Data_Sheet_1_Temperature variability increases the onset risk of ischemic stroke: A 10-year study in Tianjin, China.docx

BackgroundEpidemiological evidence suggests a correlation between ambient temperature and ischemic stroke. However, evidence on the impact of daily temperature variability on the onset of ischemic stroke is lacking and limited.
ObjectiveWe aimed to investigate the short-term association between temperature variability and ischemic stroke occurrence in Tianjin.
MethodsWe performed a 10-year analysis of ischemic stroke patients hospitalized in two affiliated hospitals of Tianjin Medical University from 2011 to 2020. Daily meteorological data were collected from the Tianjin Meteorological Bureau. Temperature variability was calculated from the standard deviation (SD) of daily minimum and maximum temperatures over exposure days. A quasi-Poisson generalized linear regression combined with distributed lag non-linear model (DLNM) was used to estimate the effect of temperature variability on daily stroke onset, while controlling for daily mean temperature, relative humidity, long-term trend and seasonality, public holiday, and day of the week.
ResultsTemperature variability was positively associated with ischemic stroke. A 1°C increase in temperature variability at 0–1 days (TV0–1) was associated with a 4.1% (1.9–6.3%) increase of ischemic stroke onset. In a stratified analysis, men, people aged ≤65 years, and individuals with pre-existing hypertension, hyperlipidemia, hyperhomocysteinemia were more susceptible to temperature variability. Furthermore, the influence pattern of temperature variability on ischemic stroke was different in the cold season (November–April) and the warm season (May–October).
ConclusionOur findings suggested that short-term temperature variability exposure could increase the risk of ischemic stroke, which may provide new insights into the impact of climate change on health.

研究背景：流行病学证据显示，环境温度与缺血性脑卒中（ischemic stroke）存在相关性。但目前关于每日温度变异性对缺血性脑卒中发作影响的相关研究证据仍较为匮乏且有限。
研究目的：本研究旨在探讨天津市每日温度变异性与缺血性脑卒中发病之间的短期关联。
研究方法：本研究对2011年至2020年天津医科大学两所附属医院收治的缺血性脑卒中患者开展了为期10年的回顾性分析。每日气象数据来源于天津市气象局。温度变异性通过暴露期内每日最低气温与最高气温的标准差（SD）进行计算。本研究采用准泊松广义线性回归结合分布滞后非线性模型（distributed lag non-linear model, DLNM），以评估温度变异性对每日脑卒中发作的影响，同时控制了日平均气温、相对湿度、长期趋势与季节周期性、公共假期以及星期几效应等混杂因素。
研究结果：温度变异性与缺血性脑卒中呈正相关。暴露于0~1天的温度变异性（TV0~1）每升高1℃，缺血性脑卒中的发病风险增加4.1%（95%置信区间：1.9%~6.3%）。分层分析结果显示，男性、年龄≤65岁的人群以及既往患有高血压、高脂血症、高同型半胱氨酸血症的个体对温度变异性更为易感。此外，温度变异性对缺血性脑卒中的影响模式在寒冷季节（11月至次年4月）与温暖季节（5月至10月）存在显著差异。
研究结论：本研究结果表明，短期温度变异性暴露可增加缺血性脑卒中的发病风险，该发现可为气候变化对健康的影响提供新的研究视角。