Endothelial NO synthase gene polymorphisms and risk of ischemic stroke in Asian population: a meta-analysis

The association between polymorphism 4b/a, T-786C and G894T in endothelial NO synthase gene (eNOS) and ischemic stroke (IS) remains controversial in Asian. A meta-analysis was performed to better clarify the association between eNOS gene and IS risk. Based on the search of PubMed, Web of Science (ISI), CNKI (National Knowledge Infrastructure), Wan Fang Med Online and CBM (Chinese Biology Medical Literature Database) databases, all eligible case-control or cohort studies were identified. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) from fixed and random effect models were calculated. Heterogeneity among studies was evaluated using the I(2). Meta-regression was used to explore the potential sources of between-study heterogeneity. Begg's test was used to estimate publication bias. Our study included 27 articles, contained 28 independent case-control studies, involved a total of 3,742 cases and 3,691 controls about 4b/a, 1,800 cases and 1,751 controls about T-786C and 2,747 cases and 2,872 controls about G894T. A significant association of 4a allele with increased risk of IS was found in dominant (FEM: OR = 1.498, 95% CI = 1.329-1.689), recessive (FEM: OR = 2.132, 95% CI = 1.383-3.286) and codominant (REM: OR = 1.456, 95% CI = 1.235-1.716) models. For T-786C and G894T, there were significant associations with dominant and codominant genetic models, but not with recessive genetic model. The meta-analysis indicated that eNOS gene 4b/a, T-786C, G894T polymorphism might be associated with IS.