Energy and tissue metabolism in patients with cancer during nutritional support.

The present study evaluates the energy and skeletal muscle metabolism in malnourished patients, with and without cancer, in response to nutrition. The energy balance was positive in all patients receiving nutritional support. This led to an increase in body weight and body potassium levels. Glucose turnover increased in all patients. In patients with cancer, elevated glucose turnover reflected increased utilization of glucose preferentially for synthetic pathways rather than for oxidation. Protein synthesis and RNA content in skeletal muscles increased during nutrition. Nutritional support improved energy balance and protein synthesis capacity in skeletal muscles in patients with cancer to the same extent as in malnourished patients without cancer. Malignant cachexia seems to be a consequence of a relative lack of energy and not of impaired energy utilization in host tissues, at least early in the disease.