ABSTRACT
Objective To study the genotype distribution of insulin receptor substrate-2(IRS-2)gene 1057G/A polymorphism in Han population from Southwest China,and to explore its association with the metabolism of glucose and lipids,insulin resistance and islet?-cell function in type 2 diabetic patients and subjects with impaired glucose tolerance(IGT).Methods A total of 929 Hans[462 patients with type 2 diabetes(DM group) and 164 subjects with IGT(IGT group)and 303 normal controls(NC group)]from Chongqing and nearby regions were screened for 1057G/A polymorphism of IRS-2 gene by PCR-RFLP assay.Body mass index(BMI),plasma glucose,serum insulin and lipid profile,high-sensitive C-reactive protein(hsCRP)and non-esterified fatty acid were measured.Homeostasis model assessment of insulin resistance(HOMA-IR)and disposition index(DI)were used to estimate insulin resistance and?-cell function respectively.Results In DM group,A allele frequency was significantly lower than that in NC group(0.326 vs 0.388,X~2=6.19,P=0.01).Compared with NC group,AA genotype frequeney was lower and GG genotype frequeney was higher in DM group(0.104 vs 0.135 and 0.452 vs 0.360 respectively,X~2=6.80,P