One Year of Growth Hormone Treatment in Adults with Prader-Willi Syndrome Improves Body Composition: Results from a Randomized, Placebo-Controlled Study

Context: Prader-Willi syndrome (PWS) is a multisymptomatic disease that shares many similarities with the GH deficiency syndrome, including altered body composition with more body fat than lean body mass. Objective: Our objective was to investigate the effect of GH on body composition in adults with PWS. Design and patients: Forty-six adults with PWS were randomized to GH or placebo treatment for 12 months in a double-blind trial. Main Outcome Measures: We evaluated change in regional body composition of the abdomen and thigh as measured by computed tomography and change in total body composition as measured by dual-energy x-ray absorptiometry. Results: Forty patients completed the study. Baseline median IGF-I SD score was -0.4. GH treatment increased IGF-I by 125 mu g/liter (1.51 SD score), and based upon computed tomography, body composition improved with a decrease in visceral fat mass of 22.9 ml (P = 0.004), abdominal sc fat mass 70.9 ml (P = 0.003), and thigh fat mass 21.3 ml (P = 0.013), whereas thigh muscle mass increased 6.0 ml (P = 0.005). By dual-energy x-ray absorptiometry, lean body mass improved 2.25 kg (P = 0.005), and total fat mass decreased 4.20 kg (P < 0.001). No major side effects were seen. Conclusion: Unrelated to the GH-IGF-I levels at baseline, our results showed that long-term treatment with GH effectively improved body composition and represents a safe, potential treatment option, relieving some of the negative consequences of PWS. (J Clin Endocrinol Metab 95: 4943-4950, 2010)