Age-related differences in the metabolic response to injury.
OBJECTIVE
To investigate the effect of age on the metabolic response to injury.


METHODS
Fifty-two trauma patients meeting entrance criteria were prospectively enrolled. Patients were grouped by age: elderly, >60 years; and young, < or =60 years. After 4 days of nutrition support, physiologic and laboratory data were collected. Energy and nitrogen metabolism, and body composition were evaluated.


RESULTS
Elderly patients demonstrated a reduced incidence of fever (48% vs. 77%,p = 0.027). Independent of body composition, temperature, and injury severity, oxygen consumption was 8% lower in the elderly (p = 0.0032). However, nitrogen loss and myofibrillar catabolic rate was not altered by age. Elderly subjects were more often hyperglycemic (38% vs. 0%, p < 0.0001) and azotemic (62% vs. 22%, p = 0.004), despite similar carbohydrate and protein intake.


CONCLUSIONS
Fever is less common and oxygen consumption lower in elderly trauma patients. Postinjury myofibrillar protein catabolism and nitrogen loss are not influenced by aging. Metabolic complications of nutrition support (hyperglycemia, azotemia) are more common in elderly trauma patients.
Frankenfield
D
D
Department of Clinical Nutrition, Milton S. Hershey Medical Center, Hershey, PA 17033, USA.
Cooney
R N
RN
Smith
J S
JS
Rowe
W A
WA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D001823:Body Composition; D004040:Dietary Carbohydrates / Q000378:metabolism; D004044:Dietary Proteins / Q000378:metabolism; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D006943:Hyperglycemia / Q000209:etiology; D015994:Incidence; D007249:Inflammation; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000150:complications / Q000276:immunology / Q000378:metabolism* / Q000628:therapy; D018529:Nutritional Support; D010101:Oxygen Consumption; D011446:Prospective Studies; D014511:Uremia / Q000209:etiology
D004040:Dietary Carbohydrates; D004044:Dietary Proteins