SleepNFS4NCT03333512
The Cognitive and Metabolic Effects of Sleep Restriction in Adolescents
A study testing Nap in people with Sleep and Sleep Restriction, run by Duke-NUS Graduate Medical School at 1 site in Singapore.
Trial summary
The aim of this study is to examine the neurobehavioural and glucose metabolic responses to two successive cycles of sleep restriction and recovery in adolescents, and to determine the benefits of napping on cognitive performance, alertness, mood and glucose metabolism. Read more about this study
- Who is it for?
- Ages 15 to 19 yearsHealthy volunteers can take part
- Conditions the study is for
- Sleep, Sleep Restriction
- What is being tested?
- Nap
- 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
- 28 Nov 2017to 20 Jan 2018
- 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 15 to 19 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- healthy
- no sleep disorder
- body mass index not greater than 30
Who cannot join
- smoker
- habitual short sleeper (time in bed during term time of less than 6 hours and no sign of sleep extension of greater than 1 hour on weekends)
- consumption of more than 5 cups of caffeinated beverages a day
- travelling across more than 2 time zones in the month prior to the study protocol
- diagnosed with any psychiatric conditions
Trial locations and contacts
1 site in 1 country.
About this study
The aim of this study is to examine the neurobehavioural and glucose metabolic responses to two successive cycles of sleep restriction and recovery in adolescents, and to determine the benefits of napping on cognitive performance, alertness, mood and glucose metabolism. Using a split-sleep design, 60 participants, aged 15 to 19 years old, are divided into a nap and a no-nap group. Both groups undergo two cycles of sleep restriction and recovery over a period of 15 days. The no-nap group receives a 6.5-hour sleep opportunity on sleep restriction nights, with no daytime nap opportunity. The nap group receives a 5-hour sleep opportunity on sleep restriction nights, and has a 1.5-hour nap opportunity the following afternoon.
Read the detailed description
The present study investigates whether a continuous stretch of night time sleep (6.5 hours) will lead to better neurobehavioural outcomes relative to nocturnal sleep restriction (5 hours) and daytime nap (1.5 hours) of the same total duration, and how sleep restriction affects glucose metabolism. The 15-day protocol is conducted in a dormitory on 60 high school students, aged 15 to 19 years old. Participants are assigned to a nap or no-nap group. Both groups start with two 9-hour adaptation and baseline nights, followed by two successive cycles of sleep restriction (5-h time in bed (TIB); 01:00-06:00 or 6.5-h TIB; 00:15-06:45) and recovery (9-h TIB; 23:00-08:00). Following each sleep-restricted night, the nap group receives a 1.5-h nap opportunity, while participants in the no-nap group watch a documentary. Throughout the protocol, sleep-wake patterns are assessed with actigraphy and polysomnography. Sleepiness levels, mood, vigilance, working memory / executive functions, and speed of processing are assessed 3 times daily (10:00, 16:15, and 20:00). Other cognitive functions such as memory and mindfulness levels are investigated through computer-based tasks. Glucose metabolism is measured using oral glucose tolerance tests in the mornings after the second baseline night, the third night of sleep restriction and second recovery night in the first cycle, as well as the last sleep restriction night in the second cycle.
All participants stay in air-conditioned, twin-share bedrooms with en-suite bathrooms. Bedroom windows are fitted with blackout panels to ensure participants are not woken up prematurely by sunlight. Earplugs are provided, and participants are allowed to adjust the temperature of their bedrooms to their personal comfort. Three main meals are served each day, with snacks being provided for upon request. Caffeinated drinks, unscheduled sleep, and strenuous physical activities are prohibited.
Outside of scheduled sleep, meal, and cognitive testing times, participants spend the majority of their free time in a common room that is illuminated by natural and artificial lighting. They are allowed to read, play non-physically exerting games, watch videos, and interact with research staff and other participants. Participants are under constant supervision by the research staff.
