The Efficacy and Safety of Long-term Norditropin® Treatment in Children with Prader-Willi Syndrome

Abstract

Prader-Willi syndrome is a genetic disorder that is associated with short stature, partial growth hormone deficiency, small hands and feet, learning and behavioural problems, and hyperphagia leading to severe, often morbid, obesity. Growth hormone therapy is associated with an improvement in height and body composition. We evaluated the efficacy and safety of long-term growth hormone treatment in a retrospective observational multinational study of 41 prepubertal children (mean age 3.8±3.0 years) with genetically diagnosed Prader-Willi syndrome treated with growth hormone (0.03-0.06 mg/kg/day) for >12 months [mean duration 4.1 (range 0.9-9.5) years]. Height, weight, and body composition measurements were recorded at baseline and at 6 month intervals until last observation. Mean (SD) gain in height at 12 months was 0.9 (0.2) SD score (p<0.0001). At last observation (after approximately 6 years) mean gain in height was 1.3 (0.3) (p=0.0001) with 85% of children achieving height>- 2 SD score. Body composition improved during treatment with an estimated 9.1% increase in lean body mass and 9.1% decrease in fat mass at last observation (p=0.019). Scoliosis was reported in 3 patients at baseline and 8 patients at last observation. Sleep apnoea was recorded in 3 (7.3%) patients. There were no other severe adverse events reported. Long-term growth hormone treatment of prepubertal children with Prader-Willi syndrome was associated with significant improvements in height and body composition. Treatment was well tolerated. The development of scoliosis warrants monitoring by an orthopaedic specialist.