Plasma amino acids in anorexia nervosa

Abstract

Objective: To evaluate the amino acid pro®le 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. Design: Plasma amino acid concentrations of a random group of patients with anorexia nervosa compared with values obtained from a`healthy' adolescent population. Setting: The study was performed at the tertiary children's Hospital Sant Joan de De Âu. Subjects: Female adolescents (n 92, age: 15 AE 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. Interventions: 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 signi®cantly 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 signi®cantly 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 signi®cant 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 pro®le 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 de®cient concentrations for oxidative damage should be further evaluated.

Hyperlactatemia in human immunodeficiency virus-infected children receiving antiretroviral treatment

“…Only when this injury becomes chronic is an increase in ketone bodies and alanine observed, leading to intracellular fat accumulation and hyperalaninemia, respectively. 22,23 Physiologic variability and lack of specificity when determining LA concentrations are widely known problems in this procedure. 2,21 The optimal conditions required when obtaining venous blood samples and the concomitant determination of alanine values probably minimized false positive cases of pathologic hyperlactatemia in our study.…”

“…Analytical procedures and normal sex-and age-matched concentrations for both techniques have previously been validated in our laboratory and reported elsewhere. 21,22 Patients were initially defined as hyperlactatemic or nonhyperlactatemic. For the remaining laboratory variables, the mean of the consecutive measurements values throughout the study was used as a single value for each individual.…”

Cerebral folate deficiency and leukoencephalopathy caused by a mitochondrial DNA deletion

“…4,5 CSF 5-methyltetrahydrofolate (5-MTHF), 5-hydroxyindoleacetic, and homovanilic acids, and neopterin and biopterin concentrations were analyzed by high-performance liquid chromatography with electrochemical and fluorescence detection. 6,7 Histochemical studies of mitochondrial oxidative phosphorylation in muscle were performed with standard procedures.…”

Hyperlactatemia in Human Immunodeficiency Virus–Uninfected Infants Who Are Exposed to Antiretrovirals

“…Analytical procedures and normal gender-and age-matched concentrations for LA and alanine techniques were previously validated in our laboratory and have been reported elsewhere. 18,19 …”