[Metabolism under total parenteral nutrition: the influence of different compositions of energy substrate]

Metabolism under total parenteral nutrition according to different compositions of energy substrate was studied using expiratory gas analysis in preoperative and postoperative esophageal cancer patients. The patients were derived from Group G (only glucose was administrated as a non-protein energy source) and group G+F (glucose and fat were administrated as non-protein energy sources). In the preoperative study, there was a significantly positive correlation between non-protein RQ and the energy sufficiency ratio (energy intake/BEE) and non-protein RQ in group G+F was lower than in group G at the same total energy intake. It was revealed that there was a limit to oxidation of exogenous glucose and whether exogenous energy sources are efficiently utilized or not depends on two factors, namely total energy intake and the combination of glucose and fat. In the postoperative study, fat was efficiently utilized in group G+F and glycogen recycling was dominant over fat recycling. Urinary epinephrine, 17-OHCS and 17-KS excretion were significantly high in group G+F. It was clear that energy metabolism and hormonal effect differ with exogenous energy substrate.