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.