Seasonal variation in types of stroke and its common risk factors

Mymensingh Med J. 2012 Jan;21(1):13-20.

Abstract

The present descriptive cross-sectional study was conducted in the Department of Medicine, Mymensingh Medical College Hospital, Mymensingh, Bangladesh over a period of one year during November 2009 to October 2010. The study was conducted to describe the variations in types of stroke (ischemic stroke and hemorrhagic stroke) during summer and winter. An attempt was also made to observe the frequency of common risk factors of stroke by seasons. A total of 292 patients of any age irrespective of sex fulfilling the WHO criteria of acute stroke and confirmed by CT scan were selected from consecutive admission in the Department of Medicine, Mymensingh Medical College Hospital. Detail history and thorough clinical examinations were done. Routine and relevant investigations were carried out. The mean age of the patients was 59.9±14.3 years. A male preponderance was observed in the study. In summer 66% of patients and in winter 34% of patients were presented. Ischemic stroke was present in 54.1% patients and 45.9% patients had haemorrhagic stroke. The study found that the frequency of ischaemic stroke during summer (62.4%) was significantly greater than that during winter (37.8%). The frequency of haemorrhagic stroke during winter (62.2%) was significantly greater than that during summer (37.6%). Hypertension was the most important risk factor and other risk factors were smoking, diabetes mellitus, tobacco chewing, ischemic heart disease, dyslipidemia, oral contraceptive pill, alcohol consumption, atrial fibrillation and past history of stroke. Increasing age was also noted as a risk factor (60.7% >60 years). Most of the risk factors were homogenously distributed between two seasons and between ischemic and haemorrhagic group. Hypertension was significantly higher in haemorrhagic stroke patients compared to ischemic stroke patients.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Brain Ischemia / epidemiology
  • Cerebral Hemorrhage / epidemiology
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Seasons*
  • Stroke / epidemiology*