Myanmar Health Sciences Research Journal
Volume 27, Number 1
TITLE: Insulin receptor substrate-1 Gene (G972R) polymorphism and insulin resistance in overweight and obese Type 2 Diabetes Mellitus patients
AUTHOR: Thae Nu Htwe; Myat Mon Oo; Saw Wut Hmon; Moh Moh Htun; Ohnmar Myint Thein; Myat Thandar
SOURCE: Myanmar Health Sciences Research Journal. 2015; 27(1):66-71
ABSTRACT: The insulin receptor substrate-1 gene (IRS-1) gene has been considered a candidate for insulin resistance in type-2 diabetes and coronary artery disease. The most common IRS-1 variant, a glycine to arginine change at codon 972(G972R) is more prevalent among subjects who have features of insulin resistance syndrome associated with type 2 diabetes patients. The aim of the present study was to determine the insulin receptor substrate-1 gene (G972R) polymorphism and insulin resistance in overweight and obese type 2 diabetes mellitus patients. The genomic DNA of the subjects was amplified by polymerase chain reaction (PCR) and digested by restriction fragment length polymorphism (RFLP) with BstN1 used for codon 972. Fasting insulin and fasting glucose were determined and insulin resistance was evaluated using homeostasis model assessment index for insulin resistance (HOMA-IR). The prevalence of IRS-1(G972R) polymorphism was 19% in the study population, 18 patients were of heterozygous (A/G) genotype and only one patient was of homozygous (A/A) genotype. Remaining 81 patients were of wild type, (G/G) genotype. The percentage of patients with family history of diabetes mellitus was significantly higher in the G972R carrier group than in the non-carrier group. There was a significant association between family history of diabetes mellitus and IRS-1(G972R) polymorphism in the type 2 diabetic patients (p=0.02). Between IRS-1(G972R) carriers and non-carriers, there was no significant difference in insulin resistance. It was concluded that IRS-1(G972R) poly-morphism might have a role in the genetic susceptibility of development of type 2 diabetes mellitus in those with family history. But, IRS-1(G972R) polymorphism does not significantly increase insulin resistance compared to the wild type individuals.
SUBJECT HEADINGS: IRS-1gene, G972R, Polymorphism, T2DM