Association between Polymorphisms of Antioxidant Gene (MnSOD, CAT, and GPx1) and Risk of Coronary Artery Disease

Objective. Reactive oxygen species (ROS) been cited as one of the major causes of atherosclerosis and coronary artery disease which are possible agents inducing DNA damage. Manganese superoxide dismutase (MnSOD), catalase (CAT), and glutathione peroxidase-1 (GPx1) have evolved to address primary defense against free radical mediated damage in mitochondria. The aim of this study was to delineate the association ofMnSOD,CAT, andGPx1polymorphisms and risk of CAD in Taiwan.Methods. We conducted a case-control study with 657 participants recruited at a medical center. All subjects were evaluated by noninvasive stress test and then quantitative coronary angiography to confirm the diagnosis of CAD. 447 CAD cases were defined as >50% stenosis of coronary artery and 210 controls were stenosed below 50%. Polymorphisms ofMnSOD(Val16Ala),CAT(C-262T), andGPx1(Pro198Leu) genes were determined by polymerase chain reaction methods. Multivariate logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).Results. TheMnSODVal/Ala+Ala/Ala genotype was significantly associated with an increased risk of CAD compared to the Val/Val genotype (OR = 1.86, 95% CI = 1.15-3.01). This polymorphism was also associated with the severity of CAD of single and two vessel diseases. The corresponding ORs were 2.31 (95% CI = 1.32-4.03) and 1.92 (95% CI = 1.02-3.61), respectively. Among cigarette smokers, the harmful genetic effect ofMnSODAla allele on CAD risk was much higher (OR = 2.23, 95% CI = 1.02-4.88). However, the interaction betweenMnSODgenotype and cigarette smoking on CAD risk was not significant. No significant association betweenCATandGPx1polymorphisms and CAD risk was observed.Conclusion. Our results suggest thatMnSODpolymorphism is an independent risk factor for susceptibility to CAD in the Chinese population.