108 Iron Deficiency After Bariatric Surgery: The Impact of Inflammation and Weight Loss Across Procedure Types

Abstract Aim Iron deficiency is a common complication following bariatric surgery and may vary by procedure type. This study aims to evaluate how weight loss and inflammation influence post-operative iron status in patients undergoing Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Method This is Stage 2 of a two-phase retrospective cohort study at a national bariatric centre. Adults who underwent RYGB or SG between 2017 and 2022 were included (n = 384; SG = 201, RYGB = 183). Data collected included pre- and post-operative serum iron, ferritin, transferrin saturation, total iron-binding capacity (TIBC), C-reactive protein (CRP), weight loss, and iron supplementation status. Iron deficiency was defined as ferritin <30 µg/L or transferrin saturation <20%. Paired t-tests and Wilcoxon signed-rank tests will assess changes. Multivariate regression will evaluate the association between CRP reduction (≥10 mg/L vs <10 mg/L), weight loss, and post-operative iron status. Results Stage 1 of the study identified pre-operative iron deficiency in the patient cohort: 37.9% had low transferrin saturation, 15.5% had low serum iron, and 12.1% had low ferritin. Higher BMI (β = –0.206, p = 0.031) and elevated CRP (β = –0.320, p < 0.001) were significantly associated with iron deficiency. Stage 2 will examine how these parameters evolve post-operatively and compare outcomes between RYGB and SG. Conclusions This study will be among the first to assess how weight loss and inflammation resolution influence iron recovery after bariatric surgery. Findings may support procedure-specific supplementation protocols and personalised post-operative monitoring. Final results will be presented at the conference.