Elevated energy expenditure in cancer patients with solid tumours

Abstract

Cancer patients (n = 106) and non-cancer subjects (n = 96) were classified as weight stable (n = 70) or weight-losing (n = 132). Cancer patients had elevated resting energy expenditure (REE) compared with either weight-losing (23.6 [0.4] vs. 20.5 [0.5] kcal/kg per day, P less than 0.001) or weight-stable controls (22.0 [0.6] vs. 17.9 [0.4], P less than 0.001). Cancer patients had increased fat oxidation irrespective of weight loss (1.24 [0.07] vs. 0.87 [0.04] mg/kg per min; 1.07 [0.04] vs. 0.78 [0.04], P less than 0.001). Elevated energy expenditure was counter-regulated by a decrease in thyroid hormones. Abnormal liver function had no impact on REE in either group. Heart rate was the most powerful factor for prediction of high energy expenditure in both patients and controls. Elevated energy expenditure was related to the increased heart rate in cancer patients in a significantly higher proportion than that in controls. Increased metabolic rate is a significant component behind weight loss in cancer disease, independent of malnutrition and an elevated adrenergic state may be a likely explanation.