Describing energy expenditure in children with a chronic disease: a systematic review.

BACKGROUND: Understanding energy expenditure in children with chronic disease is critical due to the impact on energy homeostasis and growth.

OBJECTIVE: This systematic review aimed to describe available literature of resting (REE) and total energy expenditure (TEE) in children with chronic disease measured by gold standard methods of indirect calorimetry (IC) and doubly-labelled water (DLW), respectively.

METHODS: A literature search was conducted using OVID Medline, Embase, CINAHL Plus, Cochrane and Scopus until July 2023. Studies were included if the mean age of participants was ≤ 18 years, participants had a chronic disease and measurement of REE or TEE was conducted using IC or DLW, respectively. Studies investigating energy expenditure in premature babies, acute illness and intensive care patients were excluded. The primary outcomes are the type of data (REE, TEE) obtained and REE/TEE stratified by disease group.

RESULTS: 271 studies across 24 chronic conditions were identified. Over 60% of retrieved studies were published > 10 years ago and conducted in relatively small population sizes (n range=1-398). Most studies obtained REE samples (82%) rather than that of TEE (8%), with very few exploring both samples (10%). There was variability in the difference in energy expenditure in children with chronic disease compared to healthy controls across and within disease groups. Eighteen predictive energy equations were generated across included studies. Quality assessment of the studies identified poor reporting of energy expenditure protocols which may limit the validity of results.

CONCLUSION: Current literature on energy expenditure in children with chronic disease whilst extensive, reveals key future research opportunities. International collaboration and robust measurement of energy expenditure should be conducted to generate meaningful predictive energy equations to provide updated evidence that is reflective of the emerging disease modifying therapies.

PROSPERO REGISTRY NUMBER: CRD42020204690.