Spatiotemporal Trends of Stroke Burden Attributable to Ambient PM2.5 in 204 Countries and Territories, 1990-2019: A Global Analysis

Abstract

Background and objectives: Previous studies suggested that long-term exposure to ambient fine particulate matter (PM_2.5) is associated with increased risk of stroke. However, limited studies evaluated the stroke burden attributable to ambient PM_2.5 globally, especially comprising across different regions, countries, and social-economic levels. We thus conducted this study to estimate the spatial and temporal trends of ambient PM_2.5-related stroke burden by sex, age, and subtypes from 1990 to 2019 at global, regional, and national levels.

Methods: Information on the ambient PM_2.5-related stroke burden from 1990 to 2019 was obtained from the Global Burden of Disease study 2019. The burdens of stroke attributable to ambient PM_2.5 (i.e., age-standardized mortality rate [ASMR] and age-standardized disability-adjusted life-year rate [ASDR]) were estimated by sex, age, and subtypes from 1990 to 2019 at global, regional, and national levels. The estimated annual percentage change (EAPC) was used to evaluate the changing trends of ASDR and ASMR attributable to ambient PM_2.5 from 1990 to 2019. The Spearman correlation coefficient was used to examine the correlation between sociodemographic index (SDI) and EAPC of ASMR and ASDR at the national level.

Results: In 2019, the global ambient PM_2.5-related stroke mortality and disability-adjusted life years were 1.14 million and 28.74 million, respectively, with the corresponding ASDR and ASMR of 348.1 and 14.3 per 100,000 population, respectively. The ASDR and ASMR increased with age and were highest among male patients, in the middle SDI regions, and for intracerebral hemorrhage (ICH). From 1990 to 2019, the absolute death number of stroke attributable to ambient PM_2.5 and the corresponding ASMR and ASDR were both in an increasing trend. The corresponding EAPCs in ASMR and ASDR were 0.09 (95% CI -0.05 to 0.24) and 0.31 (95% CI 0.18-0.44), respectively. The significant increases of ASMR and ASDR were observed in the low, low-middle, and middle SDI regions, and for ICH. However, a decreasing trend was observed in high and middle-high SDI regions, and for subarachnoid hemorrhage.

Discussion: The global burden of stroke attributable to ambient PM_2.5 showed an increasing trend over the past 30 years, especially in male patients, low-income countries, and for ICH. Continued efforts on reducing the level of ambient PM_2.5 are necessary to reduce the burden of stroke.