[Effect of diurnal temperature range on the number of elderly inpatients with ischemic stroke in Hunan Province].

Objective: To study the effect of diurnal temperature range on the number of elderly inpatients with ischemic stroke in Hunan Province. Method: Demographic and disease data, meteorological data, air quality data, population, economic and health resource data of elderly inpatients with ischemic stroke were collected in 122 districts/counties of Hunan Province from January to December 2019. The relationships between the diurnal temperature range and the number of elderly inpatients with ischemic stroke were analyzed by using the distributed lag non-linear model, including the cumulative lag effect of the diurnal temperature range in different seasons, extremely high diurnal temperature range and extremely low diurnal temperature range. Results: In 2019, 152 875 person-times were admitted to the hospital for ischemic stroke in the elderly in Hunan Province. There was a non-linear relationship between the diurnal temperature range and the number of elderly patients with ischemic stroke, with different lag periods. In spring and winter, with the decrease in diurnal temperature range, the risk of admission of elderly patients with ischemic stroke increased (Ptrend<0.001, Ptrend=0.002);in summer, with the increase in diurnal temperature range, the risk of admission of elderly patients with ischemic stroke increased (Ptrend=0.024);in autumn, the change in the diurnal temperature range would not cause a change in admission risk (Ptrend=0.089). Except that the lag effect of the extremely low diurnal temperature range in autumn was not obvious, the lag effect occurred in other seasons under extremely low and extremely high diurnal temperature ranges. Conclusion: The high diurnal temperature range in summer and the low diurnal temperature range in spring and winter will increase the risk of admission of elderly patients with ischemic stroke, and the risk of admission of elderly patients with ischemic stroke will lag under the extremely low and extremely high diurnal temperature ranges in the above three seasons.目的： 研究日温差对湖南省老年人缺血性脑卒中入院人次的影响。 方法： 收集湖南省122个区/县2019年1至12月老年人缺血性脑卒中患者的人口学和疾病资料，气象数据资料，空气质量资料，人口、经济和卫生资源数据。采用分布滞后非线性模型分析日温差与老年人缺血性脑卒中入院人次的关系，以及不同季节日温差、极高日温差、极低日温差累积滞后效应。 结果： 2019年湖南省老年人缺血性脑卒中入院152 875人次，日温差与老年人缺血性脑卒中入院人次呈非线性关系，且存在一定的滞后性。春冬两季，随着日温差减小，老年人缺血性脑卒中入院风险增加（P趋势<0.001、P趋势=0.002）；夏季，随着日温差增大，入院风险增加（P趋势=0.024）；秋季，日温差的变化不会引起入院风险的变化（P趋势=0.089）。除秋季极低温差滞后效应不明显外，其余季节在极低、极高温差下均呈现滞后效应。 结论： 夏季高日温差、春冬两季低日温差会增加老年人缺血性脑卒中入院风险，且在以上三季极低、极高温差下老年人缺血性脑卒中入院风险均会出现滞后。.