Research

Association of blood lead concentrations with mortality in older women: a prospective cohort study

Naila Khalil¹ , John W Wilson² , Evelyn O Talbott¹ , Lisa A Morrow³ , Marc C Hochberg⁴ , Teresa A Hillier⁵ , Susan B Muldoon⁶ , Steven R Cummings⁷ and Jane A Cauley¹

¹  University of Pittsburgh, Department of Epidemiology, Pittsburgh, PA, USA

²  University of Pittsburgh, Department of Biostatistics, Pittsburgh, PA, USA

³  University of Pittsburgh, Department of Psychiatry, Pittsburgh, PA, USA

⁴  University of Maryland, Departments of Medicine, Epidemiology, and Preventive Medicine Baltimore, MD, USA

⁵  Center for Health Research Northwest/Hawaii, Kaiser Permanente, Portland, OR, USA

⁶  University of Louisville, School of Public Health and Information Sciences, Louisville, KY, USA

⁷  California Pacific Medical Center Research Institute, San Francisco Coordinating Center, San Francisco, CA, USA

author email corresponding author email

Environmental Health 2009, 8:15doi:10.1186/1476-069X-8-15

Published:	3 April 2009

Abstract

Background

Blood lead concentrations have been associated with increased risk of cardiovascular, cancer, and all-cause mortality in adults in general population and occupational cohorts. We aimed to determine the association between blood lead, all cause and cause specific mortality in elderly, community residing women.

Methods

Prospective cohort study of 533 women aged 65–87 years enrolled in the Study of Osteoporotic Fractures at 2 US research centers (Baltimore, MD; Monongahela Valley, PA) from 1986–1988. Blood lead concentrations were determined by atomic absorption spectrometry. Using blood lead concentration categorized as < 8 μg/dL (0.384 μmol/L), and ≥ 8 μg/dL (0.384 μmol/L), we determined the relative risk of mortality from all cause, and cause-specific mortality, through Cox proportional hazards regression analysis.

Results

Mean blood lead concentration was 5.3 ± 2.3 μg/dL (range 1–21) [0.25 ± 0.11 μmol/L (range 0.05–1.008)]. After 12.0 ± 3 years of > 95% complete follow-up, 123 (23%) women who died had slightly higher mean (± SD) blood lead 5.56 (± 3) μg/dL [0.27(± 0.14) μmol/L] than survivors: 5.17(± 2.0) [0.25(± 0.1) μmol/L] (p = 0.09). Women with blood lead concentrations ≥ 8 μg/dL (0.384 μmol/L), had 59% increased risk of multivariate adjusted all cause mortality (Hazard Ratio [HR], 1.59; 95% confidence interval [CI], 1.02–2.49) (p = 0.041) especially coronary heart disease (CHD) mortality (HR = 3.08 [CI], (1.23–7.70)(p = 0.016), compared to women with blood lead concentrations < 8 μg/dL(< 0.384 μmol/L). There was no association of blood lead with stroke, cancer, or non cardiovascular deaths.

Conclusion

Women with blood lead concentrations of ≥ 8 μg/dL (0.384 μmol/L), experienced increased mortality, in particular from CHD as compared to those with lower blood lead concentrations.