Different Mortality of Ischemic and Hemorrhagic Stroke in Relation to Outdoor Temperature

Abstract

S-29B1-5 Background/Aims: Outdoor temperature has been reported to have a significant influence on the seasonal variations in mortality of stroke, but different mortality of ischemic and hemorrhagic strokes in response to outdoor temperature was not evaluated. The main goal of the study was to examine the effect of temperature on ischemic and hemorrhagic strokes, particularly for extreme temperature. Methods: We investigated the association between outdoor temperature and stroke mortality in Seoul during 1992–2007. We used time series analysis of the counts for ischemic and hemorrhagic stroke deaths by means of the generalized additive and generalized linear models, and estimated the % change of mortality associated with 1°C increase in outdoor temperature. Results: The estimated % change of mortality for hemorrhagic cerebral disease were 0.36 (95% CI: −0.08, 0.81) below 10°C and −0.53 (−1.06, 0.0) at 10°C or higher with 1°C increase in outdoor temperature. For the ischemic cerebral disease, the estimated % changes were 0.59 (0.25, 0.93) below 23°C and 3.30 (2.22, 4.38) at 23°C or higher. Conclusion: These findings support the hypothesis that mortality of ischemic and hemorrhagic strokes show different patterns in relation to outdoor temperature. The ischemic stroke is more responsive to outdoor temperature and both extreme temperatures, cold and hot, were harmful for ischemic stroke.