Ambient Air Pollution and the Risk of Atrial Fibrillation and Stroke: A Population-Based Cohort Study
- DOI
- Language of the publication
- English
- Date
- 2019-08-26
- Type
- Article
- Author(s)
- Shin, Saeha
- Burnett, Richard T.
- Kwong, Jeffrey C.
- Hystad, Perry
- van Donkelaar, Aaron
- Brook, Jeffrey R.
- Goldberg, Mark S.
- Tu, Karen
- Copes, Ray
- Martin, Randall V.
- Liu, Ying
- Kopp, Alexander
- Chen, Hong
- Publisher
- National Institute of Environmental Health Sciences
Abstract
Background: Although growing evidence links air pollution to stroke incidence, less is known about the effect of air pollution on atrial fibrillation (AF), an important risk factor for stroke. Objectives: We assessed the associations between air pollution and incidence of AF and stroke. We also sought to characterize the shape of pollutant–disease relationships. Methods: The population-based cohort comprised 5,071,956 Ontario residents, age 35–85 y and without the diagnoses of both outcomes on 1 April 2001 and was followed up until 31 March 2015. AF and stroke cases were ascertained using health administrative databases with validated algorithms. Based on annual residential postal codes, we assigned 5-y running average concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) from satellite-derived data, a land-use regression model, and a fusion-based method, respectively, as well as redox-weighted averages of NO2 and O3 (Ox) for each year. Using Cox proportional hazards models, we estimated the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of AF and stroke with each of these pollutants, adjusting for individual- and neighborhood-level variables. We used newly developed nonlinear risk models to characterize the shape of pollutant–disease relationships. Results: Between 2001 and 2015, we identified 313,157 incident cases of AF and 122,545 cases of stroke. Interquartile range increments of PM2.5, NO2, O3, and Ox were associated with increases in the incidence of AF [HRs (95% CIs): 1.03 (1.01, 1.04), 1.02 (1.01, 1.03), 1.01 (1.00, 1.02), and 1.01 (1.01, 1.02), respectively] and the incidence of stroke [HRs (95% CIs): 1.05 (1.03, 1.07), 1.04 (1.01, 1.06), 1.05 (1.03, 1.06), and 1.05 (1.04, 1.06), respectively]. Associations of similar magnitude were found in various sensitivity analyses. Furthermore, we found a near-linear association for stroke with PM2.5, whereas Ox-stroke, PM2.5-, and Ox-AF relationships exhibited sublinear shapes. Conclusions: Air pollution was associated with stroke and AF onset, even at very low concentrations.
Plain language summary
"Under the Federal Clean Air Regulatory Agenda (CARA), Health Canada conducts scientific research to evaluate the health risks of ambient air pollution. Exposures to common air pollutants such as fine particulate matter (PM2.5) and nitrogen dioxide (NO2) are known to increase cardiovascular mortality and morbidity. More recently, there is growing evidence linking air pollution to stroke incidence, but less is known about the effect of air pollution on atrial fibrillation (AF), the leading arrhythmia and an important risk factor for stroke. Health Canada led a large cohort study in collaboration with researchers from other organizations to investigate the associations between air pollution and incidence of AF and stroke and also to describe the shape of pollutant-disease relationships. In this study, a population-based cohort comprising about 5.1 million long-term Ontario residents was followed up from 2001 through 2015. The occurrence of AF and stroke were established from data linkage to population-based health administrative databases using validated algorithms. There was an increased risk of AF and stroke in association with PM2.5, NO2, ozone, and a novel measure of oxidative capacity of gaseous pollutants (Ox), with a 1-5% higher risk of developing AF and stroke after adjusting for various covariates. There was also evidence suggesting a near-linear shape of association for stroke with PM2.5, whereas for Ox-stroke, PM2.5- and Ox-AF relationships, these exhibited sublinear shapes. These results suggest that ambient air pollution is linked to stroke and AF onset, even at very low concentrations. This study also highlights the importance of considering association-specific shapes when conducting health impact assessments of air pollution."
Subject
- Health,
- Health and safety