Growth hormone therapy for Prader-Willi syndrome: a critical appraisal.

Prader-Willi syndrome (PWS) is characterized by hypothalamic dysfunction resulting in obesity, hypotonia, hypogonadism, and behavioral abnormalities. Clinical features of PWS resemble those of GH deficiency (decreased total lean body mass, IGF-I levels, and poor linear growth). Marked reductions in muscle mass are associated with diminished strength, physical function, and energy expenditure. Lifelong morbidities of PWS include osteoporosis, type 2 diabetes mellitus, respiratory disorders, and cardiorespiratory failure related to obesity and hypotonia. Recent studies show that GH therapy improves linear growth, final height, physical strength, and agility in patients with PWS. Some effects of GH therapy wane with time, however, and strategies for treating adults with PWS remain uncertain. In addition, deaths in markedly obese, GH-treated children with PWS have been reported, and a possible contribution of GH to these events has not yet been definitively excluded. Consequently, critical evaluation should continue of the long-term benefits, risks, and costs of GH therapy for patients with PWS.