ABSTRACT
BACKGROUND: Nitric oxide, also known as endothelial derived relaxing factor(EDRF), regulates the vascular tone and inhibits the proliferation of vascular smooth muscle cells and platelet adhesions and endothelium-leukocyte interactions. Thus, nitric oxide may be involved in the pathogenesis of atherosclerosis and vasospasm. We analyzed the genotype distributions of two eNOS gene polymorphisms in normal healthy Koreans and compared it with those in the patients with acute coronary syndrome and variant angina. METHODS: We analyzed the two eNOS polymorphisms (eNOS A/B polymorphism is the variable numbers of tandem repeat in intron 4 and eNOS T/G polymorphism is a mis-sense mutation in exon 7) using PCR and clinical characteristics of the risk factors for coronary artery disease in 142 normal healthy Koreans and 164 patients with acute coronary syndrome and 104 patients with variant angina. RESULTS: The genotype distribution of A/B polymorphism of eNOS gene, A/A, A/B, B/B was 4.9%, 21.1%, 74% in control group and 2.4%, 12.8%, 84.8% in the patients with acute coronary syndrome(p=0.02) and 2.9%, 16.3%, 80.8% in the patients with variant angina(p=NS), respectively. The genotype distribution of T/G polymorphism of eNOS gene, T/T, T/G, G/G was 1.4%, 15.5%, 83.1% in control group and 0.6%, 21.3%, 78.1% in the patients with acute coronary syndrome(p=NS) and 0%, 18.3%,81.7% in the patients with variant angina(p=NS), respectively. The odds ratio for acute coronary syndrome of non B/B(A/A & A/B) to B/B was 0.489 (95% CI : 0.257-0.928). We found that age, sex (male), diabetes mellitus, hyperlipidemia, smoking, B/B genotype were independent risk factors for acute coronary syndrome. But, in variant angina, smoking was the only significant independent risk factor(odds ratio=5.934, 95% CI 2.843-12.388, p< 0.05). CONCLUSION: The B/B genotype frequency of eNOS gene was significantly higher in patients with acute coronary syndrome than in normal controls. But neither A/B nor T/G polymorphism of eNOS gene was associated with variant angina. These results suggest that eNOS gene may play some roles in the pathogenesis of ACS rather than vasospasm.