Plasma amino acid concentrations during late rehabilitation in patients with traumatic brain injury.
OBJECTIVE
To investigate whether the basal plasma amino acid concentrations in patients with traumatic brain injury (TBI) have returned to levels found in healthy controls at about 17 months postinjury and to determine the effect of intake of a mixture of essential amino acids (EAA) on plasma amino acid concentrations in TBI versus healthy controls.


METHODS
Peripheral venous amino acid concentrations in subjects with TBI were compared with concentrations in healthy controls both at rest and for 1 hour after intake of 7g of EAA.


METHODS
Postacute brain injury rehabilitation center.


METHODS
Six men with TBI (age +/- standard deviation, 27+/-6y; months postinjury, 17+/-4) and 6 healthy men (age, 43+/-7y).


METHODS
Intake of a drink consisting of 7g of EAA.


METHODS
Individual and total plasma amino acid concentrations.


RESULTS
Total amino acid concentration was about 12% lower in TBI versus controls (P=.022). Valine was reduced by 33% in the TBI group versus controls (P=.003), whereas the other EAA did not differ between groups. After intake of the EAA drink, plasma non-EAA increased to a significantly higher level in controls versus TBI subjects (P=.017).


CONCLUSIONS
Plasma total amino acid concentration is still reduced 17 months postinjury in patients with TBI versus healthy controls, mainly because of a lower valine level. This may be of importance for both brain and muscle metabolic functions, and warrant further study. Further, ingested EAA are apparently not as readily converted to non-EAA in TBI patients as in healthy controls, suggesting that in recovery from TBI, certain non-EAA may become provisionally essential.
Børsheim
Elisabet
E
Department of Surgery, Metabolism Unit, Shriners Hospital for Children/UTMB, Galveston, TX 77550, USA. elborshe@utmb.edu
Bui
Quynh-Uyen T
QU
Wolfe
Robert R
RR
D000328:Adult; D000596:Amino Acids / Q000097:blood*; D000601:Amino Acids, Essential / Q000008:administration & dosage*; D001628:Beverages; D001930:Brain Injuries / Q000097:blood / Q000534:rehabilitation*; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012146:Rest / Q000502:physiology; D013997:Time Factors
D000596:Amino Acids; D000601:Amino Acids, Essential