“Serum ferritin – a nutritional marker for Anorexia Nervosa?”

Abstract

Introduction: A new marker that correlates with nutritional recovery in Anorexia Nervosa would be of great value. Our study aimed to analyse the influence of Body Mass Index variations on serum ferritin levels in adolescents with Anorexia Nervosa followed up in a specialised consultation. Methods: We conducted a retrospective, observational, single-centre study in adolescents with Anorexia Nervosa evaluated between 2011 and 2019. Serum ferritin values ​​at baseline and during follow-up were analysed, together with the corresponding Body Mass Index (BMI) and Z-Score values. Further analytical data such as hematological and inflammatory markers were recorded. Results: The study included 53 adolescents with Anorexia Nervosa. Patients were found to have higher initial serum ferritin levels compared to the last, under treatment, assessed values (p<0.001). There was a significant increase in BMI and BMI Z-Score during follow-up (p<0.001), reflecting nutritional recovery. Analysing the variation of these values, we found a negative linear association between the variation of serum ferritin and the variation of BMI Z-Score (ß -0.1; R2 0,39; p<0,001). In analysing the change of BMI Z-Score and serum ferritin as a function of time, a linear regression model was used (ß -0,39; R2 0,12; p <0,001), showing that the quicker the recovery of BMI Z-Score, the faster the decrease in ferritin value. None of the patients presented anaemia, and in most cases, the other inflammatory markers remained normal. Conclusion: Serum ferritin could be of value in the evaluation of patients with Anorexia Nervosa in the absence of other diseases, in particular when other markers of malnutrition are normal.