| Lead Levels and Ischemic Heart Disease in a Prospective Study of Middle-Aged and Elderly Men: the VA Normative Aging Study Nitin B. Jain,1 Vijayalakshmi Potula,2 Joel Schwartz,3 Pantel S. Vokonas,4 David Sparrow,1,4 Robert O. Wright,1,3 Huiling Nie,1,3 and Howard Hu1,3 1Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; 2Health Investigations Branch, Centers for Disease Control and Prevention, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia, USA; 3Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA; 4Normative Aging Study, VA Boston Healthcare System and Department of Medicine at Boston University School of Medicine, Boston, Massachusetts, USA Abstract
Background: Lead exposure has been associated with higher blood pressure, hypertension, electrocardiogram abnormalities, and increased mortality from circulatory causes. Objective: We assessed the association between bone lead—a more accurate biomarker of chronic lead exposure than blood lead—and risk for future ischemic heart disease (IHD) . Methods: In a prospective cohort study (VA Normative Aging Study) , 837 men who underwent blood or bone lead measurements at baseline were followed-up for an ischemic heart disease event between 1 September 1991 and 31 December 2001. IHD was defined as either a diagnosis of myocardial infarction or angina pectoris that was confirmed by a cardiologist. Events of fatal myocardial infarction were assessed from death certificates. Results: An IHD event occurred in 83 cases (70 nonfatal and 13 fatal) . The mean blood, tibia, and patella lead levels were higher in IHD cases than in noncases. In multivariate Cox-proportional hazards models, one standard deviation increase in blood lead level was associated with a 1.27 (95% confidence interval, 1.01–1.59) fold greater risk for ischemic heart disease. Similarly, a one standard deviation increase in patella and tibia lead levels was associated with greater risk for IHD (hazard ratio for patella lead = 1.29 ; 95% confidence interval, 1.02–1.62) . Conclusions: Men with increased blood and bone lead levels were at increased risk for future IHD. Although the pathogenesis of IHD is multifactorial, lead exposure may be one of the risk factors. Key words: angina, epidemiology, myocardial infarction. Environ Health Perspect 115:871–875 (2007) . doi:10.1289/ehp.9629 available via http://dx.doi.org/ [Online 6 February 2007]
Address correspondence to N.B. Jain, Programs in Research, 1400 VFW Parkway, West Roxbury, MA 02132 USA. Telephone: (857) 203-5160. Fax: (857) 203-5670. E-mail: njain1@partners.org We gratefully acknowledge the assistance of K. Croom in managing the Normative Aging Study databases and programming the extraction of dataset for analysis. We are also, as always, indebted to the continued enthusiastic cooperation of participants in the VA Normative Aging Study. Support for this research was provided by National Institute of Environmental Health Sciences (NIEHS) grants ES 05257 and P42-ES05947 (with funding from the U.S. Environmental Protection Agency) , National Institutes of Health (NIH) /National Center on Minority Health and Health Disparities P20 MD000501, and NIEHS Occupational and Environmental Health Center grant no. 2 P30 ES00002. The Normative Aging Study is supported by the Co-operative Studies Program/Epidemiology Research and Information Centers (ERIC) of the U.S. Department of Veterans Affairs and is a component of the Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC) , Boston, MA. Subjects were evaluated in the outpatient Clinical Research Center of the Brigham and Women's Hospital with support from NIH grant NCRR GCRC M01RR02635. The KXRF instrument used in this work was developed by ABIOMED, Inc., of Danvers, Massachusetts, with support from NIH grant SBIR 2R44 ES03918-02. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry. The authors declare they have no competing financial interests. Received 18 August 2006 ; accepted 6 February 2007.
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