Bioavailable Estradiol May Be an Important Determinant of Osteoporosis in Men: The MINOS Study

P. Szulc
2001 Journal of Clinical Endocrinology and Metabolism  
During recent years, experimental data, case reports, and epidemiological studies have suggested an important role for estradiol in bone metabolism in men. In a cohort of 596 men, aged 51-85 yr, we measured bone mineral density (BMD) of the lumbar spine, hip, total body, and forearm; serum levels of sex steroid hormones [total and free testosterone, total estradiol (17␤E 2 ), bioavailable estradiol (bio-17␤E 2 ), androstenedione, and sex hormone-binding globulin]; and markers of bone turnover
more » ... of bone turnover [serum osteocalcin, bone alkaline phosphatase, N-terminal extension propeptide of type I collagen, and ␤-isomerized C-terminal telopeptide of collagen type I (␤CTX)], as well as urinary excretion of ␤CTX and deoxypyridinoline (DPyr). An age-related decrease was found for bio-17␤E 2 (r ϭ Ϫ0.16; P Ͻ 0.001), free testosterone (r ϭ Ϫ0.25; P Ͻ 0.001), free testosterone index (r ϭ Ϫ0.32; P Ͻ 0.001), and androstenedione (r ϭ Ϫ0.22; P Ͻ 0.001), but not for total 17␤E 2 or total testosterone. 17␤E 2 and bio-17␤E 2 , but not other hormones, were correlated with BMD after adjustment for age and body weight. In men with a bio-17␤E 2 level in the lowest quartile, the average BMD was lower than in men having a bio-17␤E 2 level in the highest quartile by 6.6 -8.7% according to the site of measure-
doi:10.1210/jc.86.1.192 pmid:11232000 fatcat:cgi7ejxoxnhhdlcpztb6ip4gze