Association between extreme temperature and acute myocardial infarction hospital admissions in Beijing, China: 2013–2016

Over the past few decades, a growing body of epidemiological studies found the effects of temperature on cardiovascular disease, including the risk for acute myocardial infarction (AMI). Our study aimed to investigate whether there is an association between extremely temperature and acute myocardial infarction hospital admission in Beijng, China. We obtained 81029 AMI cases and daily temperature data from January 1, 2013 to December 31, 2016. We employed a time series design and modeled distributed lag nonlinear model (DLNM) to analyze effects of temperature on daily AMI cases. Compared with the 10th percentile temperature measured by daily mean temperature (Tmean), daily minimum temperature (Tmin) and daily minimum apparent temperature (ATmin), the cumulative relative risks (CRR) at 1st percentile of Tmean, Tmin and ATmin for AMI hospitalization were 1.15(95% CI: 1.02, 1.30), 1.24(95% CI: 1.11, 1.38) and 1.41(95% CI: 1.18, 1.68), respectively. Moderate low temperature (10th vs 25th) also had adverse impact on AMI events. The susceptive groups were males and people 65 years and older. No associations were found between high temperature and AMI risk. The main limitation of the study is temperature exposure was not individualized. These findings on cold-associated AMI hospitalization helps characterize the public health burden of cold and target interventions to reduce temperature induced AMI occurrence.

近数十年来，越来越多的流行病学研究证实了气温对心血管疾病的影响，其中包括急性心肌梗死（acute myocardial infarction, AMI）的发病风险。本研究旨在探讨中国北京市极端气温与急性心肌梗死住院病例之间是否存在关联。本研究获取了2013年1月1日至2016年12月31日期间的81029例AMI病例数据与逐日气温数据。研究采用时间序列设计，运用分布滞后非线性模型（distributed lag nonlinear model, DLNM）分析气温对每日AMI病例数的影响。以日平均气温（daily mean temperature, Tmean）、日最低气温（daily minimum temperature, Tmin）及日最低表观温度（daily minimum apparent temperature, ATmin）的第10百分位数作为参照，当日均温、日最低温及日最低表观温度处于第1百分位数时，AMI住院的累积相对风险（cumulative relative risks, CRR）分别为1.15（95%置信区间：1.02, 1.30）、1.24（95%置信区间：1.11, 1.38）及1.41（95%置信区间：1.18, 1.68）。轻度低温（第10百分位数与第25百分位数组对比）同样对AMI事件存在不良影响。易感人群为男性及65岁及以上老年群体。未发现高温与AMI发病风险存在关联。本研究的主要局限性在于气温暴露未实现个体化评估。上述针对寒冷相关AMI住院病例的研究结果，有助于明确寒冷相关的公共健康负担，并为制定针对性干预措施以减少气温诱导的AMI发生提供科学依据。