Factors Associated with Altered Resting Energy Expenditure in Patients with Incurable Cancer

Abstract

Background and aim: There are indications that patients with cancer experience alterations in resting energy expenditure (REE) due to metabolic changes. Nutrition therapy is an integral part of palliative care, and alterations in REE can cause errors in estimating REE, leading to inadequate nutritional therapy and undesirable health outcomes. However, no studies have investigated potential factors affecting REE in patients with incurable cancer. This thesis aims to explore the association between the difference in measured REE by indirect calorimetry (IC) and predicted REE by the Harris-Benedict (HB) equation and a set of potential explanatory variables, such as cancer diagnosis, weight change, chemotherapy and degree of inflammation.

Method: An explorative, descriptive, single-centre study (the REPAT study) was conducted on patients with incurable cancer hospitalized at the Cancer Clinic at St. Olavs University Hospital. This preliminary analysis includes data from the first 75 out of 150 planned patients. Data collected from each patient included measured REE by indirect calorimetry, patient- and disease characteristics, and patient-reported outcomes such as symptoms and weight loss from September 2023 to March 2024.

Results: Most patients were hypermetabolic due to a measured REE 10% higher than the predicted REE by the HB equation. Hypermetabolic patients had a higher prevalence of weight loss >10 % compared to the hypo- or normometabolic patients and were the only group reporting a higher food intake last two weeks. C-reactive protein (CRP) and weight change last six months were statistically significantly associated with the difference in REE between measured REE by IC and predicted REE by the HB equation.

Conclusion: The majority of the included patients were characterized by hypermetabolism and a high prevalence of weight loss. An association between CRP, percent weight change last six months and the difference between measured and predicted REE was detected. However, the observed change in difference in REE for each unit increment in CRP or weight change did not seem clinically significant. More studies conducted on larger populations and prospectively measurements of REE during disease and treatment trajectories are needed to better understand the relationship between potential explanatory variables and altered REE in patients with incurable cancer.