Objective To describe the polymorphism distribution of TRB3 + 251A/G, and to identify its correlation with impaired glucose tolerance (IGT) and insulin resistance.
Methods A total of 112 IGT subjects and 209 control subjects were genotyped by Taqman probe method. Questionnaire survey, physical examination, and biochemical measurements of glucose, lipid, and insulin were conducted. Homeostasis model assessment for β-cell function index (HOMA-B), index of early phase insulin secretion (ΔI30/ΔG30), homeostasis model assessment for insulin resistance index (HOMA-IR), insulin sensitivity index by Cederholm (ISIc) were calculated to assess insulin release and insulin sensitivity.
Results In comparison between the IGT and control groups, there was no statistical difference in gender or age, but differences were observed in 10 tested indicators, including body mass index, glucose (0 h and 2 h), hemoglobin A1c, free fatty acids, insulin (0 h and 2 h), ΔI30/ΔG30, HOMA-IR, and ISIc. The gene polymorphisms of TRB3 + 251A/G were identified．The frequencies of AA,AG,GG were 64.29%, 28.57%, and 7.14% genotypes in the IGT group versus 64.11%, 32.54%, and 3.35% in the control group respectively, and there was no significant difference (χ2=0.006,P=0.938). In comparison of clinical characteristics, the participants with IGT carrying AG/GG versus those carrying AA showed higher levels of insulin (0 h) and HOMA-IR (P<0.05); no significant difference was observed in glucose, lipid, insulin, HOMA-B, or HOMA-IR between AA and AG/GG genotypes in the controls.
Conclusion TRB3 + 251A/G polymorphism is not associated with IGT in the studied population. However, it might be correlated with liver insulin resistance among IGT subjects.
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