Metabolic response to total parenteral nutrition in cancer patients

In order to evaluate the metabolic response of nutritionally deprived cancer patients to parenteral nutrition, metabolic parameters including glucose turnover, oxidation, and Cori cycle activity were measured in eight patients before and during short-term (5 to 10 days) i.v. nutrition, with solutions containing amino acids and hypertonic glucose. Before parenteral nutrition, five patients had essentially normal glucose turnover, oxidation, and Cori cycle activity, whereas three patients had moderately increased glucose turnover and markedly increased Cori cycle activity. In response to parenteral nutrition, plasma glucose, insulin, and venous lactate concentration increased and free fatty acid decreased. The percentage of respiratory CO2 from glucose oxidation and the rate of oxidation increased. CO2 production increased, whereas O2 consumption was essentially unchanged. Respiratory quotient rose to greater than 1.0. Endogenous glucose production and high basal Cori cycle activity were decreased. Total parenteral nutrition was judged clinically beneficial in five patients, whereas one patient was unchanged. Deleterious responses, including moderate lactic acidemia, occurred in two of three patients with elevated basal Cori cycle activity.