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)

Glucose metabolism in advanced lung cancer patients.

Although it is generally accepted that altered nutrient intake and metabolism are responsible for the progressive loss of body weight observed in most advanced cancer patients, there is still considerable controversy regarding the contributory role of changes in both resting energy expenditure (REE) and glucose metabolism. Several studies suggest increases in both REE and glucose appearance in advanced cancer patients compared with healthy control subjects, whereas others revealed no changes in either metabolic parameter. We measured REE with indirect calorimetry and glucose kinetics with a primed constant infusion of D-[U-14C]glucose and D-[6-3H]glucose over the last 4 h of a 24-h fast in 32 advanced lung cancer patients immediately after diagnosis and before any chemotherapy or radiotherapy and in 19 healthy volunteer subjects. REE for the lung cancer group was not significantly different from that in the control group (1535.8 +/- 78.0 vs. 1670.2 +/- 53.9 kcal/day, respectively, p = 0.151). When REE was expressed as a function of body weight, or lean body mass, no differences between the two groups were observed. The rate of glucose appearance was 9.88 +/- 0.36 mumol.kg-1.min-1 in the cancer patients and 10.15 +/- 0.53 mumol.kg-1.min-1 in control subjects (p = 0.667), of which 50.4 versus 58.2%, respectively, was oxidized. The amount of glucose recycled was 13.54 +/- 1.22% in cancer patients and 15.08 +/- 0.99% in control subjects (p = 0.394). The amount of VCO2 from direct oxidation of glucose was 23.39 +/- 0.74% in cancer patients and 27.45 +/- 1.36% in control subjects (p = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)