SleepSTAVARNCT04731662
Performance, Mood, and Brain and Metabolic Functions During Different Sleep Schedules
A study testing Short sleep and Variable short sleep in people with Sleep and Sleep Restriction, run by National University of Singapore at 1 site in Singapore.
Trial summary
This proposed project will investigate whether a variable or a stable sleep schedule will be more effective in minimizing neurobehavioural and metabolic deficits when total sleep opportunity across two weeks is below the recommended sleep duration. Read more about this study
- Who is it for?
- Ages 21 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Sleep, Sleep Restriction
- What is being tested?
- Short sleep and Variable short sleep
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 59 participants
- Where
- 1 siteSingapore
- Study dates
- 1 Feb 2021to 22 Dec 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 21-35 years of age
- Healthy
- BMI between 18.5 and 24.9
- Not habitual short sleepers
- Not extreme chronotypes
- Not a shift worker
Show all 17Show fewer
- Not a smoker
- Daily consumption of ≤ 5 cups of caffeinated beverages
- Weekly consumption of ≤ 14 units of alcohol
- Do not intend to travel across > 2 time zones 1 month prior to the experiment
- Not a fussy eater
- Do not have any food allergy
- No strict dietary requirements
- No intention to lose or gain weight in the next 6 months
- Not pregnant during the study
- Do not have any metallic implants
- Do not suffer from claustrophobia (last three inclusion criteria are only applicable for fMRI)
Who cannot join
- The reverse of the inclusion criteria
Trial locations and contacts
1 site in 1 country.
Singapore1 site
MD 11- NUS Yong Loo Lin School of Medicine
Singapore, Singapore, 117597
About this study
Official title: Effects of Recurrent Short and Variable Sleep on Cognitive Performance, Brain Dynamics, Psychological Well-being, and Glucose Metabolism
This proposed project will investigate whether a variable or a stable sleep schedule will be more effective in minimizing neurobehavioural and metabolic deficits when total sleep opportunity across two weeks is below the recommended sleep duration. In this laboratory-based, stay-in study, 60 young adults will be randomized into 1 of 3 groups. After 2 nights of 8-h time-in-bed (TIB) that simulate longer sleep opportunities typical of weekends, the stable short sleep group will have a 6-h TIB in each of the following 5 'weeknights' (8866666). The variable short sleep group (8884846) will also have a total TIB of 30h during the 'weeknights', although TIB varies across the 'weeknights'. The nightly TIB of the well-rested control group will be 8h (8888888). These manipulations will repeat in the second week, enabling the tracking of outcome measures during recurrent weeks of sleep restriction on 'weekdays' and extension on 'weekends'. A test battery assessing basic cognitive functions and mood will be administered 5 times a day. A long-term memory encoding task will be administered after week 1. A functional Magnetic Resonance Imaging (fMRI) brain scan, and an Oral Glucose Tolerance Test (OGTT) will be conducted after the second 'weekend' night and after the last 'weeknight' each week. Continuous glucose monitoring will be conducted throughout the experiment. Sleep will be measured every night with polysomnography.
Read the detailed description
This proposed project will investigate whether a variable or a stable sleep schedule will be more effective in minimizing neurobehavioural and metabolic deficits when total sleep opportunity across two weeks is below the recommended sleep duration. This project involves young adults aged 21 - 35. For the two weeks leading up to the stay-in study, participants' sleep-wake patterns will be assessed via actigraphy and sleep diary. For the first week, participants will be asked to follow their habitual sleep schedule, while in the following week, the participants will be instructed to follow a specific sleep schedule with an 8-h sleep opportunity each night during the 7-night period with no napping allowed.
