Changes in muscle and plasma amino acid metabolism in severe malnutrition — The influence of total parenteral nutrition

The concentrations of free amino acids in muscle and plasma were determined in nine female patients with severe anorexia nervosa before and after 3 to 5 weeks of total parenteral nutrition (TPN). The patients had lost 25 to 42% of their pre-morbid weight. During TPN their weight gain was around 2.5 kg/week. Initially total non-essential amino acids (NEAA) in muscle were decreased 30% compared to controls. The major part of this depletion was due to a 40% reduction in glutamine. After TPN the level of glutamine normalized. Alanine, being normal before TPN, decreased after TPN. Proline and several other non-essential amino acids in muscle were decreased before and after TPN. Total essential amino acids (EAA) in muscle were initially normal and were not significantly affected by TPN. Total NEAA in plasma were decreased at admission and normalized after TPN. Total EAA in plasma, however, were normal both before and after TPN. This study demonstrates that severely malnourished patients with anorexia nervosa have changes in amino acid patterns in both muscle and plasma. These changes were largely, though not completely, reversed after 3 to 5 weeks of TPN.