvastatin on progression of carotid intima-media thickness in low-risk individuals with subclinical atherosclerosis: The METEOR Trial. JAMA. 2007 Mar 25; [Epub ahead of print]

Deedwania P, Barter P, Carmena R, Fruchart JC, Grundy SM, Haffner S, et al. Reduction of low-density lipoprotein cholesterol in patients with coronary heart disease and metabolic syndrome: analysis of the Treating to New Targets study. Lancet. 2006 Sep 9;368(9539):919-28.

Estruch R, Martinez-Gonzalez MA, Corella D, Salas-Salvado J, Ruiz-Gutierrez V, Covas MI, et al. Effects of a Mediterranean-style diet on cardiovascular risk factors: a randomized trial. Ann Intern Med. 2006 Jul 4;145(1):1-11.

Gardner CD, Kiazand A, Alhassan S, Kim S, Stafford RS, Balise RR, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA. 2007 Mar 7;297(9):969-77.

Gardner CD, Lawson LD, Block E, Chatterjee LM, Kiazand A, Balise RR, et al. Effect of raw garlic vs commercial garlic supplements on plasma lipid concentrations in adults with moderate hypercholesterolemia: a randomized clinical trial. Arch Intern Med. 2007 Feb 26;167(4):346-53.

Jolliffe CJ, Janssen I. Distribution of lipoproteins by age and gender in adolescents. Circulation. 2006 Sep 5;114(10):1056-62. Epub 2006 Aug 28.

Kastelein JJ, van Leuven SI, Burgess L, Evans GW, Kuivenhoven JA, Barter PJ, et al. Effect of torcetrapib on carotid atherosclerosis in familial hypercholesterolemia. N Engl J Med. 2007 Mar 26; [Epub ahead of print]

McCrindle BW, Urbina EM, Dennison BA, Jacobson MS, Steinberger J, Rocchini AP, et al. Drug therapy of high-risk lipid abnormalities in children and adolescents. A scientific statement from the American Heart Association Atherosclerosis, Hypertension, and Obesity in Youth Committee, Council of Cardiovascular Disease in the Young, With the Council on Cardiovascular Nursing. Circulation. 2007 Mar 21; [Epub ahead of print]

McMillan-Price J, Petocz P, Atkinson F, O'Neill K, Samman S, Steinbeck K, et al. Comparison of 4 diets of varying glycemic load on weight loss and cardiovascular risk reduction in overweight and obese young adults: a randomized controlled trial. Arch Intern Med. 2006 Jul 24;166(14):1466-75.

Nissen SE, Tardif JC, Nicholls SJ, Revkin JH, Shear CL, Duggan WT, et al. Effect of torcetrapib on the progression of coronary atherosclerosis. N Engl J Med. 2007 Mar 26; [Epub ahead of print]

Review Date:
7/23/2007
Reviewed By:
Alan Greene, MD, FAAP, Chief Medical Officer, A.D.A.M., Inc.; and Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

A.D.A.M. Copyright

adam.com

Would a Tax on Soda Make You Drink Less?

FitSugar — Fri, 18 Sep 2009 04:30:32 -0700

America's soda obsession is believed to contribute to our issue of obesity. New York City is fighting back with its Don't Drink Yourself Fat ad campaign, but public health leaders want to do more.

For a while now, there's been talk about issuing a soda tax to reduce the consumption of calorie-loaded beverages including sodas, sugary fruit drinks, and energy drinks, to help lower the rate of obesity. The extra money made would help contribute to paying off healthcare costs.

The soda tax debate has been going on for a while. Those in support think anything that discourages people from buying soda will help Americans cut down. Those against it think that a simple soda tax won't stop people from drinking soda since you can't change people's taste buds. They feel that educating people about healthier choices would be more effective, since a soda tax may just push people to opt for other unhealthy choices. Another good point is that soda isn't the only food that contributes to obesity. What about fast food, candy bars, and desserts? Will those be taxed as well?

This soda tax is far from approval, but could very well happen - in a recent Kaiser Family Foundation poll, 53 percent of people were in favor of the soda tax. So tell me . . .

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.

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 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.

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 cleansing the blood.

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.

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.

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).

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 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.

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 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.]

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.

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.

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 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)

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 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.

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.

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).

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. 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.

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 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.

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 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.

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 slower 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, 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.

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.

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

Sleep apnea

FitSugar — Wed, 08 Oct 2008 17:35:30 -0700

In This Report

Highlights
Introduction
Symptoms
Causes
Risk Factors
Prognosis
Diagnosis
Lifestyle Changes
Treatment
Dental Devices
Surgery
Resources
References

HEALTH GUIDE REFERENCE FROM A.D.A.M

Highlights

Sleep Apnea and Heart Attack

Obstructive sleep apnea can increase the risk of heart attack by as much as 30% over the course of 5 years, suggests a study presented at the 2007 American Thoracic Society International Conference. Researchers noted that the risk of developing or dying from heart disease rises with increasing sleep apnea severity.

Sleep Apnea and Diabetes

Obstructive sleep apnea may increase the risk of developing type 2 diabetes, indicates research presented at the American Thoracic Society conference. Patients who had severe obstructive sleep apnea had more than 2.5 times the risk of developing diabetes as those who did not suffer from nighttime breathing problems.
Sleep apnea may also increase the risk for women developing diabetes during pregnancy (gestational diabetes). Pregnancy-associated high blood pressure is also linked with sleep apnea.

Sleep Apnea and Depression

As sleep apnea worsens, the odds for developing depression increase, indicates a 2006 study in the Archives of Internal Medicine.

Continuous Positive Airway Pressure (CPAP)

CPAP is the best treatment for severe sleep apnea. However, according to a 2007 study in Sleep, most patients need to use it for a full night’s duration to achieve optimal benefits. The researchers noted that many patients experience some improvement in daytime sleepiness after 4 - 6 nightly hours of CPAP use, but that the best improvements in quality of life occur mostly after 7.5 hours of CPAP use each night.

Risk Factors for Sleep Apnea Surgery

According to a 2006 study in the Archives of Otolaryngology - Head & Neck Surgery, the risks for complications following uvulopalatopharyngoplasty (UPPP) increase with:

Severity of sleep apnea
Being overweight (higher body mass index)
Having other medical conditions in addition to sleep apnea
Undergoing other surgical procedures at the same time as UPPP

Introduction

Sleep apnea is a disorder in which a person stops breathing during the night, perhaps hundreds of times, usually for periods of 10 seconds or longer and sometimes for as long as a minute. These gaps in breathing are called apneas. The word apnea means absence of breath.

Sleep apnea is usually accompanied by snoring. People might not even know they have the condition. It inevitably causes daytime sleepiness.

Sleep apnea is grouped into three categories:

Obstructive
Central
Mixed

There is also another, less severe form of obstructed breathing, called upper airway resistance syndrome (UARS).

