Association Between Polymorphisms of the DNA Repair Genes XRCC1 and HOGG1 and Type 2 Diabetes Mellitus in the Polish Population

Introduction: Elevated oxidative stress in type 2 diabetic patients leads to the accumulation of DNA damage and possibly acceleration of diabetic complications. Numerous studies indicate that diabetic patients may display impaired DNA repair compared to healthy subjects.

Objectives: The aim of the study was to compare the distribution of genotypes of DNA repair genes between type 2 diabetic patients and non-diabetic subjects.

Patients And Methods: Polymerase chain reaction-based restriction fragment length polymorphism was used to determine the distribution of genotypes and frequency of alleles of polymorphisms of base excision repair genes, including the Arg399Gln polymorphism of the XRCC1 gene and Ser326Cys in the hOGG1 gene. The study population included 195 subjects, including 94 with type 2 diabetes mellitus and 101 with normal glucose metabolism. All study participants were Caucasian and inhabited the city of Łódź, Poland.

Results: The frequency of the Gln allele in XRCC1 gene (41% vs. 47%, odds ratio [OR] 0.80, CI 0.54-1.19) and Cys allele in hOGG1 gene (19% vs. 18%, OR 1.09, CI 0.65-1.82) did not differ significantly between diabetic patients and subjects with normal glucose metabolism. Linkage analysis revealed that the Arg/Gln-Ser/Ser combination of genotypes of XRCC1 and hOGG1, respectively (not associated with a decreased activity of both genes) occurs more commonly in type 2 diabetic patients.

Conclusions: The results of our study suggest no association between decreased activity of the examined DNA repair genes and type 2 diabetes mellitus in the studied population.