Extreme temperature events, functional dependency, and cardiometabolic multimorbidity: Insights from a national cohort study in China

• Published in: Ecotoxicology and environmental safety 2024-10, Vol.284, p.117013, Article 117013
• Main Authors: Mou, Pengsen, Qu, Huiyan, Guan, Jiaxin, Yao, Yuxin, Zhang, Zhongbo, Dong, Jing
• Format: Article
• Language: English
• Subjects: cardiometabolic multimorbidity; cohort study; Extreme temperature events; functional dependency; joint effect
• ISSN: 0147-6513; 1090-2414; 1090-2414
• DOI: 10.1016/j.ecoenv.2024.117013

Extreme temperature events (ETEs), including heatwaves and cold spells, are attracting increasing attention because of their impacts on human health. However, the association between ETEs and cardiometabolic multimorbidity (CMM) and the role of functional dependency in this relationship remain unclear. A prospective cohort study was conducted using data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2020, considering 12 definitions each for heatwaves and cold spells, and three levels of functional dependency. Mixed Cox models with time-varying variables were used to comprehensively assess the independent and combined effects of ETEs and functional dependency on CMM. Additionally, subgroup analyses were conducted to investigate whether the relationship between ETEs and CMM was modified by the baseline characteristics. Heatwave and cold spell exposures were associated with an increased risk of CMM (HR range: 1.028–1.102 and 1.046–1.187, respectively). Compared to participants with normal functional abilities, the risk of CMM increased with higher levels of functional dependency (HR range: 1.938–2.185). ETEs exposure and functional dependency are jointly associated with CMM risk. Participants with high-intensity ETEs exposure and high functional dependency had the greatest risk of developing CMM. Participants aged 60 and above were more susceptible to the effects of ETEs on CMM. Additionally, urban residents and those in northern regions were more vulnerable to heatwaves. Both ETEs exposure and functional dependency increase the risk of developing CMM. Participants with functional dependency exposed to high-intensity ETEs faced the highest risk of developing CMM. These findings highlight the significant impact of ETEs on CMM and the importance of protecting vulnerable populations during periods of extreme temperature. [Display omitted] •ETEs and functional dependency increase CMM risk (HR: 1.028–1.102 and 1.046–1.187).•High-intensity ETEs and functional dependency jointly increase CMM risk.•Older adults are more vulnerable to ETEs (HR: 1.024–1.127 and 1.053–1.204).•Urban and northern region residents are more affected by heatwaves.