ESPE Abstracts

Background: Prader-Willi syndrome (PWS) is known for hyperphagia with impaired satiety and a specific behavioral phenotype with stubbornness, manipulative and controlling behavior and obsessive-compulsive features. PWS is associated with hypothalamic and oxytocinergic dysfunction. In humans without PWS, intranasal oxytocin administration had positive effects on social behavior and weight balance.

Objective and hypotheses: To evaluate the effects of intranasal oxytocin compared to placebo administration on social behavior and hyperphagia in children with PWS.

Design: Randomized, double-blind, placebo-controlled, cross-over study in a PWS Reference center.

Method: Cross-over intervention with intranasal oxytocin and placebo administration, both during 4 weeks, in 25 children with PWS (aged 6 to 14 years).

Results: In the total group, no significant effects of oxytocin on social behavior or hyperphagia were found, but in the 17 children younger than 11 years, parents reported significantly less anger (P=0.001), sadness (P=0.005), conflicts (P=0.010) and food-related behavior (P=0.011), and improvement of social behavior (P=0.018) during oxytocin treatment compared with placebo. In the 8 children older than 11 years, the items happiness (P=0.039), anger (P=0.042) and sadness (P=0.042) were negatively influenced by oxytocin treatment compared to placebo. There were no side effects or adverse events.

Conclusion: This randomized, double-blind, placebo-controlled study shows that intranasal oxytocin administration has beneficial effects on social behavior and food-related behavior in children with PWS younger than 11 years of age, but not in those older than 11 years of age.