School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and National Health Commission Key Lab of Health Technology Assessment, Fudan University, Shanghai, China.
Department of Cardiology, General Hospital of Southern Theater Command of People's Liberation Army (PLA), Guangzhou, China.
Environ Health Perspect. 2023 Aug;131(8):87016. doi: 10.1289/EHP11841. Epub 2023 Aug 23.
Few studies have explored the relationships between cold spells and acute myocardial infarction (AMI) using the information of symptom onset.
We assessed the impact of cold spells on AMI onset and the potential effect modifiers.
We conducted a time-stratified case-crossover study among 456,051 eligible patients with AMI from 2,054 hospitals in 323 Chinese cities between January 2015 and June 2021 during cold seasons (November to March). Nine definitions of cold spells were used by combining three relative temperature thresholds (i.e., lower than the 7.5th, 5th, and 2.5th percentiles) and three durations of at least 2-4 consecutive d. Conditional logistic regressions with distributed lag models were applied to evaluate the cumulated effects of cold spells on AMI onset over lags 0-6 d, after adjusting for daily mean temperature.
The associations generally appeared on lag 1 d, peaked on lag 3 d, and became nonsignificant approximately on lag 5 d. Cold spells defined by more stringent thresholds of temperature were associated with higher risks of AMI onset. For cold spell days defined by a daily mean temperature of percentile and durations of , , and , the percentage changes in AMI risk were 4.24% [95% confidence interval (CI): 2.31%, 6.20%], 3.48% (95% CI: 1.62%, 5.38%), and 2.82% (95% CI: 0.98%, 4.70%), respectively. Significant AMI risks associated with cold spells were observed among cases from regions without centralized heating, whereas null or much weaker risks were found among those from regions with centralized heating. Patients years of age were more susceptible to cold spells.
This national case-crossover study presents compelling evidence that cold spells could significantly increase the risk of AMI onset. https://doi.org/10.1289/EHP11841.
利用症状发作信息，很少有研究探讨寒冷天气与急性心肌梗死（AMI）之间的关系。
我们评估了寒冷天气对 AMI 发作的影响及其潜在的效应修饰剂。
我们对 2015 年 1 月至 2021 年 6 月期间中国 323 个城市的 2054 家医院的 456051 名符合条件的 AMI 患者在寒冷季节（11 月至 3 月）进行了时间分层病例交叉研究。寒冷天气通过结合三个相对温度阈值（即低于第 7.5、5 和 2.5 百分位数）和至少连续 2-4 天的三个持续时间来定义。应用条件逻辑回归和分布式滞后模型，在调整每日平均温度后，评估寒冷天气对 AMI 发作的累积效应。
一般来说，关联出现在滞后 1 天，在滞后 3 天达到峰值，大约滞后 5 天变得不显著。由更严格的温度阈值定义的寒冷天气与 AMI 发作的更高风险相关。对于寒冷天气日，定义为每日平均温度为第 百分位数和持续时间为 、 、和 ，AMI 风险的百分比变化分别为 4.24%[95%置信区间（CI）：2.31%，6.20%]、3.48%（95% CI：1.62%，5.38%）和 2.82%（95% CI：0.98%，4.70%）。在没有集中供暖的地区，寒冷天气与 AMI 风险显著相关，而在有集中供暖的地区，这种风险为零或要弱得多。年龄在 65-74 岁的患者更容易受到寒冷天气的影响。
这项全国性病例交叉研究提供了有力的证据表明，寒冷天气会显著增加 AMI 发作的风险。https://doi.org/10.1289/EHP11841.
