Short-Term Effect of Ambient Temperature and the Risk of Stroke: A Systematic Review and Meta-Analysis

Abstract

Background and Purpose: The relationship between stroke and short-term temperature changes remains controversial. Therefore, we conducted a systematic review and meta-analysis to investigate the association between stroke and both high and low temperatures, and health assessment. Methods: We searched PubMed, Embase, Cochrane, China National Knowledge Infrastructure (CNKI) and Wanfang Data up to 14 September 2014. Study selection, quality assessment, and author-contractions were steps before data extraction. We converted all estimates effects into relative risk (RR) per 1 °C increase/decrease in temperature from 75th to 99th or 25th to 1st percentiles, then conducted meta-analyses to combine the ultimate RRs, and assessed health impact among the population. Results: 20 articles were included in the final analysis. The overall analysis showed a positive relationship between 1 °C change and the occurrence of major adverse cerebrovascular events (MACBE), 1.1% (95% confidence intervals (CI), 0.6 to 1.7) and 1.2% (95% CI, 0.8 to 1.6) increase for hot and cold effects separately. The same trends can be found in both effects of mortality and the cold effect for morbidity. Hot temperature acted as a protective factor of hemorrhage stroke (HS), −1.9% (95% CI, −2.8 to −0.9), however, it acted as a risk factor for ischemic stroke (IS), 1.2% (95% CI, 0.7 to 1.8). Conclusion: Short-term changes of both low and high temperature had statistically significant impacts on MACBE.

Particulate Matter and Hospital Admissions for Stroke in Beijing, China: Modification Effects by Ambient Temperature

“…The statistical model was adjusted by temperature and relative humidity, given that these meteorological variables are reported to be associated with the risk of stroke. 21 We used natural cubic splines with 3 df to model the nonlinear effects of temperature and relative humidity on the concurrent day of hospital admission. 15 Because prior research has found that fewer strokes occur on holidays, 22 we controlled for public holidays using binary variable (coded as public holiday = 1 and no public holiday = 0) in the model.…”

“…Conditional logistic regression was used to perform the time‐stratified case‐crossover design. The statistical model was adjusted by temperature and relative humidity, given that these meteorological variables are reported to be associated with the risk of stroke . We used natural cubic splines with 3 df to model the nonlinear effects of temperature and relative humidity on the concurrent day of hospital admission .…”

The health burden of fall, winter and spring extreme heat events in Southern California and contribution of Santa Ana Winds

“…It is thought that temperature variations can alter blood viscosity and coagulability, which can increase risk of stroke (Kyobutungi et al 2005). Interestingly, a systematic review considering effect of temperature did not find a positive association between heat and stroke morbidity (Lian et al 2015). Further work should be conducted to confirm our findings and explore the potential effect of climatic variability on hospitalizations for ischemic stroke.…”

Association Between Stroke Occurrence and Changes in Atmospheric Circulation

“…During the recent decade, many studies have focused on the impact of weather on the morbidity from stroke, and several meta-analyses or reviews were carried out [1][2][3][4][5]. Air temperature (T) and atmospheric pressure (AP) are among the most closely studied weather variables; increases, decreases, and uctuations in both have been signi cantly linked to numerous stroke subtypes.…”

“…The daily T changes have also been associated with the risk of stroke. The results of a meta-analysis have shown that a daily increase in T was a protective factor against HS, and an increase as well as a decrease in daily T acted as a risk factor for IS [1].…”