LAS VEGAS — Sibutramine (Meridia) enabled obese adolescents to shed weight and improve obesity-related risk factors in a 12-month, randomized, double-blind, placebo-controlled trial.
The proportion of teenagers who lost at least 5% of body mass index (BMI) was more than three times greater in the sibutramine group compared with the control group—62% vs. 18%, Robert I. Berkowitz, M.D., reported at the annual meeting of North American Association for the Study of Obesity. When BMI loss of 10% or more was tallied, the sibutramine advantage was 39% vs. 6% of the patients.
Along with declines in glucose, insulin, and triglyceride levels, sibutramine helped the teenagers improve their psychological and emotional well-being and their school and social functioning, said Dr. Berkowitz, psychiatrist-in-chief at Children's Hospital of Philadelphia's behavioral health center.
“The improvements were significantly greater in the sibutramine group than in the placebo group,” he said.
Few long-term studies have addressed adolescent obesity. Mainly they have looked at behavioral changes in diet and exercise. “Most report a loss of only 1–4 kg, with participants still overweight at the end of the study,” Dr. Berkowitz said.
Sibutramine is not approved for patients under age 16.
The trial enrolled 498 patients aged 12 to 16 years (mean age 13.6 years), who had a BMI two units above the 95th percentile for their ages. Two-thirds of the patients were female.
“These were very overweight teenagers,” Dr. Berkowitz noted, reporting that the population had a mean BMI of 36 kg/m
All the patients started the trial on 10 mg of sibutramine or placebo in the morning. If they had lost less than 10% of body weight at 6 months, the dose was increased to 15 mg. The regimen also included behavioral programs for all of the participants.
The patients on sibutramine reduced their BMI by 8.2% on average, with a mean absolute reduction of 2.9 kg/m
Changes in risk factors were more significant, Dr. Berkowitz reported at the meeting, which was cosponsored by the American Diabetes Association. The sibutramine arm had a 5.9% reduction in triglyceride, vs. a 9% elevation in the teenagers on placebo. HDL cholesterol increased 7% with sibutramine but stayed the same with placebo. Insulin levels went down 10.8% in the sibutramine arm, but rose 30.2% in the control group.
Systolic blood pressure and pulse rates were similar in the two groups, as were the rates of most adverse events (headaches and flu being the most frequent). Tachycardia was significantly greater with sibutramine: 13% vs. 6%.
Three-fourths of 368 teenagers on sibutramine completed the study, but less than two-thirds of 130 in the placebo group continued to the end, perhaps because of dissatisfaction with the amount of weight loss. Only 5% of the sibutramine arm and 6% of the control group withdrew because of adverse events.
Pending Food and Drug Administration review of data from the study, Dr. Berkowitz said physicians might consider using sibutramine off label in obese teenagers with serious medical problems. He cautioned, however, that physicians should be very careful to use it as indicated in the labeling for adults.
Dr. Berkowitz received grant support from and is a consultant to and advisory board member of Abbott Laboratories, which markets sibutramine.