Context: The clinical value of measuring testosterone and estradiol in older men with osteoporosis and of measuring bone mineral density (BMD) in older men with testosterone or estradiol deficiency is uncertain.

Objective: To examine the association of testosterone and estradiol deficiency with osteoporosis and rapid bone loss in older men.

Design: Cross-sectional and longitudinal analyses.

Setting: Six U.S. centers of the MrOS Study.

Participants: 2447 community-dwelling men aged 65.

Main Outcome Measures: Total testosterone deficiency defined as <200 ng/dl. Total estradiol deficiency defined as <10 pg/ml. Osteoporosis defined as femoral neck or total hip BMD T-score -2.5. Rapid bone loss defined as 3%/year.

Results: Prevalence of osteoporosis in men with deficient and normal total testosterone was 12.3% and 6.0% (P = 0.003), and in those with deficient and normal total estradiol was 15.4% and 2.8% (P < 0.0001). Among osteoporotic men and those with normal BMD, prevalence of total testosterone deficiency was 6.9% and 3.2% (P = 0.01) and prevalence of total estradiol deficiency was 9.2% and 2.4% (P = 0.0001). Incidence of rapid hip bone loss in men with deficient and normal total testosterone was 22.5% and 8.6% (P = 0.007), and in those with deficient and normal total estradiol was 14.3% and 6.3% (P = 0.08).

Conclusions: Older men with total testosterone or estradiol deficiency were more likely to be osteoporotic. Those with osteoporosis were more likely to be total testosterone or estradiol deficient. Rapid hip bone loss was more likely in men with total testosterone deficiency. BMD testing of older men with sex steroid deficiency may be clinically warranted.