To diagnose obesity, you often need only a scale, tape measure and calculator. But to treat it? That requires more resources and effort. On a personal level, obesity affects patients' health and self-image, with depression a common comorbidity. On a national level, with six out of 10 adults considered overweight or obese, it is an epidemic, with obesity treatment expenses consuming 9.4% of U.S. health care expenditures.
This complex disease "will be the major chronic health problem of this century," wrote endocrinologist Barry Gumbiner, MD, author of "Obesity," an ACP Key Diseases book published in 2001.
One longitudinal study cited in the book found that patients with a body mass index (BMI) greater than or equal to 30 were three times more likely to die from coronary heart disease than their nonobese peers. Other studies have shown a direct relationship between body weight and blood pressure, as well as between weight and diabetes.
The primary care physician's most important role, Dr. Gumbiner wrote, is "to coordinate all treatment activities to ensure overall effectiveness and safety. In the current state of health care delivery, it is unrealistic to directly provide all the elements of the treatment."
But many physicians don't even discuss weight with obese patients, said George A. Bray, MACP, professor of medicine at Louisiana State University in Baton Rouge, La., and author of the PIER obesity module. The reasons for that omission, he explained, are complex.
For one, both physicians and patients have unrealistic expectations about weight loss. According to Dr. Bray, most people who diet lose only about 10% of their starting body weight. That percentage is fine for someone only slightly overweight—but highly discouraging for someone who's obese.
Moreover, it takes sustained effort—and often dollars—to keep weight off, and insurers typically don't reimburse money spent on weight loss drugs or programs. At the same time, the country's reliance on fast processed food is still firmly entrenched, making it tough for doctors to get their lose-the-weight message heard. Despite some encouraging signs—such as a growing movement to prohibit junk food in school vending machines and cafeterias—a major cultural shift is in order, he said.
What may grab the public's attention is the economics of obesity. Major employers will sound the alarm because of rising health care costs and lost productivity, Dr. Bray said. In the meantime, obesity treatment requires perseverance and cooperation between patients and physicians.
This edition of ACP Observer Special Focus is designed to help optimize your ability to treat obesity with recommendations for screening, therapy and thorough follow-up.
Body Mass Index
Body mass index (BMI) is determined by dividing weight, measured in kilograms, by height squared, measured in meters: BMI=kg/(m)2.
The BMI has a solid correlation with risks associated with obesity and body fat, including diabetes, heart disease and certain types of cancer. The National Heart, Lung and Blood Institute and the World Health Organization have given the following definitions to different BMI levels:
- underweight: under 18.5
- normal weight: 18.5 to 24.9
- overweight: 25 to 29.9
- obesity: over 30
For Asian Americans, a BMI of 23 or more is considered overweight, while a BMI equal to or more than 25 is obese.
Provide counseling and preventive strategies for adults at risk for weight gain. Identify those patients and any associated comorbidities by noting if:
- Their body weight is increasing at a rate above one to two pounds per year.
- They have a strong family history of overweight.
- They present with abnormal waist circumference: greater than 40 inches for males or more than 35 inches for females.
- They have a low level of physical activity.
Tell these patients about the importance of:
- exercising for 30 minutes or more, five times per week;
- controlling caloric intake and blood pressure;
- lowering fat intake for weight loss or weight maintenance; and
- increasing dietary fiber.
Also tell at-risk patients that obesity carries a social stigma and shortens life expectancy. Explain that it increases their risk of diabetes, heart and gall bladder disease, sleep apnea, hypertension, osteoarthritis, erectile dysfunction, some forms of cancer and infertility. Tell recent ex-smokers that they will likely gain weight, and that the aging process isn't kind to the waistline, either. Let them know that existing back problems will worsen as their BMI goes higher.
Screen all adult patients for weight status and associated comorbidities. Measure their height and weight, and then calculate both their BMI and waist circumference, using a steel tape to measure the latter.
Assess other factors that can influence interpretation of BMI and waist circumference, including rate of increase in body weight, ethnic group, age, gender and level of physical activity. Patients who gain more than two pounds a year are at high risk for comorbidities, while several minority populations—including African Americans, Latinos and Polynesians—have a particularly high prevalence of obesity.
