Medication Plus Behavior Changes Help Obese Adolescents Lose Weight

The weight loss medication sibutramine, when combined with behavior therapy, allowed hundreds of very obese adolescents to lose an average of 14 pounds over a year, according to a multicenter study in the July 18 Annals of Internal Medicine. Adolescents in the study who received a placebo (a sugar pill) gained four pounds over the year.

In addition to reductions in body mass index and weight, the treated adolescents had improvements in disease risk factors associated with obesity. They had lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol, which are related to heart disease, and lower levels of insulin, a risk factor for diabetes. The only significant side effect was tachycardia, or rapid heart beat.

Although sibutramine, sold under the brand name Meridia, is currently used in adults with obesity, "this is the first large multicenter trial of sibutramine for obese adolescents," said study leader Robert I. Berkowitz, M.D., chief of Child and Adolescent Psychiatry at The Children's Hospital of Philadelphia. "In fact, there have been few trials evaluating any obesity drugs in adolescents."

Behavior therapy alone, said Dr. Berkowitz, usually provides only modest weight loss in adolescents, and thus medication may provide an additional treatment option for this age group.

The study enrolled 498 severely obese adolescents, aged 12 to 16, in 33 outpatient clinics throughout the United States from 2000 to 2002. The patients were randomized into two double-blinded groups, one receiving sibutramine and one receiving a placebo, while both groups received behavior therapy.

Each treatment center had its own behavior therapy program, with flexible modification approaches that included self-monitoring of eating habits and physical activity, stress management, stimulus control, problem solving and social support. Counselors encouraged patients to increase their physical activity and reduce their sedentary behaviors, and provided nutritional counseling.

At the end of the study, the 281 adolescents in the treatment group lost an average of 14 pounds, while the 79 patients in the control group gained an average of four pounds. Body mass index (BMI) decreased by 9.4 percent in the treatment group compared to 1.2 percent in the control group. Patients in both groups gained height and matured sexually at the same rate.

The standard definition of overweight in adolescents usually refers to those with a BMI greater than the 95th percentile for age and sex. This study focused on heavier patients, those with a BMI two units more than the 95th percentile, placing them at roughly the 97th percentile. Their mean weight was approximately 215 pounds.

At the end of the study, 33 percent of the patients who received sibutramine, compared to 7.6 percent in the control group, no longer had a BMI that was 2 units above the 95th percentile. Furthermore, 16.7 percent of the treated patients had their BMI drop below the 95th percentile (vs. 3.8 percent in the control group).