Obesity is no longer a cosmetic issue. Epidemic in the United States, obesity is a chronic medical disease associated with approximately 300,000 deaths annually, and it is our second leading cause of preventable deaths.1 In addition, annual costs associated with obesity and its comorbid conditions are $117 billion. Consider the following:
Poor nutrition, lifestyle factors, and physical inactivity feed the obesity epidemic. Sedentary occupations, the use of automobiles, and technology circumvent healthy physical activity. The relationship of inactivity to obesity is particularly dramatic. Each 2-hour increment of television watching daily increases obesity risk by 23% and diabetes risk by 14%.3 More than 60% of adults lack sufficient physical activity and exercise, and 27% of Americans eschew regular physical activity.2,4,5 Super-sized diets, large portions, and more fats augment inactivity. Since 1970, Americans have doubled their cheese consumption, and sugar-laden soda consumption has increased to an average of approximately 50 gallons per person per year.6 Only 25% of adults and 20% of children and adolescents eat 5 fruits and vegetables daily; more than 60% of children consume excessive dietary fat.2,4,5
BMI = weight (kg)/height (m2)
Body Mass Index
Of several techniques for measuring the proportion of body fat, body mass index (BMI) gives a quick assessment of body composition, is unaffected by age or gender, and is calculated easily:
Values above 24.9 are considered overweight (and below 18.5, underweight), and a BMI of 30 indicates that the individual is approximately 30 lb overweight, or obese. Examples are a 5-foot 6-inch person who weighs 186 lb and a 6-foot person who weighs 221 lb. An excess of 100 lb constitutes morbid obesity.
Health status is adversely affected by 2 types of body fat distribution: large waist circumference (apple shape) and large hip circumference (pear shape). Abdominal fat concentrations pose greater risk for obesity-related health problems than fat concentration elsewhere. Women are more likely to be pear shaped, and men, apple shaped.7
Obesity has been linked with more than 30 medical conditions, particularly diabetes, heart disease, and hypertension. Compared with normal-weight people, obese people at any age have higher mortality rates, and a BMI of approximately 40 doubles the chance of premature death.8 The association of type 2 diabetes with obesity is particularly strong. Its prevalence is 2.9 times higher among overweight people. Research demonstrates that 67% of type 2 diabetics have a BMI >27.8,9 The incidence of diabetes seems to parallel that of obesity. Between 1999 and 2000, obesity increased from 18.9% to 19.8%, and diabetes increased from 6.9% to 7.3%.5 Equally strong is the association of cardiovascular diseases with obesity. Among men, for example, each 10% increase in weight is associated with a 30% increase in coronary artery disease.10
Inadequate Attention to the Problem
Despite health and mortality risks, health professionals counsel only 43.1% of obese people to lose weight. Yet, that simple action?counseling?increases the probability that patients will lose weight significantly.5
With so many Americans either contemplating dieting or on a diet, pharmacists ought to be deluged with questions about weight loss. Sometimes that is the case, although often people are reluctant to discuss or ashamed to acknowledge their weight problems. Others, frustrated with yo-yo cycles of weight loss and gain, have simply given up. Interventions fall into 3 general categories: lifestyle modification, drugs, and surgery.
Lifestyle modification will be a component of any attempt to lose weight. Unfortunately, dieters? adherence to and long-term success is notoriously poor.12 Magazine racks and bookshelves are full of information about dieting and diets, but the buyer should be aware that there truly is no such thing as a "free lunch." The only way to lose weight is to create a calorie deficit; daily caloric intake of 600 kcal less than ordinarily consumed will lead to a weight loss of about 2 lb per week.13 People can create calorie deficits in either of 2 ways: consume less or exercise more.