After the two weeks of actigraphy, participants will begin the 16-day in-lab protocol. Participants will be randomised into 1 of 3 groups. All the participants will have an 8-h sleep opportunity during the first two nights (baseline nights) that simulate longer sleep opportunities typical of weekends. During the next 5 'weeknights', the participant's sleep opportunities will be manipulated depending on their assigned group. The stable short sleep group will have a 6-h TIB in each of the following 5 'weeknights' (8866666). The variable short sleep group (8884846) will also have a total TIB of 30h during the 'weeknights', although TIB varies across the 'weeknights'. The nightly TIB of the well-rested control group will be 8h (8888888). The same sleep schedules will be implemented in the second week. The protocol will end with an 8-h sleep opportunity on night 15. For each participant, wake times will remain the same (i.e., participant's own habitual wake time derived from self-report and actigraphy) for all the TIBs. Thus, bedtimes will be delayed progressively with decreasing TIBs for the short sleep groups.
A battery of cognitive tests and psychological scales (approximately 30 minutes) will be administered 5 times a day at 3-hourly intervals, starting from 1.5 hours since awakening.
A memory encoding task will be administered on Day 8 to determine whether a variable/stable short sleep schedule is less disruptive to the acquisition of long-term memory. During the task, participants will be presented with 160 images containing a stimulus (e.g. landscapes) or no stimulus on a computer screen. Each image will be displayed for 2500ms followed by a response screen to prompt participants to indicate if a stimulus was previously presented. On Day 10, a randomized set of 240 images consisting of the 160 images previously shown (i.e. "old" images) and 80 "new" images will be presented to participants. Participants are tested on their recognition of the "old images" by selecting on a 5-point scale: (1) definitely did not see, (2) probably did not see), (3) unsure, (4) probably saw, (5) definitely saw. The two tasks will take approximately 25 minutes each.
An OGTT and fMRI brain scan will be performed after the second baseline night 2 (Day 3) and the last 'weeknight' each week (Day 8 and 15). Participants will be asked to perform 8 hours of overnight fasting before each OGTT. On the morning of the OGTT, an intravenous catheter will be inserted into the forearm of participants. Thereafter, 6 mL of blood samples will be drawn in a lying/sitting position. Participants will then be given a 75-g glucose solution to finish drinking within 7-10mins. 6 mL of blood samples will be collected again at time 15, 30, 60, and 120 minutes to measure for changes in glucose and insulin levels.
In addition to OGTT, the investigators will be using continuous glucose monitoring to measure glucose responses to the various sleep schedule throughout the 16-day study via a glucose sensor applied to the back of the participants' upper arms. To ensure the validity of the continuous glucose data, the investigators will provide three main meals each day to the participants, except on the OGTT days when only lunch and dinner will be provided. The portion of the food provided each day will ensure that each participant will consume the daily calorie and macronutrient requirement, and thus, the participant will not gain or lose weight during the study. Participants will be required to finish all the food provided.
During the fMRI brain scans, resting-state and task-related brain activity will be recorded. During part of the scan, participants will be required to perform the gradual onset continuous performance task (Esterman et al., 2013) wherein participants will be presented with grayscale photographs of different scenes (e.g. mountain and city scenes) in a random manner. Each scene is presented for 1600ms with a 800ms overlap with an interpolated transitions. Participants will then be instructed to press a button if a particular scene is identified (e.g. city scene), and withhold their responses to other scenes. Before the task, participants will be given the opportunity to get familiarised with the images and have a 1-minute practice session.
Sleep macro-structure (i.e., the duration of various sleep stages) and micro-structure (such as SWA) will be measured with polysomnography (PSG) every night. Electrodes will also be affixed to the participant's scalp for electroencephalographic (EEG) recording, around the eyes for electrooculographic (EOG) recording, under the chin for electromyographic (EMG) recording, and on the chest for electrocardiogram (ECG) recording. Pulse oximetry, a non-invasive method that employs a light sensor on a finger cuff, is used in the first baseline night for oxygen saturation measurement to verify that the participants do not suffer from sleep apnea.
Throughout the 16-day in-lab protocol, participants will not be allowed to leave the lab premises or engage in any strenuous exercise. When there are no research procedures being carried out, participants are free to spend their spare time on any activity, with the exception of napping, exercising, or activities that requires the participants to leave the lab premises. Participants will be under constant supervision by the research staff.
