Effects of two energy: nitrogen ratios in patients with gastroenterological disease and malnutrition.

In 10 patients with active gastroenterological disease and protein-malnutrition (weight: 77.3 +/- 2.6 (mean +/- SEM) percent of ideal body weight, serum-albumin levels: 2.59 +/- 0.17 mg/100 ml) a randomized crossover study was performed to assess the effects of two energy:nitrogen ratios on body cell replenishment. After at least 3 days for equilibration, the total parenteral nutrition (TPN) study carried out with 354 +/- 5 mg of casein hydrolysate-nitrogen/kg/day, divided in two 7-day periods during which two nonprotein calorie supplies of 47 +/- 1 kcal/kg/day and 81 +/- 4 kcal/kg/day were given. The same 50 +/- 5% dextrose and fat emulsion energy sources were used in the two periods. Nitrogen (Kjeldahl method) and potassium retention, and weight and serum albumin concentration gains were all significantly better (Student t test) during the hypercaloric regimen than during the normocaloric regimen. In the 10 patients, the protein-sparing effect of nonprotein calories "added" during the hypercaloric regimen was demonstrated and represented 17% of the constant infused nitrogen. The more catabolic patient was prior to TPN, the more energy-dependent was the protein-sparing effect observed (r = +0.638). Preliminary data obtained with 3-methylhistidine urine determination suggests that the protein-sparing effect of "added" calories was due to an increased protein synthesis. Finally, body cell replenishment was better with the higher 230 +/- 6 energy:nitrogen ratio than with the lower 132 +/- 4 energy:nitrogen ratio, which suggests that the hypercaloric TPN regimen was useful in such patients.