Of the many fad or gimmick diets presently popular, high-protein/low-carbohydrate diets such as the Atkins diet have captivated the nation. Recently, Foster et al reported results from a 1-year, multicenter, controlled trial involving 63 weight-challenged people randomly assigned to either the Atkins diet or a conventional diet. Dieters were to some degree unsupervised to replicate real-world situations. At 3 and 6 months, people on the Atkins diet had lost more weight than those on the conventional diet. The difference at 12 months was insignificant, however. Diastolic blood pressure and insulin response to an oral glucose load improved in both groups. The Atkins diet was associated with a greater improvement in some risk factors for coronary heart disease, probably because of greater initial weight loss. Adherence and attrition were problems in both groups; 41% of subjects failed to complete the study.12 Other popular diets (eg, Protein Power, Sugar Busters, the Zone) may promote weight loss, but they are often unscientific or misleading. Anderson et al reviewed and analyzed many popular diets and concluded that most propose daily caloric intake of less than 1600, a reasonable calorie count for weight loss.14 Regardless, the challenge of dieting (or supervising a dieting patient) can defeat even highly motivated individuals, leading them to seek other interventions, such as drug therapy.
Historically, clinicians have tried all kinds of medications to treat obesity. Today, only 3 prescription medications remain approved for weight loss, and each is limited in its utility.
Phentermine is the oldest of the agents, having celebrated its 53rd birthday. Its mechanism of action is believed to be increased norepineph-rine in the central nervous system. Its side effects?increased heart rate, nervousness, constipation, and hypertension?are related to its central actions. A controlled substance in the United States, phentermine is a rarely used short-term adjuvant to modified diet.15 Sibutramine also acts centrally, boosting norepinephrine, dopamine, and serotonin availability in the synapse. Patients who take sibutramine feel full sooner and consume less. Adverse effects include constipation, dry mouth (which can contribute to dental carries), headache, rhinitis, and insomnia. Between February 1998 and September 2001, 150 sibutramine-treated individuals were hospitalized and 29 died (19 from cardiovascular problems). Consequently, regulators are watching this agent carefully, but pharmacists should note that the deaths represent a lower mortality rate than would generally be expected in the obese population.15 More studies are needed. Sibutramine doses are adjusted for individual patients, with 10 mg being the usual starting dose, increasing to 15 mg after a month.
Orlistat is a reversible inhibitor of gastric and pancreatic lipase. It is not absorbed systemically, and its adverse effects (abdominal pain or discomfort, fatty or oily stools, fecal urgency and frequency) are predictable and result from increased fat in the bowel.15 These side effects can limit treatment and often lead to therapy cessation. Krempf et al studied 696 patients taking 120 mg of orlistat daily. At 18 months, more orlistat-treated patients had maintained clinically meaningful weight reductions than those treated with placebo. This weight loss resulted in an improvement in risk factors for coronary heart disease.16 Other studies have reported similar results.
Both sibutramine and orlistat, in combination with dietary restriction, have proven to induce weight loss that is greater than that achieved with diet alone by approximately 3% to 5%. Consequently, patients have significant improvements in diabetes-associated risk factors and cardiovascular health.16-18 Rebound weight gain, once the agents are stopped, however, is common, and long-term safety data are lacking.19
Surgical options exist for the morbidly obese. For them, weight loss of 10% to 15% is rarely sufficient to improve health, and thus drastic measures may be necessary. Bariatric surgery has a success rate (defined as a sustained loss of 25% to 40% of body weight) at or near 90%, but it forces lifestyle changes. Candidates must realize that, after surgery, eating patterns will of necessity change. Today?s surgical procedures are much improved over the early attempts at reducing stomach size and are often done laparoscopically.
Patient Counseling Issues
Patients who are trying to lose weight need extensive support. Pharmacists should heed the following points when counseling patients:
Looking to the Future
Several new agents are in the drug-development pipeline. As researchers understand the complex process by which weight is determined, better alternatives will be available. To date, there are no quick fixes. Fad dieting aside, most specialists now recommend treatment goals of 10% weight reduction, followed by 6 months of weight maintenance before striving for further weight reduction.7
Views expressed in this article are those of the authors and not those of the National Cancer Institute.
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