256 A Little Heavy Metal: Exploring the Utility of Copper as a Marker of Liver Function in Bariatric Patients

Abstract Aim Obesity is a major global health issue, with half of UK adults projected to be obese by 2050. This rise is closely linked to obesity-related co-morbidities, including metabolic dysfunction-associated fatty liver disease (MAFLD). Bariatric surgery is increasingly used for severe obesity, though MAFLD may increase peri-operative risk. Current non-invasive assessments of hepatic status lack sensitivity, creating interest in novel biomarkers. Copper, an essential trace element involved in cellular metabolism, has been implicated in MAFLD pathogenesis, though its clinical utility remains unclear. Method This retrospective cohort study investigated associations between serum copper, hepatic biochemistry, and weight loss in bariatric patients. Forty patients were included, with data collected pre-operatively and at 1 and 2 years post-surgery. Median age was 43.5 years and median BMI was 46 kg/m²; 80% were female. 10 underwent sleeve gastrectomy and 30 Roux-en-Y gastric bypass. Results Preoperative copper correlated positively with alkaline phosphatase (ρ = 0.47, p = 0.002) and negatively with bilirubin (ρ = –0.36, p = 0.024) and ALT (ρ = –0.60, p = 0.715). Serum copper levels increased significantly at 1 year (z = 4.019, p < .001) and 2 years (z = 5.262, p < .001). Median weight loss was 31.4% and 28.1% at 1 and 2 years, respectively. Copper change correlated with weight loss at 2 years (ρ = 0.335, p = 0.035), but not at 1 year (ρ = 0.058, p = 0.721). Conclusions Copper demonstrates associations with hepatic markers and long-term weight loss, supporting its potential as a non-invasive biomarker in MAFLD.