Plasma amino acids in anorexia nervosa.
OBJECTIVE
To evaluate the amino acid profile in a group of adolescents with anorexia nervosa, and to apply alternative ways of presenting and assessing results, so as to increase the information available for understanding the metabolic abnormalities developed in these patients.


METHODS
Plasma amino acid concentrations of a random group of patients with anorexia nervosa compared with values obtained from a 'healthy' adolescent population.


METHODS
The study was performed at the tertiary children's Hospital Sant Joan de Deu.


METHODS
Female adolescents (n = 92, age: 15+/-1.8 y) at diagnosis of anorexia nervosa. Reference values for amino acids were obtained from apparently healthy adolescents (by history and analytical data) who underwent presurgical analysis for minor operations.


METHODS
Plasma amino acid concentrations were measured by ion exchange chromatography. Basic laboratory analysis, carnitine and IGF-I were also determined.


RESULTS
In anorexic patients plasma concentrations of taurine, asparagine, glutamine, glycine, methionine, phenylalanine, ornithine, and histidine were significantly higher than reference values (Mann-Whitney, P < 0.01-0.0001), whereas arginine and cystine were lower than our reference values (P < 0.0001). Relative amino acid values (the molar fraction of the patient medians relative to control medians) were plotted. The ratios of some amino acids were significantly greater than those obtained from the reference population: Phe/Tyr (P < 0.001), Met/Cys (P < 0.0001), and Gly/Val (P < 0.01).


CONCLUSIONS
A trend to hyperaminoacidemia is a common feature in anorexia nervosa. Although absolute amino acid values cannot play a significant role in the assessment of nutritional status in this condition, the calculation of some ratios (Phe/Tyr, Met/Cys and Gly/Val) and the graphical representation of relative values may be useful. The plasma amino acid profile in anorexia nervosa is different from those of other severe malnutrition states, showing a marasmic pattern of balanced protein-energy undernutrition. Cystine and arginine may be considered limiting amino acids in this disease, and the consequences of their deficient concentrations for oxidative damage should be further evaluated.
Serveis de Bioquímica Hospital Universitari Sant Joan de Déu, Barcelona, Spain.
D
D
Moyano
M A
MA
Vilaseca
R
R
Artuch
N
N
Lambruschini
D000293:Adolescent; D000596:Amino Acids / Q000097:blood*; D000856:Anorexia Nervosa / Q000097:blood*; D002331:Carnitine / Q000097:blood; D002852:Chromatography, Ion Exchange; D003545:Cysteine / Q000097:blood; D005260:Female; D005998:Glycine / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008715:Methionine / Q000097:blood; D010649:Phenylalanine / Q000097:blood; D012016:Reference Values; D014443:Tyrosine / Q000097:blood; D014633:Valine / Q000097:blood
D000596:Amino Acids; D014443:Tyrosine; D010649:Phenylalanine; D007334:Insulin-Like Growth Factor I; D008715:Methionine; D014633:Valine; D003545:Cysteine; D002331:Carnitine; D005998:Glycine