Association of blood lead concentrations with mortality in older women: a prospective cohort study.
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 microg/dL (0.384 micromol/L), and > or = 8 microg/dL (0.384 micromol/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 microg/dL (range 1-21) [0.25 +/- 0.11 micromol/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) microg/dL [0.27(+/- 0.14) micromol/L] than survivors: 5.17(+/- 2.0) [0.25(+/- 0.1) micromol/L] (p = 0.09). Women with blood lead concentrations > or = 8 microg/dL (0.384 micromol/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 microg/dL(< 0.384 mumol/L). There was no association of blood lead with stroke, cancer, or non cardiovascular deaths.


CONCLUSIONS
Women with blood lead concentrations of > or = 8 microg/dL (0.384 micromol/L), experienced increased mortality, in particular from CHD as compared to those with lower blood lead concentrations.
Khalil
Naila
N
University of Pittsburgh, Department of Epidemiology, Pittsburgh, PA, USA. khalil_naila@yahoo.com
Wilson
John W
JW
Talbott
Evelyn O
EO
Morrow
Lisa A
LA
Hochberg
Marc C
MC
Hillier
Teresa A
TA
Muldoon
Susan B
SB
Cummings
Steven R
SR
Cauley
Jane A
JA