Early weight loss and outcome at one year in obese adolescents treated with orlistat or placebo

BACKGROUND: Pharmacotherapy, associated with a comprehensive weight loss intervention, has emerged as a promising therapeutic approach in adolescents. Identification of subjects who best respond to a pharmacological intervention remains difficult. OBJECTIVE: To compare the value of early weight loss after 12 weeks of treatment with placebo or orlistat (120 mg three times a day) in predicting treatment outcome after 52 weeks. METHODS: Secondary analysis of a randomized control trial in 182 placebo-treated and 357 orlistat-treated obese adolescents (Body mass index [BMI] ≥ 2 kg/m(2) above the 95(th) percentile). RESULTS: Percent weight change at 12 weeks was positively correlated with percent change in weight (r(2) ≥ 0.41), BMI (r(2) ≥ 0.33) and waist circumference (r(2) ≥ 0.20) at 52 weeks in both the placebo and orlistat groups (P < 0.001). A weight loss ≥ 5% of baseline weight at 12 weeks was associated with a mean weight loss of 8.1% (95% CI: 6.4 to 9.7) at the study end that was independent of treatment. Subjects in the orlistat group were 2.44 times (95% CI: 1.34 to 4.46) more likely to experience a weight loss ≥ 5% after 12 weeks than subjects in the placebo group (P = 0.0028). CONCLUSIONS: Early weight loss predicts a favourable outcome in both placebo-treated and orlistat-treated subjects but is more than 2 times more likely to occur in the orlistat group. Addition of orlistat should be considered as part of a weight loss intervention but reevaluated after 3 months of treatment.