Cardiology Plus (Jan 2019)

Associations of extremely hot weather and cardiovascular disease mortality: Results from 2011 to 2017, Jinan City, China

  • Ruoming Cao,
  • Lin Zhou,
  • Jiayu Xu,
  • Liangliang Cui

DOI
https://doi.org/10.4103/cp.cp_36_18
Journal volume & issue
Vol. 4, no. 1
pp. 29 – 34

Abstract

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Objective: The main objective of this study is to investigate the acute effects of extremely high-temperature weather and heat waves on the risk of cardiovascular disease (CVD) resulting in the death in Jinan City, China. Methods: We collected the daily CVD death cases of permanent residents, daily weather data, and air pollution data (PM2.5, SO2, NO2, and O3) from Jinan, China, from 2011 to 2017 for May–September, when the temperatures are their highest. Three levels of extremely high-temperature weather were defined by the 90th percentile (29.5°C), the 95th percentile (30.6°C), or the 99th percentile (32.4°C) of daily mean temperature. They are represented by P90, P95, and P99, respectively. The definition of heat wave also included three levels, namely, Heat Wave I, Heat Wave II, and Heat Wave III for the P90, P95, and P99 of daily average temperatures that lasted for 3 days or longer. A time-stratified case-crossover study was used to assess the acute effects of extremely hot weather and heat waves on the risk of CVD death with a lag time of 6 days. Results: A total of 54,374 CVD deaths were detected during the study, with an average of 52 deaths/day. No Heat Wave III was present between 2011 and 2017. The maximum effect of P90, P95, and P99 on CVD death occurred in Lag 1 with odds ratio values of 1.21 (95% confidence interval [CI]: 1.16-1.66), 1.25 (95% CI: 1.18–1.32), and 1.28 (95% CI: 1.13-1.45). At Lag 1, Heat Wave I increased the risk of CVD death by 1.30 (95% CI: 1.23–1.37); at Lag 2, Heat Wave II increased the risk of CVD death by 1.47 (95% CI: 1.36–1.59). Conclusions: A 7-year analysis of Jinan City, China, found that extremely high-temperature weather and heat waves can lead to a significant increase in the risk of death from CVD, suggesting that a health-risk management and response mechanism should be established that include both extreme high temperatures (day effect) and heat waves (sustained effect).

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