The effect of gastrointestinal malignancy on resting metabolic expenditure

Abstract

It is unclear whether or not the presence of a malignancy causes an increased energy demand in the patient. As energy expenditure is normally related to body cell mass, it might be expected that an alteration in the relationship between body cell mass and energy expenditure would be observed in patients with malignant disease. This study aimed to investigate this possibility and to attempt to quantify any change in order to determine its clinical relevance. Three groups of patients were studied: a control group (group I), consisting of healthy volunteers and patients awaiting minor elective surgery for benign conditions, and two groups of patients with malignant disease the extent of which was assessed at laparotomy; group II comprised those with local disease and group III those with metastatic disease. Resting metabolic expenditure (RME) was measured by indirect calorimetry and the total body potassium (TBK) was measured as an indicator of body cell mass. The results show a close correlation between RME and TBK in all groups. The RME at a given potassium content was greatest in those patients with metastatic disease. The magnitude of the difference was small, however, amounting to a mean elevation of 289 kcal/d in this group compared to control subjects. It is concluded that malignancy may result in an increased energy demand, particularly in patients with metastatic disease. The magnitude of the increase is small and probably of little consequence when planning nutritional support, although its cumulative effect over many months may be significant.