Metabolic Biomarkers in Mice

Blood glucose, following a 6 h fast, was measured prior to start of diet, at diet switch, and at sacrifice following a 6 h fast using a Bayer Contour Blood Glucose Monitor (Bayer HealthCare LLC, Tarrytown, NY, USA). Metabolically relevant hormones including leptin, insulin, IL-6, MCP-1, and TNF-α were measured in the plasma collected at sacrifice using the Milliplex MAP Mouse Metabolic Hormone Magnetic Bead Panel in the Luminex MAGPIX system (EMD Millipore, Billerica, MA, USA). The homeostasis model assessment was used to calculate the approximate insulin resistance (HOMA_IR) using the formula (blood glucose (mg/dl at sacrifice) × plasma insulin levels (at sacrifice)/405) as previously described (14 (link), 28 (link)). Adiponectin concentrations in plasma collected at sacrifice were measured using the adiponectin mouse ELISA kit (ab108785; Abcam, Cambridge, MA, USA) following the manufacturer’s protocol. The leptin:adiponectin ratio was calculated using the measures obtained from the Luminex cytokine panel and adiponectin ELISA.