Profiling Determinants of Resting Energy Expenditure in Colorectal Cancer.

Background

Understanding resting energy expenditure (REE) is important for determining energy requirements; REE might be altered in individuals with cancer. The objective of this study was to characterize determinants of REE in patients with stages II-IV colorectal cancer (CRC).

Methods

REE was measured via indirect calorimetry in patients with newly diagnosed CRC. Computerized tomography images from medical records ascertained skeletal muscle and total adipose tissue cross-sectional areas, which were then transformed to lean soft tissue (LST) and fat mass (FM) values (in kg). Linear regression assessed determinants of REE.

Results

86 patients were included (n = 55, 64.0% male; 60 ± 12 years old; median body mass index: 27.6, interquartile range: 24.3-31.2 kg/m2), with most (n = 40) having stage III disease. Age, sex, and weight were significant predictors of REE [R2 = 0.829, standard error of the estimate (SEE): 128 kcal/day, P < 0.001]. Replacing weight with LST and FM yielded a similar model, with age, sex, LST, and FM predictive of REE (R2 = 0.820, SEE: 129 kcal/day, p < 0.001).

Conclusion

Age, sex, weight, LST, and FM were the main contributors to REE. Further investigation of REE changes over time and its relationship to total energy expenditure, dietary intake, and clinical outcomes should be explored.