Associations between PM2.5 exposure and hypertension differ by neighborhood among heart failure patients in the state of North Carolina.
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Background Both exposure to PM2.5 air pollution and neighborhood socioeconomic status (SES) are associated with adverse cardiovascular outcomes, including hypertension. In this study, we used the EPA-CARES electronic health record database to study the joint impact of neighborhood SES and PM2.5 exposure on hypertension among patients with heart failure in North Carolina.
Methods We used urbanicity, housing factors, and socioeconomic factors from the 2010 Census to create neighborhood clusters using Ward’s hierarchical clustering algorithm. We then matched neighborhood clusters and PM2.5 annual average concentrations to the primary residence of heart failure patients observed at a University of North Carolina Healthcare System affiliated hospital or clinic (N = 30,060). PM2.5 concentrations were modeled at a 1x1 km resolution using a hybrid satellite-based model. We examined the associations between PM2.5 and hypertension, by neighborhood cluster and overall, using logistic regression models adjusted for age, sex, race, chronic kidney disease, diabetes, peripheral artery disease, hyperlipidemia, and chronic obstructive pulmonary disease.
Results Hierarchical clustering resulted in seven neighborhood clusters. PM2.5 concentrations ranged from 9.5 µg/m3 in lower-SES rural cluster to 10.4 µg/m3 in upper-middle-SES urban cluster. We observed associations between PM2.5 and hypertension among lower-SES urban (OR=1.05, 95% CI 1.00-1.10), lower-middle-SES urban (OR=1.03, 95% CI 1.00-1.07), and middle-SES urban (OR 1.04, 95% CI 0.98-1.10) clusters and overall (OR=1.02, 95% CI 1.00-1.04) We did not observe associations between PM2.5 and hypertension in rural, suburban, or upper-SES urban clusters.
Conclusions Among heart failure patients, we observed associations between PM2.5 and hypertension in lower- and middle-SES urban areas. These results suggest that associations between PM2.5 and hypertension can vary by neighborhood among individuals with severe cardiovascular disease. The use of electronic health records may greatly advance our understanding of air pollutant health effects by neighborhood SES, particularly in vulnerable populations. This abstract does not reflect EPA policy.