December 12th, 2017
Abstract: Objective: To evaluate the relations among BMD and lead in blood, tibia, and patella, and how BMD modified relations among these lead biomarkers in older women. Design: Cross-sectional analysis Participants: 112 women, aged 50 to 70 years, including both whites andAfrican-Americans,residing in Baltimore. Measurements: We measured lumbar spine BMD, blood and bone lead by dual energy X-ray absorptiometry, anodic stripping voltammetry, and 109Cd-induced K-shell X-ray fluorescence, respectively. We measured VDR andAPOE genotypes using standard methods. Results: Mean (SD) BMD and lead levels in blood, tibia, and patella were 1.02 (0.16) g/cm2, 3.3 (2.2) ?g/dL, 19.7 (13.2) ?g/g, and 5.7 (15.3) ?g/g, respectively. In adjusted analysis, higher BMD was associated with higher tibia lead levels (p = 0.03). BMD was not associated with levels of lead in blood or patella. There was evidence of significant effect modification by BMD on relations of physical activity with blood lead levels and byAPOE genotype on relations of BMD with tibia lead levels. There was no evidence that BMD modified relations of tibia lead or patella lead with blood lead levels. Conclusions: We believe BMD represents the capacity of bone that can store lead, by substitution for calcium, and thus the findings may have relevance for effect size estimates in persons with higher BMD. Relevance to Clinical Practice: The results have implications for changes in lead kinetics with aging, and thus the related risk of health effects associated with substantial early- and mid-life lead exposure in older persons.