Association between apolipoprotein ε4 gene polymorphism and risk of ischemic stroke: A meta-analysis

Abstract

Background: Previous studies examining the association of apolipoprotein E (APOE) gene polymorphism with the risk of ischemic stroke (IS) have yielded conflicting results. Therefore, we performed a meta-analysis to investigate the association between APOE ε4 gene polymorphism and risk of IS. Summary: A literature search for genetic association studies published before May 30, 2015, was conducted in the PubMed, EMBASE and Google Scholar databases. The following search terms were used: (apolipoprotein E) or (APOE) and (ε4) and (polymorphism) or (polymorphisms) and (‘isch-emic stroke’ or ‘IS’) and (‘cerebral infarction’ or ‘CI’) and (‘genetic polymorphism’ or ‘single nucleotide polymorphisms’ or ‘SNP’). ORs and 95% CIs were used to calculate the strength of association. Begg’s funnel plot was used to assess the potential for publication bias. In our meta-analysis, 26 case– control studies involving 6,397 IS cases and 19,053 controls were included. Overall significant association between carrier of ε4 allele and risk of IS was observed (OR 1.43, 95% CI 1.10–1.85, p = 0.007). In the subgroup analysis based on eth nicity, a significant association between Apo ε4 carrier and risk of IS was observed in Asian studies (OR 1.53, 95% CI 1.04– 2.25, p = 0.031) whereas borderline significant association between APO ε4 carrier and risk of IS was observed in Caucasian studies (OR 1.36, 95% CI 0.95–1.93, p = 0.093). Key Messages: Our meta-analysis suggests that APOE ε4 allele is associated with higher risk of IS in Asian population as compared to Caucasian population.