Konelab i 20xti

Whole blood glucose concentrations during the CGIT procedure were measured immediately after collection using a handheld glucometer (Accu-Chek Aviva, Roche Diagnostic, Indianapolis, IN). Plasma glucose concentrations from samples collected during the feed challenge test were determined with an enzymatic assay (Konelab i 20XTi, Thermo Electron Corp., Waltham, MA). Plasma insulin concentrations were determined with a commercially available radioimmunoassay kit (PI-12K, Millipore Sigma, Burlington, MA) with has previously been validated in horses (21 (link)). All plasma samples were run in duplicate within a single assay. Average intra-assay variation was 1.3 and 5.1% for glucose and insulin, respectively.

Plasma triglycerides and cholesterol concentrations were measured with an enzymatic assay (Konelab i 20XTi, Thermo Electron Corp., Waltham, MA) using commercially available reagents [Infinity cholesterol (TR13421) and triglyceride (TR22421) reagents, Thermo Fisher, Waltham, MA] and standards [Stabio cholesterol standard (SB1012030), Thermo Fisher, Waltham, MA; triglyceride standard (T7531STD), Pointe Scientific, Canton, MI]. Plasma HMW adiponectin was measured using a commercially available kit (EZHWAM-65, Millipore Sigma, Burlington, MA) previously validated for use in lean and obese horses (22 (link)). Average intra-assay variation for plasma adiponectin was 3.14%.