Glutathione S-Transferase and Catalase Gene Polymorphisms with Type 2 Diabetes Mellitus

Abstract

Antioxidant enzymes such as glutathione S-transferases (GSTs) and catalase (CAT) play important roles in cellular defense by detoxifying various toxic substrates and can be used as important biomarkers for type 2 diabetes mellitus (T2DM). The aim of the present work was to study the association of GST and CAT gene polymorphisms with T2DM cases and controls in north Indian population. Polymorphic GST gene isoforms, GSTM1, T1 and P1 in 201 healthy control subjects and 204 T2DM cases while CAT -21A/T in 186 controls and T2DM cases were investigated. Genotypes were analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Genotype distribution and allelic frequencies were compared between patients and controls. Mean values and odds ratio (OR) with 95% confidence interval (CI) were calculated using SPSS software (version 15.0). Biochemical parameters showed highly significant association with T2DM (p<0.001). The genotype distribution, allele frequencies and multiple combinations of GSTM1 and T1 polymorphisms did not differ significantly between patients and controls. However, GSTP1 showed significant association (p<0.001). In case of CAT (-21A/T), only genotype frequencies showed significant association with T2DM (p=0.002). Our data suggest that Val105Val of GSTP1 and ‘AT’ genotype of CAT gene may increase the risk of T2DM in north Indians. Genetic polymorphism studies of antioxidant genes may provide a comprehensive understanding of the role of oxidative stress pathways and provide prognostic markers for T2DM