- Conditions
- Sleep, Sleep Restriction
- Being tested
- Nap
- Keywords
- Nap, Recovery Sleep, Cognitive Functions, Glucose Metabolism, Neurobehavioral Functions, Mood, Subjective Sleepiness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NapBehavioural
Looking at the difference between continuous sleep opportunities and split-sleep opportunities.
| Study group | Role | What they receive |
|---|---|---|
| Nap | Experimental | After each night with a 5-hour sleep opportunity, participants have a daytime nap opportunity of 1.5 hours. Receives: Behavioral: Nap |
| No nap | No intervention | After each night with a 6.5-hour sleep opportunity, participants do not have a daytime nap opportunity, but instead watch documentaries. |
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: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Change in working memory assessed with the 1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Number of correct responses in the 1-back task
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Change in executive functions assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Number of correct responses in the 3-back task
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Change in the level of subjective sleepiness assessed with the Karolinska Sleepiness Scale from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Score on the Karolinska Sleepiness Scale (1-9 points)
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 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 restriction and recovery
Total score on the positive subscale of the PANAS
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 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 restriction and recovery
Total score on the negative subscale of the PANAS
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Change in speed of processing assessed with the Mental Arithmetic Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Number of correct responses in the task
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Change in speed of processing assessed with the Symbol Digit Modalities Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Number of correct responses in the task
Measured: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Change in blood glucose level, measured using a blood glucose meter, from baseline following the first period sleep restriction, first period of recovery sleep, and second period of sleep restriction
Score on blood glucose meter
Measured: Four mornings (after baseline night 2, after sleep restriction night 3 (first sleep restriction period), after recovery night 2 (first recovery period), after sleep restriction night 3 (second sleep restriction period))
Change in meal and snack consumption from baseline following the first period sleep restriction, first period of recovery sleep, and second period of sleep restriction
Amount of meals and snacks consumed, measured on an ad libitum basis
Measured: Throughout the 15-day protocol
Change in memory performance in picture-word association task over sleep restriction nights and recovery night
Score on picture-word association task
Measured: 12 times (morning and evening): after sleep restriction night 1, 2, 3, 4 and 5 (sleep restriction period 1) and after recovery night 2 (recovery period 1)
Mind-wandering, assessed using a breath-counting task
Error rate of button presses and percentage of errors that are self-caught
Measured: Single session, during baseline
Effect of sleep versus wake during delay on the implementation of an intention in the future, where the intention will be encoded either before a 12-hr interval including a night of sleep or a day of wakefulness
Memory score of correctly remembering to perform the intention following the wake or sleep interval
Measured: Single session during the 15-day protocol, after baseline night 1 or before sleep restriction night 1 (first sleep restriction period)
Effect of sleep versus wake during delay on memory for rewarded pictures, where the pictures will be encoded either before a 12-hr interval including a night of sleep or a day of wakefulness
Memory score of correctly remembered encoded pictures following the wake or sleep interval
Measured: Single session during the 15-day protocol, after baseline night 1 or before sleep restriction night 1 (first sleep restriction period)
Effect of sleep restriction on learning of novel material (about different animal species) across separate sessions
Memory score on test of learned material
Measured: Single session during the 15-day protocol, after recovery night 2 (first recovery period)
Effect of sleep restriction on memory of spatial locations
Performance in four mountains task
Measured: Single session during the 15-day protocol, after sleep restriction night 3 (first sleep restriction period)
Effect of sleep restriction on problem-solving
Number of correctly solved equations in matchstick arithmetic task
Measured: Single session during the 15-day protocol, after sleep restriction night 5 (first sleep restriction period)
Effect of sleep restriction on picture encoding
Memory score of correctly remembered encoded pictures of non-famous people, landscapes, scenes and objects
Measured: Single session during the 15-day protocol, after recovery night 2 (second recovery period)
Effect of sleep restriction on effort/temporal discounting
Choice preference (perform a longer duration task for a higher reward, or to take a break for a lower/no reward) in effort/temporal discounting task is measured
Measured: Three sessions during the 15-day protocol (after baseline night 1, after sleep restriction night 5 (first sleep restriction period) and after recovery night 2 (first recovery period))
Effect of prior knowledge about the position of items in a previously learned hierarchy on learning of the position of novel items in a new hierarchy
Percentage of correct responses on the test
Measured: Single session, during baseline
Effect of sleep restriction on task switching performance
Difference in reaction time between switch trial and repetition trial in task-switching task
