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

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05795881
Acronym
CIRCLES
Enrollment
60
Registered
2023-04-03
Start date
2023-06-14
Completion date
2025-03-15
Last updated
2025-03-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Circadian Rhythm, Critical Illness, Enteral Nutrition, Intensive Care Unit, Sleep

Keywords

Randomized Controlled Trial

Brief summary

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.

Interventions

OTHERCyclic daytime enteral nutrition

The allocated feeding schedule is followed from the start of enteral nutrition after ICU admission until discharge from the ICU.

Sponsors

Leiden University Medical Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Investigator-Initiated Randomized Controlled Trial

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Age ≥ 18 years old * Receiving of or intention to start enteral nutrition via nasogastric or nasoduodenal tube * Arterial line * Expected duration of ICU admission \> 48 hours

Exclusion criteria

* Receiving parenteral nutrition * Prior night-time (20.00h - 8.00h) enteral tube feeding within the same hospitalization before study inclusion * Readmission to ICU with prior study inclusion * Chronic enteral tube feeding prior to current admission * Presence of one or more contraindications of enteral feeding and/or at significant risk for gastrointestinal tolerance according to standard protocol (including but not limited to gastrointestinal haemorrhage, intestinal ischemia or necrosis, impaired digestive tract integrity due to obstruction or perforation, gastrectomy, enterectomy, history of gastroparesis or oesophageal dysmotility or expected surgery within 24 hours) * Patients with glycaemic emergency (including but not limited to hyperglycaemic hyperosmolar nonketotic coma, diabetic ketoacidosis, severe hypoglycaemia resulting in ICU admission) or patients controlling their glucose levels and insulin dosing via continuous glucose monitoring * Expected death within 24 hours * Do-not-resuscitate (DNR) order * Treatment with extracorporeal membrane oxygenation * Severe neurological damage (significant neurological abnormalities such as bleeding, ischemia, neurotrauma or severe encephalopathy with Glasgow Coma Scale ≤ 8) * Suspected or confirmed pregnancy

Design outcomes

Primary

MeasureTime frameDescription
Amplitude of 24-h rhythm of core body temperatureDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Acrophase 24-h rhythm of core body temperatureDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis

Secondary

MeasureTime frameDescription
Mean daily insulin administrationFrom start of study intervention (enteral nutrition) to end of study interventionMean of number of insulin units used per day
Mean daily caloric intakeFrom start of study intervention (enteral nutrition) to end of study interventionMean of percentage of recommended calories that patient receives per day of interest during study period
Daily rates of gastric retentionFrom start of study intervention (enteral nutrition) to end of study interventionGastric retention is defined as gastric residual volume \> 200 mL
Amplitude of 24-h rhythm of plasma melatonin levelsDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Acrophase of 24-h rhythm of plasma melatonin levelsDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Amplitude of 24-h rhythm in heart rate variabilityDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Acrophase of 24-h rhythm in heart rate variabilityDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Amplitude of 24-h rhythm in systolic blood pressureDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Days on mechanical ventilationFrom ICU admission to ICU dischargeDays on mechanical ventilation
Amplitude of 24-h rhythm in heart rateDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Acrophase of 24-h rhythm in heart rateDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
Peripheral clock gene expressionDay 3 (12 p.m.) to day 4 (12 a.m.) after start of the study intervention (= start of enteral nutrition)Time of day-dependent difference in clock gene expression in PBMCs isolated from blood samples collected at 12 p.m. and 12 a.m.
Depth of sleepDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Daytime (8 a.m. to 8 p.m.) to nighttime (8 p.m. to 8 a.m.) ratio of gamma to delta spectral power ratio in EEG measured with a sleep headband
Mean daily rate of hyperglycaemia/hypoglycaemiaFrom start of study intervention (enteral nutrition) to end of study interventionHypoglycaemia is defined as glucose levels \< 3.5 mmol/L, hyperglycaemia is defined as glucose levels \>10 mmol/L
Mean daily glucose variabilityFrom start of study intervention (enteral nutrition) to end of study interventionMean of standard deviation of glucose levels per day
28-day mortalityUp to 28 days28-day mortality
Acrophase of 24-h rhythm in systolic blood pressureDay 3 (8 a.m.) to day 4 (8 a.m.) after start of the study intervention (= start of enteral nutrition)Determined by cosinor analysis
ICU length of stayFrom ICU admission to ICU dischargeICU length of stay

Countries

Netherlands

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026