Short-term effects of exposure to cold spells on blood pressure among adults in Nanjing, China

Short-term effects of exposure to cold spells on blood pressure are still relatively limited, especially large-scale studies. Thus, we explored associations between cold spells and blood pressure using a large sample of Chinese adults. A total of 50,538 participants were included in our study. They are from Zhongda Hospital Health Screening Centre between 2019 and 2021. Data about the weather and air pollution were obtained from the relevant departments in Nanjing, respectively. We defined cold spells as mean apparent temperature (Tappmean) below the third or fifth percentile of the temperature distribution for 2 or more consecutive periods during each cold season. We found blood pressure levels increased significantly 0-6 days after cold spells. The cumulative effects for cold spells (Tappmean < third percentile) at lags 0 to 6 days were significantly associated with increases in systolic blood pressure (SBP) which ranged from 0.95% to 1.69%. In subgroup analyses, stronger effects were observed in females. This longitudinal study revealed that blood pressure was significantly influenced by cold spells. Cold spells pose a greater risk to females. This discovery provides novel perspectives on the impact of cold spells on human health.