Body temperature in the acute phase and clinical outcomes after acute ischemic stroke

Background This study aimed to examine whether post-stroke early body temperature is associated with neurological damage in the acute phase and functional outcomes at three months.Methods We included 7,177 patients with acute ischemic stroke within 24 h of onset. Axillary temperature was measured daily in the morning for seven days. Mean body temperature was grouped into five quintiles (Q1: 35.1-36.5 degrees C, Q2: 36.5-36.7 degrees C, Q3: 36.7-36.8 degrees C, Q4: 36.8-37.1 degrees C, and Q5: 37.1-39.1 degrees C). Clinical outcomes included neurological improvement during hospitalization and poor functional outcome (modified Rankin scale score, 3-6) at three months. A logistic regression analysis was performed to evaluate the association between body temperature and clinical outcomes.Results The patient's mean (SD) age was 70.6 (12.3) years, and 35.7% of patients were women. Mean body temperature was significantly associated with less neurological improvement from Q2 (odds ratios [95% confidence interval], 0.77 [0.65-0.99] vs. Q1) to Q5 (0.33 [0.28-0.40], P for trend <0.001) even after adjusting for potential confounders, including baseline neurological severity, C-reactive protein levels, and post-stroke acute infections. The multivariable-adjusted risk of poor functional outcome linearly increased from Q2 (1.36 [1.03-1.79]) to Q5 (6.44 [5.19-8.96], P for trend <0.001). These associations were maintained even in the analyses excluding patients with acute infectious diseases. Multivariable-adjusted risk of poor functional outcome was higher in patients with early body temperature elevation on days 1-3 and with longer duration with body temperature >37.0 degrees C.Conclusions Post-stroke early high body temperature is independently associated with unfavorable outcomes following acute ischemic stroke.