Effects of growth hormone treatment for short stature on calcium homeostasis, bone mineralisation, and body composition.

We investigated the effect of growth hormone (GH) treatment on mineral and vitamin D homeostasis, bone mineralisation, and body composition in short-statured children without GH deficiency (GHD). 11 children received GH (0.50 +/- 0.08 IU/kg/week) for 24 weeks. 1,25-Dihydroxyvitamin D3 levels (mean +/- SD in pmol/l) rose from a baseline of 73.7 +/- 39.2 to 114.0 +/- 32.7 at 8 weeks (p < 0.05) and 111.9 +/- 39.7 at 24 weeks (p < 0.01). Body composition evaluation using dual-energy X-ray absorptiometry revealed increased lean tissue mass and a reduction in fat tissue. As a percentage of total body mass, fat decreased from 19.0 +/- 11.8% at baseline to 17.3 +/- 11.5% at 8 weeks (p < 0.005) and 16.8 +/- 11.5% at 24 weeks (p < 0.05). L2-L4 bone mineral density was 0.637 +/- 0.155 g/cm2 at baseline and 0.666 +/- 0.160 g/cm2 at 24 weeks (NS). We conclude that recombinant human GH treatment of short children without GHD has significant effects on vitamin D homeostasis and body composition.