The Oxidation of Body Fuel Stores in Cancer Patients

Abstract

In an attempt to define the mechanism of weight loss in cancer patients, fat and carbohydrate oxidation rates were calculated in 93 patients. Seventy patients with colorectal or gastric cancer were compared with a control group of 23 patients with nonmalignant illness. Twenty-seven patients with cancer and 13 control patients had lost more than 10% of their pre-illness body weight. Fat and carbohydrate oxidation rates were derived from measurements of oxygen consumption, carbon dioxide production, and urinary nitrogen excretion. Patients with cancer had significantly higher fat oxidation rates (p less than 0.01) and significantly lower carbohydrate oxidation rates (p less than 0.05) when compared with controls. Weight-losing cancer patients had significantly higher fat oxidation rates when compared with weight-stable cancer patients (p less than 0.02), weight-stable controls (p less than 0.01), and weight-losing controls (p less than 0.02). Cancer patients with liver metastases (N = 14) had significantly higher fat oxidation rates (p less than 0.01) and significantly lower carbohydrate oxidation rates (p less than 0.01) compared with cancer patients who had localized disease. There were no significant differences among the groups with respect to resting energy expenditure when expressed as kilocalorie per kilogram lean body mass per day. The presence of cancer appears to be associated with abnormal fat and carbohydrate metabolism. The increased rate of fat oxidation seen in patients with cancer, especially those with weight loss or liver metastases, may be a significant factor in the development of cancer cachexia.

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

“…This disturbance has been described predominantly for the postabsorptive state [26,27] and for euglycemic clamp situations [4,5], but has also been observed during parenteral nutrition [27]. 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.…”

“…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].…”

First Asian Congress on Cancer in Older Patients Kuching, Malaysia 22–23rd January 2011

“…14 BMI < 18 and low serum albumin predict 30-day mortality in esophageal cancer. 15 For older adults the recommended daily water intake is 30 ml/kg, 16 calorie intake 23 and 25 kcal/kg in stable weight and weight losing patients respectively 17 and protein intake of 1.2 to 2 g. 18 Based on a Cochrane review, four randomized trials on cancer patients revealed a decrease in mortality when intake of oral supplements was ≥400 kcal/day in patients ≥75-yrs old and supported for >35-days. 19 …”

Metabolic alteration in patients with cancer: Nutritional implications

“…48 reported elevated TG and VLDL in 25 patients with acute leukemia and lymphoma. Hansell et al 49 reported an increased rate of fat oxidation in 70 patients with either colorectal or gastric cancer especially those with weight loss or liver metastasis.…”