Durability of Type 2 Diabetes Remission After Bariatric Surgery: Predictors of Sustained Remission and Glycemic Relapse at Five Years in a Retrospective Single-Center Study.

BACKGROUND: Metabolic bariatric surgery (MBS) is one of the most effective treatments for obesity and type 2 diabetes mellitus (T2DM). Although high rates of diabetes remission have been reported, the durability of remission and the factors associated with glycemic relapse remain incompletely understood. OBJECTIVE: To evaluate the rates of sustained T2DM remission and glycemic relapse after metabolic bariatric surgery and to identify factors associated with both outcomes. METHODS: A retrospective cohort study was conducted including 151 patients with obesity and T2DM who underwent bariatric surgery. Partial, complete, and prolonged remission were defined according to established consensus criteria. Sustained remission was defined as the presence of remission at 5 years after surgery. Glycemic relapse was evaluated among patients who achieved remission during follow-up. Bivariate analyses and multivariable logistic regression for sustained remission and Cox proportional hazards regression for glycemic relapse were performed to identify factors associated with these outcomes. RESULTS: During follow-up, 120 patients (79.5%) achieved diabetes remission. At 5 years, 91 patients (60.3%) maintained remission, including 60 cases of complete remission and 31 cases of partial remission; prolonged remission was observed in 50 patients. In multivariable analysis, shorter diabetes duration (aOR 0.980 per month, 95% CI 0.969-0.992; p < 0.001), lower preoperative HbA1c (aOR 0.671 per 1% increase, 95% CI 0.520-0.866; p = 0.002), and higher preoperative BMI (aOR 1.120 per kg/m2, 95% CI 1.030-1.218; p = 0.008) were independently associated with sustained remission. Among patients who achieved remission, 27 (22.5%) experienced glycemic relapse. Most relapses occurred between the fourth and fifth postoperative years. Longer diabetes duration (aHR 1.015 per month, 95% CI 1.006-1.024; p = 0.001) and higher preoperative HbA1c levels (aHR 1.283 per 1% increase, 95% CI 1.050-1.567; p = 0.015) were independently associated with increased relapse risk, whereas greater %EWL at 1 year was independently associated with a lower risk of relapse (aHR 0.754 per 10-percentage-point increase, 95% CI 0.621-0.917; p = 0.005). CONCLUSIONS: Metabolic bariatric surgery achieved high rates of sustained T2DM remission in this cohort. Shorter diabetes duration and better preoperative glycemic control were associated with both a greater likelihood of sustained remission and a lower risk of glycemic relapse. These findings underscore the relevance of diabetes duration and preoperative glycemic status in long-term metabolic outcomes and the need for continued postoperative metabolic follow-up in patients with T2DM undergoing bariatric surgery.