Gastric bypass increased diabetes remission versus sleeve gastrectomy, small trial finds
At five years after gastric bypass, half of patients with type 2 diabetes and obesity had an HbA1c level less than 6%, compared to 20% of those randomized to sleeve gastrectomy, according to a secondary analysis of a Norwegian trial.
Patients were more likely to have remission of type 2 diabetes if they underwent gastric bypass versus sleeve gastrectomy, a new analysis of a randomized trial found.
The trial was conducted at a public tertiary obesity center in Norway and included adults with type 2 diabetes, a previously verified body mass index (BMI) of at least 35 kg/m2, and a current BMI of at least 33 kg/m2. They were randomized to laparoscopic gastric bypass (n=54) or sleeve gastrectomy (n=55) in 2012 to 2017. This prespecified secondary analysis looked at outcomes five years after surgery. Results were published by The Lancet Diabetes & Endocrinology on April 1.
Among the 93 patients (85%) who completed five-year follow-up, the proportion with remission of type 2 diabetes, when defined as an HbA1c level less than 6%, was higher in the gastric bypass group than the sleeve gastrectomy group at 50% versus 20% (risk difference, 29.5%; 95% CI, 10.8% to 48.3%). More patients in the bypass group also achieved an HbA1c level less than 6.5% (63% vs. 30%; risk difference, 33.5% [95% CI, 14.1% to 52.9%]). Bypass was also associated with greater reductions in weight (mean weight loss, 22.2% vs. 17.2%; treatment difference, 5.0% [95% CI, 2.4% to 7.7%]) and low-density lipoprotein cholesterol level (treatment difference, –0.5 mmol/L [–19.3 mg/dL]; 95% CI, –0.08 to –0.1 [–3.09 to –3.98 mmol/L]). Rates of erosive esophagitis and Barrett's esophagus were similar between groups, but pathological acid reflux occurred more frequently after sleeve gastrectomy. Symptomatic postprandial hypoglycemia was more common after gastric bypass (28% vs. 2%).
“To the best of our knowledge, these findings are the first to support the generally accepted notion that patients with type 2 diabetes who undergo gastric bypass have a substantially higher likelihood of long-term remission of diabetes compared with patients who undergo sleeve gastrectomy, whether defined as HbA1c less than or equal to 6.0% or HbA1c less than 6.5%, without the use of antidiabetic medication,” the study authors wrote. “This novel evidence has the potential to change clinical practice regarding the preferred surgical procedure in patients with type 2 diabetes and obesity, and should be addressed in the shared decision-making process before surgery.”
An accompanying comment added a cautionary note, pointing to baseline differences in the two groups that could have affected the outcomes, including longer duration of type 2 diabetes (by a year) and higher preoperative HbA1c level (by 0.5%) in those randomized to sleeve gastrectomy, and the limitations of the small trial size. The comment noted the findings are not consistent with other randomized controlled trials' results at five years. “There is some evidence that gastric bypass might be associated with the improved control of type 2 diabetes,” the comment said. “To detect a difference of 10 percentage points in the remission rate of type 2 diabetes between the procedures, statistical power calculations show that approximately 700 patients with type 2 diabetes would need to be enrolled.”