Objective: Cachexia and weight loss are frequently seen in cancer patients. We investigated lipid metabolism to elucidate a metabolic basis for adequate nutrition of cancer patients.
Design: Lipid metabolism was assessed by indirect calorimetry and triglyceride clearance rates after randomised injection of a lipid bolus (long-chain triglycerides (LCT) or medium-chain triglycerides (MCT) during an euglycemic clamp protocol in cancer patients.
Setting: Rudolf-Virchow Krankenhaus, Berlin, Germany.
Subjects: Eighteen patients were included. Twelve patients had upper gastrointestinal cancer: a weight stable cancer group (Caws, n = 6) with a body mass index (BMI) of 22.9 +/- 1.7 kg/m2 and a weight losing cancer group (Cawl, n = 6) with a mean weight loss of 7.4 +/- 3.1 kg or 11% of the initial body weight during the previous three months (present BMI 21.8 +/- 0.8 kg/m2). The data were compared with six control patients with benign gastrointestinal diseases (BMI = 25.0 +/- 0.8 kg/m2).
Main outcome: Cancer patients had an increased basal lipid oxidation rate that was more pronounced in Cawl (+92% vs +42% in Caws; P < 0.01 and 0.05 vs controls, respectively). Utilisation of LCT was increased in cancer patients, this was most pronounced in Cawl (+150 vs +65% in Caws; P < 0.01 and 0.05, respectively). Metabolically, there were no differences in the utilisation of LCT and MCT/LCT containing lipid emulsions.
Conclusions: Cancer patients have an increased lipid oxidation and an enhanced utilisation of exogeneous lipids. This is most pronounced in Cawl. To prevent further weight loss or to increase body weight, they should increase their fat intake. In contrast, fat-reduced or prudent diets seem to be inadequate for the nutrition of cancer patients.