Relationship of stroke occurrence and meteorological factors in Hiroshima, Japan

ObjectiveTo clarify the relationship between meteorological factors and the occurrence of stroke.MethodsThe data of cerebral infarction and intracerebral hemorrhage used in the analysis were collected by the Emergency Medical Division of the Hiroshin a city, Japan Meteorological Agency. Daily mean atmospheric temperature(℃)and atnospheric pressure (hPa) were defined as category variables Poisson regression model was fitted to estinate risk of stroke at the different levels of atmospheric temperature and pressure.ResultsThere were 629 cerebral infarction(female: 43.1%)and 677 intmcerbral hemorrhage(female:44.3%)patients in the 892 days. We found a U-shaped relationship between cerebral infarction and atmospheric temperature, with the lowest risk at 21-24℃, and the risks increased for the ahnosphere temperature lower than 15℃ and higher than 30℃ (P<0.05).The risk of cerebral infarction increased when daily mean atmospheric pressure increasing from 1 015 hPa(P<0.05).The risk of intracerebral hemorrhage increased with the decreasing of temperature (P<0.05) and increased with the increasing of pressure (P<0.05).Meanwhile there was a dose-response relationship.ConclusionThe occurrence of cerebral infarction and intracerebral hemorrhage was associated with atnospheric temperature and pressure.