Bone mineral density and body composition in Noonan's syndrome: effects of growth hormone treatment.

We assessed bone mineral density (BMD) and body composition in children with Noonan's syndrome (NS) before and during growth hormone (GH) treatment. Sixteen children (12 boys, 4 girls) with NS aged 5.8-14.2 (mean 10.0) years were studied for 2 years. Anthropometry, BMD measurements by radiographic absorptiometry and bioimpedance measurements (Akern-BIA 101/S) were performed at baseline and after 3, 6, 12 and 24 months. Daily GH dosage was 0.05 mg/kg. Trabecular volumetric BMD was normal; cortical BMD was in the lower normal range at baseline and slightly increased over the 2 years. Fat free mass and total body water were below normal at the start and increased significantly over the first 3 months, with a slight increment thereafter. Percentage fat mass decreased over the first 6 months and increased thereafter. These findings are comparable to the data on body composition in short normal children and girls with Turner's syndrome treated with GH.