Abstract
Background: Numerous studies have suggested that long-term exposure to particulate matter ≤2.5 μm (PM2.5) may cause cardiovascular morbidity and mortality. However, susceptibility among those with a history of ischemic heart disease is less clearly understood. We aimed to evaluate whether long-term PM2.5 exposure is related to mortality among patients with ischemic heart disease. Methods: We followed up 306,418 patients hospitalized with ischemic heart disease in seven major cities in South Korea between 2008 and 2016 using the National Health Insurance Database. We linked the modeled PM2.5 data corresponding to each patient's administrative districts and estimated hazard ratios (HRs) of cause-specific mortality associated with the long-term exposure to PM2.5 in time-varying Cox proportional hazard models after adjusting for individual- and area-level characteristics. We also estimated HRs by sex, age group (65–74 vs. ≥75 years), and household income. Results: Of the patients with ischemic heart disease, mean age at the discharge was 76.8 years, and 105,913 died during a mean follow-up duration of 21.4 months. The HR of all-cause mortality was 1.10 [95% confidence intervals (CI): 1.07, 1.14] per 10 μg/m3 increase in a 12-month moving average PM2.5. The HRs of cardiovascular, stroke, and ischemic heart disease were 1.17 (95% CI: 1.11, 1.24), 1.17 (95% CI: 1.06, 1.30), and 1.25 (95% CI: 1.15, 1.35), respectively. The subgroup analyses showed that participants aged 65–74 years were more susceptible to adverse effects of PM2.5 exposure. We did not observe any differences in the risk by sex and household income. Conclusion: Mortality from all-cause and cardiovascular disease following hospitalization due to ischemic heart disease was higher among individuals with greater PM2.5 exposure in seven major cities in South Korea. The result supports the association of long-term exposure to air pollution with poor prognosis among patients with ischemic heart disease.
Original language | English |
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Article number | 114440 |
Journal | Environmental Research |
Volume | 216 |
DOIs | |
State | Published - 1 Jan 2023 |
Bibliographical note
Funding Information:This study was supported by the National Strategic Project-Fine Particle of the National Research Foundation of Korea , funded by the Ministry of Science, Information, Communications, and Technology, the Ministry of Environment, and the Ministry of Health and Welfare (grant numbers 2017M3D8A1092008 and 2017M3D8A1092009 ), and the Korea Environment Industry & Technology Institute through Digital Infrastructure Building Project for Monitoring Surveying and Evaluating the Environmental Health funded by the Korea Ministry of Environment (NTIS 1485017934 ).
Publisher Copyright:
© 2022 The Authors
Keywords
- Cohort studies
- Ischemic heart disease
- Mortality
- Particulate matter
- Survival analysis