An interventional study of Time-of-day of enteral nutrition provision (daytime first) and Time-of-day of enteral nutrition provision (nighttime first) in Feeding Patterns, Sleep and Glucose Intolerance, sponsored by Massachusetts General Hospital. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-19.
Sponsored by Massachusetts General Hospital · Not applicable, Interventional, and Supportive care
The purpose of this study is to determine whether modifying the timing of nutrition support from overnight to daytime enhances sleep quality, preserves circadian rhythms, and improves overall inflammation and cardiometabolic profiles in postoperative patients in the cardiac surgical ICU on enteral nutrition.
Intensive care unit (ICU) environments do not support sleep or preserve circadian rhythms of postoperative critically ill patients. Among the contributing factors is the common practice of administering nutrition support through feeding tubes overnight. The overall objective of the study is to examine a novel dimension of clinical nutrition by determining whether enhancing sleep quality and preserving robust circadian rhythms through daytime instead of overnight feeds will attenuate inflammation and improve cardiometabolic profiles of postoperative cardiac ICU patients on nutrition support. The investigators hypothesize that overnight nutrition support results in fragmented sleep and blunted circadian rhythms and thus represent a modifiable mechanism exacerbating inflammation and cardiometabolic derangements in postoperative cardiac patients. Results of this study will help in the development of evidence-based, cost-efficient, and effective enteral nutrition timing countermeasures against fragmented sleep, disrupted circadian rhythms, inflammation and cardiometabolic derangements and potentially modify the current widespread practice of overnight nutrition likely affecting 250,000 hospital admissions annually in the United States.
Exclusion Criteria:
Patients will start nighttime cycled enteral feeds first for 12 hours. Following a 24-hour washout period, patients will then start daytime cycled enteral feeds for 12 hours.
Dietary Supplement: Time-of-day of enteral nutrition provision (nighttime first)
Patients will start daytime cycled enteral feeds first for 12 hours. Following a 24-hour washout period, patients will then start nighttime cycled enteral feeds for 12 hours.
Dietary Supplement: Time-of-day of enteral nutrition provision (daytime first)
Enteral nutrition (tube feeds) will be provided during the daytime followed by nighttime.
Enteral nutrition (tube feeds) will be provided during the nighttime followed by daytime.
Sleep fragmentation
Sleep fragmentation is defined as the number of shifts from deeper (N2, N3, REM) to lighter (W or N1) sleep stages by hours of sleep. Sleep fragmentation will be assessed objectively through EEG measures.
Time frame: Approximately 12 hours. Estimated from nighttime sleep following daytime cycled enteral feeds and during nighttime cycled enteral feeds.
Circadian rhythms amplitude
Amplitude is defined as peak-to-nadir difference in rhythms estimated from body temperature and actigraphy.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
Sleep arousals
Sleep arousals is defined as n shifts from N1, N2, N3, REM to wake divided by hours of sleep. Sleep arousals will be assessed objectively through EEG measures.
Time frame: Approximately 12 hours. Estimated from nighttime sleep following daytime cycled enteral feeds and during nighttime cycled enteral feeds.
Total sleep time
Measure of sleep duration and assessed objectively through EEG measures.
Time frame: Approximately 12 hours. Estimated from nighttime sleep following daytime cycled enteral feeds and during nighttime cycled enteral feeds.
Duration of sleep stages
Duration of the following sleep stages will be estimated: N1, N2, N3, REM sleep. Sleep stages will be assessed objectively through EEG measures.
Time frame: Approximately 12 hours. Estimated from nighttime sleep following daytime cycled enteral feeds and during nighttime cycled enteral feeds.
Sleep midpoint
Sleep midpoint is defined as the midpoint between start and end of sleep episode. Sleep midpoint will be determined objectively from EEG measures.
Time frame: Approximately 12 hours. Estimated from nighttime sleep following daytime cycled enteral feeds and during nighttime cycled enteral feeds.
Acrophase
Acrophase is defined as the time of peak activity.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
Midpoint of least-active 5h timing
Measure of sleep timing as determined from actigraphy.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
Midpoint of most-active 10h timing
Measure of sleep timing as determined from actigraphy.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
Inactivity duration
Duration of inactivity outside of sleep episode as determined from actigraphy.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
12 hours average systolic and diastolic blood pressure
Continuously measured using ECG. Systolic and diastolic blood pressure will be averaged during each 12-hour cycled feed.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
12 hours average glucose
Continuously measured using continuous glucose sensors. Blood glucose will be averaged during each 12-hour cycled feed.
Time frame: Estimated from data collected 12 hours prior to and the 12 hours during daytime cycled and nighttime cycled enteral feeds.
C-reactive protein
The inflammatory biomarker C-reactive protein will be measured from serum.
Time frame: Blood draw scheduled at 8 am and 8 pm on days on daytime cycled and nighttime cycled enteral feeds.
Interleukin-6
The inflammatory biomarker Interleukin-6 will be measured from serum.
Time frame: Blood draw scheduled at 8 am and 8 pm on days on daytime cycled and nighttime cycled enteral feeds.
Tumor necrosis factor α
The inflammatory biomarker Tumor necrosis factor α will be measured from serum.
Time frame: Blood draw scheduled at 8 am and 8 pm on days on daytime cycled and nighttime cycled enteral feeds.
Plan to share: No
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Massachusetts General Hospital