Relationship of ischemic and hemorrhagic stroke clinical parameters with climate-related factors

Objective: Two known consequences of climate change are global warming and air pollution. The aim of our study was to investigate the relationship between climate change, meteorological and air quality factors with the incidence of ischemic and hemorrhagic stroke and their effect on clinical parameters. Materials and method: Between January 1 and December 31, 2023, a total of 729 stroke cases (671 ischemic stroke, 58 hemorrhagic stroke, 729 stroke cases in total) over the age of 18 years, who were followed up with ischemic and hemorrhagic stroke diagnoses after detailed systemic and neurological examination, cranial imaging (cranial CT and/or MRI) were included in the study retrospectively in Selçuk University Faculty of Medicine Hospital Neurology Clinic ward and intensive care unit. The distribution of the incidence of patients classified as hemorrhagic and ischemic stroke according to months and seasons and the relationship between demographic, clinical parameters and meteorological and air quality data were examined. Results: In September, the incidence of hemorrhagic stroke in male patients was statistically significantly higher than the incidence of ischemic stroke (6/31, 19.35% vs. 26/361, 7.20%, p=.018). When the incidence of ischemic stroke was compared by season, the incidence of ischemic stroke was significantly higher in winter (27.12%) and spring (28.17%) compared to fall (19.67%). There was also no significant change in the burden of hemorrhagic stroke by season. There was no significant difference between hemorrhagic and ischemic stroke burden according to meteorological parameters. In terms of functional impairment, there was a significant and negative correlation between daily maximum temperature (°C), daily minimum temperature (°C), daily average temperature (°C) and daily vapor pressure (hPa) and NIHSS score in ischemic stroke cases (Spearman rho=-0.098, p=.011, Spearman rho=-0.087 p= 025, Spearman rho=-0.122 p=.002, Spearman rho=–0.107 p=.005). In ischemic stroke cases, there was a statistically significant and negative correlation between daily maximum temperature (°C), daily minimum temperature (°C), daily mean temperature (°C) and daily vapor pressure (hPa) and RANKIN score (Spearman rho=-0.087 p=.025, Spearman rho=-0.092 p=.018, Spearman rho=-0.122 p=.002, Spearman rho=-0.079 p=.040). When clinical and laboratory parameters were evaluated in ischemic stroke cases, a statistically significant and negative correlation was found between daily maximum temperature (°C), daily minimum temperature (°C) and daily mean temperature and systolic pressure ( Spearman rho=-0.114 p=.003, Spearman rho=-0.103 p=.008, Spearman rho=-0.114 p=.003). There was a positive correlation between mean daily relative humidity (%) and systolic and diastolic blood pressure in ischemic stroke cases ( Spearman rho=0.120 p=.002, Spearman rho=0.077 p=.042). A statistically significant and negative correlation was found between daily maximum temperature (°C), daily minimum temperature (°C), daily mean temperature (°C) and daily vapor pressure (hPa) and LDL value in ischemic stroke cases (Spearman rho=-0.117 p=.018, Spearman rho=-0.100 p=.044, Spearman rho=-0.102 p=.041, Spearman rho=0.113 p=.024). Statistically significant and negative correlation between PM10 level and hemoglobin value for cases hospitalized with hemorrhagic stroke (Spearman rho=-0.259, p=.049). There was a statistically significant and positive correlation between SO2 level and NIHSS (Spearman rho=0.086, p=.025). There was a statistically significant and negative correlation between O3 level and systolic blood pressure in ischemic stroke patients (Spearman rho=-0.085, p=.027). There was a statistically significant and negative correlation between SO2 level and triglyceride level in ischemic stroke cases (Spearman rho=-0.120, p=.024). Age, DM (3-fold) and hemoglobin were determined as significant risk factors in ischemic stroke cases (p=<.001, p=<.001, p=.034). In hemorrhagic stroke cases, systolic and diastolic blood pressure were found to be significant risk factors (p=<.001). Conclusions: In winter and spring, ischemic stroke was more frequent than in autumn. Hemorrhagic stroke was more common in men in september. Daily maximum, minimum, average temperature, vapor pressure and environmental parameters are associated with ischemic stroke severity (NIHSS) and functionality (RANKIN). In ischemic stroke cases, a significant positive association was found between SO2 level and NIHSS, suggesting that air pollution may increase stroke severity. In addition, there was a negative association between O3 level and systolic blood pressure, and a negative association between SO2 level and triglyceride level. Age, diabetes mellitus (DM) and hemoglobin levels were found to be important risk factors for ischemic stroke. In cases of hemorrhagic stroke, systolic and diastolic blood pressure were found to increase the risk of stroke. These findings suggest that environmental factors and clinical risk parameters play an important role in the management of stroke cases and that health policies should be shaped by considering these factors. Keywords: Climate change, ischemic stroke, hemorrhagic stroke, meteorological parameters, air quality