- Conditions
- Sleep, Sleep Restriction
- Being tested
- Short sleep, Variable short sleep
- Keywords
- Glucose Metabolism, fMRI, Subjective Sleepiness, Neurobehavioral Functions, Cognitive Functions, Sleep Variability
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Short sleepBehavioural
6-hours time-in-bed during weeknights
Variable short sleepBehavioural
Variable hours of time-in bed during weeknights
| Study group | Role | What they receive |
|---|---|---|
| Control Group (8888888) | No intervention | The Control group will have 8-hours time-in-bed, both weeknights and weekends. |
| Stable Short Sleep (8866666) | Experimental | The short sleep group will have 6-hours time-in-bed on weeknights and 8-hours time-in-bed on weekends. Receives: Behavioral: Short sleep |
| Variable short sleep group (8884846) | Experimental | The short sleep group time in-bed will vary across weeknights but will maintain the same amount of total time-in bed as the stable short sleep (8866666). Receives: Behavioral: Variable short sleep |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in sustained attention assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Number of attention lapses (>500ms)
Measured: 5 times daily for 16 days
Change in mean reaction time assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Mean reaction time
Measured: 5 times daily for 16 days
Change in median reaction time assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Median reaction time
Measured: 5 times daily for 16 days
Change in standard deviation in reaction time of sleep restriction and recovery
Standard deviation in reaction time
Measured: 5 times daily for 16 days
Change in number of commission errors / false starts assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Number of commission errors / false starts
Measured: 5 times daily for 16 days
Change in number of correct matches assessed with the 1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of correct matches in the 1-back task
Measured: 5 times daily for 16 days
Change in number of correct mismatches assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of correct mismatches in the 1-back task
Measured: 5 times daily for 16 days
Change in number of incorrect matches assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of incorrect matches in the 1-back task
Measured: 5 times daily for 16 days
Change in incorrect mismatches assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of incorrect mismatches in the 1-back task
Measured: 5 times daily for 16 days
Change in discriminability measure (A') assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Discriminability measure (A')
Measured: 5 times daily for 16 days
Change in bias measure (B"D) assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Bias measure (B"D)
Measured: 5 times daily for 16 days
Change in number of correct matches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of correct matches in the 3-back task
Measured: 5 times daily for 16 days
Change in number of correct mismatches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of correct mismatches in the 3-back task
Measured: 5 times daily for 16 days
Change in number of incorrect matches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of incorrect matches in the 3-back task
Measured: 5 times daily for 16 days
Change in number of incorrect mismatches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of incorrect mismatches in the 3-back task
Measured: 5 times daily for 16 days
Change in discriminability measure (A') assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Discriminability measure (A')
Measured: 5 times daily for 16 days
Change in bias measure (B"D) assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Bias measure (B"D)
Measured: 5 times daily for 16 days
Change in the level of subjective sleepiness assessed with the Karolinska Sleepiness Scale from morning to afternoon then evening from baseline days to the first and second cycle of sleep manipulation and recovery
Score on the Karolinska Sleepiness Scale (1-9 points)
Measured: 5 times daily for 16 days
Change in positive mood assessed with the Positive and Negative Affect Scale (PANAS) from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Total score on the positive subscale of the PANAS
Measured: 5 times daily for 16 days
Change in negative mood assessed with the Positive and Negative Affect Scale (PANAS) from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Total score on the negative subscale of the PANAS
Measured: 5 times daily for 16 days
Change in the level of depressive symptomatology from the mornings of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Score on the Mood and Anxiety Symptom Questionnaire (Scale 1-5)
Measured: 3 separate days (Day 3, 8 and 15)
Change in the level of anxiety symptomatology from the mornings of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Score on the Mood and Anxiety Symptom Questionnaire (Scale 1-5)
Measured: 3 separate days (Day 3, 8 and 15)
Change in the level of satisfaction with life from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Score on the Satisfaction with Life Scale (1-7 scale)
Measured: 5 times daily (09:00, 12:00, 15:00, 18:00, 21:00) for 16 days
Change in speed of processing assessed with the Mental Arithmetic Test (MAT) from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of correct response in the task
Measured: 5 times daily (09:00, 12:00, 15:00, 18:00, 21:00) for 16 days
Change in speed of processing assessed with the Symbol Digit Modalities Test from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Number of correct responses in the task
Measured: 5 times daily (09:00, 12:00, 15:00, 18:00, 21:00) for 16 days
Changes in the blood glucose levels from morning of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Area under the curve for plasma glucose
Measured: 3 days (Day 3, 8 and 15) 6mL blood sample collection at 15, 30, 60, and 120 minutes
Changes in the insulin levels from morning of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Area under the curve for insulin
Measured: 3 days (Day 3, 8 and 15) 6mL blood sample collection at 15, 30, 60, and 120 minutes
Changes in interstitial fluid glucose levels from morning to afternoon then evening from baseline days to the first and second cycles of sleep manipulation and recovery.
