P796 - THE PARADOX OF HYPERCOBALAMINEMIA IN ANOREXIA NERVOSA: INDICATOR OF CLINICAL AND METABOLIC SEVERITY OR SIMPLE ANOMALY: A RETROSPECTIVE STUDY

P796

THE PARADOX OF HYPERCOBALAMINEMIA IN ANOREXIA NERVOSA: INDICATOR OF CLINICAL AND METABOLIC SEVERITY OR SIMPLE ANOMALY: A RETROSPECTIVE STUDY

D. Belcastro^1,*, L. Mendolicchio², E. Apicella ³, S. Colosimo⁴, S. Savino², G. Lezzi², L. Rinaldi¹, A. Genovesi⁵

¹Department of Psychiatry, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, L.go Agostino Gemelli 8, 00168 , Rome, ²U.O. dei Disturbi del Comportamento Alimentare, Istituto Auxologico Italiano IRCCS, Ospedale San Giuseppe, 28824 Piancavallo, ³U.O. dei Disturbi del Comportamento Alimentare, Istituto Auxologico Italiano IRCCS, ⁴Department of Nutrition, Istituto Auxologico Italiano IRCCS, Ospedale San Giuseppe, 28824 Piancavallo, Verbania , ⁵Department of Nutrition, Doctorate School of Nutrition Science, University of Milan, 20122 Milan, Milan, Italy

Rationale: Anorexia nervosa (AN) is a disorder characterized by severe malnutrition with a high mortality rate. Paradoxically, some patients with AN show elevated levels of vitamin B12 (hypercobalaminemia) despite malnutrition. This study aims to evaluate the prevalence of hypercobalaminemia in AN and its correlations with clinical and biochemical.

Methods: Retrospective observational study on 266 patients with AN (DSM-5) admitted to the Istituto Auxologico Italiano (2022-2024). Anthropometric and biochemical (vitamin B12, folate, liver enzymes) data were collected. Patients were divided into groups with normal or elevated vitamin B12 levels (>775 ng/L). Statistical analysis included parametric and non-parametric tests and correlation analysis.

Results: 44.1% of patients showed hypercobalaminemia. A significant negative correlation was observed between vitamin B12 levels and BMI (r=-0.31, p<0.001) and positive with liver transaminases (AST: r=0.28, ALT: r=0.26, p<0.001). The prevalence of hypercobalaminemia was significantly higher in the purging type compared to the restrictive type (47.3% vs 39.3%, p=0.028), with significant correlations also with folate, ferritin, and components of body composition.

Conclusion: Hypercobalaminemia is a common phenomenon in AN, more frequent in cases of severe malnutrition and in the purging subtype. The correlation with liver alterations suggests that hypercobalaminemia could be due to hepatocellular damage caused by malnutrition. This biochemical parameter could represent a marker of clinical severity useful for risk stratification and treatment personalization in patients with AN.

Disclosure of Interest: None declared