Measured: Four sessions during the 15-day protocol (after baseline night 1, after sleep restriction night 3 (first sleep restriction period), after recovery night 2 (first recovery period) and after sleep restriction night 3 (second sleep restriction period))
Effect of sleep restriction on attentional bias to threat assessed using visual cues that are coupled either to an aversive sound (threat cue) or a neutral sound (neutral cue)
Correct responses to a target that is presented at the same (valid) or opposite (invalid) location of stimulus
Measured: Three session during the 15-day protocol (after baseline night 1, after sleep restriction night 5 (first sleep restriction period), after recovery night 1 (first recovery period))
Effect of verbal reward on procedural memory assessed using a finger tapping task
Accuracy of performance on the finger-tapping task
Measured: Two sessions during the 15-day protocol (before baseline night 1 and after baseline night 1)
Secondary outcomes (10)
Change in total sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Total duration of nocturnal sleep was determined to establish baseline sleep characteristics (first and second nights) and changes in the first sleep restriction period (third, fifth and seventh night), the first recovery period (eighth night), the second sleep restriction period (tenth and twelfth night), and the second recovery period (13th night).
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in N1 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Duration of nocturnal N1 sleep was determined to establish baseline sleep characteristics (first and second nights) and changes in the first sleep restriction period (third, fifth and seventh night), the first recovery period (eighth night), the second sleep restriction period (tenth and twelfth night), and the second recovery period (13th night).
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in N2 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Duration of nocturnal N2 sleep was determined to establish baseline sleep characteristics (first and second nights) and changes in the first sleep restriction period (third, fifth and seventh night), the first recovery period (eighth night), the second sleep restriction period (tenth and twelfth night), and the second recovery period (13th night).
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in N3 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Duration of nocturnal N3 sleep was determined to establish baseline sleep characteristics (first and second nights) and changes in the first sleep restriction period (third, fifth and seventh night), the first recovery period (eighth night), the second sleep restriction period (tenth and twelfth night), and the second recovery period (13th night).
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in Rapid Eye Movement (REM) sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Duration of nocturnal REM sleep was determined to establish baseline sleep characteristics (first and second nights) and changes in the first sleep restriction period (third, fifth and seventh night), the first recovery period (eighth night), the second sleep restriction period (tenth and twelfth night), and the second recovery period (13th night).
Measured: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in total sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Total duration of sleep during the selected nap episodes was determined to track changes in this parameter from the first sleep restriction period (third, fifth and seventh day) to the second sleep restriction period (tenth and twelfth day)
Measured: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in N1 sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Duration of N1 sleep during the selected nap episodes was determined to track changes in this parameter from the first sleep restriction period (third, fifth and seventh day) to the second sleep restriction period (tenth and twelfth day)
Measured: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in N2 sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Duration of N2 sleep during the selected nap episodes was determined to track changes in this parameter from the first sleep restriction period (third, fifth and seventh day) to the second sleep restriction period (tenth and twelfth day)
Measured: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in N3 sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Duration of N3 sleep during the selected nap episodes was determined to track changes in this parameter from the first sleep restriction period (third, fifth and seventh day) to the second sleep restriction period (tenth and twelfth day)
Measured: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in REM sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Duration of REM sleep during the selected nap episodes was determined to track changes in this parameter from the first sleep restriction period (third, fifth and seventh day) to the second sleep restriction period (tenth and twelfth day)
Measured: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Nov 2017
- Study start28 Nov 2017
- Primary completion20 Jan 2018
- Study completion20 Jan 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)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
- Duke-NUS Graduate Medical School
- Sponsor type
- University, hospital or other
- Collaborators
- National Medical Research Council (NMRC), Singapore
- Responsible party
- Principal investigator, Michael WL Chee, MBBS, Duke-NUS Graduate Medical School
- Investigators
- Michael WL Chee, MBBS, Principal investigator, Duke-NUS Graduate Medical School
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03333512
- Sponsor's protocol ID
- NFS4
- Acronym
- NFS4
- Status last verified
- Jan 2018
- First submitted
- 2 Oct 2017
- Last updated
- 1 Feb 2018
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Leong RLF, Tian L, Yu N, Teo TB, Ong JL, Chee MWL. Bidirectional associations between the duration and timing of nocturnal sleep and daytime naps in adolescents differ from weekdays to weekends. Sleep. 2024 Sep 9;47(9):zsae147. doi: 10.1093/sleep/zsae147.
