Plasma Metabolite and Insulin Resistance Analysis

The levels of cholesterol, triglycerides, total proteins, albumin, and globulins in the plasma were measured with a commercially available kit (Bioclin, Belo Horizonte, MG, Brazil). The low-density lipoprotein cholesterol (LDL-c) and very-low-density lipoprotein cholesterol (VLDL-c) levels were calculated according to Friedewald et al. [44 (link)]. Blood samples were collected from the tail and glycemia was measured with an Accu-Chek Active blood glucose monitor (Roche, Mannheim, Germany) [42 (link)]. Insulin was determined using a rat/mouse insulin enzyme-linked immunosorbent assay (ELISA) kit from Millipore/Sigma-Aldrich (catalog number EZRMI13K-St Charles, MO, USA). The Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was calculated using the following formula: HOMA-IR (mmol/L) = fasting glucose value (mg/dL) × fasting insulin value (ng/dL)/405 [45 (link)]. The β-cell function was obtained by the HOMA-β method using the following formula: HOMA-β = 20 × fasting insulin value (µU/mL)/fasting glucose value (mmoL/L) −3.5) [46 (link)].