Area under the curve for interstitial fluid glucose
Measured: All 16-days with 8-hour interval readings
Changes in the task related brain functional connectivity from the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Brain functional connectivity in fMRI analysis
Measured: 3 days (Day 3, 8, 15)
Changes in the resting-state brain functional connectivity from the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Brain functional connectivity in fMRI analysis
Measured: 3 days (Day 3, 8, 15)
Effect of variable sleep on picture encoding response time
Mean response time
Measured: Single session (Day 8)
Effect of variable sleep on picture encoding response accuracy
Response accuracy
Measured: Single session (Day 8)
Effect of variable sleep on picture recognition response time
Mean response time
Measured: Single session (Day 10)
Effect of variable sleep on picture recognition hit rate
Hit rate
Measured: Single session (Day 10)
Effect of variable sleep on picture recognition false alarm rate
False alarm rate
Measured: Single session (Day 10)
Effect of variable sleep on picture recognition discriminability measure (A')
Discriminability measure (A')
Measured: Single session (Day 10)
Secondary outcomes (14)
Change in total sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total duration of nocturnal sleep will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in wake after sleep onset duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total duration of wake after sleep onset will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change sleep efficiency at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total sleep efficiency will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change slow wave activity/ slow wave energy at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total slow wave activity/ slow wave energy will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change spindle activity at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total spindle activity will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N1 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total duration of nocturnal N1 sleep duration will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N1 sleep percentage at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Percentage of nocturnal N1 sleep duration will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N2 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Duration of nocturnal N2 sleep will be determined to established baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)(first and second nights) and changes in the first sleep manipulation (third, forth, fifth, sixth
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N2 sleep percentage at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Percentage of nocturnal N2 sleep will be determined to established baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)(first and second nights) and changes in the first sleep manipulation (third, forth, fifth, sixth
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N2 sleep latency at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Duration of nocturnal N2 sleep latency will be determined to established baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)(first and second nights) and changes in the first sleep manipulation (third, forth, fifth, sixth
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N3 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Total duration of nocturnal N3 sleep will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth, and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N3 sleep percentage at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Percentage of nocturnal N3 sleep will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth, and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in the Rapid Eye Movement (REM) sleep duration at night with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Duration of nocturnal sleep REM sleep will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in the Rapid Eye Movement (REM) sleep percentage at night with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Percentage of nocturnal sleep REM sleep will be determined to establish baseline sleep characteristics (first and second night) and changes in the first sleep manipulation period (third, fourth, fifth, sixth and seventh sleep) the first recovery period (eight and ninth night), the second sleep manipulation period (tenth, eleventh, twelfth, thirteenth, fourteenth), and the second recovery period (15th night)
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Feb 2021
- Study start1 Feb 2021
- Primary completion22 Dec 2022
- Study completion22 Dec 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for SleepStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 59 participants (actual)
Sponsor and investigators
- Lead sponsor
- National University of Singapore
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, June Chi Yan Lo, National University of Singapore
- Investigators
- June Chi Yan Lo, Principal investigator, National University of Singapore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04731662
- Sponsor's protocol ID
- STAVAR
- Acronym
- STAVAR
- Status last verified
- Nov 2024
- First submitted
- 26 Jan 2021
- Last updated
- 14 Nov 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Cheung YYY, Tan TYL, Koa TB, Khoo CM, Lo JC. Glucose homeostasis during recurrent periods of sleep restriction and recovery in healthy young adults. Sleep. 2026 Apr 16;49(4):zsaf339. doi: 10.1093/sleep/zsaf339.