Obstructive sleep apnea (OSA) is the most common form of apnea. It occurs when tissues in the upper throat collapse at different times during sleep, thereby blocking the passage of air. In general, OSA occurs as follows:

On its way to the lungs, air passes through the nose, mouth, and throat (the upper airway).
Under normal conditions, the back of the throat is soft and tends to collapse inward as a person breathes.
Dilator (widening) muscles work against this collapse to keep the airway open. Interference or abnormalities in this process cause air turbulence.
If the tissues at the back of the throat collapse and become momentarily blocked, apnea occurs. Breath is temporarily stopped. In most cases the person is unaware of it, although sometimes they awaken and gasp for breath.
In some cases, the interference is incomplete (called obstructive hypopnea) and causes continuous but slow and shallow breathing. In response, the throat vibrates and makes the sound of snoring. Snoring can occur whether a person breathes through the mouth or the nose. (Snoring also occurs without sleep apnea.)
Apnea decreases the amount of oxygen in the blood, and eventually this lack of oxygen triggers the lungs to suck in air.
At this point, the patient may make a gasping or snorting sound but does not usually fully wake up.

Obstructive sleep apnea is defined as five or more episodes of apnea or hypopnea per hour of sleep in individuals who have excessive daytime sleepiness.

Central sleep apnea is much less common. It is caused by some problem in the central nervous system, most likely a failure of the brain to signal the airway muscles to breathe. In such cases, oxygen levels drop abruptly and usually the sleeper wakes with a start. Often people with central sleep apnea recall waking up. They generally experience less sleepiness during the day than people with obstructive sleep apnea. Heart disease, and in particular heart failure, is the most common cause of central sleep apnea.

Mixed apnea is the term used when the two apneas occur together.

Upper airway resistance syndrome (UARS) is a condition in which patients snore, wake frequently during the night, and have excessive daytime sleepiness. However, UARS patients do not have the breathing abnormalities that characterize sleep apnea and they do not show a reduction in blood oxygen levels. Unlike apnea, UARS is more likely to occur in women than in men. Treatments are similar to those of sleep apnea. It is not known if UARS has any serious health complications.

In sleep studies, subjects spend about one-third of their time asleep, suggesting that most people need about 8 hours of sleep each day. Individual adults differ in the amount of sleep they need to feel well rested, however. Infants may sleep up to 16 hours a day.

The daily cycle of sleeping and waking is called the circadian rhythm. It's commonly referred to as the biologic clock. Circadian means "about a day." Hundreds of bodily functions follow biologic clocks, but sleeping and waking comprise the most prominent circadian rhythm. The sleeping and waking cycle is approximately 24 hours. (People who are confined to windowless homes, with no clocks or other time cues, sleep and wake on a slightly longer cycle.) The 24-hour circadian rhythm typically adheres to the following factors:

Humans are designed for daytime activity and nighttime rest.
There is a natural peak in sleepiness at mid-day, the traditional siesta time.

In addition, daily rhythms mix with other factors that may interfere or change individual patterns:

The firing of nerve cells in the brain may be faster or slower in different individuals.
The monthly menstrual cycle in women can shift the pattern.
Light signals coming through the eyes reset the circadian cycles each day, so changes in season or various exposures to light and dark can unsettle the pattern. The importance of sunlight as a cue for circadian rhythms is dramatized by the problems experienced by people who are totally blind. They commonly suffer trouble sleeping and other rhythm disruptions.

The Response in the Brain to Light Signals

The response to light signals in the brain is an important key factor in sleep:

Light signals travel to a tiny cluster of nerves in the hypothalamus in the center of the brain, the body's master clock, which is called the supra chiasmatic nucleus or SCN.
This nerve cluster takes its name from its location. It sits just above (supra) the optic chiasm, a major junction for nerves transmitting information about light from the eyes.
The approach of dusk each day prompts the SCN to signal the nearby pineal gland to produce the hormone melatonin.
Melatonin is thought to act as the body's time-setting hormone. The longer a person is in darkness the longer the duration of melatonin secretion. Secretion can be diminished by staying in bright light. Melatonin also appears to trigger the need to sleep.

Sleep Cycles

Sleep consists of two distinct states that alternate in cycles and reflect differing levels of brain nerve cell activity:

Non-Rapid Eye Movement Sleep (NonREM). NonREM sleep is also termed quiet sleep. NonREM is further subdivided into three stages of progression:

Stage 1 (light sleep)
Stage 2 (so-called true sleep)
Stage 3 to 4 (deep "slow-wave" or delta sleep)

With each descending stage, awakening becomes more difficult. It is not known what governs NonREM sleep in the brain. A balance between certain hormones, particularly growth and stress hormones, may be important for deep sleep.

Rapid Eye-Movement Sleep (REM). REM sleep is termed active sleep. Most vivid dreams occur in REM sleep. REM-sleep brain activity is comparable to that in waking, but the muscles are virtually paralyzed, possibly preventing people from acting out their dreams. In fact, except for vital organs like lungs and heart, the only muscles not paralyzed during REM are the eye muscles. REM sleep may be critical for learning and for day-to-day mood regulation. When people are sleep-deprived, their brains must work harder than when they are well rested.

The REM/NREM Cycle. The cycle between quiet (NonREM) and active (REM) sleep generally follows this pattern:

After about 90 minutes of NonREM sleep, eyes move rapidly behind closed lids, giving rise to REM sleep.
As sleep progresses the NonREM/REM cycle repeats.
With each cycle, NonREM sleep becomes progressively lighter, and REM sleep becomes progressively longer, lasting from a few minutes early in sleep to perhaps an hour at the end of the sleep episode.

Symptoms

People with sleep apnea usually do not remember waking during the night.

Symptoms may include:

Excessive daytime sleepiness
Morning headaches
Irritability and impaired mental or emotional functioning
Snoring (bed partners may report very loud and interrupted snoring)
Heartburn (acid back-up that causes heartburn may be responsible for some cases of sleep apnea)

Sleep apnea occurs in about 2% of children. They may have symptoms that differ from adults, including:

Longer total sleep time than normal in some children, especially obese children or those with severe apnea.
Snoring. (An estimated 3 - 12% of all children snore. However, not all of them have sleep apnea.)
More effort in breathing (flaring nostrils, heaving chests, sweating). The chest may have an inward motion during sleep.
Behavioral difficulties without any obvious cause, such as hyperactivity and inattention. (Some patients may even be misdiagnosed with attention-deficit hyperactivity disorder.)
Irritability
Bed-wetting
Morning headaches
Failure to grow and gain weight

Causes

Any structural abnormality in the face, skull, or airways that causes some obstruction or collapse in the upper airways and reduces air pressure can produce sleep apnea syndrome. Abnormalities in tissues that lie between the back of the mouth and the esophagus (food pipe) are one of the most common structural causes of sleep apnea. Enlarged soft palates (the base of the tongue and surrounding throat walls) are also associated with many cases of sleep apnea.

Researchers have identified several physiologic abnormalities that may play a role in causing sleep apnea or in making it worse. These include an inability to regulate levels of carbon dioxide, impaired brain and nervous system responsiveness to various chemical messengers, and poor reflexes or muscle tone in the upper airways. The underlying reasons for these disturbances and their connection to apnea require further study.

Obesity is strongly associated with sleep apnea and is a cause of it in some cases. Imaging scans have shown fatty cells clogging the throat tissue, which indicates that they narrow the airways. In one study, the more obese a person with sleep apnea was, the higher the pressure on the airway and therefore the greater the obstruction of the airway. (Obstructive sleep apnea may also contribute to obesity itself, however, since a sleepy person tends to be sedentary.)

Snoring. Chronic snoring itself may actually be a cause of sleep apnea. Over time, the vibrations and the increased pressure against the upper airways as snoring people inhale may cause the soft palate to lengthen. This stretched palate is more prone to collapse and obstruction.

