Background: Nitric oxide (NO) plays a major role in the regulation of vascular tone Associations between NO genotypes, coronary artery disease (CAD) and other risk factors have been described by many authors. The aim of this study was to investigate the role of endothelial nitric oxide synthase (eNOS) gene intron 4 a/b variable number of tandem repeats (VNTR) polymorphism and other risk factors in the development of CAD in subjects living in Southern Turkey.
Methods: Two-hundred and sixty-six patients (154 males and 112 females, aged between 30 and 80 years, mean 52.4+/-10.3) whose coronary arteries were evaluated by means of coronary angiography were enrolled in the study. Of the total, 133 had CAD (Group I) and the remaining had normal coronary arteries (Group II). The eNOS gene intron 4 a/b VNTR polymorphism was analyzed by polymerase chain reaction. The plasma lipid levels and other risk factors were also determined in all subjects.
Results: The a allele frequencies and genotypes carrying a allele were significantly higher in Group I. Plasma lipids, except HDL-C, were also increased in this group. We found that hypertension (HT), diabetes mellitus (DM), male gender, age and smoking were the independent predictors of CAD.
Conclusion: a allele of eNOS intron 4 a/b VNTR polymorphism is not an independent predictor of CAD. eNOS intron 4 a/b polymorphism (presence of a allele) is a risk factor in addition to HT, DM, male gender, age and smoking for the development of CAD in Southern Turkey.