2.5. Determination of IR in Rats

IR and β-cell function were assayed using homeostasis model assessments of IR (HOMA-IR). The glucose-insulin index and clinical HOMA-IR were determined to evaluate IR and compare groups after the concentrations of plasma glucose and insulin were measured. The glucose-insulin index was calculated as the product of the glucose and insulin areas under the curve (AUCs). HOMA-IR  =  [fasting glucose (mmol/L)]  ×  [fasting insulin (pmol/mL)]/22.5 [40,45].