The role of diabetes severity scores in predicting disease remission in patients with BMI > 50 kg/m² undergoing Roux-En-Y gastric bypass and sleeve gastrectomy: a multi-centered study

Background: Roux-En-Y gastric bypass (RYGB) and Sleeve Gastrectomy (SG) have shown to be two of the most effective interventions to enhance weight loss and associated type-2 diabetes mellitus (T2DM) remission. However, a significant number of patients, particularly with BMI ≥ 50 kg/m², do not achieve T2DM remission after bariatric surgeries. The individualized metabolic surgery (IMS) and Robert et al. scores are two scores that characterize T2DM severity and predict disease remission after bariatric surgeries. We aim to assess the validity of these scores in predicting T2DM remission in our cohort of patients with BMI ≥ 50 kg/m² with long-term follow-up. Methods: This is a retrospective cohort study of all patients with T2DM, have a BMI ≥ 50 kg/m², and underwent RYGB or SG in two different US bariatric surgery centers of excellence. The study endpoints included validating the IMS and Robert et al. scores in our cohort and evaluating the presence of any significant differences between RYGB and SG in terms of T2DM remission predicted by each of these scores. Data are presented as mean (standard deviation). Results: A total of 160 patients (66.3% females, mean age 51.0 [11.8] years) had IMS score and 238 patients (66.4% females, age 50.8 [11.4] years) had Robert et al. score data. Both scores predicted T2DM remission in our patients with BMI ≥ 50 kg/m² with ROC AUC 0.79 for the IMS score and 0.83 for Robert et al. score. Patients with lower IMS scores and higher Robert et al. scores had higher T2DM remission rates. RYGB and SG had similar T2DM remission rates over the long-term follow-up. Conclusion: We demonstrate the ability of the IMS and Robert et al. scores to predict T2DM remission in patients with BMI ≥ 50 kg/m². T2DM remission was shown to decrease with more severe IMS scores and lower Robert et al. scores.