Associations of outdoor fine particulate air pollution and cardiovascular disease in 157?436 individuals from 21 high-income, middle-income, and low-income countries (PURE): a prospective cohort study

摘要

BackgroundMost studies of long-term exposure to outdoor fine particulate matter (PM2·5) and cardiovascular disease are from high-income countries with relatively low PM2·5concentrations. It is unclear whether risks are similar in low-income and middle-income countries (LMICs) and how outdoor PM2·5contributes to the global burden of cardiovascular disease. In our analysis of the Prospective Urban and Rural Epidemiology (PURE) study, we aimed to investigate the association between long-term exposure to PM2·5concentrations and cardiovascular disease in a large cohort of adults from 21 high-income, middle-income, and low-income countries.MethodsIn this multinational, prospective cohort study, we studied 157?436 adults aged 35–70 years who were enrolled in the PURE study in countries with ambient PM2·5estimates, for whom follow-up data were available. Cox proportional hazard frailty models were used to estimate the associations between long-term mean community outdoor PM2·5concentrations and cardiovascular disease events (fatal and non-fatal), cardiovascular disease mortality, and other non-accidental mortality.FindingsBetween Jan 1, 2003, and July 14, 2018, 157?436 adults from 747 communities in 21 high-income, middle-income, and low-income countries were enrolled and followed up, of whom 140?020 participants resided in LMICs. During a median follow-up period of 9·3 years (IQR 7·8–10·8; corresponding to 1·4 million person-years), we documented 9996 non-accidental deaths, of which 3219 were attributed to cardiovascular disease. 9152 (5·8%) of 157?436 participants had cardiovascular disease events (fatal and non-fatal incident cardiovascular disease), including 4083 myocardial infarctions and 4139 strokes. Mean 3-year PM2·5at cohort baseline was 47·5 μg/m3(range 6–140). In models adjusted for individual, household, and geographical factors, a 10 μg/m3increase in PM2·5was associated with increased risk for cardiovascular disease events (hazard ratio 1·05 [95% CI 1·03–1·07]), myocardial infarction (1·03 [1·00–1·05]), stroke (1·07 [1·04–1·10]), and cardiovascular disease mortality (1·03 [1·00–1·05]). Results were similar for LMICs and communities with high PM2·5concentrations (>35 μg/m3). The population attributable fraction for PM2·5in the PURE cohort was 13·9% (95% CI 8·8–18·6) for cardiovascular disease events, 8·4% (0·0–15·4) for myocardial infarction, 19·6% (13·0–25·8) for stroke, and 8·3% (0·0–15·2) for cardiovascular disease mortality. We identified no consistent associations between PM2·5and risk for non-cardiovascular disease deaths.InterpretationLong-term outdoor PM2·5concentrations were associated with increased risks of cardiovascular disease in adults aged 35–70 years. Air pollution is an important global risk factor for cardiovascular disease and a need exists to reduce air pollution concentrations, especially in LMICs, where air pollution levels are highest.FundingFull funding sources are listed at the end of the paper (see Acknowledgments).