Patient-reported outcomes, weight loss, and remission of type 2 diabetes 3 years after gastric bypass and sleeve gastrectomy (Oseberg); a single-centre, randomised controlled trial.

Background: Little is known about the comparative effects of various bariatric procedures on patient-reported outcomes. We aimed to compare 3-year effects of gastric bypass and sleeve gastrectomy on patient-reported outcome measures in patients with obesity and type 2 diabetes.

Methods: The Oseberg trial was a single-centre, parallel-group, randomised trial at Vestfold Hospital Trust, a public tertiary obesity centre in Tønsberg, Norway. Eligible patients were aged 18 years or older with previously verified BMI 35·0 kg/m or greater. Diabetes was diagnosed if glycated haemoglobin was at least 6·5% (48 mmol/mol) or by their use of anti-diabetic medications with glycated haemoglobin at least 6·1% (43 mmol/mol). Eligible patients were randomly assigned (1:1) to gastric bypass or sleeve gastrectomy. All patients received identical preoperative and postoperative treatment. Randomisation was done with a computerised random number generator and a block size of ten. Study personnel, patients, and the primary outcome assessor were blinded to allocations for 1 year. The prespecified secondary outcomes reported here were 3-year changes in several clinically important patient-reported outcomes, weight loss, and diabetes remission. Analyses were done in the intention to treat population. This trial is ongoing, closed to recruitment and is registered with ClinicalTrials.gov, NCT01778738.

Findings: Between Oct 15, 2012 and Sept 1, 2017, 319 consecutive patients with type 2 diabetes scheduled for bariatric surgery were assessed for eligibility. 101 patients were not eligible (29 did not have type 2 diabetes according to inclusion criteria and 72 other exclusion criteria) and 93 declined to participate. 109 patients were enrolled and randomly assigned to sleeve gastrectomy (n=55) or gastric bypass (n=54). 72 (66%) of 109 patients were female and 37 (34%) were male. 104 (95%) of patients were White. 16 patients were lost to follow up and 93 (85%) patients completed the 3-year follow-up. Three additional patients were contacted by phone for registration of comorbidities Compared with sleeve gastrectomy, gastric bypass was associated with a greater improvement in weight-related quality of life (between group difference 9·4, 95% CI 3·3 to 15·5), less reflux symptoms (0·54, 0·17 to -0·90), greater total bodyweight loss (8% difference, 25% vs 17%), and a higher probability of diabetes remission (67% vs 33%, risk ratio 2·00; 95% CI 1·27 to 3·14). Five patients reported postprandial hypoglycaemia in the third year after gastric bypass versus none after sleeve-gastrectomy (p=0·059). Symptoms of abdominal pain, indigestion, diarrhoea, dumping syndrome, depression, binge eating, and appetitive drive did not differ between groups.

Interpretation: At 3 years, gastric bypass was superior to sleeve gastrectomy in patients with type 2 diabetes and obesity regarding weight related quality of life, reflux symptoms, weight loss, and remission of diabetes, while symptoms of abdominal pain, indigestion, diarrhoea, dumping, depression and binge eating did not differ between groups. This new patient-reported knowledge can be used in the shared decision-making process to inform patients about similarities and differences between expected outcomes after the two surgical procedures.

Funding: Morbid Obesity Centre, Vestfold Hospital Trust.

Translation: For the Norwegian translation of the abstract see Supplementary Materials section.