Residential Exposure to Urban Air Pollution Is Associated With Coronary Calcification

Abstract

ISEE-265 Objective: Epidemiologic evidence suggests that long-term exposure to particulate matter (PM) accelerates atherogenesis, thereby increasing cardiovascular mortality. We examined the relationship between exposure to 2 different measures of urban air pollution, namely residential traffic exposure and long-term background PM2.5 exposure, and the degree of coronary artery calcification. Material and Methods: We used baseline data from the Heinz Nixdorf Recall-Study, an ongoing population-based, prospective cohort study. Traffic exposure was assessed by residential proximity to a major road (autobahn and federal highways with mean daily vehicle counts of 10,000–130,000). Annual mean PM2.5 concentrations were derived from a small-scale dispersion model, using emission data on a scale of 1-km meteorological and topographic data. The main outcome was a coronary artery calcification score (CAC) above the age- and gender-specific 75th percentile, assessed quantitatively by electron-beam computed tomography. We evaluated the association between measures of air pollution and CAC with logistic regression, controlling for individual-level risk factors for coronary heart disease (CHD). Results: Of the 4494 participants included in the analysis, 358 (8%) were considered highly exposed to traffic. Quartiles of PM2.5 exposure were 21.5 (Q1), 22.6 (Q2), and 23.8 (Q3) μg/m3. Compared with participants living more than 200 m away from a major road, participants living within 50 m, 51 to 100 m, and 101 to 200 m had an OR of 1.65 (95% CI 1.16–2.34), 1.38 (95% CI 1.03–1.84), and 1.10 (95% CI 0.86–1.40), respectively, for a high CAC score. High background PM2.5 (highest vs. lowest quartile) was associated with CAC in the subgroup of elderly participants who had not been working full time during the last 5 years (OR 1.48; 95% CI 0.98–2.24). Conclusions: We showed that long-term exposure to urban air pollution is associated with coronary atherosclerosis, the leading cause of cardiovascular morbidity. Prospective studies are needed to corroborate these results.