The Impact of Meteorological Factors and Geomagnetic Activity on Occurrence of Stroke in Northeast of Iran

Stroke has a high prevalence and is associated with a high premature mortality rate. Thus, it is important to identify the effective factors in increasing the incidence of stroke. The aim of this study was to investigate the role of seasonal changes and environmental factors in the occurrence of stroke.

This descriptive-analytical study was done on 3,639 patients including 3,102 (85.3%) with ischemic stroke, 472 (12.9%) with intracerebral hemorrhage and 65 (1.9%) with subarachnoid hemorrhage patients. After measuring environmental factors such as air temperature, air pressure, humidity and geomagnetic field, admission data of stroke patients between 2015-2019 were extracted from the Sayyad Shirazi Hospital information system.

The mean occurrence of intracerebral hemorrhage was highest in winter, especially in January and March, and lowest in summer, especially in July and August. Intracerebral hemorrhage had a positive significant correlation with air pressure (P=0.001, r=0.452) and a negative correlation with ambient temperature (P<0.001, r= - 0.457). Subarachnoid hemorrhage and ischemia were not related to the season or the month. It was also found that ischemic stroke had a significant positive correlation with geomagnetic field fluctuations. Subarachnoid hemorrhage was not associated with any of the variables, but intracerebral hemorrhage was significantly positively associated with air pressure and inversely associated with temperature.

This study illustrated that winter, low temperature, high air pressure and high geomagnetic fluctuations are associated with a higher risk of stroke. Therefore, the underlying physiopathological causes of this relationship should be carefully investigated in future studies.