Plasma and erythrocyte amino acid concentrations in anorexia nervosa.

Plasma and erythrocyte amino acid concentrations in seven female patients in the acute stage of anorexia nervosa were compared with values in the same subjects after refeeding, and with normal controls. We also compared these values with literature values from patients with protein-calorie malnutrition and prolonged starvation in an attempt to identify a biological indicator of severity and prognosis. Our data indicate: (1) Routine laboratory analyses that reflect protein status do not differentiate normal subjects from patients with anorexia nervosa. (2) The plasma aminogram in the acute stage of anorexia nervosa differs from normal, and differs from values reported for both protein malnutrition and prolonged starvation. (3) The Whitehead ratio clearly separates the acutely ill anorectic state from the treated state and from normal controls. (4) Both erythrocyte and plasma amino acid concentrations differ from normal in anorexia nervosa, but changes in erythrocyte concentrations are more obvious. (5) Erythrocyte glycine concentrations are unique, in that values were persistently elevated at all stages of illness in anorexia nervosa. (6) Erythrocyte-to-plasma amino acid ratios do not provide a biological index of severity and prognosis for patients with anorexia nervosa, in contrast to data reported for individuals with protein malnutrition.