Behavioral therapies for adolescents who are overweight or obese have met with only modest success. Additional treatment options are, therefore, clearly required to promote additional weight loss.OBJECTIVE
To evaluate the safety and efficacy of sibutramine in adolescents who underwent behavioral weight-loss therapy.DESIGN AND INTERVENTION
This was a 12-month, US-based, multicenter, randomized, double-blind, placebo-controlled trial. Eligible participants were aged 12-16 years with a BMI ≥2 kg/m2 above the 95th percentile for their age and sex in the US. Exclusion criteria included BMI >44 kg/m2, systolic blood pressure >130 mmHg, diastolic blood pressure >85 mmHg, pulse rate >95 beats/min, type 1 or type 2 diabetes, cardiovascular disease, and use of weight-loss medications. At baseline, participants were randomly allocated to receive 10 mg sibutramine or placebo daily. If necessary, the dose was increased to 15 mg daily after 6 months. All participants received behavioral intervention, which included nutritional advice and self-monitoring of eating habits and exercise. A daily dietary deficit of 500 kcal was encouraged. Study visits were weekly for the first 2 weeks, fortnightly until week 12, and monthly thereafter.OUTCOME MEASURES
The primary outcome measure was the absolute change in BMI from baseline. Secondary outcome measures included percentage change in BMI, change in body weight, waist circumference, lipid profile, and glycemic parameters, and the incidence and severity of adverse events.RESULTS
Sibutramine or placebo was administered to 368 and 130 participants, respectively. The completion rate was 76% with sibutramine and 62% with placebo. Compliance in the sibutramine and placebo groups was 89.1% and 83.9%, respectively. At month 12, the estimated mean reduction in BMI was 3.1 kg/m2 with sibutramine, compared with 0.3 kg/m2 with placebo (P<0.001). A reduction in BMI ≥5% was observed in 69.8% of participants who received sibutramine and 21.5% of participants who received placebo. At month 12, 16.7% of participants in the sibutramine group and 3.8% of participants in the placebo group had a BMI below the 95th percentile. The estimated mean reduction in body weight at month 12 was 6.5 kg with sibutramine versus 1.9 kg with placebo. Similarly, sibutramine resulted in an 8.2 cm reduction in waist circumference versus a 1.8 cm reduction with placebo. Insulin sensitivity and levels of fasting triglycerides, HDL cholesterol, and insulin were improved with sibutramine (P<0.001); however, there was no difference between groups for LDL cholesterol, total cholesterol, or serum glucose levels. Blood pressure and pulse rate showed greater improvement with placebo than sibutramine. The incidence and severity of adverse events was similar in both groups; however, sibutramine was associated with an increased incidence of tachycardia (12.5% versus 6.2% with placebo, P = 0.049). Five adolescents treated with sibutramine withdrew after they developed hypertension.CONCLUSION
Sibutramine improved weight loss in adolescents who underwent behavioral therapy.