Lead and hypertension in a sample of middle-aged women

Objectives. The role of lead exposure as a risk factor for hypertension is less well defined among women than among men. This case-control study assessed the relation of blood and bone lead concentrations to hypertension in women. Methods. Cases and controls were a subsample of women from the Nurses' Health Study. Hypertension was defined as a physician diagnosis of hypertension between 1988 and 1994 or measured systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg. Results. Mean (SD) blood lead concentration was 0.15 (0.11) μmol/L; mean tibia and patella lead concentrations by K-x-ray fluorescence were 13.3 (9.0) and 17.3 (11.1) μg/g, respectively. After adjustment for potentially confounding factors, an increase from the 10th to the 90th percentile of patella lead values (25 μg/g) was associated with approximately 2-fold (95% confidence interval = 1.1, 3.2) increased risk of hypertension. There was no association between hypertension and either blood or tibia lead concentrations. Conclusions. These findings support a potentially important role for low-level lead exposure as a risk factor for hypertension among non-occupationally exposed women.