Association of ABO Blood Groups with Ischemic and Hemorrhagic Stroke in Adults over 45 years: A Cross-Sectional Study at Jinnah Postgraduate Medical Center, Karachi.

Abstract

Objective: To examine the relationship between ABO blood groups and ischemic and hemorrhagic stroke among adults
aged over 45 years admitted to Jinnah Postgraduate Medical Center, Karachi.
Methodology: Our study was a cross-sectional analysis of neurology ward within six months. With the help of the nonprobability
consecutive sampling, we recruited 219 patients aged 45 years and above. Demographic, comorbid, and
ABO blood groups data were obtained and analyzed. The chi-square test was used to determine associations between
blood groups and clinical variables and a p-value of less than 0.05 was considered significant.
Results: Out of the 219 respondents, 65.3% were men and 86.8% resided in the urban set up. The hemorrhagic stroke
was more common as compared to the ischemic stroke (68.9 versus 31.1). The group O was the most prevalent (52.5)
and it was followed by A (37), B (20.5), and AB (27.9). Blood group A was found to have a high correlation with
dyslipidemia ( p=0.02), and blood group B was associated with a reduced frequency of lipid abnormalities ( p=0.03). The
male gender and smoking were significantly more prevalent in an individual of blood group AB (p=0.01), but smoking
was less prevalent in an individual of blood group O (p=0.04). All the blood groups were not significantly correlated with
the subtype of stroke.
Conclusion: A distinct behavioral and metabolic trends were observed. Blood group A was related to dyslipidemia, blood
group B to lower lipid levels, and blood group AB to male gender and smoking, while smoking was less common in
blood group O. These findings suggest that ABO blood groups may influence vascular risk indirectly through metabolic
and behavioral factors. Further large-scale, multicenter studies are needed to confirm these associations and explore
their biological mechanisms.

Keywords: ABO blood group, ischemic stroke, hemorrhagic stroke, dyslipidemia, vascular risk factors, Karachi.