Base your diagnosis of overweight or obesity on BMI modified by waist circumference, comorbidities and other factors.
Take a thorough history to determine the patient's family history of being overweight; the occurrence of life events such as quitting smoking, pregnancy, surgery with disability or recent injury; family income and educational level; level of physical activity; and medication history. Also ask about patients' eating patterns: Do they skip breakfast, eat mainly at night or have food cravings?
Use physical examination to establish the presence of obesity, central adiposity and associated comorbid conditions, including hypertension, endocrinopathies such as hypothyroidism and Cushing's syndrome, and reproductive disorders such as polycystic ovary disorders.
Use lab testing to confirm clinical evaluation and assess for comorbidities. All patients with a BMI greater than 25 or associated comorbid conditions should have blood tests for glucose and creatinine levels; and a sleep test to confirm sleep apnea in patients with somnolence or plethora, or a history of snoring.
Use clinical and laboratory evaluation to look for diseases associated with obesity, including:
- Sleep apnea and alveolar hypoventilation
- Diabetes mellitus
- Gallbladder disease and gallstones
- Cushing's disease
Evaluate for metabolic syndrome, indicated by at least three of the following criteria: waist circumference, greater than 40 inches in men, 35 in women; serum triglyceride concentration of 150 mg/dL or more; serum HDL cholesterol concentration less than 40 mg/dL in men and less than 50 mg/dL in women; blood pressure, 130/85 mm Hg or greater; and fasting plasma glucose level of 110 mg/dL or greater.
Other, rarer diseases to look for include polycystic ovary syndrome, Prader-Willi syndrome and other genetic disorders, pituitary or hypothalamic lesions, melanocortin receptor defect, PPAR-y defects, and leptin and leptin receptor deficiency.
When you take patients' medication history, see if they are taking any of the following classes that can cause weight gain: antipsychotics, antidepressants, anticonvulsants, antidiabetic drugs (including insulin), antimigraines, antihypertensives and steroid hormones.
Consider appropriate consultation if hypothalamic, endocrine or genetic factors require evaluation. Refer to an endocrinologist for help in evaluating patients with suspected Cushing's disease, polycystic ovary syndrome or hypothyroidism.
Hospitalize patients with serious complications from obesity. These include severe hypercapnia from alveolar hypoventilation requiring assisted ventilation, symptomatic gallbladder disease requiring surgery and acute cardiovascular events.
Also hospitalize patients for initial bariatric surgical procedures and for serious complications of these procedures, including leaks at suture lines, inadequate weight loss, severe wound infections and sepsis.
Institute lifestyle modifications, including diet and exercise, in all overweight patients. Consider behavioral therapy—which can reduce body weight by 5% and 10% for most patients—for overweight patients who need or want to lose weight.
Patients should record their food intake and increase their physical activity. But they also must understand that the amount and rate of weight loss depends on their faithfulness to the diet and exercise program.
Tell patients that reducing their caloric intake with very low calorie diets, using structured meal plans and eating low-fat foods with a low glycemic index can help them lose weight. Eating more high-fiber foods and those containing more protein may make patients feel less hungry.
Patients also need to be told that increasing exercise is critical to weight loss. Overweight patients should exercise 30 to 60 minutes five or more days a week, by increasing walking or other comparable activities.
Keep in touch with dieting patients. Studies show that therapist contact, including phone and e-mail contacts, can be useful.
And consider surgery for patients whose BMI is 35 or more and who have comorbidities. Patients who have a BMI of 40 or higher and comorbid conditions, and whose previous efforts at diet, drug therapy and exercise have failed, should have surgery, according to ACP's obesity guidelines published in the April 5, 2005 Annals of Internal Medicine.
ACP guidelines recommend sending patients who need or agree to surgery to only experienced specialists and high-volume surgery centers. A surgical "team" would optimally include an internist with experience caring for obese patients, a dietitian, and a behavioral therapist or psychologist to help with perioperative problems.
