Long-acting octreotide treatment causes a sustained decrease in ghrelin concentrations but does not affect weight, behaviour and appetite in subjects with Prader–Willi syndrome

ObjectiveGhrelin is secreted primarily by the stomach and circulates as both acylated and desacyl ghrelin. Acylated (but not desacyl) ghrelin stimulates appetite. Both concentrations are elevated in Prader–Willi syndrome (PWS), suggesting that ghrelin may contribute to hyperphagia and overweight in these subjects. We evaluated whether long-acting octreotide (Oct) decreases acylated and desacyl ghrelin concentrations, body mass, appetite and compulsive behaviour towards food in adolescents with PWS.DesignA 56-week prospective, randomized, cross-over trial.MethodsNine subjects with PWS (age 14.6 (10.8–18.9) years, body mass index (BMI) Z-score +1.9 (0.6–3.0)) received either Oct (30 mg) or saline i.m. every 4 weeks for 16 weeks and were switched over to the other treatment after a 24-week washout period.ResultsEight subjects completed the study. Oct caused a decrease in both acylated (−53%) and desacyl (−54%) fasting ghrelin concentrations (PConclusionsOct treatment caused a prolonged decrease in ghrelin concentrations in adolescents with PWS but did not improve body mass or appetite. Future intervention studies aiming at clarifying the role of ghrelin in PWS should focus on the administration of specific inhibitors of ghrelin secretion or ghrelin receptor activity that do not interfere with other appetite-regulating peptides.