Objectives: We investigated the association of the intron 4 polymorphism of the endothelial nitric oxide synthase (eNOS) gene with coronary artery disease (CAD).
Background: Genetic alterations in the gene encoding for eNOS could contribute to the development and progression of CAD.
Methods: We genotyped for the eNOS intron 4 polymorphism in 194 subjects undergoing coronary angiography. Genotyping was performed with polymerase chain reaction-restriction fragment length polymorphism for the variable number of tandem repeats in intron 4. Coronary artery disease (CAD) was assessed by quantitative coronary angiography, and endothelial function was measured by brachial ultrasonography. We performed logistic regression analysis for the effect of eNOS intron 4 polymorphism and other coronary risk factors on multi-vessel CAD and endothelial function.
Results: The 4a-allele frequency in African Americans was 0.31, while the 4a-allele frequency in Caucasians was 0.15 (P<.001). The prevalence of the 4a-allele was highest among subjects with multi-vessel disease both for African Americans and for Caucasians. A race-adjusted comparison of the prevalence of the 4a-allele among subjects with multi-vessel disease vs those without was statistically significant (P=.03). No correlation was found between the eNOS intron 4 polymorphism and endothelial function.
Conclusions: The eNOS intron 4 polymorphism may be a marker of multi-vessel CAD in African Americans and Caucasians.