Unveiling Predictors of Hypoalbuminemia Following One Anastomosis Gastric Bypass (OAGB): A Retrospective Analysis

Introduction: Hypoalbuminemia is a potential postoperative complication of One-Anastomosis Gastric Bypass (OAGB). This study aimed to identify predictors of hypoalbuminemia and develop a clinical scoring system to stratify risk in OAGB patients. Methods: This retrospective study analyzed data from patients who underwent primary OAGB at a single academic MBS center over the past 8 years. Key demographic, clinical, and laboratory variables were compared between groups. Significant risk factors were identified and incorporated into a predictive model, which was evaluated for its discriminative ability using AUROC analysis. Results: Between the years 2017 and the year 2025, 3 763 patients who underwent OAGB at our academic center were assessed for this study and the patients classified into the Patients Without Hypoalbuminemia group and Patients with Hypoalbuminemia group). Risk factors for hypoalbuminemia included age ≥45 (OR: 2.10, p<0.01), creatinine ≥ 1.3 mg/dl (OR: 4.42, p=0.03), female sex (OR: 2.71, p=0.02), and biliopancreatic limb length adjusted for height ≥1 (OR: 3.22, p<0.01). The clinical prediction score showed an AUROC of 0.746 (95% CI: 0.703 - 0.790) with a sensitivity of 69% and specificity of 70% at the optimal cutoff. Kaplan-Meier survival analysis revealed significant differences in hypoalbuminemia-free survival between low-risk (score < 6) and high-risk (score ≥ 6) groups (p<0.001). Conclusion: Older age, female sex, severe obesity and higher biliopancreatic limb length adjusted for height ratio relative to stature independently predict hypoalbuminemia after OAGB. The score system stratifies risk and may guide intensified nutritional monitoring during the vulnerable early postoperative period.