Aims: DNA damage resulting from oxidative stress contributes significantly to the development and progression of atherosclerosis in type 2 diabetic (T2DM) individuals, thereby implicating polymorphisms in DNA repair genes in the modulation of DNA repair efficiency. Based on this premise, we explored the association between X-ray repair cross-complementing group 1 (XRCC1) gene Arg399Gln polymorphism, coronary artery disease (CAD), and myocardial infarction (MI) in type 2 diabetic patients. We screened 283 T2DM patients, inclusive of 160 with angiographically defined CAD, 73 with MI, 89 without MI, and 121 T2DM individuals with no evidence of CAD for XRCC1 Arg399Gln polymorphism.
Results: There appeared to be a significant difference in the distribution of genotype and allele frequencies of XRCC1 Arg399Gln polymorphism between T2DM groups with and without CAD (p=0.03), albeit no significant association with MI was observed (p=0.055). A further analysis revealed that the frequencies of the Arg/Gln, Gln/Gln genotypes and 399Gln allele were considerably higher in patients with triple vessel disease (TVD) as compared with those with the single and double vessel disease (p=0.03), thereby associating this polymorphism with severity of CAD in T2DM individuals. Multiple logistic regression analysis revealed a significant and independent association of XRCC1 Arg399Gln polymorphism and other putative risk factors with CAD/TVD in T2DM individuals.
Conclusions: These findings reveal a significant association between XRCC1 gene Arg399Gln polymorphism, CAD/TVD, and coincident putative risk factors in T2DM individuals in the South Indian population.