A successful weight loser is one who sheds more than four pounds in four weeks, loses more than 5% of their body weight at six months and keeps the lost weight off for a year.
Consider drug therapy for patients with a BMI equal to or greater than 30 who have failed other treatments. You should do the same for patients whose BMI is equal to or greater than 27 and who have comorbidities such as sleep apnea, diabetes, hypertension or dyslipidemia.
When taken properly, sibutramine helps obese patients lose weight and maintain weight loss. But it raises blood pressure or prevents it from falling, even in hypertensive patients. Orlistat also produces dose-related weight loss, but it decreases LDL cholesterol more than can be accounted for by weight loss. Combining the two drugs does not enhance efficacy—and you need to remind patients that diet drugs work only if they are taken as prescribed.
Sibutramine and orlistat produce weight loss in diabetic patients and improve diabetic control. Sympathomimetic drugs—such as phentermine, diethylpropion, benzphetamine and phendimetrazine—are also effective but are FDA-approved only for short-term treatment.
Consider discontinuing drug therapy, switching to another drug or combining drugs when weight loss:
- is less than four pounds in two months
- is less than 5% after six months of therapy
- fails to remain less than 5% below baseline at 12, 18 or 24 months
And remind patients that over-the-counter herbal preparations sold for weight loss have limited efficacy and safety data. The FDA has removed supplements containing ephedra and ma huang from the market, citing safety concerns.
Remind patients about realistic weight loss goals, the importance of adhering to therapy and the value of exercise as a long-term strategy of weight loss maintenance.
Tell them that it's inevitable that their weight will reach a plateau when resistance to weight reduction counteracts therapeutic effects. Also tell them that a decrease of 5% to 10% is realistically attainable through behavioral therapy, diet and drug therapy and is associated with proven health benefits. Explain to patients that only surgery consistently provides weight loss of greater than 10%.
Advise them that a change in therapy is probably in order if they lose less than 5% on the chosen diet strategy. And offer them support. Use ongoing office visits or behavioral therapy to reinforce or boost previously learned procedures, or refer patients to outside groups such as Weight Watchers, Take Off Pounds Sensibly (TOPS) or Overeaters Anonymous. Studies show that self-help groups can produce weight loss.
Lifestyle therapies to recommend include behavioral specialists such as clinical psychologists or trained dietitians. Remember that behavioral therapists with training in weight loss therapy are better prepared to assist with necessary lifestyle changes. Dietitian-led lifestyle case management may improve health indicators among obese patients with type 2 diabetes mellitus. And exercise specialists have more training in fitness and with exercise equipment.
Use scheduled follow-up to:
- Monitor weight
- Review all treatments
- Monitor for drug side effects
- Check for surgical complications when applicable
- Monitor comorbid conditions
- Address relapse
Access to PIER's obesity module is online.
The module author is George A. Bray, MACP, Pennington Biomedical Research Center/Louisiana State University, Baton Rouge.
The information included herein should never be used as a substitute for clinical judgment and does not represent an official position of ACP.
Weight loss realities
Joseph K. Berkson, MD, a family physician based in Seattle who works with Group Health Cooperative, is a specialist in behavioral change management. He recently spoke with ACP Observer about the challenges of treating patients with obesity.
On effective weight loss procedures: What works are intensive behavioral change programs involving both dietary and behavioral change counseling. "Intensive" means a commitment to making behavioral changes-and that takes going to a program that meets weekly for at least an hour. It's hard to maintain the commitment; those who are successful are able to make behavioral changes.
On people who try to lose weight: They all feel like they are failures. It's one reason why doctors don't send them to weight management centers—they don't want to set them up for failure. A large percentage is clinically depressed, at least 50%. It's a huge issue.
On the primary care physician's role: Studies show that most people want to lose 17% of their weight, although 5%-10% is a more realistic goal. One of the major issues for physicians is trying to change people's expectations, because some will think, "If I can't lose the 17%, why try?" I stress the clinical gains [of losing less weight] but it doesn't always work. People want to look better and not be discriminated against.
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