S810 Redefining Success in Bariatric Surgery: Total Body Weight Loss Thresholds Predict Remission of Obesity-Related Medical Conditions

Introduction: Metabolic and bariatric surgery (MBS) is the most effective long-term treatment for severe obesity and leads to resolution of obesity-related medical conditions (ORMC) including type 2 diabetes (T2D), hypertension (HTN), hyperlipidemia (HLP), and obstructive sleep apnea (OSA). However, surgical success remains defined by arbitrary weight-based endpoints, such as total body weight loss (TBWL) >20% or body mass index (BMI) <30 kg/m², rather than remission of disease. The optimal degree of weight loss required to achieve ORMC resolution is not well established. Methods: We conducted a retrospective cohort study of adults who underwent primary sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), or biliopancreatic diversion with duodenal switch (BPD-DS) at a single academic center between 2008–2023. Patients were stratified by time-updated TBWL (<15%, 15–24%, ≥25%) and residual BMI (<30 vs ≥30 kg/m²). The primary outcome was ORMC remission, defined as off-treatment normalization of clinical parameters sustained at 2 visits ≥3 months apart. Multivariable Cox models estimated adjusted hazard ratios (aHRs) for remission by TBWL and BMI category, stratified by procedure. Results: Among 2,448 patients (mean age 48 ± 12 years; 78% women), median follow-up was 51 months. Achieving ≥25% TBWL was significantly associated with higher remission rates for T2D (aHR 1.43; 95% confidence interval [CI] 1.04–1.96), HTN (aHR 2.43; 1.70–3.47), HLP (aHR 2.42; 1.53–3.82), and OSA (aHR 2.40; 1.75–3.28) compared to <15% TBWL. Intermediate TBWL (15–24%) was also associated with improved remission for HTN and OSA but not for T2D or HLP. In contrast, a BMI <30 kg/m² was not significantly associated with T2D remission and performed inconsistently across other endpoints. Procedure-specific models showed the strongest TBWL-remission gradients after SG, though TBWL remained predictive across all procedures. Conclusion: In this large cohort, TBWL emerged as the most clinically meaningful predictor of ORMC remission following bariatric surgery. Achieving ≥25% TBWL was associated with significantly greater resolution of T2D, HTN, HLP, and OSA, while even 15–24% TBWL conferred benefits for select conditions. These findings support using TBWL-based thresholds, rather than universal BMI targets, to guide postoperative goals, better align surgical success with metabolic outcomes, and inform individualized care.