Materials and methods
obesity, T2D
OBESITY
A prospective single-center, non-blinded non-randomized controlled trial study was conducted, including patients with classes II and III obesity and T2D undergoing mRYGB. Patients were consecutively recruited from the obesity outpatient clinic of Bellvitge University Hospital. The inclusion criteria were as follows: age between 18 and 60 years old, body mass index (BMI) 35–43 kg/mAt baseline and one year after surgery, patients underwent an anthropometric and body composition analysis with DEXA (HoQDR 4500; Hologic Inc., Waltham, MA), a complete biochemical examination, a standardized meal tolerance test (MTT), and a lipid test (LT). MTT consisted in the intake of 200ml of a standard meal (16% proteins, 49% carbohydrates, and 30% lipids [320 kcal]; Isosource EnergyAll pharmacological treatment was stopped three days before the functional tests, except insulin treatment which was stopped 12 hours before the tests. Proton pump inhibitors were prescribed after surgery for only three months. In the month preceding the surgical procedure, all patients adhered to a very low-calorie diet, characterized by an intake of <800 kcal/day. This dietary regimen was achieved through the implementation of meal replacement with OptifastDuring the MTT and LT, plasma, insulin, C-peptide, GLP-1 and GLP-2 were determined at all-time points, whereas succinate, IL-6 and zonulin concentrations were only determined in the fasting state. Plasma insulin and C-peptide were determined by immunochemiluminometric assay (ADVIA Centaur, Siemens Healthcare, Erlangen, Germany), total plasma GLP-1 and GLP-2 by ELISA technique (respectively, EZGLP1T-36K and EZGLP-2-37K, Merck KGaA, Darmstadt, Germany, respectively) and plasma succinate on plasma filtrate (10.000 kD) using a fluorometric assay (EnzyChromTM Succinate Assay Kit, BioAssay Systems; USA). Fasting IL-6 and zonulin were analyzed by using ELISA high sensitivity kit (HS600C, USA R&D Systems, Inc., Minneapolis, MN) and ELISA (K5601, Immundiagnostik AG, Bensheim, German), respectively. Glucose and cholesterol were quantified using molecular absorption spectrometry, employing the Cobas