Effect of orlistat on weight and body composition in obese adolescents - A randomized controlled trial

Context The prevalence of overweight and obesity in children and adolescents is increasing rapidly. In this population, behavioral therapy alone has had limited success in providing meaningful, sustained weight reduction, and pharmacological treatment has not been extensively studied. Objective To determine the efficacy and safety of orlistat in weight management of adolescents. Design, Setting, and Patients Multicenter, 54-week (August 2000-October 2002), randomized, double-blind study of 539 obese adolescents (aged 12-16 years; body mass index [BMI] >= 2 units above the 95th percentile) at 32 centers in the United States and Canada. Interventions A 120-mg dose of orlistat (n=357) or placebo (n=182) 3 times daily for 1 year, plus a mildly hypocaloric diet (30% fat calories), exercise, and behavioral therapy. Main Outcome Measures Change in BMI; secondary measures included changes in waist and hip circumference, weight loss, lipid measurements, and glucose and insulin responses to oral glucose challenge. Results There was a decrease in BMI in both treatment groups up to week 12, thereafter stabilizing with orlistat but increasing beyond baseline with placebo. At the end of the study, BMI had decreased by 0.55 with orlistat but increased by 0.31 with placebo (P=.001). Compared with 15.7% of the placebo group, 26.5% of participants taking orlistat had a 5% or higher decrease in BMI (P=.005); 4.5% and 13.3%, respectively, had a 10% or higher decrease in BMI (P=.002). At study end, weight had increased 0.53 kg with orlistat and 3.14 kg with placebo (P<.001). Dual-energy x-ray absorptiometry showed that this difference was explained by changes in fat mass. Waist circumference decreased in the orlistat group but increased in the placebo group (-1.33 cm vs +0.12 cm; P<.05). Generally mild to moderate gastrointestinal tract adverse events occurred in 9% to 50% of the orlistat group and in 1% to 13% of the placebo group. Conclusions In combination with diet, exercise, and behavioral modification, orlistat statistically significantly improved weight management in obese adolescents compared with placebo. The use of orlistat for 1 year in this adolescent population did not raise major safety issues although gastrointestinal adverse events were more common in the orlistat group.