PubMed 38938171Lo JC, Ang JWA, Koa TB, Ong JL, Lim J. Predicting vigilance vulnerability during 1 and 2 weeks of sleep restriction with baseline performance metrics. Sleep Adv. 2022 Oct 25;3(1):zpac040. doi: 10.1093/sleepadvances/zpac040. eCollection 2022.
PubMed 37193393Lo JC, Koa TB, Ong JL, Gooley JJ, Chee MWL. Staying vigilant during recurrent sleep restriction: dose-response effects of time-in-bed and benefits of daytime napping. Sleep. 2022 Apr 11;45(4):zsac023. doi: 10.1093/sleep/zsac023.
PubMed 35089345Lee XK, Chee NIYN, Ong JL, Teo TB, van Rijn E, Lo JC, Chee MWL. Validation of a Consumer Sleep Wearable Device With Actigraphy and Polysomnography in Adolescents Across Sleep Opportunity Manipulations. J Clin Sleep Med. 2019 Sep 15;15(9):1337-1346. doi: 10.5664/jcsm.7932.
PubMed 31538605Lo JC, Twan DCK, Karamchedu S, Lee XK, Ong JL, Van Rijn E, Gooley JJ, Chee MWL. Differential effects of split and continuous sleep on neurobehavioral function and glucose tolerance in sleep-restricted adolescents. Sleep. 2019 May 1;42(5):zsz037. doi: 10.1093/sleep/zsz037.
PubMed 30753648
Study at a glance
From the registry record, last updated by the sponsor on 1 Feb 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Cognitive and Metabolic Effects of Sleep Restriction in Adolescents
- ClinicalTrials.gov ID
- NCT03333512
- Acronym / sponsor ID
- NFS4 / NFS4
- Conditions
- Sleep, Sleep Restriction
- Keywords
- Nap, Recovery Sleep, Cognitive Functions, Glucose Metabolism, Neurobehavioral Functions, Mood, Subjective Sleepiness
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 59 participants (actual)
- Lead sponsor
- Duke-NUS Graduate Medical SchoolUniversity, hospital or other
- Collaborators
- National Medical Research Council (NMRC), Singapore
- Study start
- 28 Nov 2017 (actual)
- Primary completion
- 20 Jan 2018 (actual)
- Study completion
- 20 Jan 2018 (actual)
- First posted
- 7 Nov 2017 (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.
The aim of this study is to examine the neurobehavioural and glucose metabolic responses to two successive cycles of sleep restriction and recovery in adolescents, and to determine the benefits of napping on cognitive performance, alertness, mood and glucose metabolism. Using a split-sleep design, 60 participants, aged 15 to 19 years old, are divided into a nap and a no-nap group. Both groups undergo two cycles of sleep restriction and recovery over a period of 15 days. The no-nap group receives a 6.5-hour sleep opportunity on sleep restriction nights, with no daytime nap opportunity. The nap group receives a 5-hour sleep opportunity on sleep restriction nights, and has a 1.5-hour nap opportunity the following afternoon.
