Daily Meteorological Parameters Influence the Risk of Intracerebral Hemorrhage in a Subtropical Monsoon Basin Climate

Peng Wang,1,&ast; Shuwen Cheng,1,&ast; Weizheng Song,1 Yaxin Li,2 Jia Liu,1 Qiang Zhao,1 Shuang Luo1 1Department of Neurosurgery, Chengdu Fifth People’s Hospital/Affiliated Chengdu No.5 People’s Hospital of Chengdu University of TCM, Chengdu, People’s Republic of China; 2West China Fourth Hospital/West China School of Public Health, Sichuan University, Chengdu, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Shuang LuoDepartment of Neurosurgery, Chengdu Fifth People’s Hospital/Affiliated Chengdu No.5 People’s Hospital of Chengdu University of TCM, 33# Mashi Street, Wenjiang, Chengdu, People’s Republic of ChinaTel/Fax +86 28 82726171Email luoshuang2000@126.comBackground and Purpose: The correlation between meteorological parameters and intracerebral hemorrhage (ICH) occurrence is controversial. Our research explored the effect of daily meteorological parameters on ICH risk in a subtropical monsoon basin climate.Methods: We retrospectively analyzed patients with ICH in a teaching hospital. Daily meteorological parameters including temperature (TEM), atmospheric pressure (PRE), relative humidity (RHU), and sunshine duration (SSD) were collected, with the diurnal variation (daily maximum minus minimum) and day-to-day variation (average of the day minus the previous day) calculated to represent their fluctuation. We adopted a time-stratified case-crossover approach and selected conditional logistic regression to explore the effect of meteorological parameters on ICH risk. The influence of monthly mean temperature proceeded via stratified analysis. Air pollutants were gathered as covariates.Results: Our study included 1052 eligible cases with ICH. In a single-factor model, the risk of ICH decreased by 5.9% (P< 0.001) for each 1°C higher of the daily mean TEM, and the risk increased by 2.4% (P=0.002) for each 1hPa higher of the daily mean PRE. Prolongation of daily SSD inhibited the risk of ICH, and OR was 0.959 (P=0.007). The risk was raised by 7.5% (P=0.0496) with a 1°C increment of day-to-day variation of TEM. In a two-factor model, the effect of daily mean TEM or daily SSD on ICH risk was still statistically significant after adjusting another factor. The influence of meteorological parameters on ICH risk continued in cold months but disappeared in warm months after stratified analysis.Conclusion: This research indicates daily TEM and SSD had an inverse correlation to ICH risk in a subtropical monsoon basin climate. They were independent when adjusted by another factor. Daily PRE and day-to-day TEM variation were positively related to ICH risk. The correlation of daily meteorological factors on ICH risk was affected by the monthly thermal background.Keywords: intracerebral hemorrhage, temperature, atmospheric pressure, relative humidity, sunshine duratio