Abstract:

Objective To explore the impact of extreme temperatures（heatwaves and cold spells） on cardiovascular mortality in Tianjin and assess the risk variations of specific cardiovascular diseases under different levels of temperature fluctuations. Methods Based on daily mortality data from seven districts in Tianjin from 2019 to 2022，a time-series analysis using generalized linear models was employed to assess the impact of extreme temperature events of different intensities（severe heatwaves，mild heatwaves，severe cold spells，and mild cold spells） on daily cardiovascular mortality，controlling for lag effects and other confounding factors. Results Both heatwaves and cold spells significantly increased the risk of cardiovascular mortality. Exposure to severe heatwaves raised the risk of ischemic heart disease（IHD） mortality by 2.15 times. During cold spells，the risk of stroke mortality increased significantly，with severe cold spells raising the risk by 1.41 times. Mortality risk for other types of cardiovascular diseases also increased. Conclusion Extreme temperature events have a significant impact on cardiovascular mortality，with particularly pronounced effects of high and low temperatures on ischemic heart disease and stroke mortality. Relevant departments should develop public health interventions for extreme climate conditions to reduce the adverse effects of climate change on cardiovascular health.

Key words: Extreme temperatures, Cardiovascular, Risk variation, Sensitive diseases