Effect of major trauma on plasma free amino acid concentrations in geriatric patients

Aging is associated with a variety of metabolic changes, including loss of protein from muscles. The rate of protein synthesis decreases, and this may be related to the availability of amino acids, which are the building blocks of which proteins are made. Elderly people recover less easily from major trauma, and this loss in capacity to respond to injury may be related to disturbed protein metabolism. The relationship between availability of amino acids in the blood stream and the early metabolic reactions to major trauma in 9 geriatric (aged 61 to 81) and 13 young (aged 20 to 38) patients was studied. These trauma patients were also compared with healthy controls; eight controls were elderly and 10 were young. Older controls had reduced levels of total amino acids and of certain specific amino acids. Such declines were less obvious in traumatized elderly patients because they were compared with young trauma patients, who experienced even greater declines in certain amino acid levels in response to trauma. Geriatric patients had specific declines of the amino acids arginine and methionine, while ornithine and citrulline increased. The results suggest that geriatric trauma patients would be aided by balanced amino acid supplementation, which would enable optimum synthesis of new proteins by the body in response to trauma. (Consumer Summary produced by Reliance Medical Information, Inc.)