Metabolic Effects of Duodenal Jejunal Bypass Liner for Type 2 Diabetes Mellitus

A total of 18 subjects (4 women and 14 men) aged 39 to 66 years underwent implantation of the DJBL.The subjects were regular patients of the Diabetes Center at the Herz- und Diabeteszentrum Nordrhein-Westfalen (HDZ NRW), Germany and gave informed consent for related procedures and data handling. The subjects had body mass index (BMI) ≥35 kg/m2, type 2 diabetes mellitus (T2DM), and a history of frustrated weight loss attempts. Exclusion criteria were: history of gastric surgery, gastric or duodenal ulcers, thyroid disorders, gastrointestinal disorders associated with intestinal resorption dysfunction, therapy with oral anticoagulants like marcumar, use of acetyl salicylic acid or non-steroidal anti-inflammatory drugs, drug abuse (incl. alcohol), symptomatic cardiovascular disease including heart failure New York Heart Association (NYHA) IV, renal insufficiency defined as glomerular filtration rate (GFR) \<50 ml/min, pregnancy or breast feeding.

Study design All patients received the DJBL due to medical reasons, not for study purposes. All patients underwent pre-implantation and follow-up examinations (1 week, 32 weeks and 52 (explantation) weeks after implantation). Every examination included a thorough body examination, electrocardiogram (ECG), and the body composition measurement by bio-impedance scaling (type: BC418MA, Tanita, Amsterdam, the Netherlands). Upon implantation, antidiabetic medication was adapted, patients were followed up to adjust antidiabetic regimen. Dietary advice was given to the patients by a professional dietician upon implantation procedure, and liquid diet was started the day before implantation and continued for two additional days followed by puréed diet for four days. Patients decided to turn back to normal diet upon tolerance; fibre rich dietary components were prohibited during the treatment period. Treatment with glucagon-like peptide-1 (GLP-1) or dipeptidyl-peptidase-4 (DPP4) based medication (Exenatide, Liraglutide, Lixisenatide or Sitagliptin, Vildagliptin) was initiated in cases that fasting C-peptide levels were >750 pmol/l. Insulin dosage was reduced after implantation to avoid risk of hypoglycaemia. Sulfonylurea treatment was stopped after implantation.

Mixed meal tolerance tests Mixed meal tolerance tests (MMTT) were performed in fasting state as routine diagnostic tool to assess metabolism parameters and gut hormones described below. In the course of a MMTT every patient consumed a highly caloric drink (Fortimel regular 2 093 Kilojoules (KJ), Nutricia GmbH, Erlangen, Germany) containing carbohydrates (41 energy(EN)%), proteins (40 EN%) and fats (19 EN%), simulating an average meal. Blood samples were taken at fixed intervals: before drinking, after 10, 30, 60, 90, 120 min. DPP4 inhibitor was added to prevent autodigestion of GLP-1 immediately after sampling, Hydroxymercuribenzoic acid was added to plasma per protocol to prevent ghrelin digestion. Samples were stored after centrifugation at -80°C until assayed for the gut hormones ghrelin, GLP-1, gastric inhibitory peptide, leptin as well as the metabolism parameters glucose, insulin, C-peptide, and proinsulin.

Biochemical assessment Laboratory assessments were done in fasting state. Venipuncture was performed the morning after overnight fasting one day before the planned procedure, one week, 8, and 12 months after implantation. Blood samples were processed for subsequent analysis within 20 min of venipuncture. Serum concentrations were measured by commercial available kits of total ghrelin (ELISA, Merck Chemicals Gesellschaft mit beschränkter Haftung (GmbH), Schwalbach, Germany), leptin (ELISA, DRG-International, Inc., USA), active GLP-1 (ELISA, epitope Diagnostics, San Diego, USA), gastric inhibitory Peptide (GIP) (ELISA, DRG-International, Inc., USA), Insulin (CMIA, Abbott, Wiesbaden, Germany), C-peptide (CMIA, Abbott, Wiesbaden, Germany), Proinsulin (ELISA, TecoMedical Bunde, Germany) and glucose (CMIA, Abbott, Wiesbaden Germany).