PubMed 41165770Koa TB, Ong JL, Lo JC. Changes in sleep architecture during recurrent cycles of sleep restriction: a comparison between stable and variable short sleep schedules. Sleep Adv. 2025 Mar 15;6(2):zpaf016. doi: 10.1093/sleepadvances/zpaf016. eCollection 2025 Apr.
PubMed 40385325Koa TB, Gooley JJ, Chee MWL, Lo JC. Neurobehavioral functions during recurrent periods of sleep restriction: effects of intra-individual variability in sleep duration. Sleep. 2024 Mar 11;47(3):zsae010. doi: 10.1093/sleep/zsae010.
PubMed 38219041
Study at a glance
From the registry record, last updated by the sponsor on 14 Nov 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Recurrent Short and Variable Sleep on Cognitive Performance, Brain Dynamics, Psychological Well-being, and Glucose Metabolism
- ClinicalTrials.gov ID
- NCT04731662
- Acronym / sponsor ID
- STAVAR / STAVAR
- Conditions
- Sleep, Sleep Restriction
- Keywords
- Glucose Metabolism, fMRI, Subjective Sleepiness, Neurobehavioral Functions, Cognitive Functions, Sleep Variability
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 59 participants (actual)
- Lead sponsor
- National University of SingaporeUniversity, hospital or other
- Study start
- 1 Feb 2021 (actual)
- Primary completion
- 22 Dec 2022 (actual)
- Study completion
- 22 Dec 2022 (actual)
- First posted
- 1 Feb 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This proposed project will investigate whether a variable or a stable sleep schedule will be more effective in minimizing neurobehavioural and metabolic deficits when total sleep opportunity across two weeks is below the recommended sleep duration. In this laboratory-based, stay-in study, 60 young adults will be randomized into 1 of 3 groups. After 2 nights of 8-h time-in-bed (TIB) that simulate longer sleep opportunities typical of weekends, the stable short sleep group will have a 6-h TIB in each of the following 5 'weeknights' (8866666). The variable short sleep group (8884846) will also have a total TIB of 30h during the 'weeknights', although TIB varies across the 'weeknights'. The nightly TIB of the well-rested control group will be 8h (8888888). These manipulations will repeat in the second week, enabling the tracking of outcome measures during recurrent weeks of sleep restriction on 'weekdays' and extension on 'weekends'. A test battery assessing basic cognitive functions and mood will be administered 5 times a day. A long-term memory encoding task will be administered after week 1. A functional Magnetic Resonance Imaging (fMRI) brain scan, and an Oral Glucose Tolerance Test (OGTT) will be conducted after the second 'weekend' night and after the last 'weeknight' each week. Continuous glucose monitoring will be conducted throughout the experiment. Sleep will be measured every night with polysomnography.
Detailed description
This proposed project will investigate whether a variable or a stable sleep schedule will be more effective in minimizing neurobehavioural and metabolic deficits when total sleep opportunity across two weeks is below the recommended sleep duration. This project involves young adults aged 21 - 35. For the two weeks leading up to the stay-in study, participants' sleep-wake patterns will be assessed via actigraphy and sleep diary. For the first week, participants will be asked to follow their habitual sleep schedule, while in the following week, the participants will be instructed to follow a specific sleep schedule with an 8-h sleep opportunity each night during the 7-night period with no napping allowed.