It should be stressed that snoring is very common. Snoring occurs in about a third of the population, while apnea, according to one study, occurs in only 6%. Snoring, then, does not always cause apnea, nor is it always a sign of the respiratory disorder. Furthermore, while snoring is also associated with daytime sleepiness regardless of whether apneas are present, snoring alone does not appear to pose any major health risks.

Mouth Breathing. Some evidence suggests that a tendency to breathe through the mouth (rather than the nose) during childhood can actually produce structural changes in the face (longer face, narrow jaw, receding chin). Such facial characteristics may eventually put people at risk for sleep apnea.

Sleep apnea occurs in about 2% of children and can occur even in very young children. The most likely causes are the following:

Facial or skull abnormalities in infants.
Overgrown tonsils, adenoids, or both in small children. (Removal of tonsils or adenoids can free the airways and solve the problem.)
Premature infants also commonly have a form of apnea that may be related to lung or nervous system problems.

Risk Factors

Gender. More men than women appear to have sleep apnea. In the U.S., about 4% of men and 2% of women age 30 - 60 meet the criteria for obstructive sleep apnea. Such people have at lease five episodes of apnea or hypopnea (shallow nighttime breathing) for each hour of sleep plus excessive daytime sleepiness. A much higher percentage has just one of these two conditions.

Sleep apnea actually may be underdiagnosed in women, particularly older women. In general, older women have the same incidence of sleep apnea as men their own age. It is not clear why apnea occurs more often in men than women before menopause and why prevalence equalizes after menopause. Men tend to have larger necks and to weigh more than women and women tend to gain weight and develop larger necks after menopause. However, studies have not found that these physical factors fully explain the differences in risk by gender in young adults or the increase in sleep apnea in postmenopausal women.

Age. Sleep apnea is most common and its symptoms are worse in middle-aged adults age 40 - 60 years old. Nevertheless, it affects people of all ages.

Ethnicity. African-Americans face a higher risk for sleep apnea than any other ethnic group in the United States. Other groups at increased risk include Pacific Islanders and Mexicans.

Obesity, especially having fat around the abdomen (the so-called apple shape), is a particular risk factor for sleep apnea, even in adolescents and children. However, many people with sleep-related breathing disorders, particularly women and small children, are not obese. Also, not all people who are obese have sleep apnea. Specific anatomical and physiological properties in the airways are more likely to be present in obese individuals with apnea.

Having a Larger Neck. Having a large neck is a risk factor for sleep apnea. In fact, larger necks in men may be the primary reason for their higher risk for sleep apnea compared to women. A neck measurement of 17 inches or greater in men or at least 16 inches in women is one indicator that may suggest the condition. Postmenopausal women are more likely than younger women to have sleep apnea, in part because they tend to be heavier and have larger necks.

Specific Facial and Skull Characteristics. Structural abnormalities in the face and skull may be responsible for many cases of sleep apnea. These are likely to be the cause in many non-obese people with early-onset sleep apnea, particularly if they also have a family history of the problem.

Specific physical characteristics that may increase the risk for sleep apnea in both adults and children include:

A long lower part of the face
Brachycephaly, a birth defect in which the head tends to be shorter and wider than average
A narrow upper jaw
A receding chin
An overbite
A larger tongue

Characteristics in the Soft Palate. Some people have specific abnormalities in the soft area (palate) at the back of the mouth and throat that may lead to sleep apnea. These abnormalities include:

The soft palate is stiffer, larger than normal, or both. An enlarged soft palate may be a significant risk factor for sleep apnea.
The soft palate and the walls of the throat around it collapse easily.

Smoking. Smokers are at higher risk for apnea. Those who smoke more than two packs a day have a risk 40 times greater than nonsmokers.

Alcohol. Alcohol use has been associated with apnea, although studies are mixed. A major survey reported that 53% of people who use alcohol to help fall sleep experience symptoms of sleep apnea. Another study found no relationship.

Diabetes. Diabetes is associated with sleep apnea and snoring. It is not clear if there is an independent relationship between the two conditions or whether obesity is the only common factor.

Gastroesophageal Reflux Disease (GERD). GERD is a condition caused by acid backing up into the esophagus. It is a common cause of heartburn. GERD and sleep apnea often coincide. In one study, almost half of apnea patients had symptoms of GERD. Some experts suggest that the backup of stomach acid in GERD may produce spasms in the vocal cords (larynx), thereby blocking the flow of air to the lungs and causing apnea. Or, apnea itself may cause pressure changes that trigger GERD. Some evidence suggests that treating sleep apnea with continuous positive airway pressure (CPAP) may reduce GERD symptoms by nearly 50%. However, obesity is common in both conditions. More research is needed to clarify the association.

Polycystic Ovary Syndrome (PCOS). In a 2000 study, women with PCOS were 30 times more likely than other premenopausal women to have obstructive sleep apnea and excessive daytime sleepiness. Women with PCOS produce high amounts of male hormones, particularly testosterone, which can cause obesity, facial hair, and acne. About half of PCOS patients also have diabetes. Obesity and diabetes are both associated with sleep apnea and may be the common factors.

Chronic Problems in the Upper Airways. A 2001 Swedish study found that people with respiratory tract disorders, including asthma, chronic bronchitis, or seasonal allergies, reported symptoms of sleep apnea more often than those without any of these ailments.

Hypothyroidism. In rare cases, hypothyroidism (low thyroid) has been reported as a possible cause of sleep apnea. In such cases, treating the thyroid condition improves the sleep apnea.

Prognosis

Sleep apnea has a strong association with several diseases, particularly those related to the heart and circulation.

Researchers are intensively investigating why a problem in the upper airways is associated with serious conditions of the heart and circulatory system. Here are some of their findings:

Major known risk factors for hypertension and heart disease (obesity, smoking, and alcohol abuse) are associated with sleep apnea. These factors, however, do not explain all cases of higher heart-related risks in people with sleep apnea. For example, among overweight people, those who have sleep apneas have a greater risk of heart problems than those without them.
When breathing stops during episodes of apnea, carbon dioxide levels in the blood increase and oxygen levels drop. This effect may trigger a cascade of physical and chemical events that can then increase risk for heart problems.
Apnea also causes decreased levels of the gas nitric oxide (NO), a potent substance that causes blood vessels to be elastic and expand. NO plays a crucial role in blood pressure control and heart health.
Apnea may also increase levels of a substance called angiotensin-converting enzyme (ACE), which is known to play a role in high blood pressure and congestive heart failure.
Researchers have reported high levels of certain immune factors called tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) in people with sleep apnea, particularly those who are obese. High levels of TNF-alpha and IL-6 produce a damaging inflammatory response, which can harm cells in the body, including those in the arteries. Elevated TNF-alpha may be associated with fatigue, shortness of breath, and a diminished heart-pumping action.

At this time, however, evidence of a clear causal relationship with any of these health problems is still weak. Some studies have found no significant independent risk for heart disease from obstructive sleep apnea. The following are some discussions on the possible effects of apnea on specific health problems.

High Blood Pressure. A number of studies have found a strong association between sleep apnea and high blood pressure (hypertension). (In the past, the link between sleep apnea and hypertension was thought to be due to obesity, a risk factor for both conditions, but more recent studies contradict that theory.) A 2000 study followed patients for 4 years; the more nightly apnea episodes they had in the first year, the more likely they were to develop hypertension by the fourth year. A weak, but still higher-than-normal, association with high blood pressure has also been observed in those who snore, wake frequently during the night, or have mild sleep apnea.

