Metabolic response of whole body and peripheral tissues to enteral nutrition in weight-losing cancer and noncancer patients.

This study evaluated whether or not the efficiency of utilizing energy substrates and nitrogen differs among cancer and control patients during enteral feeding. Oxygen uptake and glucose, lipid, and amino acid metabolism across the leg were measured in cancer patients who had lost approximately 18% of their body weight and were compared with that of patients without cancer with similar body-weight loss. Metabolic balances across the leg were evaluated relative to food intake, energy expenditure, energy balance, nitrogen balance, and urinary excretion of urea, creatinine, adrenaline, and noradrenaline. All measurements were performed twice in each patient: first in the fasted state and second during nutrition after 14 days of a controlled enteral infusion of a formula diet of 35 kcal/kg . day. Quantitative measurements of metabolism across the leg before and after 14 days of enteral nutrition were compared with changes in nutritional status. Whole body utilization of energy and of nitrogen were not significantly different among cancer patients and controls, whereas the simultaneously measured net balances of glycerol and free fatty acids across the leg of cancer patients were statistically significantly more negative during the constant infusion of the formula diet. The results in this study emphasize that malnourished cancer patients are quite comparable with patients with benign malnutrition in terms of whole body and peripheral metabolism both before and in the response to enteral feeding.