Growth hormone (GH) and adult bone remodeling: the potential use of GH in treatment of osteoporosis.

Decreased osteoblastic activity seems to be of major importance in the pathogenesis of postmenopausal and senile osteoporosis and several lines of evidence suggest that GH may become useful in treatment of osteoporosis. GH stimulates osteoblastic proliferation and differentiation in vitro and increases production of Insulin-like Growth Factor-I and II (IGF-I and IGF-II) which both have profound stimulatory effects on osteoblasts and are important local regulators of bone remodeling. GH affects several other osteotropic hormones in vivo and increases bone turnover while the effect on bone mass is less pronounced and depends on the skeletal compartment. The few published clinical studies on the use of GH in treatment of osteoporosis have been inconclusive and well controlled studies of adequate size are greatly needed. Future research should focus on intermittent use of GH in combination with other hormones stimulating IGF production or antiresorptive agents.