A 2004 data analysis of over 200,000 patient records revealed that people who took both antidepressants and antihypertensives were 18 times more likely to be diagnosed with obstructive sleep apnea than those who did not take the medications. The probability was highest among adults age 20 - 39 years. These drugs do not cause sleep apnea, but antidepressants may be prescribed to treat hypertensive patients’ complaints of fatigue even if sleep apnea is the real cause. The researchers recommended that patients being treated for high blood pressure, depression, and fatigue should also be evaluated for sleep apnea.

One way that apnea may directly affect blood pressure, regardless of other risk factors:

Blood pressure fluctuates widely and suddenly in response to episodes of apnea and hypopnea (shallow nighttime breathing).
Such fluctuations are possibly due to a sudden surge in the sympathetic nervous system, which controls involuntary muscle responses, importantly those in the blood vessels and heart, and may also play a role in sleep apnea.
These fluctuations lead to transient constriction of blood vessels that, over time, could possibly lead to sustained hypertension and heart damage.
Effective treatment of sleep apnea with continuous positive airway pressure (CPAP) may reduce blood pressure. Sleep apneas must be significantly reduced, however, to have any effect on blood pressure. Even a 50% reduction in apneas has no effect.

Coronary Artery Disease and Heart Attack. Sleep apnea has been associated with heart disease regardless of the presence of high blood pressure or other heart risk factors. In a 2001 study, researchers observed that the more episodes of apnea and hypopnea a patient had, the higher the risk for a heart attack.

Many of the factors associated with stroke and sleep apnea (a risk for blood clots and narrowing of the arteries) may also increase the risk for heart attacks. Research presented at the 2007 American Thoracic Society conference suggested that severe obstructive sleep apnea can increase the risk of dying from a heart attack by as much as 30% over a 4 - 5 year period. Obstructive sleep apnea, however, may have other effects that increase the risk for heart problems:

Some evidence suggests that obstructive apneas cause an increase in stiffness and inflammation in the arteries, which is now proving to be an important aspect of heart disease, particularly in older adults.
A 2002 study reported that the white blood cells of patients with apnea have an increased number of proteins called adhesion molecules on their surface that may bind to the lining of blood vessels and cause inflammation. Increasingly, scientists believe that inflammation plays an important role in the development of coronary artery disease, heart attacks, and many other major ailments.

Stroke. Sleep apnea doubles the risk for stroke. The worse the sleep apnea, the greater the risk; moderate-to-severe obstructive sleep apnea can triple the risk of stroke. Sleep apnea is also associated with high blood pressure, a known risk factor for stroke. However, people who have sleep apnea, but not high blood pressure, are also still at increased risk for stroke. Sleep apnea in stroke patients is also associated with a higher risk for worse symptoms after a stroke, including delirium, depression, poor response to speech, and difficulty conducting daily chores.

A 2000 study observed that blood becomes more viscous (stickier) in the morning in people with obstructive sleep apnea compared to people without the sleep disorder. Such "sticky" blood is more apt to form clots that can lead to strokes. To support this, another 2000 study reported that stroke victims with sleep apnea tended to have higher levels of the blood protein fibrinogen than stroke victims without sleep apnea. Fibrinogen is a factor in blood that causes it to clot. Higher levels of fibrinogen have been linked to both strokes and heart attacks.
A 1998 study reported that the carotid artery, the major artery to the brain, is in far greater danger of becoming sclerotic (hardened and narrower) in people with obstructive sleep apnea than in the average person. People with both diabetes and sleep apnea are at particularly high risk for this effect.

Heart Failure. Studies suggest that 11 - 37% of patients with heart failure also have sleep apnea. Both central and obstructive sleep apnea are linked with heart failure. The evidence for the association between heart failure and sleep apnea includes:

High blood pressure, which is associated with sleep apnea, is a major cause of later heart failure.
Sleep apnea reduces oxygen levels and causes abnormal changes in blood pressure and heart rate that add to the burden of the failing heart.
Obstructive sleep apnea can affect breathing functions that are particularly harmful for patients with existing congestive heart failure.
Sleep apnea is associated with poorer survival in patients with heart failure. Some studies have suggested that treating sleep apnea with CPAP may improve heart function in these patients. However, a 2005 New England Journal of Medicine study found that CPAP did not improve survival in patients with heart failure and central sleep apnea

Atrial Fibrillation. Sleep apnea is more common in people with atrial fibrillation (irregular heartbeat) than in patients with other heart conditions. In a 2005 study published in Circulation, 49% of patients with atrial fibrillation were at risk for developing apnea, compared with 32% of general cardiology patients. An earlier study indicated that patients with untreated obstructive sleep apnea may be at increased risk for recurrence of atrial fibrillation. Patients with atrial fibrillation who received CPAP treatment had a lower risk for recurrence.

Metabolic Syndrome. The metabolic syndrome (also called Syndrome X) is a cluster of abnormalities that cause insulin resistance. Some of these factors, including hypertension and obesity, are also associated with sleep apnea. A 2004 study found that metabolic syndrome was nine times more common among patients with obstructive sleep apnea, independent of obesity.

Diabetes. Severe obstructive sleep apnea may more than double the risk of developing type 2 diabetes. Sleep apnea also increases the risk for diabetes during pregnancy (gestational diabetes).

When it comes to sleep apnea and obesity, it is not always clear which condition is responsible for the other. For example, obesity is often a risk factor and possibly a cause of sleep apnea, but it is also likely that sleep apnea increases the risk for weight gain. Some studies indicate that sleep apnea disrupts rapid eye movement (REM) sleep, which, in turn, increases the risk for obesity. Research indicates that animals deprived of REM sleep tend to eat more. People with apnea may also become too tired to exercise and so put on weight.

Sleep apnea is associated with a higher incidence of many medical conditions, other than heart and circulation. The links between apneas and the conditions are unclear.

Pulmonary hypertension.
Asthma. Sleep apnea may worsen asthma symptoms and interfere with the effectiveness of asthma medications. Treating the apnea may help asthma control.
Kidney failure.
Peripheral nerve damage (tingling, pain, or numbness in the hands and feet).
Liver damage in obese individuals with sleep apnea. Recent research suggests that severe apnea may increase the risk of liver disease regardless of weight.
Seizures, epilepsy, and other nerve disorders. Sleep apnea appears to pose a particularly risk for nocturnal epilepsy, a condition in which seizures occur during sleep.
Headaches. Sleep disorders, including apnea, may be the underlying causes of some chronic headaches. In some patients with both chronic headaches and apnea, treating the sleep disorder has cured the headache, even the very severe and disabling form known as a cluster headache.
High-risk pregnancies. Sleep apnea causes higher rates of pregnancy complications, including gestational diabetes and high blood pressure.
Eye disorders, including glaucoma, conjunctivitis, dry eye, and various other infections and irritations. Findings presented at the 2003 annual meeting of the American Academy of Ophthalmology suggested that patients with sleep apnea may be at increased risk for glaucoma and should be tested for this eye disease. A vision-damaging condition called intracranial hypertension has also been observed in some patients with sleep apnea.

Studies report an association between severe apnea and psychological problems. In one study, 32% of patients had symptoms of depression. According to a 2006 study, the risk for depression rises with increasing severity of sleep apnea. Sleep-related breathing disorders can also worsen nightmares and post-traumatic stress disorder. Certainly, daytime sleepiness interferes with mental alertness and quality of life.

