Insulin Cessation and Diabetes Remission After Bariatric Surgery in Adults With Insulin-Treated Type 2 Diabetes

OBJECTIVEThe impact of bariatric surgeries on insulin-treated type 2 diabetes (I-T2D) in the general population is largely undocumented. We assessed changes in insulin treatment after bariatric surgery in a large cohort of I-T2D patients, comparing Roux-en-Y gastric bypass surgery (RYGB) with laparoscopic adjustable gastric banding (LAGB), controlling for differences in weight loss between procedures.RESEARCH DESIGN AND METHODSOf 113,638 adult surgical patients in the Bariatric Outcomes Longitudinal Database (BOLD), 10% had I-T2D. Analysis was restricted to 5,225 patients with I-T2D and at least 1 year of postoperative follow-up. Regression models were used to identify factors that predict cessation of insulin therapy. To control for differences in weight loss patterns between RYGB and LAGB, a case-matched analysis was also performed.RESULTSOf I-T2D patients who underwent RYGB (n = 3,318), 62% were off insulin at 12 months compared with 34% (n = 1,907) after LAGB (P < 0.001). Regression analysis indicated that RYGB strongly predicted insulin cessation at both 1 and 12 months postoperatively. In the case-matched analysis at 3 months, the proportion of insulin cessation was significantly higher in the RYGB group than in the LAGB group (P = 0.03), and the diabetes remission rate was higher at all time points after this surgery. RYGB was a weight-independent predictor of insulin therapy cessation early after surgery, whereas insulin cessation after LAGB was linked to weight loss.CONCLUSIONSI-T2D patients have a greater probability of stopping insulin after RYGB than after LAGB (62% vs. 34%, respectively, at 1 year), with weight-independent effects in the early months after surgery. These findings support RYGB as the procedure of choice for reversing I-T2D.