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 greater than or equal to 140 mm Hg or diastolic blood pressure greater than or equal to 90 mm Hg. Results. Mean (SD) blood lead concentration was 0.15 (0.11) mu moI/L; mean tibia and patella lead concentrations by K-x-ray fluorescence were 13.3 (9.0) and 17.3 (11.1) mu g/g, respectively. After adjustment for potentially confounding factors, an increase from the 10th to the 90th percentile of patella lead values (25 mu g/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.