After the two weeks of actigraphy, participants will begin the 16-day in-lab protocol. Participants will be randomised into 1 of 3 groups. All the participants will have an 8-h sleep opportunity during the first two nights (baseline nights) that simulate longer sleep opportunities typical of weekends. During the next 5 'weeknights', the participant's sleep opportunities will be manipulated depending on their assigned group. The stable short sleep group will have a 6-h TIB in each of the following 5 'weeknights' (8866666). The variable short sleep group (8884846) will also have a total TIB of 30h during the 'weeknights', although TIB varies across the 'weeknights'. The nightly TIB of the well-rested control group will be 8h (8888888). The same sleep schedules will be implemented in the second week. The protocol will end with an 8-h sleep opportunity on night 15. For each participant, wake times will remain the same (i.e., participant's own habitual wake time derived from self-report and actigraphy) for all the TIBs. Thus, bedtimes will be delayed progressively with decreasing TIBs for the short sleep groups.
A battery of cognitive tests and psychological scales (approximately 30 minutes) will be administered 5 times a day at 3-hourly intervals, starting from 1.5 hours since awakening.
A memory encoding task will be administered on Day 8 to determine whether a variable/stable short sleep schedule is less disruptive to the acquisition of long-term memory. During the task, participants will be presented with 160 images containing a stimulus (e.g. landscapes) or no stimulus on a computer screen. Each image will be displayed for 2500ms followed by a response screen to prompt participants to indicate if a stimulus was previously presented. On Day 10, a randomized set of 240 images consisting of the 160 images previously shown (i.e. "old" images) and 80 "new" images will be presented to participants. Participants are tested on their recognition of the "old images" by selecting on a 5-point scale: (1) definitely did not see, (2) probably did not see), (3) unsure, (4) probably saw, (5) definitely saw. The two tasks will take approximately 25 minutes each.
An OGTT and fMRI brain scan will be performed after the second baseline night 2 (Day 3) and the last 'weeknight' each week (Day 8 and 15). Participants will be asked to perform 8 hours of overnight fasting before each OGTT. On the morning of the OGTT, an intravenous catheter will be inserted into the forearm of participants. Thereafter, 6 mL of blood samples will be drawn in a lying/sitting position. Participants will then be given a 75-g glucose solution to finish drinking within 7-10mins. 6 mL of blood samples will be collected again at time 15, 30, 60, and 120 minutes to measure for changes in glucose and insulin levels.
In addition to OGTT, the investigators will be using continuous glucose monitoring to measure glucose responses to the various sleep schedule throughout the 16-day study via a glucose sensor applied to the back of the participants' upper arms. To ensure the validity of the continuous glucose data, the investigators will provide three main meals each day to the participants, except on the OGTT days when only lunch and dinner will be provided. The portion of the food provided each day will ensure that each participant will consume the daily calorie and macronutrient requirement, and thus, the participant will not gain or lose weight during the study. Participants will be required to finish all the food provided.
During the fMRI brain scans, resting-state and task-related brain activity will be recorded. During part of the scan, participants will be required to perform the gradual onset continuous performance task (Esterman et al., 2013) wherein participants will be presented with grayscale photographs of different scenes (e.g. mountain and city scenes) in a random manner. Each scene is presented for 1600ms with a 800ms overlap with an interpolated transitions. Participants will then be instructed to press a button if a particular scene is identified (e.g. city scene), and withhold their responses to other scenes. Before the task, participants will be given the opportunity to get familiarised with the images and have a 1-minute practice session.
Sleep macro-structure (i.e., the duration of various sleep stages) and micro-structure (such as SWA) will be measured with polysomnography (PSG) every night. Electrodes will also be affixed to the participant's scalp for electroencephalographic (EEG) recording, around the eyes for electrooculographic (EOG) recording, under the chin for electromyographic (EMG) recording, and on the chest for electrocardiogram (ECG) recording. Pulse oximetry, a non-invasive method that employs a light sensor on a finger cuff, is used in the first baseline night for oxygen saturation measurement to verify that the participants do not suffer from sleep apnea.
