Effects of growth hormone and insulin-like growth factor I in men with idiopathic osteoporosis.
Injections with growth hormone (GH) or insulin-like growth factor I (IGF-I) have been proposed for anabolic therapy in osteoporosis. In a cross-over study, 12 men with idiopathic osteoporosis received daily subcutaneous injections of GH (2 IU/m2) or IGF-I (80 micrograms/kg) for 7 days with 12 weeks of wash-out. Serum levels of procollagen type I increased by 29% following treatment with GH (P < 0.001) and by 43% with IGF-I (P < 0.001 compared with pretreatment levels; P < 0.05 compared with GH injections), whereas both treatments rendered a 20% increase in osteocalcin concentrations (P < 0.001), indicating enhanced bone formation. There was also evidence of stimulated bone resorption, as the urinary levels of deoxypyridinoline increased by 44% following GH injections (P < 0.001) and by 29% following IGF-I (P < 0.001), and there were 28% higher serum concentrations of IGF-I after GH than after IGF-I injections. Although markers of bone metabolism increased under both treatments, comparison of the treatments suggests that IGF-I enhanced formation of collagen type I more than did GH. Furthermore, the stimulation of bone resorption was detected as soon as 4 days after the initiation of GH injections. Some of the differences might be dose-dependent, but could also indicate separate mechanisms at the cellular level.
Johansson
A G
AG
Department of Internal Medicine, University of Hospital, Uppsala, Sweden.
Lindh
E
E
Blum
W F
WF
Kollerup
G
G
Sørensen
O H
OH
Ljunghall
S
S
D000328:Adult; D001846:Bone Development / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D018592:Cross-Over Studies; D004311:Double-Blind Method; D013006:Growth Hormone / Q000627:therapeutic use*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy* / Q000378:metabolism
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D003094:Collagen; D002118:Calcium