Global, regional, and national impact of air pollution on stroke burden: changing landscape from 1990 to 2021

BACKGROUND: Exposure to air pollution contributes to cardiovascular disease-related deaths and morbidity, including stroke. However, few studies have examined the global stroke burden linked to air pollution. This study aimed to evaluate the global stroke morbidity and mortality associated with air pollution from 1990 to 2021. METHOD: With the Global Burden of Disease Study (GBD) 2021, the numbers, and age-standardized rates (ASRs) of deaths and disability-adjusted life years (DALYs) for air pollution-related stroke were reported globally. Further subgroup analyses were conducted by age, sex, region and country, and stroke subtypes. A linear regression model explored global temporal trends and a cluster analysis examined temporal trends across GBD regions. To predict trends until 2040, the age-period-cohort (APC) model and the Bayesian age-period-cohort (BAPC) model were applied. RESULTS: In 2021, there were 1,989,686 (95% uncertainty interval [95% UI], 1,530,479-2,493,238) deaths and 44,962,167 (95% UI, 35,020,339 - 55,467,024) DALYs due to air pollution-related stroke. The ASRs increased with age, peaking generally over 85 years. Males, the Central African region, and Guinea-Bissau showed higher stroke burdens Intracerebral hemorrhage was the most lethal subtype, with an ASR of 11.69 (95% UI 8.94-14.69) for deaths and 276.93 (95% UI 212.21-344.36) for DALYs. From 1990 to 2021, the crude number of deaths and DALYs increased by 13.4% and 6.3%, respectively, for the global stroke burden but showed a declining trend when age-standardized. Most GBD regions in Asia and Africa experienced an increasing stroke burden linked to air pollution, while Europe and America showed a decreasing trend. Predictions indicated a gradual reduction in ASRs, with higher rates in males from 2020 to 2040. CONCLUSIONS: The global stroke burden associated with air pollution remained significant despite a decreasing trend until 2021. Although future predictions suggested a reduction, the crude counts for stroke burden remained substantial, with significant regional disparities. This warranted the implementation of public health policies and ongoing efforts.