Single-centre, triple-blinded, randomised, 1-year, parallel-group, superiority study to compare the effects of Roux-en-Y gastric bypass and sleeve gastrectomy on remission of type 2 diabetes and β-cell function in subjects with morbid obesity: a protocol for the Obesitysurgery in Tønsberg(Oseberg) study

Abstract

IntroductionBariatric surgery is increasingly recognised as an effective treatment option for subjects with type 2 diabetes and obesity; however, there is no conclusive evidence on the superiority of Roux-en-Y gastric bypass or sleeve gastrectomy. The Oseberg study was designed to compare the effects of gastric bypass and sleeve gastrectomy on remission of type 2 diabetes and β-cell function.Methods and analysisSingle-centre, randomised, triple-blinded, two-armed superiority trial carried out at the Morbid Obesity Centre at Vestfold Hospital Trust in Norway. Eligible patients with type 2 diabetes and obesity were randomly allocated in a 1:1 ratio to either gastric bypass or sleeve gastrectomy. The primary outcome measures are (1) the proportion of participants with complete remission of type 2 diabetes (HbA1c≤6.0% in the absence of blood glucose-lowering pharmacologic therapy) and (2) β-cell function expressed by the disposition index (calculated using the frequently sampled intravenous glucose tolerance test with minimal model analysis) 1 year after surgery.Ethics and disseminationThe protocol of the current study was reviewed and approved by the regional ethics committee on 12 September 2012 (ref: 2012/1427/REK sør-øst B). The results will be disseminated to academic and health professional audiences and the public via publications in international peer-reviewed journals and conferences. Participants will receive a summary of the main findings.Trial registration numberNCT01778738;Pre-results.

Bone Mineral Density and Turnover After Sleeve Gastrectomy and Gastric Bypass: A Randomized Controlled Trial (Oseberg)

“…Patients with severe obesity and type 2 diabetes were randomized and allocated (1:1) to either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy. The study protocol was approved by the Regional Committees for Medical and Health Research Ethics in Norway (2012/1427/REK sør-øst B) and has been published previously ( 24 ). The primary outcome of the Oseberg study was diabetes remission at 1 year ( 25 ).The study is ongoing with annual visits at 2, 3, 4, and 5 years after the surgical procedure.…”

“…Inclusion criteria were age ≥18 years, current BMI ≥ 33.0kg/m 2 with previously verified BMI ≥ 35.0kg/m 2 , and type 2 diabetes (Hemoglobin A1c [HbA1c] ≥ 6.5% or use of antidiabetic medications with HbA1c ≥ 6.1%). Key exclusion criteria were previous major abdominal surgery, cancer, severe medical conditions associated with increased risk of complications, drug or alcohol addiction, pregnancy, severe gastroesophageal reflux disease, and long-term systemic corticosteroid use (3 months cumulative use in the last 12 months or treatment the past 2 months) ( 24 ). All patients provided written informed consent.…”

“…Both groups were, when discharged from the hospital after surgery, prescribed identical vitamin and mineral supplementations, including daily oral supplementation with 2 multivitamin/mineral tablets, 1000 mg calcium carbonate, 800 IU vitamin D3, and 100 mg ferrous sulphate (in premenopausal women), and intramuscular injections of 1 mg vitamin B12 every third month. Vitamin and mineral supplementations were adjusted at each visit according to specific predefined algorithms aiming for serum levels of 25-OH-vitamin D between 50 and 125 nmol/l and calcium levels within the normal rage (2.10–2.60 mmol/l) ( 24 ).…”

“…Gastric bypass (25 ml pouch, 120 cm Roux-limb, and 60 cm biliopancreatic limb) and sleeve gastrectomy (35 Fr Bougie) were performed laparoscopically using identical skin incisions, as previously described ( 24 ).…”

“…The Oseberg study was powered (significance level to 5% and power to 80%) to detect differences in diabetes remission rates (n = 110) and changes in beta cell function (n = 100) ( 24 ).…”