The effects of muscle-building exercise on forearm bone mineral content and osteoblast activity in drug-free and anabolic steroids self-administering young men

Bone Miner. 1991 Apr;13(1):77-83. doi: 10.1016/0169-6009(91)90052-2.

Abstract

We measured bone mineral content (BMC) and bone density (BD) at appendicular sites by single photon absorptiometry in 18 men engaged in body-building exercises for at least 2 years, and in 14 age- and weight-matched controls. Eight exercises were using anabolic steroids by self-administration. Serum levels of bone Gla-protein (BGP), a reliable index of bone formation were also measured in all subjects. It was observed that muscle-building exercise was associated with increased BMC and BD at the distal radius, which contains both cortical and trabecular (more than 50%) bone. Previous authors have failed to detect any increase in BMC at mid radius, a site consisting almost entirely of cortical bone. Serum BGP levels were significantly higher in exercisers than in controls. If compared to drug-free exercisers, subjects taking steroids showed no significant increase of BMC, BD and serum levels of BGP. This study shows that muscle-building exercise is associated with increase in BMC and BD also at non-weight bearing sites, and that anabolic steroids did not provide, at the time of the observation, any further stimulus for osteoblast activity and bone formation.

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Anabolic Agents / pharmacology*
  • Bone Density / drug effects*
  • Exercise*
  • Forearm
  • Humans
  • Male
  • Osteoblasts / physiology
  • Osteocalcin / blood
  • Weight Lifting*

Substances

  • Anabolic Agents
  • Osteocalcin