Treatment with growth hormone and IGF-I in growing rats increases bone mineral content but not bone mineral density.

Published

Journal Article

Human growth hormone (hGH) and insulin-like growth factor I (IGF-I) both stimulate bone formation and have been proposed as therapeutic agents for osteoporosis. We examined the effect of hGH and IGF-I alone and in combination on bone size, bone mineral content (BMC), and bone mineral density (BMD) in 10- to 12-week old growing female Sprague-Dawley rats. Sixty rats were assigned to treatment with either placebo, hGH, IGF-I, or both for 4 weeks. After 4 weeks, the right femurs and tibias were excised, and ex vivo BMC and the area of the tibia and femur were measured by dual-energy X-ray absorptiometry (DXA); volume of these bones was measured by Archimedes' principle. In addition, proximal tibial bone density was measured directly by peripheral quantitative computerized tomography (pQCT). Bone length, area, and volume in all treated groups was greater than controls. Areal bone density by DXA (BMC/area) was higher in IGF-treated rats and lower in GH-treated rats than in controls. Volumetric bone density (BMC/volume) was lower in treated groups than in controls. Measurements by pQCT confirmed that true bone density was lower in all treated groups than in controls. We conclude that treatment with hGH or IGF-I increased bone size and mineral content but decreased bone density in growing rats. Because areal correction of BMC did not adequately correct for the increased bone volume in IGF-treated rats, results of areal bone density by DXA should be interpreted with caution when treatment causes a disparity in bone size between groups.

Full Text

Duke Authors

Cited Authors

  • Rosen, HN; Chen, V; Cittadini, A; Greenspan, SL; Douglas, PS; Moses, AC; Beamer, WG

Published Date

  • September 1995

Published In

Volume / Issue

  • 10 / 9

Start / End Page

  • 1352 - 1358

PubMed ID

  • 7502707

Pubmed Central ID

  • 7502707

International Standard Serial Number (ISSN)

  • 0884-0431

Digital Object Identifier (DOI)

  • 10.1002/jbmr.5650100912

Language

  • eng

Conference Location

  • United States