Abstract 153: Synergistic Effects of Air Pollution Exposure and Neighborhood Socioeconomic Disadvantage on Initial Stroke Severity
Background: Stroke risk and severity are patterned by neighborhood socioeconomic disadvantage (ND). Air pollution may also influence stroke severity through biologic mechanisms. We sought to identify potential synergistic effects of ND and air pollution on initial stroke severity in a large population-based stroke study.
Methods: We identified incident ischemic stroke cases from the BASIC project from 2000-2012. NIH Stroke Scale (NIHSS) was determined from the medical record or abstracted. Particulate matter (PM2.5) and ozone (O3) data were obtained from a state website. An ND score was created for census tracts (proxy for neighborhood) of residence using 12 Census variables. The association between pollutants, ND, and NIHSS was modeled continuously (NIHSS score) and dichotomously (upper quartile (≥7) vs. lower quartiles (<7)). Generalized estimating equations accounted for clustering within neighborhoods. Models were adjusted for demographics and stroke risk factors and run as single exposure models of pollution and ND, dual exposure models including both pollution and ND, and by adding interactions between pollution and ND.
Results: A total of 3,035 ischemic strokes occurred; mean age was 70 (SD=13), 51% female and 53% Mexican American. The difference from the 10th to 90th percentile of the ND score (more disadvantage) was associated with a 24% (95% CI: 0.98 - 1.57) higher odds of severe stroke (Table). Higher previous-day O3 levels were associated with both continuous NIHSS and severe stroke in single and dual exposure models; these associations were not modified by ND. Larger associations between PM2.5 and severe stroke were found for those in higher ND areas than those in lower ND areas (p=0.03). Same-day PM2.5 was not associated with continuous NIHSS nor modified by ND.
Conclusion: Synergistic effects of air pollution and ND score on stroke severity existed; increases in PM2.5 were associated with greater odds of severe stroke as ND increased.
Author Disclosures: J.J. Wing: None. B.N. Sanchez: None. S.D. Adar: None. W.J. Meurer: None. L.B. Morgenstern: None. M.A. Smith: None. L.D. Lisabeth: None.
- © 2015 by American Heart Association, Inc.