Association of IL-4 and IL-1RN (receptor antagonist) gene variants and the risk of type 2 diabetes mellitus: a study in the north Indian population

Abstract

Background: Inflammation is a key event closely associated with the pathophysiology of type 2 diabetes mellitus (T2DM). Association of genetic polymorphisms of inflammatory cytokines with T2DM is largely unknown. Our objective was to investigate the relationship of polymorphism of IL-1RN and IL-4, two important biomarkers of inflammation, with the risk of T2DM. Setting and Design: We recruited 120 clinically diagnosed T2DM patients and 150 normal healthy controls for this study in order to evaluate the nature of polymorphisms of IL-1RN and IL-4. Material and Methods: Genomic DNA was isolated from the blood of all subjects, and the variable number of tandem repeat (VNTR) polymorphisms of IL-1RN and IL-4 genes was identified by polymerase chain reaction. Statistical Analysis Used: Genotype distribution and allelic frequencies were compared between patients and control group. Means, as well as odds ratios (ORs) with 95% confidence intervals (CI), were calculated using SPSS software (version 11.5). Result: Our study revealed that distribution of both IL-4 and IL-1RN (VNTR) gene polymorphisms was significantly associated with T2DM subjects. We, however, failed to find any association of gene-gene (IL-4 and IL-1RN) interaction with T2DM. Conclusions: Both IL-4 and IL-1RN (VNTR) gene polymorphisms were significantly associated with T2DM subjects. This may suggest that the genetic polymorphisms of IL-4 and IL-1RN genes could serve as susceptibility indicators for T2DM in the Indian population, but the actual mechanism of these associations will require more elaborate investigations. Lack of association of gene-gene (IL-4 and IL-1RN) interaction with T2DM may indicate the independent nature of influence of both these genes on the risk of T2DM.