Riboflavin and riboflavin-derived cofactors in adolescent girls with anorexia nervosa

Abstract

Background: Thyroid hormones, riboflavin, riboflavin cofactors, and organic acids were assessed in girls with anorexia nervosa. Objective: The objective was to examine the effect of malnutrition and low thyroid hormone concentrations on erythrocyte and plasma riboflavin metabolism and their relation with urinary organic acid excretion. Design: Seventeen adolescent girls with anorexia nervosa [body mass index (BMI; in kg/m 2 ): 14.8 ± 2.2] and 17 age-matched, healthy girls (control subjects; BMI: 20.5 ± 2.2) took part in the feeding study. Erythrocyte and plasma riboflavin as well as riboflavin cofactors (flavin mononucleotide and flavin adenine dinucleotide) were assessed by HPLC, whereas urinary organic acids were assessed by gas chromatography-mass spectrometry. Results: Anorectic patients who began a feeding program had higher erythrocyte riboflavin (3.5 ± 2.2 compared with < 0.1 nmol/mol hemoglobin; P < 0.001), lower plasma flavin adenine dinucleotide (57.8 ± 18.5 compared with 78.5 ± 54.3 nmol/L; P < 0.05), and higher urinary ethymalonic acid (7.12 ± 4.39 compared with 1.3 ± 2.8 mol/mmol creatinine; P < 0.001) and isovalerylglycine (7.65 ± 4.78 compared with 3.8 ± 0.9 mol/mmol creatinine; P < 0.05) concentrations than did control subjects. Triiodothyronine concentrations were low and negatively correlated with plasma riboflavin concentrations (r = Ϫ0.69, P < 0.01). Not all patients showed improvements in these biochemical indexes after 30 d of refeeding. Conclusions: The low triiodothyronine concentrations observed in anorexia nervosa could alter the extent of riboflavin conversion into cofactors, thus leading to high erythrocyte riboflavin concentrations, low plasma flavin adenine dinucleotide concentrations, and high rates of ethylmalonic acid and isovalerylglycine excretion.Am J Clin Nutr 1999;69:672-8.

Revisión del tratamiento dietético-nutricional de la anorexia nerviosa

“…En relación con los déficits de tiamina se han recogido complicaciones como el síndrome de Wernicke 61 . Con respecto a otros micronutrientes hay resultados dispares, que no permiten establecer pautas generales 62,63 .…”

Micronutrient Deficiencies and Supplementation in Anorexia and Bulimia Nervosa

“…Research on riboflavin in adolescent girls with anorexia has shown some evidence of deficiency, but it is unclear if this finding is a result of inadequate intake or ineffective metabolism resulting from low levels of thyroid hormone. 31,34 Oral contraceptives have been linked to low riboflavin levels. No recommendation is available beyond supplementation at the RDA for patients with generally poor nutrition.…”

Prise en charge nutritionnelle des troubles du comportement alimentaire chez l'adolescent

“…Le corticoreleasing-factor (CRF, qui a des propriétés anorexigènes) est augmenté de même que la cortisolémie. La fonction thyroï-dienne est perturbée avec baisse de l'hormone active, la T3, qui constitue un élément de l'adaptation à la dénutrition [27,29]. L'IGF1 est abaissée alors que la sécrétion de GH est augmentée montrant un état de résistance à la GH.…”

“…Le suivi de l'ostéocalcine sérique est un bon index de l'anabolisme osseux [42]. Parmi les vitamines, il n'y a pas de déficit en vitamines liposolubles en particulier en vitamine D. Seules les vitamines C et B1 [21,22] peuvent être déficitaires, certains déficits vitaminiques pouvant être plus apparents que réels comme nous l'avons montré pour la riboflavine [29].…”