Protein and energy balance following femoral neck fracture in geriatric patients.
To elucidate the effect of total peripheral parenteral nutrition (TPPN) on protein kinetics following injury, we compared the whole-body leucine kinetic response using a primed-constant infusion of L-[1-14C]leucine in 33 elderly patients (aged 82 +/- 1.0 years) following hip fracture and 33 healthy elderly control subjects (aged 75 +/- 0.7 years). Following a 36-hour fast, leucine release from protein breakdown was 1.2 +/- 0.10 mumol.kg-1.min-1 and leucine incorporation into protein was 0.94 +/- 0.095 mumol.kg-1.min-1 in control subjects, and in injured subjects leucine release from protein breakdown was 1.3 +/- 0.14 mumol.kg-1.min-1 and leucine incorporation into protein was 0.97 +/- 0.092 mumol.kg-1.min-1. Control and injured subjects were then administered TPPN (protein, 1.5 g amino acids.kg-1; carbohydrate, 10.0 kcal.kg-1; lipid, 15.0 kcal.kg-1) for 24 hours, and leucine kinetics were redetermined. Compared with protein kinetics in the fasting state, leucine release from protein decreased to 1.0 +/- 0.14 mumol.kg-1.min-1 and leucine incorporation into protein increased to 1.16 +/- 0.097 mumol.kg-1.min-1 in control subjects. Injured patients also responded to TPPN with a decrease in leucine release from protein breakdown (1.12 +/- 0.156 mumol.kg-1.min-1) and an increase in leucine incorporation into protein (1.29 +/- 0.164 mumol.kg-1.min-1). These results indicate that in a geriatric population, whole-body leucine kinetics following hip fracture and the anabolic response to TPPN are not significantly altered from those of uninjured subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Nelson
K M
KM
Department of Research, Baptist Medical Centers, Birmingham, AL.
Richards
E W
EW
Long
C L
CL
Martin
K R
KR
Geiger
J W
JW
Brooks
S W
SW
Gandy
R E
RE
Blakemore
W S
WS
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D001769:Blood / Q000378:metabolism; D004734:Energy Metabolism; D005260:Female; D005272:Femur Neck / Q000293:injuries*; D006620:Hip Fractures / Q000378:metabolism*; D006801:Humans; D007930:Leucine / Q000493:pharmacokinetics*; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D010289:Parenteral Nutrition, Total; D012016:Reference Values
D007930:Leucine; D009584:Nitrogen