Blood Lead, Blood Pressure, and Hypertension in Perimenopausal and Postmenopausal Women

CONTEXT: Lead exposures have been shown to be associated with increased blood pressure and risk of hypertension in older men. In perimenopausal women, skeletal lead stores are an important source of endogenous lead exposure due to increased bone demineralization. OBJECTIVE: To examine the relationship of blood lead level with blood pressure and hypertension prevalence in a population-based sample of perimenopausal and postmenopausal women in the United States. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional sample of 2165 women aged 40 to 59 years, who participated in a household interview and physical examination, from the Third National Health and Nutrition Examination Survey conducted from 1988 to 1994. MAIN OUTCOME MEASURES: Associations of blood lead with blood pressure and hypertension, with age, race and ethnicity, cigarette smoking status, body mass index, alcohol use, and kidney function as covariates. RESULTS: A change in blood lead levels from the lowest (quartile 1: range, 0.5-1.6 micro g/dL) to the highest (quartile 4: range, 4.0-31.1 microg/dL) was associated with small statistically significant adjusted changes in systolic and diastolic blood pressures. Women in quartile 4 had increased risks of diastolic (>90 mm Hg) hypertension (adjusted odds ratio OR, 3.4; 95% confidence interval CI, 1.3-8.7), as well as moderately increased risks for general hypertension (adjusted OR, 1.4; 95% CI, 0.92-2.0) and systolic (>140 mm Hg) hypertension (adjusted OR, 1.5; 95% CI, 0.72-3.2). This association was strongest in postmenopausal women, in whom adjusted ORs for diastolic hypertension increased with increasing quartile of blood lead level compared with quartile 1 (adjusted OR, 4.6; 95% CI, 1.1-19.2 for quartile 2; adjusted OR, 5.9; 95% CI, 1.5-23.1 for quartile 3; adjusted OR, 8.1; 95% CI, 2.6-24.7 for quartile 4). CONCLUSIONS: At levels well below the current US occupational exposure limit guidelines (40 microg/dL), blood lead level is positively associated with both systolic and diastolic blood pressure and risks of both systolic and diastolic hypertension among women aged 40 to 59 years. The relationship between blood lead level and systolic and diastolic hypertension is most pronounced in postmenopausal women. These results provide support for continued efforts to reduce lead levels in the general population, especially women.