Plasma amino acid concentrations in elderly patients with protein energy malnutrition.

OBJECTIVE to compare amino acid concentrations in healthy and malnourished elderly patients. METHOD plasma amino acid concentrations were examined in 24 men and women (80-100 years of age) with protein energy malnutrition (PEM) and compared with those of 44 healthy, similarly-aged controls. Plasma samples were determined by using cation exchange columns with ninhydrin detection in an high performance liquid chromatography system. RESULTS essential amino acid and non-essential amino acid plasma concentrations were significantly decreased in PEM (0.01 < P < 0.0001). Branched-chain amino acids and urea cycle amino acid plasma concentrations fell significantly (P < 0.0001). Plasma concentrations of alanine and glutamic acid + glutamine were also significantly reduced (P < 0.0001). CONCLUSIONS in underweight elderly patients, the plasma amino acid pattern reflects the severity of the metabolic disturbance.