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


METHODS
Seventeen adolescent girls with anorexia nervosa [body mass index (BMI; in kg/m2): 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 ethylmalonic acid (7.12 +/- 4.39 compared with 1.3 +/- 2.8 micromol/mmol creatinine; P < 0.001) and isovalerylglycine (7.65 +/- 4.78 compared with 3.8 +/- 0.9 micromol/mmol creatinine; P < 0.05) concentrations than did control subjects. Triiodothyronine concentrations were low and negatively correlated with plasma riboflavin concentrations (r = -0.69, 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.
Capo-chichi
C D
CD
Laboratoire de Pathologie Cellulaire et Moléculaire en Nutrition, Faculté de Médecine de Nancy, Vandoeuvre-les-Nancy, France.
Guéant
J L
JL
Lefebvre
E
E
Bennani
N
N
Lorentz
E
E
Vidailhet
C
C
Vidailhet
M
M
D015502:Absorptiometry, Photon; D000293:Adolescent; D000596:Amino Acids / Q000097:blood / Q000652:urine; D000856:Anorexia Nervosa / Q000097:blood* / Q000628:therapy; D002648:Child; D002851:Chromatography, High Pressure Liquid; D002149:Energy Intake; D005260:Female; D005415:Flavins / Q000097:blood; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D009752:Nutritional Status; D012016:Reference Values; D012256:Riboflavin / Q000097:blood* / Q000378:metabolism; D014284:Triiodothyronine / Q000097:blood*
D000596:Amino Acids; D005415:Flavins; D014284:Triiodothyronine; D012256:Riboflavin