Endothelial Constitutive Nitric Oxide Synthase Gene Polymorphism in Turkish Population

Objective and design: Endothelial dysfunction may play an important role in the pathogenesis of risk factors for coronary artery disease (CAD), and of chronic heart failure (CHF). The association between a variable number of tandem repeats (VNTRs) polymorphism in intron 4 of the endothelial constitutive nitric oxide synthase (ecNOS) gene and essential hypertension (EH), CHF, and the distribution of risk factors for CAD were investigated.
METHOD
The study group consisted of 65 controls, 57 EH, and 50 CHF patients. The VNTRs of the ecNOS gene was amplified by the polymerase chain reaction to determine the number of repeats, and the allele frequencies were compared between the patients and control group.
RESULTS
Two alleles (a, b) containing four and five repeats were identified. The ab genotype was associated with EH (p=0.048, odds ratio= 2.54 (95% confidence interval (CI) 0.99-6.55), was more frequent in dilated CHF without reaching statistical significance, was similar in ischemic CHF compared to controls. Ab genotype patients with ischemic CHF were significantly younger (55±10 vs 65±80 years of age; p=0.047), had significantly lower high density lipoprotein cholesterol levels (0.7±0.16 vs 1.09±0.21 mmol/L (27±6 vs 42±8 mg/dl); p=0.005) compared to bb genotype.
CONCLUSION
In this Turkish population the ecNOS gene is not associated with ischemic CHF, but with EH, and may be associated with non ischemic CHF. Young ab genotype patients with low HDL levels are at increased risk for CAD and CHF.