Continued Diabetes Remission Despite Weight Recurrence: Gastric Bypass Long-Term Metabolic Benefit

Abstract

BACKGROUND: Roux-en-Y gastric bypass (RYGB) demonstrates high rates of type 2 diabetes mellitus (T2DM) remission, a phenomenon hypothesized to be mediated mainly by weight loss. Compared with procedures that do not bypass the proximal small intestines, such as sleeve gastrectomy (SG), RYGB exhibits weight loss–independent intestinal mechanisms conducive to T2DM remission. We investigated continued diabetes remission (CDR) rates despite weight recurrence (WR) after RYGB compared with an SG cohort. STUDY DESIGN: A retrospective review of patients who underwent successful primary RYGB or SG with a BMI value of 35 kg/m2 or more and a preoperative diagnosis of T2DM was performed. Patients with less than 5 years of follow-up, absence of WR, or lack of T2DM remission at nadir weight were excluded. After selecting the optimal procedure for glycemic control, rates of CDR were then stratified into WR quartiles and compared. RESULTS: A total of 224 RYGB and 46 SG patients were analyzed. The overall rate of CDR was significantly higher in the RYGB group (75%) compared with the SG group (34.8%; p < 0.001). The odds of T2DM recurrence were 5.5 times higher after SG compared with RYGB. Rates of CDR were stratified into WR quartiles (85.5%, <25%; 81.7%, 25% to 44.9%; 63.2%, 45% to 74.9%; and 60%, >75%). Baseline insulin use, higher preoperative glycosylated hemoglobin, and longer preoperative duration of T2DM were associated with T2DM recurrence, whereas WR was not. CONCLUSIONS: T2DM remission rates after RYGB are maintained despite WR, arguing for a concurrent weight loss–independent metabolic benefit likely facilitated by bypassing the proximal small intestine.