Roux-en-Y gastric bypass associated with better long-term diabetes outcomes than sleeve gastrectomy

While both procedures were associated with high rates of type 2 diabetes remission, the rate of remission five years after surgery was about 10% higher in patients who had gastric bypass than in those who had sleeve gastrectomy.

Patients with type 2 diabetes who had Roux-en-Y gastric bypass (RYGB) had a higher rate of diabetes remission, a lower rate of relapse, greater weight loss, and better glycemic control than those who had sleeve gastrectomy in a recent study.

Researchers used data from the National Patient-Centered Clinical Research Network to compare diabetes-related outcomes in adults with type 2 diabetes who had either RYGB or sleeve gastrectomy between Jan. 1, 2005, and Sept. 30, 2015, at 34 U.S. health system sites. The primary outcomes were remission from and relapse of type 2 diabetes. Remission was defined as the first postsurgical occurrence of an HbA1c level less than 6.5% following at least six months without type 2 diabetes medication prescription orders, and relapse was defined as the occurrence of HbA1c levels of 6.5% or more and/or a prescription for type 2 diabetes medication after remission. Secondary outcomes were percentage of total weight lost and change in HbA1c. Outcomes were assessed up to five years after surgery, and results were published by JAMA Surgery on March 4.

Overall, 9,710 patients (mean age, 49.8 years; 72.6% women; 72.2% white; mean body mass index [BMI], 49.0 kg/m2) were included, with a median follow-up time of 2.7 years. The type 2 diabetes remission rate was about 10% higher in patients who had RYGB (hazard ratio, 1.10; 95% CI, 1.04 to 1.16) compared to those who had sleeve gastrectomy. Estimated adjusted cumulative type 2 diabetes remission rates for patients who had RYGB and sleeve gastrectomy were, respectively, 59.2% (95% CI, 57.7% to 60.7%) and 55.9% (95% CI, 53.9% to 57.9%) at one year after surgery and 86.1% (95% CI, 84.7% to 87.3%) and 83.5% (95% CI, 81.6% to 85.1%) at five years.

Among 6,141 patients who experienced remission, the subsequent relapse rate was about 25% lower for those who had RYGB compared to those who had sleeve gastrectomy (hazard ratio, 0.75; 95% CI, 0.67 to 0.84). Estimated relapse rates for those who had RYGB and sleeve gastrectomy, respectively, were 8.4% (95% CI, 7.4% to 9.3%) and 11.0% (95% CI, 9.6% to 12.4%) at one year and 33.1% (95% CI, 29.6% to 36.5%) and 41.6% (95% CI, 36.8% to 46.1%) at five years. Weight loss was significantly greater with RYGB than sleeve gastrectomy at one year (mean difference, 6.3 percentage points; 95% CI, 5.8 to 6.7 percentage points) and five years (mean difference, 8.1 percentage points; 95% CI, 6.6 to 9.6 percentage points). At five years, compared with baseline, HbA1c decreased by 0.45 percentage point (95% CI, 0.27 to 0.63 percentage point) more for patients who had RYGB versus patients who had sleeve gastrectomy.

Limitations of the study included its observational design and the potential for unmeasured confounders, as well as the reliance on prescription data to help define type 2 diabetes relapse and remission, the authors said. They concluded that patients with more advanced type 2 diabetes at the time of surgery for whom remission is more difficult to achieve (e.g., due to older age, insulin use, more complex diabetes medications, poor glycemic control) may expect larger improvements in diabetes with RYGB compared to sleeve gastrectomy, whereas those with a higher likelihood of remission are likely to see similar five-year outcomes with either procedure.

Although the American Diabetes Association recommends considering bariatric surgery in patients with diabetes and class 1 obesity (BMI of 30.0 to 34.9 kg/m2) or higher, those with class 1 obesity do not meet BMI criteria for bariatric surgery, an accompanying commentary noted. “The lack of universal insurance coverage for bariatric surgery remains a substantial barrier. Very few insurance plans cover it for patients with class 1 obesity and diabetes,” the editorialists wrote. “Continued advocacy for bariatric surgery coverage, including expansion for patients with [type 2 diabetes] and class 1 obesity, will be critical.”