Metabolic changes in elderly cancer patients after glucose ingestion

Abstract

load. Furthermore, the role of tumor necrosis factor-a (TNF-a) on cancer-induced metabolic changes is still a neglected area. Michele Varricchio, M.D. METHODS. In 25 cancer patients and 16 healthy subjects matched with regard to Department of Geriatric Medicine and Metabolic age, body mass index, and fat-free mass, indirect calorimetry was made before Diseases, II University of Naples, Naples, Italy. and after administration of a glucose load (75 g per subject, administered orally). RESULTS. Cancer patients had fasting plasma concentrations of insulin (74 { 3.3 vs. 67 { 4.1 pmol/L; P õ 0.05), lactate (0.68 { 0.11 vs. 0.41 { 0.1 mmol/L; P õ 0.05), free fatty acids (884 { 121 vs. 342 { 76 mmol/mL; P õ 0.001), and TNF-a (1.23 { 0.31 vs. 0.45 { 0.11 ng/mL; P õ 0.01) greater than controls, whereas plasma glucose concentrations (4.8 { 0.5 vs. 5.1 { 0.3 mmol/L; P Å not significant) were not different from controls. Indirect calorimetry at baseline demonstrated that basal metabolic rate, fat oxidation, and protein oxidation were significantly greater in cancer patients than in controls. After administration of the glucose load, carbohydrate oxidation progressively rose in both cancer patients and controls, with no differences between the two groups, whereas glucose uptake (59.3 { 3.8 vs. 69.1 { 3.6 g/kg fat-free mass [FFM] 1 240 minutes; P õ 0.01) and storage (49.1 { 4.1 vs. 60.2 { 3.3 g/kg FFM 1 240 minutes; P õ 0.05) were markedly reduced in cancer patients as compared with controls. Finally, glucose-induced thermogenesis (GIT) was lower in cancer patients than in controls. CONCLUSIONS. This study demonstrated that GIT is lower in cancer patients than in healthy subjects matched with regard to age and body mass index. An overacti-vity of the glucose fatty acid cycle is responsible for such results. Plasma concentrations of TNF-a might play a modulating role in the metabolic changes that occur after administration of a glucose load. The role of TNF-a on glucose and lipid metabolism in cancer patients would be a worthy subject of future investigations. high carbohydrate diet is frequently used to avoid weight loss in cancer patients; nevertheless, whether glucose administration has Diseases, Servizio di Astanteria Medica, Piazza a positive or adverse effect on energy expenditure and substrate oxida-Miraglia 2, I-80138 Naples, Italy. tion is still poorly understood. In fact, glucose administration has been shown to enhance energy expenditure and to stimulate insulin

Effects of a high-fat diet on body composition in cancer patients receiving chemotherapy: a randomized controlled study

“…Whole-body glucose oxidation is reduced in the fasting state [6,7] and also tends to be lowered after meals [28]. An inability to deposit normal amounts of glucose as glycogen [3][4][5], not only in the liver [29] but also in muscle [4], appears to be one of the most profound disorders of glucose metabolism. In contrast to glucose, fatty acids are utilized by cancer patients either normally or even to a higher extent than in healthy persons [5,7].…”

“…During parenteral nutrition, peripheral fatty acid uptake was found to be in the reference range [27]. Lipid oxidation is intensified in postabsorptive cancer patients [3,6,7], and the clearance of lipid emulsions is accelerated [7].…”

“…However, relevant changes in either total body nitrogen or muscle mass do not occur [1]. This has been attributed to cancer-induced metabolic abnormalities, among which the impairment of glucose utilization is the most notable feature [3][4][5], together with intensification of lipid clearance and oxidation [6,7]. In contrast to the tumor-bearing organism, malignant tissues rely mainly on glucose as the predominant fuel [8].…”