Impacts of exposure to ambient temperature and altitude on the burden of stroke.

Objective: To evaluate the impact of ambient temperature and altitude exposure on the burden of stroke in a Chinese cohort.

Methods: This study was conducted using data from the National Stroke High-Risk Population Screening System 2020, which assess the overall prevalence, incidence, and mortality rate of stroke in China. For this study, we obtained the annual mean ambient temperature, diurnal temperature range, and altitude for each city. Body mass index (BMI) of participants were calculated.

Result: The sample comprised 676,394 adults aged 40 years or older from 170 cities in 31 provinces in China. A negative linear relationship between mean ambient temperature and stroke risk (incidence and prevalence) as well as a negative association between mean ambient temperature and stroke mortality had been found. A nonlinear relationship with decreased risk in both high and low diurnal temperature range is observed for stroke burden (incidence, prevalence, and mortality). There is no significant correlation between city altitude and stroke burden. The U-shaped relationships of BMI with the incidence and prevalence of stroke indicate that the lowest incidence and prevalence are observed when BMI is approximately 20.

Conclusion: Overall, our study provides important insights into the environmental and individual factors that contribute to the burden of stroke in China, and may inform public health interventions aimed at reducing this burden.