Detailed description
The present study investigates whether a continuous stretch of night time sleep (6.5 hours) will lead to better neurobehavioural outcomes relative to nocturnal sleep restriction (5 hours) and daytime nap (1.5 hours) of the same total duration, and how sleep restriction affects glucose metabolism. The 15-day protocol is conducted in a dormitory on 60 high school students, aged 15 to 19 years old. Participants are assigned to a nap or no-nap group. Both groups start with two 9-hour adaptation and baseline nights, followed by two successive cycles of sleep restriction (5-h time in bed (TIB); 01:00-06:00 or 6.5-h TIB; 00:15-06:45) and recovery (9-h TIB; 23:00-08:00). Following each sleep-restricted night, the nap group receives a 1.5-h nap opportunity, while participants in the no-nap group watch a documentary. Throughout the protocol, sleep-wake patterns are assessed with actigraphy and polysomnography. Sleepiness levels, mood, vigilance, working memory / executive functions, and speed of processing are assessed 3 times daily (10:00, 16:15, and 20:00). Other cognitive functions such as memory and mindfulness levels are investigated through computer-based tasks. Glucose metabolism is measured using oral glucose tolerance tests in the mornings after the second baseline night, the third night of sleep restriction and second recovery night in the first cycle, as well as the last sleep restriction night in the second cycle.
All participants stay in air-conditioned, twin-share bedrooms with en-suite bathrooms. Bedroom windows are fitted with blackout panels to ensure participants are not woken up prematurely by sunlight. Earplugs are provided, and participants are allowed to adjust the temperature of their bedrooms to their personal comfort. Three main meals are served each day, with snacks being provided for upon request. Caffeinated drinks, unscheduled sleep, and strenuous physical activities are prohibited.
Outside of scheduled sleep, meal, and cognitive testing times, participants spend the majority of their free time in a common room that is illuminated by natural and artificial lighting. They are allowed to read, play non-physically exerting games, watch videos, and interact with research staff and other participants. Participants are 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
- 2
| Arm | Type | Receives |
|---|---|---|
| Nap | Experimental | Behavioral: NapAfter each night with a 5-hour sleep opportunity, participants have a daytime nap opportunity of 1.5 hours. |
| No nap | No intervention | –After each night with a 6.5-hour sleep opportunity, participants do not have a daytime nap opportunity, but instead watch documentaries. |
Who may qualify
- Ages
- 15 to 19 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- healthy
- no sleep disorder
- body mass index not greater than 30
Key exclusion criteria (5 listed)
- smoker
- habitual short sleeper (time in bed during term time of less than 6 hours and no sign of sleep extension of greater than 1 hour on weekends)
- consumption of more than 5 cups of caffeinated beverages a day
- travelling across more than 2 time zones in the month prior to the study protocol
- diagnosed with any psychiatric conditions
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 |
|---|---|---|
| NapLooking at the difference between continuous sleep opportunities and split-sleep opportunities. | Behavioural | Nap |
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: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Number of attention lapses (>500ms)
Change in working memory assessed with the 1-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Number of correct responses in the 1-back task
Change in executive functions assessed with the 3-back task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Number of correct responses in the 3-back task
Change in the level of subjective sleepiness assessed with the Karolinska Sleepiness Scale from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 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 restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 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 restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Total score on the negative subscale of the PANAS
Change in speed of processing assessed with the Mental Arithmetic Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Number of correct responses in the task
Change in speed of processing assessed with the Symbol Digit Modalities Task from morning to afternoon and then evening from baseline days to the first and second cycles of sleep restriction and recovery
Time frame: 3 times daily (10:00, 16:15, and 20:00) for 15 days
Number of correct responses in the task
Change in blood glucose level, measured using a blood glucose meter, from baseline following the first period sleep restriction, first period of recovery sleep, and second period of sleep restriction
Time frame: Four mornings (after baseline night 2, after sleep restriction night 3 (first sleep restriction period), after recovery night 2 (first recovery period), after sleep restriction night 3 (second sleep restriction period))
Score on blood glucose meter
Change in meal and snack consumption from baseline following the first period sleep restriction, first period of recovery sleep, and second period of sleep restriction
Time frame: Throughout the 15-day protocol
Amount of meals and snacks consumed, measured on an ad libitum basis
Change in memory performance in picture-word association task over sleep restriction nights and recovery night
