Association of ischemic and hemorrhagic strokes hospital admission with extreme temperature in Nanchang, China-A case-crossover study

Despite consistent evidence of a higher short-term risk of stroke mortality associated with ambient temperature, there are no findings on the association between extreme temperature and stroke. A total of 16,264 stroke hospital admissions were observed in three hospitals of Nanchang between 2008 and 2015. The case-crossover design was utilized for our study. Conditional logistic regression models were used to calculate the odds ratios. Extreme high temperature exposure during the 3 days before the stroke was associated with both ischemic (OR = 1.18; 95% CI: 1.07-1.36) and hemorrhagic stroke admissions (OR = 1.34; 95% CI: 1.26-1.42) as compared to 3-day control periods (1-3 days last week before the onset of stroke). Extreme low temperature was associated with hemorrhagic stroke admission (OR = 1.42; 95% CI: 1.28-1.58) but not ischemic stroke (OR = 1.06; 95% CI: 0.93-1.13). This study suggests that extreme high temperature might be a risk factor for both hemorrhagic and ischemic strokes, and that extreme low temperature might be a risk factor of hemorrhagic stroke. Further studies are necessary in order to clarify this relationship and provide evidence for stroke prevention. (C) 2017 Published by Elsevier Ltd.