Selenium deficiency is associated with disease severity, disrupted reward processing, and increased suicide risk in patients with Anorexia Nervosa.

BACKGROUND & AIMS: Patients with Anorexia Nervosa (AN) present many nutritional deficiencies (macro- and often also micro-nutrients), possibly explained by their inadequate food intake. Previous studies reported that selenium (Se) deficiency is common in the general population. As Se can be easily added as a supplement, the goal of this study was to evaluate the clinical impact of Se deficiency in patients with AN.

METHODS: This cross-sectional study concerned 153 patients with AN (92.9% women) followed at the Eating Disorder Unit of Lapeyronie Academic Hospital, Montpellier, France. Patients underwent an extensive neuropsychological assessment, and completed validated questionnaires. Blood samples were collected for Se quantification. Results were compared with the t-test, Mann-Whitney U, and Chi square tests, and univariate linear and multivariate logistic regression models.

RESULTS: Se plasma levels were below the cut-off of 80 µg/L in 53.6% (N = 82) of patients. AN onset was earlier in patients with Se deficiency, (p = .005), whereas disease duration was comparable between groups (p = .77). General eating disorder symptomatology in the past 28 days (Eating Disorder Examination Questionnaire) was more severe in patients with Se deficiency (p = .010). The suicide risk (MINI International Neuropsychiatric Evaluation) tended to be higher (p = .037), and suicide attempt history was more frequent (28.39% vs 9.85%, p = .004) in patients with low Se levels. Se plasma concentration was negatively correlated with the performance in the temporal delayed discounting task (p = .006).

CONCLUSIONS: Our findings suggest that in patients with AN, Se plasma concentration might be implicated in disease severity and suicide risk. The finding that Se deficiency in patients with AN was associated only with reward-related processes, but not with other psychological functions suggests the selective involvement of dopamine-related pathways. Our results suggest that it might be useful to monitor the plasma micronutrient profile in patients with AN. Future studies should determine whether Se supplementation in AN might improve clinical outcomes.