Because sleep apnea so often includes noisy snoring, the condition can also adversely affect the sleep quality of a patient's bed partner. Spouses or partners may also suffer from sleeplessness and fatigue. In some cases, the snoring can disrupt relationships. Diagnosis and treatment of sleep apnea in the patient can help eliminate these problems.

Failure to Thrive. Small children with undiagnosed sleep apnea may "fail to thrive," that is, they do not gain weight or grow at a normal rate and they have low levels of growth hormone. In severe cases, this may affect the heart and central nervous system. Most often, sleep apnea in children is caused by overgrown tonsils or adenoid. Their removal often completely solves all of these problems, including resolution of sleep apnea and restoring weight gain and normal growth hormone levels.

Attention Deficits and Hyperactivity. Problems in attention and hyperactivity are common in children with sleep apnea. There is some evidence that such children may be misdiagnosed with attention-deficit hyperactivity disorder. Snoring, rather than sleepiness, is a stronger risk factor for hyperactivity in many of these children, especially boys under 8 years old. (Even children who snore and do not have sleep apnea may be at higher risk for poor concentration.)

Some researchers believe that sleepiness associated with sleep apnea is the greatest risk factor for car accidents. As many as 200,000 automobile accidents in the U.S. and 1,500 deaths from such accidents are caused by sleepiness. Studies continue to report that drowsy driving is as risky as drunk driving. Several studies have suggested that people with sleep apnea have two to three times as many car accidents, and five to seven times the risk for multiple accidents.

Diagnosis

Not all people with suspected sleep apnea require medical tests. Expensive diagnostic efforts are probably not required for individuals who have no other health risk factors and whose suspected apnea does not affect their quality of life or safety on the road.

Doctors, however, should order diagnostic sleep studies if:

The patient has a serious medical condition that might be worsened or caused by sleep apnea. Such conditions include heart disease, high blood pressure, heart failure, diabetes, chronic headaches, epilepsy, obstructive lung disease, or severe acid reflux (GERD).
A child who shows signs of sleep apnea also has attention deficit problems or fails to thrive.
The sleep apnea is severe enough to impair quality of life, increase the risk for accidents, or both.

In some cases of an uncertain diagnosis, high-risk patients may need to consult a sleep specialist or go to a sleep disorders center. At most centers, patients undergo an in-depth analysis, usually supervised by a multi-disciplinary team of consultants who can provide both physical and psychiatric evaluations. Centers should be accredited by the American Academy of Sleep Medicine.

To help determine the presence of sleep apnea, the doctor will ask the following questions:

Is the patient taking any medications?
How many periods of sleepiness are there each day and when do they occur? (Patients with apnea often do not describe this symptom as feeling "sleepy." They are more apt to describe this feeling as "lack of energy" or "feeling tired all day.")
How restful is sleep?
Do headaches occur regularly in the morning?
Is the patient taking or withdrawing from stimulants, such as coffee or tobacco?
How much alcohol is consumed per day?
Does the patient have any problems with mental or emotional functioning?
Does the patient suffer from heartburn?
What is the normal sleeping position (back, side, or stomach)?
If there is a sleeping partner, does he or she complain about the patient's snoring or gasping for breath? (Many times it is useful to interview the bed partner.)

Keeping a Record of Sleep. To help answer these questions, the patient may need to keep a sleep diary. Every day for 2 weeks, the patient should record all sleep-related information, including responses to questions listed above described on a daily basis. Recording sleep behavior using an extended-play audio or videotape can be very helpful in diagnosing sleep apnea.

To diagnose sleep apnea, the doctor will check for physical indications of sleep apnea, including:

Abnormalities in the soft palate or upper airways, including enlarged tonsils
Upper body obesity
A wide neck measurement

Some evidence suggests that doctors may accurately identify nearly all cases of suspected sleep apnea using physical criteria, including taking measurements of body mass (the indication of obesity), neck circumference, and four areas inside the mouth.

If sleep apnea is not obvious after a physical examination and history, the doctor will need to rule out any other problems. These include sleep disorders, (such as narcolepsy, insomnia, or restless legs disorder), or any medical or psychologic conditions (chronic fatigue syndrome, depression) that may be causing daytime sleepiness.

Polysomnography is the technical term for an overnight sleep study that involves recording brain waves and other sleep-related activity. Polysomnography involves many measurements and is typically performed at a sleep center.

The patient arrives about 2 hours before bedtime without having made any changes in daily habits. Polysomnography electronically monitors the patient as he or she passes, or fails to pass, through the various sleep stages. Polysomnography tracks:

Brain waves
Body movements
Breathing
Heart rate
Eye movements

Changes in breathing and blood oxygen levels are also recorded. In patients with suspected sleep apnea, the sleep expert will track instances of apnea and hypopnea that last longer than 10 seconds. In general, if there are more than five episodes per hour, apnea is significant and if there are more than 15, the condition is serious.

Overnight polysomnography has been the gold standard for diagnosing obstructive sleep apnea in both adults and children. It is very labor-intensive and expensive, however, and also misses snoring-induced arousals. It is not always covered by health insurance, and some centers have waiting lists that are months long.

A number of portable devices are available, or are being developed, so that patients have the convenience of being monitored at home. Experts hope that such monitors eventually will replace the need for overnight sleep clinics or the need for attended monitoring at home. Limited evidence exists, however, on the accuracy of many portable monitors. Patients with serious medical conditions, including heart failure or a history of stroke or respiratory failure, should not use home tests.

The following are descriptions of some home monitoring techniques.

Home Oximetry. Pulse oximetry is a procedure that determines if oxygen levels in the blood are low. This is called hypoxia. Normal levels during the night would generally rule out sleep apnea. With this procedure, a device called a pulse oximeter is attached to the patient's finger. The oximeter transmits red and infrared light through the capillaries in the finger. Hemoglobin, a molecule in the blood that carries oxygen, absorbs part of these light waves. The ratio of the two light beams provides the measurement of oxygen. The test is not always accurate, however. A combination with polysomnography, especially heart rate measurements, may be best for diagnosing sleep apnea.

Home oximetry monitors are available to rule out sleep apnea, but their accuracy is unclear. A 2003 study indicated that home oximetry alone was not very helpful in discriminating between patients with or without sleep apnea. Home oximetry however, may be helpful in identifying patients with unsuspected and seriously low oxygen levels.

Unattended Monitoring with Auto-CPAP. This method is a recent and simple method for detecting impaired breathing. It uses an auto-CPAP machine, which is programmed to apply pressure through the airways via a tube that attaches to a mask that fits the nose. A monitor is attached that digitizes and records on a computer all the information on any apnea episodes during sleep.

Nasal Pressure Recording. One promising technique uses a very simple prong device that attaches to the nostrils. A monitor records the airflow through the mouth and nose.

Peripheral Arterial Tonometry. An investigative technique called peripheral arterial tonometry measures changes in blood flow in the arteries of the fingertips during sleep. Such measurements are proving to be accurate in detecting sleep apnea in 80% of cases.

The Epworth Sleepiness Scale uses a simple questionnaire to measure excessive sleepiness during eight situations.


