A short course of recombinant human growth hormone treatment stimulates osteoblasts and activates bone remodeling in normal human volunteers

Abstract

The effects of recombinant human growth hormone (rhGH) on biochemical markers of bone turnover and bone mineral content (BMC) were investigated in 20 normal male volunteers (aged 22‐31 years) randomized to treatment for 7 days with either rhGH (0.1 IU/kg subcutaneously twice a day) or placebo. Serum somatomedin C rose during treatment (p < 0.001) but was not significantly different from baseline at day 14. The fasting urinary hydroxyproiine/creatinine (p < 0.001) and calcium/creatinine ratios (p < 0.01) increased during treatment and remained elevated for 4 and 2 weeks, respectively. Serum bone 7‐carboxyglutamic acid‐containing protein (BGP) increased during treatment (p < 0.001) and remained elevated for 6 months (p < 0.02). Serum bone alkaline phosphatase (B‐AP), after an initial fall in the treatment period (p < 0.001), increased slightly in the following months (p < 0.01). In the rhGH group BMC was significantly higher than the prestudy value at day 14 (p < 0.05) but was unaltered at the end of study. The simultaneous increase in markers of bone resorption and formation during rhGH treatment followed by a decline in resorption parameters within a few weeks and the prolonged effect on BGP and B‐AP demonstrate that rhGH treatment stimulates osteoblasts and activates bone remodeling.