Laboratory measurements

Fasting venous blood samples were collected after an overnight fast (≥ 8 h) both at baseline and during follow-up. Glycated haemoglobin and FPG were measured on whole never-frozen blood immediately after blood collection. Glycated haemoglobin was measured using boronate affinity chromatography assay (Trinity Biotech, County Wicklow, Ireland) and FPG was measured using enzymatic colourimetric assay (F. Hoffmann-La Roche, Basel, Switzerland). The other collected tubes of blood were centrifuged at 4000 g for5.5 min at 4°C, plasma separated, aliquoted, and stored at −80°C for future analyses.Amylin, C-peptide, glucagon, glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide-1 (GLP-1), insulin, pancreatic polypeptide, and peptide YY were measured in plasma samples using the MILLIPLEX^® MAP human metabolic hormone magnetic bead panel. Protease (Merck KGaA) and DPP-IV inhibitors (Merck KGaA) were added to the samples. All assays were conducted as per the user’s manual. Results were quantified using the Belysa^TM immunoassay curve fitting software (Merck KGaA).