Situation	Chance of Dozing 0 = no chance of dozing 1 = slight chance of dozing 2 = moderate chance of dozing 3 = high chance of dozing
Sitting and reading.	(Indicate a score of 0 to 3)
Watching TV.	(Indicate a score of 0 to 3)
Sitting inactive in a public place (a theater or a meeting).	(Indicate a score of 0 to 3)
As a passenger in a car for an hour without a break.	(Indicate a score of 0 to 3)
Lying down to rest in the afternoon when circumstances permit.	(Indicate a score of 0 to 3)
Sitting and talking to someone.	(Indicate a score of 0 to 3)
Sitting quietly after a lunch without alcohol.	(Indicate a score of 0 to 3)
In a car, while stopped for a few minutes in traffic.	(Indicate a score of 0 to 3)
Score Results	1-6: Getting enough sleep 4-8: Tends to be sleepy but is average. 9-15: Very sleepy and should seek medical advice. Over 16: Dangerously sleepy

Lifestyle Changes

Sleeping on the back causes sleep apnea in about half of all people with mild sleep apnea. Body position greatly affects the number and severity of episodes of obstructive sleep apnea, with at least twice as many apneas occurring in people who lay on their back as in those who sleep on their side. This may be due to the effects of gravity, which cause the throat to narrow when a person lies on the back. (Indeed, astronauts show a marked reduction in apneas and snoring in the weightlessness of space.) Positional sleep apnea affects people of all ages, including young children.

As a first step in dealing with sleep apnea, the patient should simply try rolling over onto the side. Patients who sleep on their backs and have 50 - 80 apneas per hour can sometimes nearly eliminate them when they shift to one side or the other. (Changing positions is less effective the more overweight a person is, but it still helps.)

Here are some suggestions that might help a person maintain a low-risk sleeping position:

Sew a small pocket to the back of the pajamas and place a tennis ball or other small ball into it.
A special pillow that helps to stretch the neck may reduce snoring and improve sleep for people with mild sleep apnea.
Sleeping in an upright position may improve oxygen levels in overweight people with sleep apnea. Elevating the head of the bed may help.

Over-the-counter nasal strips, such as the Breathe Right strip or other devices that open the nostrils, are inexpensive and useful to prevent snoring. They may significantly improve early-stage sleep in people with sleep disorders associated with nasal obstruction and help reduce morning tiredness. They are not intended as treatments for sleep apnea, however.

All patients with obstructive sleep apnea who are overweight should attempt a weight-reducing program. Weight loss certainly reduces snoring in many people, sometimes stopping it completely. It also improves sleep and significantly reduces daytime sleepiness. A 2000 study suggested that people who lost 10% of body weight experienced an average 26% reduction in risk for developing sleep apnea in the first place. (Gaining 10% of their body weight, on the other hand, increased the odds of sleep apnea 6-fold.)

Smokers should quit, since smoking worsens apnea
Alcohol should be avoided within 4 hours of sleep

Treatment

Treatment for sleep apnea depends on the severity of the problem. Given the data on the long-term complications of sleep apnea, it is important for patients to treat the problem as they would any chronic disease. Simply trying to treat snoring will not treat sleep apnea. Because of its association with heart problems and stroke, sleep apnea that does not respond to lifestyle measures should be treated by a doctor, ideally a sleep disorders specialist.

At this time, the most effective treatments for sleep apnea are devices that deliver slightly pressurized air to keep the throat open during the night. There are a number of such devices available.

The best treatment for severe obstructive and mixed sleep apnea is a system known as continuous positive airflow pressure (CPAP), sometimes referred to as nasal continuous positive airflow pressure (nCPAP). It is safe and effective in sleep apnea patients of all ages, including children. CPAP is not recommended for patients with mild apnea. Patients with apnea but no daytime sleepiness report little or no benefit from this treatment.

CPAP works in the following way:

The device itself is a machine weighing about 5 pounds that fits on a bedside table.
A mask containing a tube connects to the device and fits over just the nose.
The machine supplies a steady stream of air through a tube and applies sufficient air pressure to prevent the tissues from collapsing during sleep.

Effects on Sleep and Wakefulness. A major 2003 analysis confirmed the benefits of CPAP on both objective and subjective measures of sleep. After using CPAP regularly many patients report the following benefits:

Restoration of normal sleep patterns.
Greater alertness and less daytime sleepiness.
Less anxiety and depression and better mood.
Improvements in work productivity.
Better concentration and memory. Some adults with symptoms of attention deficit hyperactivity disorder have improved after CPAP treatments for apnea. In two studies, however, equal improvements were also observed in people on sham CPAP, suggesting that the actual cognitive benefits from CPAP may be modest.
Patients' bed partners also report improvement in their own sleep when their mates use CPAP, even though objective sleep tests showed no real difference in the partners' sleep quality.

If patients do not experience less sleepiness after a period of time and are still complying with the regimen, then the airflow pressure may not be high enough. Patients may require retesting. Many patients report feeling more alert after CPAP treatments even if objective laboratory tests fail to show significant differences in the number of apneas and wake-up periods.

Protection from Accidents. Studies suggest that treatment with CPAP can reduce the risk for accidents. In a 2001 study, untreated patients had a risk for automobile accidents that was three times the risk in the general population. When these patients were treated, their risk fell to normal.

Effects on the Heart and Circulation. Evidence is mixed on whether CPAP treatment may reduce serious heart conditions. Early studies suggested that CPAP could improve heart function, lower blood pressure, and prevent new cardiac events (such as heart attacks) in patients with congestive heart failure and coronary artery disease. However, a 2005 study in the New England Journal of Medicine found that, while CPAP helped improve some heart disease symptoms, it did not affect overall survival in patients with heart failure and central sleep apnea. (Patients with heart failure often have central sleep apnea.)

It is also unclear whether CPAP improves blood pressure. A 2006 study of patients with high blood pressure and sleep apnea indicated that short-term (4 weeks) CPAP treatment has no significant effect on lowering blood pressure. (It is possible that longer-term treatment may be helpful.) Other studies have found blood pressure benefits from short-term CPAP treatment. Treatment for sleep apneas must be very effective, however, to have any benefits on blood pressure. Even a 50% reduction in apneas has no effect.

Effects on Other Medical Conditions. Some studies suggest other benefits with the use of CPAP:

Fewer morning headaches
Reduction in abdominal fat (abdominal fat has been related to a higher risk for diabetes and heart disease)
Lower blood sugar levels in patients with type 2 diabetes
Improved thinking and concentration in people with impaired mental function from sleep apnea
Modest lung improvement in patients with both apnea and chronic obstructive lung disease (such as emphysema)

CPAP works well for both adults and children, but many patients have problems getting used to the device. Unfortunately, CPAP devices are often cumbersome, which can lead to patients becoming discouraged and stopping treatment. All patients should be warned that the first few nights of CPAP therapy are unnerving. The device often produces anxiety, primarily because of the mask. Starting out with low pressure to get used to the mask may help. Patients may actually experience less sleep or sleep of a different quality in the beginning of treatment.

