2.3.2. Glycemic Control Indicators
AutoSep, Venous fasting blood samples, high-density lipoprotein cholesterol
Venous fasting blood samples were collected at baseline (t1), 12 weeks (t2), and the 12-week follow-up (t3) after a 12-h overnight fast in Venoject-II AutoSep tubes with serum or NaF for plasma. Tubes with EDTA were used to determine blood glycosylated hemoglobin (HbA1c). Serum and plasma samples were transferred to separate tubes and frozen immediately at −80 °C. Fasting samples were used to measure the levels of plasma glucose, serum insulin, serum triglyceride, serum total cholesterol (TC), serum low-density lipoprotein cholesterol (LDL-C), serum high-density lipoprotein cholesterol (HDL-C), serum apolipoprotein (Apo)A-1, serum ApoB, and serum liver and renal function indicators (e.g., uric acid, creatinine, and γ-GT) by KingMed Diagnostics Inc. (Xi’an, China). At t1 and t2, a standard 75 g oral glucose tolerance test (OGTT) was also performed between 08:30 and 11:00, and plasma glucose and serum insulin levels were determined at 0, 30, 60, 90, and 120 min. Serum samples obtained at 6 and 12 weeks during the interventions were subjected to 25(OH)D analysis using electrochemiluminescence immunoassays (Roche Diagnostics GmbH, Mannheim, Germany). The intra- and inter-assay variation coefficients for 25(OH)D were 1.96% and 3.78%, respectively. The HOMA-IR index was the primary endpoint and calculated as follows: HOMA-IR = G