The Effect of Winter Temperature on Patients with Ischemic Stroke

Abstract

Background The incidence of ischemic stroke increases in winter. This study aimed to explore the effect of winter temperatures on the risk factors, etiology, coagulation, and degree of neurological impairment in patients with ischemic stroke using temperature and rainfall data from the Guangzhou Meteorological Bureau during the winter months of December, January, and February. Material/Methods We divided 112 patients with ischemic stroke into low-temperature and non-low-temperature groups. The low-temperature group experienced an average daily winter temperature of <13°C for five consecutive days within the 14 days before hospital admission and an average temperature of <13°C on admission. The non-low-temperature group experienced an average daily temperature of >13°C in the 14 days before hospital admission and an average daily temperature of >13°C on admission. Neurological deficits were scored and monitored using the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) for disability in stroke. Blood pressure and coagulation indices of prothrombin time (PT) and thromboplastin time (TT) were recorded. Results Compared with the non-low-temperature group, the low-temperature group showed a significantly increased proportion of patients with hypertension and large artery atherosclerotic stroke, more prolonged PT, and higher NIHSS scores. However, TT was reduced in the low-temperature group (P<0.05). Conclusions When the average winter temperature was <13°C, the risk factors, etiology, coagulation factors, and degree of neurological impairment of patients with ischemic stroke were significantly different from patients with ischemic stroke during warmer temperature.

Prognostication of Incidence and Severity of Ischemic Stroke in Hot Dry Climate From Environmental and Non-Environmental Predictors

“…Presumably, economy-related lifestyle habits rather than genetic factors account for the difference. Some studies have shown that low temperature may contribute to high IS severity [37], [78]. But in our work, change in RH two consequent days before IS was a predictor of severe IS.…”

The effects of heatwaves and cold spells on patients admitted with acute ischemic stroke

“…Cold temperatures could also lead to vasoconstriction and subsequent elevation of blood pressure. In our study, the elevated blood pressure of participants exposed to cold spells was consistent with previous findings (23,30,32). Some thrombogenic factors-such as fibrinogen level, platelet aggregation, blood cell count, and CRP-increase in response to exposure to cold, which increases the risk of brain ischemia (6,15).…”

“…The t-test was used for continuous variables with normal distribution and the Mann-Whitney-Wilcoxon test for continuous variables without normal distribution. The Chi-square test was used for categorical variables (23). General linear models were used to analyze the association between extreme temperatures and the continuous variables that were statistically significant in the inter-group comparison.…”

“…The health effects of cold temperature can last longer than those of heat, lasting for as long as 2 weeks (6). Therefore, patients admitted during cold spells and the following consecutive 14 days were defined as the cold-spell group; otherwise, patients were assigned to the non-coldspell group (23).…”

“…Moreover, these associations have rarely been examined in patients with ischemic stroke. A recent study in subtropical zones of southern China found that the blood pressure, coagulation factors, and neurological impairment of patients with ischemic stroke who had been exposed to average temperatures <13 ℃ differed from those of patients admitted during warm spells in winter (23). However, studies about the potential effects of both heatwaves and cold spells on the mechanistic roles of thrombus formation, systemic inflammation, and blood pressure in ischemic stroke are scarce.…”