Effect of Rimonabant on Weight Gain and Body Composition in Adults With Prader Willi Syndrome

The purpose of this study is to evaluate the effect of rimonabant, a cannabinoid receptor-1 blocking drug, on the appetite, body weight, body fat and growth hormone level of subjects with Prader-Willi Syndrome (PWS). This will be a double blind placebo controlled clinical trial involving a total of 18 young adults aged 18 to 35 years with PWS. Patients will be divided in to the two groups of control and intervention, and treated with either placebo (inactive drug), or rimonabant 20 mg once a day for a total duration of 6 months. Body weight, fat distribution, objective and subjective assessment of the hunger, fasting blood sample for measurement of ghrelin and leptin (two hormones regulating appetite), serum lipids , IGF-1(growth hormone related protein), insulin and glucose concentrations will be measured upon enrollment, at 3 months, and at the end of the study. The proportion of body fat to muscle will be determined using a radiological technique, whole body dual-energy x-ray absorptiometry (DEXA) scan, and also by measurement of skin fold thickness, waist and hip circumference at the enrollment prior to the intervention, and at the end of the study.