Effect of the doily mean temperature on the death of cardiovascular and cerebrovascular diseases in Pingyi, Shandong Province: a time-series study

ObjectiveTo explore the impact of daily mean temperature on the daily death of residents with cardiovascular and cerebrovascular diseases (CVD and CBD) in Pingyi County, Shandong Province.

MethodsThe daily death data of CVD and CBD and meteorological data of the same period from 2015 to 2019 in this region were collected.The Poisson linear regression combined with distributed lag nonlinear model was used to study the lag and cumulative impact of daily mean temperature on total death of CVD and CAD after controlling the confounding factors of seasonality, long-term trends and other meteorological indicators.The susceptible subgroups were identified by stratification based on cause of death and basic demographic characteristics(sex, age and address).

ResultsThe expose-response curve of daily mean temperature and total CVD and CBD death in Pingyi County was inverted "J" shape, and the extreme temperature increased the risk of total CVD and CBD death.The extreme low temperature had a significant delay effect, which lasted from the second day to the tenth day, and the strongest effect appeared on the fifth day(RR=1.089, 95%CI: 1.041-1.140).However, the extreme high temperature was mainly a short-term immediate effect, which decreased after the maximum on that day (RR=1.236, 95%CI: 1.154-1.324) and lasted until the fourth day behind.The cumulative effect of extreme low temperature was the strongest at 0-21 d(RR=2.565, 95%CI: 1.300-5.061), the cumulative effect of extreme high temperature reached the maximum at 0-7 d(RR=1.775, 95%CI: 1.409-2.237), and the cumulative effect of cold effect was stronger than that of heat effect.In subgroups, the cardiovascular disease and women were more sensitive to cold and heat, people aged less than 65 years old and urban residents were more sensitive to extreme cold for their respective groups, and people aged 65 or older and in rural areas were more sensitive to extreme heat.

ConclusionsThe extremely low temperature and extremely high temperature are the risk factors of CVD and CBD death, and the cumulative effect of the former is stronger and lasts longer.People with cardiovascular and women need to be particularly aware of the effects of extreme temperatures, while people aged less than 65 years old and urban residents should avoid the harmful effect of cold, and those aged 65 or older and rural areas can strengthen the prevention of heat.