Hplc method

All measures were carried out by a research nurse. Body mass index (BMI) was calculated as weight in kg over height in m²(kg/m²). Waist circumference was calculated in cm and was taken in the midpoint between the iliac crest and the lowest rib. A blood sample was drawn at baseline, 3 months, and 6 months and analyzed at the hospital clinical laboratory for HbA1c using a high performance liquid chromatography (HPLC) method (Tosoh Bioscience) on diabetes control and complications-aligned equipment.

Fasting blood plasma samples were drawn during the health examination, which were analyzed for lipids (total cholesterol, HDL-cholesterol, and triglycerides) and glucose, insulin, and glycated haemoglobin (HbA1c). Lipids were measured using colorimetric slide methods with Vitros 4600/5600 Ortho Clinical Diagnostics (OCD), and non-HDL cholesterol was calculated by using the equation: Total cholesterol − HDL-cholesterol. Glucose was assessed by the hexokinase/glucose-6-phosphate dehydrogenase assay (Roche Diagnostics, former Boehringer Mannheim, Germany), insulin was assessed by the flouroimmunoassay technique, AutoDelfia (Perkin Elmer-Wallac, Finland), and HbA1c was assessed by the HPLC method (TOSOH, Minato, Japan). The homeostasis model of insulin resistance, HOMA-IR, was calculated using the formula: ((fasting plasma insulin [pmol/L]* fasting plasma glucose [pmol/L]/22.5) × 0.144) [29 (link)]. Based on the concept that blood glucose and insulin concentrations are related by the feedback of glucose on beta-cells to increase insulin secretion, this model is used as a surrogate measure of insulin sensitivity [29 (link)].