Association between short-term exposure to ambient air pollution and hospital admissions for transient ischemic attacks in Beijing, China

Numerous studies have examined the associations between air pollution and stroke. However, little is known about the associations between air pollution and transient ischemic attack (TIA). In this study, we aimed to conduct a time-series study to systematically examine the associations between hospital admissions for TIA and air pollutants. Admissions for TIA (ICD-10: G45) from 1 January 2014 to 31 December 2016 were identified based on the primary diagnosis from 134 hospitals in Beijing, China. Hourly measurements of air pollutants were obtained from the National Air Pollution Monitoring System. Generalized additive models with quasi-Poisson regression were used to determine the associations for each pollutant. Additionally, stratified analysis was implemented to examine whether age, gender, temperature, and season were the potential effect modifiers. Restricted cubic spline was applied to investigate the exposure-response curve. In total, 109,975 hospital admissions for TIA were included. The positive associations were detected between PM(2.5), PM(10), SO(2), NO(2), and CO and hospital admissions for TIA. The effects of PM(2.5) and PM(10) in men are stronger than in women. Additionally, the effects of PM(2.5), PM(10), SO(2), and O(3) are more pronounced on warm days than cool days. From exposure-response curves, we observe a nearly linear relationship for PM(2.5), PM(10), CO, and NO(2). Further studies are needed to verify the association. This research contributes evidence on the association between air pollution and admissions for TIA in the low- and middle-income countries and may promote related public health policy development.