NADH/NADPH oxidase p22 phox C242T polymorphism and coronary artery diseasein the Australian population

Background: Oxidative stress induced by the superoxide anion (. O-2(-)) has been implicated in atherogenesis. The NADH/NADPH oxidase system is involve d in . O-2(-) production and p22 phox is an essential component of that sys tem. Material and methods: We analysed the p22 phox C242T polymorphism in 689 co nsecutive Australian Caucasians aged less than or equal to 65 years with an d without angiographically documented coronary artery disease (CAD) Results: We report the rare T allele frequency of 0.33, which is 3 fold hig her than that reported in the Japanese population by Inoue et al. [7]. The genotype distributions were not different among patients with CAD (CC:0.422 , CT:0.459 and TT:0.119 in men; 0.447, 0.439 and 0.114 in women) and withou t CAD (0.479, 0.420 and 0.101%, chi(2) = 0.794, P = 0.672 in men; 0.443, 0. 471 and 0.86, chi(2) = 0.442, P = 0.802 in women). The frequencies of the r are TT homozygotes or of the 'T' allele frequency were also not associated with the number of significantly stenosed vessels (chi(2) = 4.466, P = 0.61 4 in men; chi(2) = 4.736, P = 0.578 in women) or with a myocardial infarcti on (MI) history (chi(2) = 2.310, P = 0.315 in men; chi(2) = 1.178, P = 0.55 5 in women). However, when the analysis was conducted in young male patient s aged less than or equal to 45 years (n = 44), TT + TC patients tended to have an increased risk for CAD (odds ratio: 5.71 95% CI: 1.22 - 26.75, P = 0.0271). Conclusion: The p22 phox C242T polymorphism is not associated with the occu rrence or severity of CAD or with a history of MI in Australian Caucasian p atients aged less than or equal to 65 years. However, the polymorphism coul d be associated with an increased CAD risk in young patients, which require s confirmation in large populations.