EFFECT OF GROWTH-HORMONE THERAPY ON BONE METABOLISM OF GROWTH-HORMONEDEFICIENT CHILDREN

The effects of human growth hormone (hGH) therapy on biochemical marke rs of bone metabolism were studied in 17 children(10 boys and 7 girls, aged 3.7-13.1 years old) with idiopathic GH deficiency, before and 1 and 6 months after GH therapy (0.5-0.7 IU/kg weekly, SC). Serum levels of calcium, phosphate, alkaline phosphatase, osteocalcin, parathyroid hormone, 1,25 dihydroxyvitamin D, insulin-like growth factor I (IGF-I ) and renal phosphate per 100 mi glomerular filtrate (TPO4/GFR) were a ssessed. During therapy with hGH, a significant decrease of serum calc ium levels and increases of phosphate, osteocalcin, parathyroid hormon e 1,25 dihydroxyvitamin D and IGF-I were observed. TPO4/GFR was also s ignificantly increased. Growth response (increment in HV) was positive ly related with changes in alkaline phosphatase and IGF-I levels after 6 months of hGH therapy. There was also a significant positive correl ation between increment in HV and increment in TPO4/GFR after 1 month of GH therapy, whereas no correlation between HV and changes in osteoc alcin levels was found. Conclusion GH treatment significantly influenc es mineral metabolism and the measurement of TPO4/GFR after 1 month of GH therapy may serve as a useful predictor of growth response to hGH therapy in GH-deficient children.