Gastric Bypass Beats Sleeve Gastrectomy for Diabetes Remission

By Will Boggs MD

November 26, 2019

NEW YORK (Reuters Health) - Among obese patients with type 2 diabetes, gastric bypass is associated with higher rates of diabetes remission at one year than is sleeve gastrectomy, researchers from Norway report.

"These results were actually nearly identical with what we anticipated before study start," Dr. Joeran Hjelmesaeth of Vestfold Hospital Trust, in Tonsberg, and the University of Oslo told Reuters Health by email. "However, we were surprised that the superiority of gastric bypass was not explained by better pancreatic beta-cell function."

Weight loss in patients with obesity and type 2 diabetes is associated with improved insulin sensitivity and beta-cell function and can induce remission of diabetes.

Open-label studies have found superior outcomes for bariatric surgery versus intensive lifestyle intervention, but whether gastric bypass or sleeve gastrectomy provides better remission rates has been unclear.

Dr. Hjelmesaeth and colleagues compared rates of diabetes remission with the two approaches in a single-center, triple-blind randomized Oseberg trial including 109 with severe obesity (mean BMI, 42.3) and a median hemoglobin (Hb) A1c of 7.9% (63 mmol/mol). They defined remission as HbA1c of 6.0% (42 mmol/mol) or lower without the use of glucose-lowering medication.

Diabetes remission rates at five and 16 weeks were similar between the gastric bypass and sleeve gastrectomy groups. But after one year of follow-up, complete remission rates were significantly higher in the gastric bypass group (40/53, 75%) than in the sleeve gastrectomy group (26/54, 48%), the team reports in The Lancet Diabetes and Endocrinology, online October 30.

The disposition index, a measure of beta-cell function, improved as much as eight times from baseline to the one-year follow-up, with no significant difference between the groups.

HbA1c decreased by approximately two percentage points in both groups during follow-up, and acute insulin response to glucose and insulin sensitivity improved in both groups, albeit to a greater extent in the gastric bypass group.

Total body weight loss at one year was significantly greater in the gastric bypass group (29%) than in the sleeve gastrectomy group (23%).

About one-third of the effect of surgical group on remission was mediated by weight loss, and about two-thirds of the effect was mediated by the type of surgery.

Complications and side effects were similar between the two groups.

"Gastric bypass has other adverse effects than sleeve gastrectomy, e.g., internal herniation and possibly higher risk of abdominal pain, but these possible differences have to be explained to the individual patient in the shared decision-making between the patient and the doctor," Dr. Hjelmesaeth said.

"We argue that our findings, in view of previous trends of superiority of gastric bypass in observational and randomized trials, confirm that gastric bypass is superior to sleeve gastrectomy regarding remission of type 2 diabetes and weight loss short term (1-year)," he said. "Further study is necessary to confirm the longer-term effects."

Dr. Paul O'Brien of Monash University's Center for Obesity Research and Education, in Melbourne, Australia, who wrote an accompanying editorial, told Reuters Health by email, "In the management algorithm for the obese (or overweight) person with diabetes, most physicians do not focus sufficiently on weight loss as a central part of treatment. There should always be a serious effort with a medical weight loss program as the first step."

"But if or when this fails, the data in this study show that bariatric surgery must then be considered as part of the treatment plan," he said. "The effect is so substantial, in this and many other lesser studies, that a physician who fails to promote bariatric surgery as an option could now be criticized. This would be one main message that I hope physicians would take away."

"There are several bariatric procedures now in use or development, and this study shows that, of the two most popular options, bypass is the better," Dr. O'Brien said. "Until equivalent quality data are presented regarding the other options, bypass should be the default position. I cannot easily pick a subgroup where I would put sleeve as a better option."

"Durability of effect is critical, and the greatest weakness of the report is the follow-up of just 12 months," he added. "The interested physicians should base their current decision on the Oseberg study, supported by other randomized controlled trials, and watch for reports of longer follow-up at Oseberg, comparison with other types of bariatric surgery, cost-effectiveness studies, patient acceptability, and patient-related outcome measures."

Dr. Mitchell Roslin from Northwell Health-Lenox Hill Hospital, in New York, who recently reviewed bariatric surgery in the management of diabetes, told Reuters Health by email, "A question is why with data this good are gastric bypass (RYGB) numbers declining. RYGB, which used to be more than 50% of cases, is down to 22%. Sleeve gastrectomy is over 60%."

"There are many reasons," added Dr. Roslin, who was not involved in the new work. "Short-term complications are less. It is thought of as an easier procedure and easier to revise. With time, patients with bypass have issues with ulcers, small-bowel obstructions, bone hunger, and anemia. The sleeve gastrectomy certainly has lower bowel obstructions, but higher rate of gastroesophageal reflux disease. Many patients are more willing to have sleeve gastrectomy than RYGB."

He added that newer alternatives to these surgeries have shown promise. In particular, he favors "a single anastomosis duodenal switch where I make a slightly bigger sleeve and attach 3 meters from the terminal ileum. This approach appears to provide less glucose variability than with RYGB," he said, "with fewer swings into hyper- or hypoglycemia."


Lancet Diabetes Endocrinol 2019.