Nearly all patients complain about at least one side effect. Nearly half of complaints are related to the mask. Many of these problems can be reduced with a well-chosen mask that is comfortable and reduces leakage as much as possible. Common complaints include:

Irritation in the nose and throat. The most common complaints are nasal congestion and sore or dry mouth, which are caused by leakage that dries the airway. (This may be severe in elderly people or patients who have had uvulopalatopharyngoplasty, a surgical treatment for sleep apnea. Such patients are more likely to stop using CPAP.) Chin straps, nasal salt water sprays, or humidifiers may prevent these side effects. Heated humidification devices are also now available for CPAP users.
Excessive application of pressure making exhalation difficult.
A feeling of claustrophobia is a major factor in noncompliance. This can be improved by a lightweight and transparent mask or with masks known as nasal pillows, which are used only around the nostrils.
Up to 30% of patients experience irritation and sores over the bridge of the nose. Getting a properly fitted and cushioned mask can help reduce this effect.
Eye irritation or conjunctivitis.
Upper respiratory infections. It is very important to keep the unit clean.
Patients may also experience temporary chest muscle discomfort, which is caused by an increase in lung volume.
Severe side effects are very rare but may include heart rhythm disorders (arrhythmias), severe nose bleeding, and air pockets in the skull.
In addition to initial difficulties with its use, the fixed CPAP needs to be periodically readjusted. Patients can be trained to adjust the CPAP at home, thereby avoiding trips to the sleep professional for machine adjustments and making the process more convenient.

Although studies have reported that long-term compliance with CPAP systems is low, with about one-third of patients giving up the treatment, recent information suggests that it is improving, probably due to better technologies and better education. Patient education and support groups, a dedicated nurse to ensure close follow-up of patients (particularly in the first 2 weeks of therapy), and ready access to doctors to make adjustments as needed have all been shown to greatly improve compliance. (However, sleeping pills do not appear to help patients adapt to the device.) Not surprisingly, patients whose symptoms are noticeably relieved by the procedure early on are more likely to continue the therapy.

Because many patients find CPAP uncomfortable and difficult, they tend not to use it for the duration of the entire night. A 2007 study indicated that while some patients’ daytime sleepiness may improve after 4 - 6 hours of CPAP use each night, maximum benefits in quality of life require at least 7.5 hours of nightly CPAP use. It appears that longer nightly duration of CPAP use is best for achieving normal daytime functioning.

Bilevel Positive Airway Pressure. Bilevel positive airway pressure (BPAP) systems may be particularly helpful for patients with coexisting lung disease and those with excessive levels of carbon dioxide. These devices have a sensing feature that helps determine and vary the appropriate pressure depending on whether a person is breathing in or out. Greater pressure is needed on inhalation and less on exhalation. These machines are more expensive than the CPAP and may not be covered by insurance.

Automatic Titrating (Auto)-CPAP Pressure Devices. Even more sophisticated systems, called auto-CPAP devices, are available. These devices automatically customize air pressure for the individual patient. They usually use one of three methods:

Overall pressure is kept low until a specific problem is detected. At that time the pressure is automatically increased rapidly.
Pressure is low when there are no problems but is raised gradually when they are detected.
Pressure is gradually raised and lowered in response to problems or their absence. In addition, the device can change depending on problems within single breaths.

Brands include AutoAdjust, Virtuoso, and AutoSet. These devices are more expensive than those that provide continuous airflow. A 2003 study indicated that they may improve compliance, particularly in patients who require high CPAP use. They may be especially helpful for patients who require varying levels of pressure due to other conditions, such as seasonal allergies. They may also be useful as home diagnostic tools for sleep apnea. Auto-CPAP devices are not recommended for all patients, particularly those with heart failure or serious lung disease.

In general, drugs have not been very beneficial except for specific situations. Medications that treat accompanying disorders associated with sleep apnea may be helpful. The following may be helpful for certain patients:

Modafinil (Provigil), which is also used to treat narcolepsy, was approved by the FDA in 2004 as the first drug to treat the sleepiness associated with obstructive sleep apnea. However, Provigil is meant to be used in combination with -- not as a substitute for -- standard apnea treatments such as CPAP. Sleep experts stress that patients who take Provigil should adhere to CPAP treatment as the drug treats only the symptom of sleepiness, not the underlying health risks associated with sleep apnea.
Thyroid hormone may help sleep apnea in those with low thyroid (hypothyroidism).
Theophylline, a drug commonly used for asthma management, has shown promise in treating central sleep apnea in patients with heart failure.
Omeprazole (Prilosec), a drug used for patients with severe heartburn, may help patients with both sleep apnea and gastroesophageal reflux disorder (GERD).

Note on Sedatives. Sedatives, narcotics, and anti-anxiety drugs can actually worsen the breathing disturbances and arousal conditions that occur with sleep apnea. These substances cause the soft tissues in the throat to sag and diminish the body's ability to inhale. Apnea sufferers should never use sleeping pills or tranquilizers. Apnea patients undergoing surgery should be sure that their surgeons, anesthesiologists, and other doctors are aware of their sleeping disorder in considering sedatives, anesthetics, and medications taken to relieve pain due to surgery.

Dental Devices

Oral appliances, also called dental appliances or devices, may be an option for patients who cannot tolerate CPAP. The American Academy of Sleep Medicine recommends dental devices for patients with mild-to-moderate obstructive sleep apnea who are not appropriate candidates for CPAP or who have not been helped by it. (CPAP should be used for patients with severe sleep apnea whenever possible.)

Several different dental devices are available. A trained dental professional such as a dentist or orthodontist should fit these devices. Devices include:

Mandibular advancement device (MAD). This is the most widely used dental device for sleep apnea. It is similar in appearance to a sports mouth guard. MAD forces the lower jaw forward and down slightly, which keeps the airway open.
Tongue retraining device (TRD). This is a splint that holds the tongue in place to keep the airway as open as possible.

Patients fitted with one of these devices should have a check-up early on to see if it is working; short-term success usually predicts long-term benefits. It may need to be adjusted or replaced periodically.

MAD and similar devices seem to offer the following benefits:

Significant reduction in apneas for those with mild-to-moderate apnea, particularly if patients sleep either on their backs or stomachs. They do not work as well if patients lie on their side. The devices may also improve airflow for some patients with severe apnea.
Improvement in sleep in many patients.
Improvement and reduction in the frequency of snoring and loudness of snoring in most (but not all) patients.
Higher compliance rates than with CPAP.

According to a 2006 review, dental devices help control sleep apnea in 52% of treated patients. A 2002 report indicated that long-term use of a dental device achieved an 81% success rate in apnea improvement, which was significantly higher than the 53% success rate noted for uvulopalatopharyngoplasty (UPPP), the standard surgical treatment. There were also few complications with the dental device.

Dental devices, including MAD, are not as effective as CPAP therapy. The cost of these devices tends to be high. Side effects associated with dental devices include:

Nighttime pain, dry lips, tooth discomfort, and excessive salivation. In general, these side effects are mild, although over the long term they cause nearly half of patients stop using dental devices. Devices made of softer materials may produce fewer side effects.
Permanent changes in the position of the teeth or jaw have occurred in some cases of long-term use. Patients should have regular visits with a health professional to check the devices and make adjustments.
In a small percentage of patients, the treatment may worsen apnea. Patients should be monitored with polysomnography (sleep lab evaluation) before and after therapy and when apnea symptoms worsen or recur.

An orthodontic treatment called rapid maxillary expansion, in which a screw device is temporarily applied to the upper teeth and tightened regularly, may help patients with sleep apnea and a narrow upper jaw. This nonsurgical procedure helps to reduce nasal pressure and improve breathing.

Surgery

Surgery is sometimes recommended, usually by throat specialists, for severe obstructive sleep apnea. A patient should be sure to seek a second opinion from a specialist in sleep disorders. Few randomized clinical trials, the gold standard of medical research, have been conducted to verify the long-term efficacy of sleep apnea surgery.

