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Effect of Continuous Versus Cyclic Daytime Enteral Nutrition on Circadian Rhythms in Critical Illness: CIRCLES Study

ClinicalTrials.gov · COMPLETED, 2025

60 participants

Abstract

Disruption of circadian rhythms is frequently observed in patients in the intensive care unit (ICU) and is associated with worse clinical outcomes. The ICU environment presents weak and conflicting timing cues to the circadian clock, including continuous enteral nutrition. The goal of this clinical trial is to evaluate the effect of timing of enteral nutrition on the circadian rhythm in critically ill patients. Patients admitted to the intensive care unit will be allocated to receive either continuous or cyclic daytime (8am to 8 pm) enteral feeding. Differences in circadian rhythms will be assessed by 24h patterns in core body temperature, heart rate variability, melatonin and peripheral clock gene expression. Secondary outcomes include depth of sleep, glucose variability and incidence of feeding intolerance. This study is expected to contribute to the optimalisation of circadian rhythms in the ICU.

Conditions: Critical Illness, Intensive Care Unit, Circadian Rhythm, Sleep, Enteral Nutrition.

Primary outcome: Amplitude of 24-h rhythm of core body temperature; Acrophase 24-h rhythm of core body temperature.

Enrollment: 60 participants.

How strong is the evidence?

Evidence Hub reads this as a clinical trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 60 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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