The effects of muscle-building exercise on forearm bone mineral content and osteoblast activity in drug-free and anabolic steroids self-administering young men.
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.
Fiore
C E
CE
Clinica Medica 2, University of Catania O.V.E, Italy.
Cottini
E
E
Fargetta
C
C
Di Salvo
G
G
Foti
R
R
Raspagliesi
M
M
D015502:Absorptiometry, Photon; D000328:Adult; D045930:Anabolic Agents / Q000494:pharmacology*; D015519:Bone Density / Q000187:drug effects*; D015444:Exercise; D005542:Forearm; D006801:Humans; D008297:Male; D010006:Osteoblasts / Q000502:physiology; D015675:Osteocalcin / Q000097:blood; D014891:Weight Lifting
D045930:Anabolic Agents; D015675:Osteocalcin