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.
Minhang Hospital and School of Pharmacy, Fudan University, Shanghai, China.
JAMA Netw Open. 2024 Feb 5;7(2):e240627. doi: 10.1001/jamanetworkopen.2024.0627.
Previous studies have demonstrated the associations of daily high temperature with hospitalizations and mortality from ischemic stroke, but the hourly association of ambient heat and acute ischemic stroke (AIS) onset has been rarely examined.
To evaluate the association between hourly high ambient temperature and the onset of AIS.
DESIGN, SETTING, AND PARTICIPANTS: This time-stratified case-crossover study was conducted using a nationwide registry that collects data from more than 200 stroke centers in China. Participants were adult patients with AIS who were hospitalized in the warm seasons between January 1, 2019, and December 31, 2021.
Hourly temperature and single-hour temperature exposure lag up to 24 hours before the AIS onset (lag 0 hours to lag 24 hours).
The main outcome was onset of AIS. Associations between hourly mean temperatures and AIS onset were analyzed using conditional logistic regression integrated with the distributed lag nonlinear model. Stratification analyses were applied to examine potential association modifiers. Several sensitivity analyses were conducted to examine the robustness of the results.
A total of 82 455 patients with AIS (mean [SD] age, 65.8 [11.9] years; 52 267 males [63.4%]) were included in the final analysis. A monotonically increasing risk of AIS onset was associated with higher temperatures. The excess AIS risk occurred immediately at lag 0 hours and persisted for 10 hours. Compared with the reference temperature (12.1 °C), the cumulative odds ratio (OR) over lag 0 to 10 hours of AIS onset associated with extremely high temperature (33.3 °C) was 1.88 (95% CI, 1.65-2.13) nationwide. The exposure-response curve was steeper in the north than in the south (OR, 1.80 [95% CI, 1.53-2.11] vs 1.57 [95% CI, 1.31-1.87]). The ORs were greater for males and patients with a history of dyslipidemia or atrial fibrillation, but the differences were not significant.
Results of this study suggest that hourly heat exposure is associated with increased risk of AIS onset. This finding may benefit the formulation of public health strategies to reduce cerebrovascular risk associated with high ambient temperature under global warming.
先前的研究已经证明了日高温与缺血性中风住院和死亡之间的关联，但环境热与急性缺血性中风（AIS）发病之间的小时关联很少被研究。
评估每小时高环境温度与 AIS 发病之间的关联。
设计、设置和参与者：这项时间分层病例交叉研究使用了一个全国性的登记处，该登记处从中国 200 多个中风中心收集数据。参与者为 2019 年 1 月 1 日至 2021 年 12 月 31 日温暖季节住院的患有 AIS 的成年患者。
每小时的温度和 24 小时前的单小时温度暴露（0 小时到 24 小时的滞后）。
主要结果是 AIS 的发病。使用条件逻辑回归与分布式滞后非线性模型相结合，分析了每小时平均温度与 AIS 发病之间的关系。进行分层分析以检验潜在的关联修饰符。进行了几项敏感性分析以检验结果的稳健性。
最终分析共纳入 82455 例 AIS 患者（平均[标准差]年龄，65.8[11.9]岁；52267 名男性[63.4%]）。AIS 发病风险与较高的温度呈单调递增关系。在发病 0 小时时立即出现 AIS 风险增加，并持续 10 小时。与参考温度（12.1°C）相比，与极高温度（33.3°C）相关的 AIS 发病滞后 0 至 10 小时的累积优势比（OR）为 1.88（95%CI，1.65-2.13）。全国范围内，北方的暴露-反应曲线比南方更陡峭（OR，1.80 [95%CI，1.53-2.11] vs 1.57 [95%CI，1.31-1.87]）。男性和有血脂异常或心房颤动病史的患者的 OR 更高，但差异无统计学意义。
这项研究的结果表明，每小时的热暴露与 AIS 发病风险的增加有关。这一发现可能有助于制定公共卫生策略，以减少全球变暖下与环境高温相关的脑血管风险。
