Biochemical assays

Enzymatic colorimetric assay using the glucose oxidase method was adopted to measure FBG (Parsazmun, Iran). HbA1c and hs-CRP were measured using latex-enhanced immunoturbidimetric assays using an automated analyzer and commercial kits (Parsazmun, Iran). Serum TC, TG, and HDL-C were measured by enzymatic method kits (Parsazmun, Iran), utilizing a Hitachi 902 automatic analyzer (Hitachi, Japan). Serum LDL-C was calculated using Friedewald’s formula. If serum TG concentration was > 400 mg/dL, LDL-C was determined directly by enzymatic method using the commercial kit. FINS was measured using an enzyme-linked immunosorbent assay kit (ELISA, Monobind, USA). Insulin resistance (IR) was estimated using the homeostatic model assessment for insulin resistance (HOMA-IR) index, according to the following equation (18):

HOMA-IR=fasting serum insulin (μU/mL) × fasting plasma glucose (mmol/L)/22.5.