Body composition and bone mass of children with hypopituitarism following six months of human growth hormone therapy

RESUMO

Total body composition and the bone mineral content (BMC) and density (BMD) of 8 perpubertal (4 boys and 4 girls) GH-deficient children aged 6-14 years were investigated before and during a 3-6 month period on human growth hormone (hGH) therapy (0.075 IU/Kg/day, sc.); measurements were made by dual energy x-ray absorptiometry (DEXA). Before hGH therapy, total body fat mass was 4 + 3 kg and the total body percentage of fat was 22 + 12 per cent; the total lean mass was 14 + 3 kg. Total BMC was 625 + 163 g, and total BMD was 0.777 + 0.025 g/cm2. When compared with a matched population of normal children, GH-deficient children presented decreased lean mass (-0.9 to -5.9 SD), BMC (-0.9 to - 5.6 SD) and BMD (-0.1 to -4 SD). Fat mass, as a percentage, was not significantly different between populations (22 + 12 per cent in GH-deficient children vs. 17 + 5 per cent in normal children, p>0.05). Therapy with hGH was associated with (I) a major decrease of total body percentage of fat mass -31 + 15 per cent after 6 months (p<0.05); and with (II) an increase in the total lean mass and total BMC, 14 + 8 per cent and 7 + 5 per cent, respectively (both p<0.05). Total BMD was not significantly changed after 6 months of hGH therapy. We conclude that hGH replacement therapy results in a major and rapid decrease of total fat mass and in a less pronoucend increase of total lean mass.