Determination of Insulin Resistance and Beta-Cell Function Using Homeostatic Model Assessment in Type 2 Diabetic Patients at Diagnosis

Abstract

Objective: Despite the increasing incidence of type 2 diabetes mellitus (T2DM) in South Asian countries, there have been no studies related to insulin resistance (IR) and beta-cell function (BCF) in Nepal. Measurement of both of these parameters at T2DM diagnosis can be a potential tool in evaluation, risk stratification and monitoring treatment. In this study, we used C-peptide modified homeostatic model assessment (both HOMA1 and HOMA2) and correlated the obtained IR with cardiovascular risk factors. We also intended to find out whether reduced insulin sensitivity or beta-cell failure predominates in new T2DM cases. Also there has been some dilemma in using either body mass index (BMI) or waist-hip ratio (WHR) as a better predictor of IR in our population. Lipoprotein ratios TC/ HDL and TG/HDL also needed evaluation in this regard. Results: Participants were sixty newly diagnosed T2DM patients visiting Tribhuvan University Teaching Hospital (TUTH), Nepal. The mean IR and beta-cell function were HOMA1IR=4.91 ± 1.62; HOMA2IR=2.61 ± 1.06 and HOMA1%B=40.28 ± 23.64; HOMA2%B=47.10 ± 24.67 respectively. Both HOMA1 and HOMA2 showed greater reduction in insulin sensitivity than beta-cell function at diagnosis. ROC curves analysis showed WHR and TC/HDL ratio as better predictors of IR.