Bone Versus Blood Lead as Determinants of Blood Pressure and Hypertension—A Meta-Analysis

Abstract

ISEE-696 Objective: To compare the association of blood and bone lead levels with blood pressure endpoints. For bone lead, this is the first meta-analysis on the association with blood pressure. Materials and Methods: We searched PubMed/Embase/Toxline for epidemiologic studies on blood and bone lead and blood pressure. We used inverse-variance weighted random-effects models to pool the association of lead levels in blood, cortical bone, and trabecular bone with blood pressure endpoints. To compare the magnitude of the association for blood versus bone lead within studies, we estimated the blood pressure change and hypertension risk associated with 1 standard deviation increase in blood or bone lead levels. Results: We identified 2 prospective studies and 7 cross-sectional studies. For an increase in 10 μg/g of tibia lead, the pooled change in systolic blood pressure levels was 0.51 (95% confidence interval 0.18, 0.83) mm Hg and the pooled relative risk of hypertension was 1.03 (1.00, 1.06). For an increase in 10 μg/g of trabecular bone lead, the pooled change in systolic blood pressure levels was 0.33 (−0.15, 0.80) mm Hg and the pooled relative risk of hypertension was 1.07 (0.98, 1.16). For blood lead levels and blood pressure endpoints, pooled estimates were similar to previously published meta-analyses. No consistent pattern was observed within studies when the magnitude of the association for bone lead levels was compared to blood lead levels with respect to blood pressure levels or hypertension risk. Conclusions: Lead levels measured in blood and tibia bone were associated with increased systolic blood pressure and hypertension risk. For trabecular bone, the number of studies is scarce. To compare the hypertensive effect of bone versus blood lead and to precisely evaluate the dose-response relationship of bone and blood lead levels with blood pressure and hypertension, pooled analyses using individual data from available studies are required.