Abstract P060: Reduction of Cardiovascular Mortality in the United States Population, 1988-2004: A Larger Contribution of Declining Exposures to Cadmium and Lead Compared to Traditional Cardiovascular Risk Factors
Introduction:Lead and cadmium exposures have markedly declined in the US following the banning of lead in gasoline and the implementation of tobacco control, air pollution reduction, and hazardous waste remediation policies since the mid 1970s. While lead and cadmium have been proposed as cardiovascular disease risk factors, little is known about their potential contribution to the decline in cardiovascular mortality in US adults.
Hypothesis: We assessed the hypothesis that lead and cadmium exposure reductions partly explain the decreasing trend in cardiovascular mortality that occurred in the US from 1988-1994 to 1999-2004, after controlling for traditional cardiovascular risk factors including smoking, obesity, physical inactivity, hypertension, diabetes, chronic kidney disease, and dyslipidemia.
Methods: Cohort study of 15,421 men and women ≥40 years old participating in the National Health and Nutrition Examination Survey (NHANES) 1988-1994 and 1999-2004. We implemented a mediation approach with additive hazard models to estimate the reductions in cardiovascular disease (CVD) mortality rates over time explained through changes in urine cadmium and blood lead concentrations.
Results: After adjusting for age, sex, race and smoking, urine cadmium and blood lead concentrations decreased by 20.4 and 38.2%, respectively, between 1988-1934 and 1999-2004. Age-adjusted CVD mortality rates in the US decreased from 712.0 to 356.8 /100.000 person-years comparing 1988-1994 to 1999-2004. Changes in traditional CVD risk factors explained 16% of this decline. The observed reductions in urine cadmium and blood lead levels explained an additional 27.6% of this decline.
Conclusions: The net impact of declining cadmium and lead exposures on mortality changes in the US was larger compared to traditional risk factors. These findings support that reducing cadmium and lead exposures resulted in a major public health achievement. The general population, however, remains exposed to cadmium and lead at concentrations that have been associated to CVD in the US population. Preventive strategies to enable additional reductions in exposure to cadmium and lead are needed.
Author Disclosures: A. Ruiz-Hernandez: None. A. Navas-Acien: None. R. Pastor-Barriuso: None. J. Redon: None. E. Guallar: None. M. Tellez-Plaza: None.
- © 2016 by American Heart Association, Inc.