The Procedure. Surgery known as uvulopalatopharyngoplasty (UPPP) removes soft tissue on the back of the throat. Such tissue includes all or part of the uvula (the soft flap of tissue that hangs down at the back of the mouth) and parts of the soft palate and the throat tissue behind it. If tonsils and adenoids are present, they are removed. The surgery typically requires a stay in the hospital.

The Goal of Surgery. The goal of UPPP is threefold:

Increase the width of the airway at the throat's opening
Block some of the muscle action in order to improve the ability of the airway to remain open
Improve the movement and closure of the soft palate

Success Rates. Success rates for sleep apnea surgery are rarely higher than 65% and often deteriorate with time, averaging about 50% or less over the long term. Few studies have been conducted on which patients make the best candidates. Some studies suggest that surgery is best suited for patients with abnormalities in the soft palate, which may or may not involve the tonsils. Results are poor if the problems involve other areas or the full palate. In such cases, CPAP is superior. In one study, sleeping on the side (rather than the back) after surgery significantly boosted success rates.

Complications. Uvulopalatopharyngoplasty is among the most painful treatments for sleep apnea, and recovery takes several weeks. It is recommended only for select patients with severe obstructive sleep apnea. The procedure also has a number of potentially serious complications. In fact, in one study, 42% of patients had complaints about the procedure. Some complications include:

Infection. In one study, this complication was so common that 40% of patients needed another operation because of it. Preventive antibiotics administered an hour before surgery can help reduce this risk.
Impaired function in the soft palate and muscles of the throat.
Mucus in the throat.
Changes in voice frequency.
Swallowing problems.
Regurgitation of fluids through the nose or mouth.
Impaired sense of smell.
Failure and recurrence of apnea. In such cases, CPAP is often less effective afterward, although one study found that oral appliances (plastic mouth retainer-like devices) may still help.

Experts estimate that in general about 1.6% of patients experience serious complications. Many of these complications can be avoided with proper technique and experienced surgeons. However, a patient’s health status may also affect outcomes. According to a 2006 study, patients are more likely to experience complications if they have severe sleep apnea, are overweight, have other medical problems, or undergo other surgical procedures at the same time as UPPP.

A variation on UPPP called laser-assisted uvulopalatoplasty (LAUP) is being increasingly performed to reduce snoring. It removes less tissue at the back of the throat than UPPP and can be done in a doctor's office. At this time, however, long-term success rates from LAUP are very modest, particularly for reducing apneas. Some doctors, in fact, are concerned that if LAUP eliminates snoring, they may miss a diagnosis of apnea in patients who have the more serious condition.

More than 50% of patients complain of throat dryness after surgery. Throat narrowing and scarring have also been reported. In a minority of patients, snoring becomes worse afterward.

The pillar palatal implant is a noninvasive surgical treatment for mild-to-moderate sleep apnea and snoring. It helps reduce the vibration and movement of the soft palate. In this procedure, a doctor inserts 3 short pieces of polyester string into the soft palate. The procedure can be performed in a doctor’s office and takes about 10 minutes. Unlike uvulopalatopharyngoplasty (UPPP), the pillar procedure requires only local anesthesia. Studies indicate it works as well as UPPP, with less pain and quicker recovery time.

Tracheostomy used to be the only treatment for sleep apnea. It is quite straightforward:

The surgeon makes an opening through the neck into the windpipe and inserts a tube.
It is almost 100% successful, but it requires a quarter-size opening in the throat. This produces a number of medical and psychological problems associated with recovery.

Today, this operation is performed rarely, usually only if sleep apnea is life-threatening.

A technique called radiofrequency ablation uses radiofrequency energy to shrink tissues in the upper airways:

The radio waves heat, stiffen, and shrink a small amount of tissue at the base of the tongue.
The therapy takes about 20 minutes and can be done in a doctor's office.
It typically requires 10 treatments within five or six sessions. (A newer form requires fewer treatment sessions, and it appears to be effective.)
It is far less invasive than standard surgery and results in far less pain and fewer complications. Discomfort can be controlled with simple pain relievers.

Studies reporting significant improvement in reduced snoring and less daytime sleepiness for some patients although, as with other surgeries, the benefits may be short term in the majority of patients. It may be helpful for mild obstructive sleep apnea.

Other surgical procedures may be appropriate to correct facial abnormalities or obstructions that cause sleep apnea. They may be used alone or combined with each other or with UPPP. They include:

Tongue advancement, in which an opening is cut where the tongue joins the jawbone and the area is pulled forward.
Genioplasty, which is plastic surgery on the chin.
Hyoid surgery, in which the movable bone underneath the chin is moved forward, pulling the tongue muscle along with it.
Maxillary or maxillomandibular advancement (MMA), which moves the upper (maxilla) or lower (mandible) jawbone forward. A survey of patients who had MMA found that the surgery changed their facial appearance, but most people thought it was a change for the better.
Surgery for nasal obstructions (such as a deviated septum) that contribute to snoring and other symptoms.

Adenotonsillectomy, or surgical removal of the tonsils and adenoids, is a first-line treatment for children and adolescents with sleep apnea. It cures the condition in 75 - 100% of cases. Two studies, published in 2005, suggested that adenotonsillectomy can significantly improve quality of life for children with obstructive sleep apnea.

Complications include respiratory illness, which occurs in about 25% of children after the surgery. The highest risk for respiratory complications is associated with:

Age under 3 years old
Severe sleep apnea
Heart complications
Failure to thrive
Obesity
Prematurity
Recent lung infections
Certain facial structures
Neuromuscular disease

The procedure may fail to improve apnea in some patients, such as those with very severe disease. Such children are candidates for continuous positive airway pressure (CPAP) therapy.

Removal of the tonsils and adenoids alone is not an effective treatment for adults with sleep apnea, although the procedure may be effective when combined with UPPP surgery.

Resources

www.sleepapnea.org -- American Sleep Apnea Association
www.nhlbi.nih.gov -- National Heart, Lung, and Blood Institute
www.aasmnet.org -- American Academy of Sleep Medicine
www.sleepfoundation.org -- National Sleep Foundation
www.nhlbi.nih.gov/about/ncsdr -- National Center on Sleep Disorders Research
www.sleepeducation.com -- Sleep Education from the American Academy of Sleep Medicine
www.wfsrs.org -- World Federation of Sleep Research Societies

References

Bradshaw DA, Ruff GA, Murphy DP. An oral hypnotic medication does not improve continuous positive airway pressure compliance in men with obstructive sleep apnea. Chest. 2006 Nov;130(5):1369-76.

Kezirian EJ, Weaver EM, Yueh B, Khuri SF, Daley J, Henderson WG. Risk factors for serious complication after uvulopalatopharyngoplasty. Arch Otolaryngol Head Neck Surg. 2006 Oct;132(10):1091-8.

Peppard PE, Szklo-Coxe M, Hla KM, Young T. Longitudinal association of sleep-related breathing disorder and depression. Arch Intern Med. 2006 Sep 18;166(16):1709-15.

Weaver TE, Maislin G, Dinges DF, Bloxham T, George CF, Greenberg H, et al. Relationship between hours of CPAP use and achieving normal levels of sleepiness and daily functioning. Sleep. 2007 Jun 1;30(6):711-9.

Review Date:
7/18/2007
Reviewed By:
Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

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