A tailed primers protocol to identify the association of eNOS gene variable number of tandem repeats polymorphism with ischemic stroke in Chinese Han population by capillary electrophoresis

Endothelial nitric oxide synthase (eNOS) plays an important role in mediating endothelium-dependent vasodilatation and antithrombotic action and is thus involved in the development of ischemic stroke (IS). Controversial results regarding the association of eNOS gene variable number of tandem repeats (VNTR) polymorphism with IS have been reported by conventional PCR-polyacrylamide gel electrophoresis methods. We aimed to identify any common association of eNOS gene VNTR polymorphism with IS in Chinese Han population by capillary electrophoresis (CE). The VNTR polymorphism of 27 bp within the eNOS intron-4 was determined by CE with specially designed tailed primers in Chinese Han patients with IS (n = 457) and matched elderly controls without IS (n = 457). Significant differences in BMI, WHR, hypertension, diabetes, smoking, TG, HDL, LDL, LDL, and FBG were observed between cases and controls. The distributions of eNOS VNTR polymorphism were not significantly associated with IS after adjustment for cardiovascular risk factors (OR = 1.18, 95% CI: 0.82–1.69). This finding was consistent with the further meta-analysis in Asians. The meta-analysis in Americans demonstrated that 4a/4b + 4a/4a genotype was significantly associated with IS risk with an OR of 1.54 (95% CI, 1.09–2.17) compared with the 4b/4b genotype. Our data suggests that BMI, WHR, hypertension, diabetes, smoking, TG, LDL, and FBG may increase the risk of IS. However, eNOS VNTR polymorphism may be not an independent major contributor for IS in Chinese Han population. The VNTR polymorphism might be associated with IS in Americans based on meta-analysis.