Throughout the 16-day in-lab protocol, participants will not be allowed to leave the lab premises or engage in any strenuous exercise. When there are no research procedures being carried out, participants are free to spend their spare time on any activity, with the exception of napping, exercising, or activities that requires the participants to leave the lab premises. Participants will be under constant supervision by the research staff.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Control Group (8888888) | No intervention | –The Control group will have 8-hours time-in-bed, both weeknights and weekends. |
| Stable Short Sleep (8866666) | Experimental | Behavioral: Short sleepThe short sleep group will have 6-hours time-in-bed on weeknights and 8-hours time-in-bed on weekends. |
| Variable short sleep group (8884846) | Experimental | Behavioral: Variable short sleepThe short sleep group time in-bed will vary across weeknights but will maintain the same amount of total time-in bed as the stable short sleep (8866666). |
Who may qualify
- Ages
- 21 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (17 listed)
- 21-35 years of age
- Healthy
- BMI between 18.5 and 24.9
- Not habitual short sleepers
- Not extreme chronotypes
Key exclusion criteria (1 listed)
- The reverse of the inclusion criteria
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Short sleep6-hours time-in-bed during weeknights | Behavioural | Stable Short Sleep (8866666) |
| Variable short sleepVariable hours of time-in bed during weeknights | Behavioural | Variable short sleep group (8884846) |
Primary outcome
Change in sustained attention assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 5 times daily for 16 days
Number of attention lapses (>500ms)
Change in mean reaction time assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 5 times daily for 16 days
Mean reaction time
Change in median reaction time assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 5 times daily for 16 days
Median reaction time
Change in standard deviation in reaction time of sleep restriction and recovery
Time frame: 5 times daily for 16 days
Standard deviation in reaction time
Change in number of commission errors / false starts assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 5 times daily for 16 days
Number of commission errors / false starts
Change in number of correct matches assessed with the 1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of correct matches in the 1-back task
Change in number of correct mismatches assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of correct mismatches in the 1-back task
Change in number of incorrect matches assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of incorrect matches in the 1-back task
Change in incorrect mismatches assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of incorrect mismatches in the 1-back task
Change in discriminability measure (A') assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Discriminability measure (A')
Change in bias measure (B"D) assessed with the1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Bias measure (B"D)
Change in number of correct matches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of correct matches in the 3-back task
Change in number of correct mismatches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of correct mismatches in the 3-back task
Change in number of incorrect matches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of incorrect matches in the 3-back task
Change in number of incorrect mismatches assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Number of incorrect mismatches in the 3-back task
Change in discriminability measure (A') assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Discriminability measure (A')
Change in bias measure (B"D) assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Bias measure (B"D)
Change in the level of subjective sleepiness assessed with the Karolinska Sleepiness Scale from morning to afternoon then evening from baseline days to the first and second cycle of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Score on the Karolinska Sleepiness Scale (1-9 points)
Change in positive mood assessed with the Positive and Negative Affect Scale (PANAS) from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Total score on the positive subscale of the PANAS
Change in negative mood assessed with the Positive and Negative Affect Scale (PANAS) from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily for 16 days
Total score on the negative subscale of the PANAS
Change in the level of depressive symptomatology from the mornings of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Time frame: 3 separate days (Day 3, 8 and 15)
Score on the Mood and Anxiety Symptom Questionnaire (Scale 1-5)
Change in the level of anxiety symptomatology from the mornings of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Time frame: 3 separate days (Day 3, 8 and 15)
Score on the Mood and Anxiety Symptom Questionnaire (Scale 1-5)
Change in the level of satisfaction with life from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily (09:00, 12:00, 15:00, 18:00, 21:00) for 16 days
Score on the Satisfaction with Life Scale (1-7 scale)
Change in speed of processing assessed with the Mental Arithmetic Test (MAT) from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily (09:00, 12:00, 15:00, 18:00, 21:00) for 16 days
Number of correct response in the task
Change in speed of processing assessed with the Symbol Digit Modalities Test from morning to afternoon and then evening from baseline days to the first and second cycles of sleep manipulation and recovery
Time frame: 5 times daily (09:00, 12:00, 15:00, 18:00, 21:00) for 16 days
Number of correct responses in the task
Changes in the blood glucose levels from morning of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Time frame: 3 days (Day 3, 8 and 15) 6mL blood sample collection at 15, 30, 60, and 120 minutes
Area under the curve for plasma glucose
Changes in the insulin levels from morning of the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Time frame: 3 days (Day 3, 8 and 15) 6mL blood sample collection at 15, 30, 60, and 120 minutes
Area under the curve for insulin
Changes in interstitial fluid glucose levels from morning to afternoon then evening from baseline days to the first and second cycles of sleep manipulation and recovery.
