Abstract T P151: Ethnic Differences in Associations Between Short-Term Exposures to Ambient Air Pollution and the Risk of Acute Ischemic Stroke
Background: Air pollution may contribute to ethnic differences in stroke risk, but little research has been conducted in diverse US populations. We investigated the association between daily changes in ambient pollution (PM2.5 and ozone (O3)) and the risk of ischemic stroke among individuals living in a biethnic community and whether the association differed by ethnicity.
Methods: We identified incident ischemic stroke cases from the population-based Brain Attack Surveillance in Corpus Christi (BASIC) project between 2000 and 2012. Air pollutant data were obtained from a state website. The association between average daily levels of PM2.5 and O3, measured on the same-day and lags of 1-3 days, and odds of ischemic stroke was assessed using a time-stratified case-crossover study design. We explored race/ethnicity of Mexican American (MA) and non-Hispanic white (NHW) as an interaction of the associations between air pollution and stroke.
Results: There were 2,948 ischemic strokes during the study period. Median age was 71 years (interquartile range: 59-80); 51% were women and 56% were MA. In models combining ethnic groups, an association between lag 1 O3 and stroke was found (OR: 1.05, 95% CI: 1.00-1.10); no other significant associations were noted. Ethnic differences in the associations between PM2.5 and O3 with stroke were suggested (Figure). When stratified by ethnicity, increases in O3 were consistently associated with increased odds of stroke for NHWs, but not for MAs. Increases in same-day PM2.5 were marginally associated with increases in the odds of stroke in MAs (OR: 1.12, 95% CI: 0.98-1.27), but not for NHWs.
Conclusion: We observed an association between previous-day O3 and ischemic stroke, but found little evidence of an association between PM2.5 and ischemic stroke. Ethnic differences in the associations with both O3 and PM2.5 and stroke were also noted, suggesting that further study of environmental influences on stroke in diverse populations is warranted.
Author Disclosures: J.J. Wing: None. S.D. Adar: None. B.N. Sanchez: None. L.B. Morgenstern: None. M.A. Smith: None. L.D. Lisabeth: None.
This research has received full or partial funding support from the American Heart Association, Midwest Affiliate – Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, Wisconsin.
- © 2015 by American Heart Association, Inc.