Associations between bone mineral density, grip strength, and lead body burden in older men.

Objectives: To study the association between blood lead concentration (BPb) and bone mineral density (BMD), physical function, and cognitive function in noninstitutionalized community-dwelling older men.

Design: Cross-sectional study.

Setting: University of Pittsburgh clinic, Pittsburgh, Pennsylvania.

Participants: Non-Hispanic Caucasian men aged 65 and older (N = 445) recruited as a subset of a prospective cohort for the Osteoporotic Fractures in Men Study.

Measurements: BPb was measured in 2007/08. From 2007 to 2009, BMD (g/cm(2)) was measured using dual-energy X-ray absorptiometry. At the same time, physical performance was measured using five tests: grip strength, leg extension power, walking speed, narrow-walk pace, and chair stands. Cognitive performance was assessed using the modified Mini-Mental State Examination and the Trail-Making Test Part B. Participants were categorized into quartiles of BPb. Multivariate regression analysis was used to evaluate the independent relationship between BPb, BMD, and cognitive and physical function.

Results: Mean BPb ± standard deviation was 2.25 ± 1.20 μg/dL (median 2 μg/dL, range 1-10 μg/dL). In multivariate-adjusted models, men in higher BPb quartiles had lower BMD at femoral neck and total hip (P-trend < .001 for both). Men with higher BPb had lower age-adjusted score for grip strength (P-trend < .001), although this association was not significant in multivariate-adjusted models (P-trend < .15). BPb was not associated with lumbar spine BMD, cognition, leg extension power, walking speed, narrow-walk pace, or chair stands.

Conclusion: Environmental lead exposure may adversely affect bone health in older men. These findings support consideration of environmental exposure in age-associated bone fragility.