Time frame: All 16-days with 8-hour interval readings
Area under the curve for interstitial fluid glucose
Changes in the task related brain functional connectivity from the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Time frame: 3 days (Day 3, 8, 15)
Brain functional connectivity in fMRI analysis
Changes in the resting-state brain functional connectivity from the second baseline day to the last day of the first sleep manipulation cycle and the last day of the second sleep manipulation cycle.
Time frame: 3 days (Day 3, 8, 15)
Brain functional connectivity in fMRI analysis
Effect of variable sleep on picture encoding response time
Time frame: Single session (Day 8)
Mean response time
Effect of variable sleep on picture encoding response accuracy
Time frame: Single session (Day 8)
Response accuracy
Effect of variable sleep on picture recognition response time
Time frame: Single session (Day 10)
Mean response time
Effect of variable sleep on picture recognition hit rate
Time frame: Single session (Day 10)
Hit rate
Effect of variable sleep on picture recognition false alarm rate
Time frame: Single session (Day 10)
False alarm rate
Effect of variable sleep on picture recognition discriminability measure (A')
Time frame: Single session (Day 10)
Discriminability measure (A')
14 secondary outcomes
Change in total sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in wake after sleep onset duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change sleep efficiency at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change slow wave activity/ slow wave energy at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change spindle activity at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N1 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N1 sleep percentage at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N2 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N2 sleep percentage at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N2 sleep latency at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N3 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in N3 sleep percentage at night assessed with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in the Rapid Eye Movement (REM) sleep duration at night with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Change in the Rapid Eye Movement (REM) sleep percentage at night with polysomnography from baseline nights to the first and second cycles of sleep manipulation and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 4, 5, 6 & 7 (first sleep manipulation period), 8 & 9 (first recovery period), 10,11,12, 13, 14 (second sleep manipulation period), & 15 (second recovery period)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Nov 2024.
- Derived from this study: PubMed 41165770Cheung YYY, Tan TYL, Koa TB, Khoo CM, Lo JC. Glucose homeostasis during recurrent periods of sleep restriction and recovery in healthy young adults. Sleep. 2026 Apr 16;49(4):zsaf339. doi: 10.1093/sleep/zsaf339.
- Derived from this study: PubMed 40385325Koa TB, Ong JL, Lo JC. Changes in sleep architecture during recurrent cycles of sleep restriction: a comparison between stable and variable short sleep schedules. Sleep Adv. 2025 Mar 15;6(2):zpaf016. doi: 10.1093/sleepadvances/zpaf016. eCollection 2025 Apr.
- Derived from this study: PubMed 38219041Koa TB, Gooley JJ, Chee MWL, Lo JC. Neurobehavioral functions during recurrent periods of sleep restriction: effects of intra-individual variability in sleep duration. Sleep. 2024 Mar 11;47(3):zsae010. doi: 10.1093/sleep/zsae010.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
June Chi Yan Lo principal investigator
National University of Singapore
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Short sleep and Variable short sleep in people with Sleep and Sleep Restriction, run by National University of Singapore at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 17 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Nov 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in sustained attention assessed with the Psychomotor Vigilance Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery (time frame: 5 times daily for 16 days). The study lists 36 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04731662, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Nov 2024.