Time frame: 12 times (morning and evening): after sleep restriction night 1, 2, 3, 4 and 5 (sleep restriction period 1) and after recovery night 2 (recovery period 1)
Score on picture-word association task
Mind-wandering, assessed using a breath-counting task
Time frame: Single session, during baseline
Error rate of button presses and percentage of errors that are self-caught
Effect of sleep versus wake during delay on the implementation of an intention in the future, where the intention will be encoded either before a 12-hr interval including a night of sleep or a day of wakefulness
Time frame: Single session during the 15-day protocol, after baseline night 1 or before sleep restriction night 1 (first sleep restriction period)
Memory score of correctly remembering to perform the intention following the wake or sleep interval
Effect of sleep versus wake during delay on memory for rewarded pictures, where the pictures will be encoded either before a 12-hr interval including a night of sleep or a day of wakefulness
Time frame: Single session during the 15-day protocol, after baseline night 1 or before sleep restriction night 1 (first sleep restriction period)
Memory score of correctly remembered encoded pictures following the wake or sleep interval
Effect of sleep restriction on learning of novel material (about different animal species) across separate sessions
Time frame: Single session during the 15-day protocol, after recovery night 2 (first recovery period)
Memory score on test of learned material
Effect of sleep restriction on memory of spatial locations
Time frame: Single session during the 15-day protocol, after sleep restriction night 3 (first sleep restriction period)
Performance in four mountains task
Effect of sleep restriction on problem-solving
Time frame: Single session during the 15-day protocol, after sleep restriction night 5 (first sleep restriction period)
Number of correctly solved equations in matchstick arithmetic task
Effect of sleep restriction on picture encoding
Time frame: Single session during the 15-day protocol, after recovery night 2 (second recovery period)
Memory score of correctly remembered encoded pictures of non-famous people, landscapes, scenes and objects
Effect of sleep restriction on effort/temporal discounting
Time frame: Three sessions during the 15-day protocol (after baseline night 1, after sleep restriction night 5 (first sleep restriction period) and after recovery night 2 (first recovery period))
Choice preference (perform a longer duration task for a higher reward, or to take a break for a lower/no reward) in effort/temporal discounting task is measured
Effect of prior knowledge about the position of items in a previously learned hierarchy on learning of the position of novel items in a new hierarchy
Time frame: Single session, during baseline
Percentage of correct responses on the test
Effect of sleep restriction on task switching performance
Time frame: Four sessions during the 15-day protocol (after baseline night 1, after sleep restriction night 3 (first sleep restriction period), after recovery night 2 (first recovery period) and after sleep restriction night 3 (second sleep restriction period))
Difference in reaction time between switch trial and repetition trial in task-switching task
Effect of sleep restriction on attentional bias to threat assessed using visual cues that are coupled either to an aversive sound (threat cue) or a neutral sound (neutral cue)
Time frame: Three session during the 15-day protocol (after baseline night 1, after sleep restriction night 5 (first sleep restriction period), after recovery night 1 (first recovery period))
Correct responses to a target that is presented at the same (valid) or opposite (invalid) location of stimulus
Effect of verbal reward on procedural memory assessed using a finger tapping task
Time frame: Two sessions during the 15-day protocol (before baseline night 1 and after baseline night 1)
Accuracy of performance on the finger-tapping task
10 secondary outcomes
Change in total sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in N1 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in N2 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in N3 sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in Rapid Eye Movement (REM) sleep duration at night assessed with polysomnography from baseline nights to the first and second cycles of sleep restriction and recovery
Time frame: Nocturnal sleep on nights 1 & 2 (baseline), 3, 5 & 7 (first sleep restriction period), 8 (first recovery period), 10 & 12 (second sleep restriction period), & 13 (second recovery period)
Change in total sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Time frame: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in N1 sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Time frame: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in N2 sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Time frame: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in N3 sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Time frame: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period
Change in REM sleep duration during daytime naps assessed with polysomnography from the first to the second sleep restriction period
Time frame: Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction 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 1 Feb 2018.
- Derived from this study: PubMed 38938171Leong RLF, Tian L, Yu N, Teo TB, Ong JL, Chee MWL. Bidirectional associations between the duration and timing of nocturnal sleep and daytime naps in adolescents differ from weekdays to weekends. Sleep. 2024 Sep 9;47(9):zsae147. doi: 10.1093/sleep/zsae147.
- Derived from this study: PubMed 37193393Lo JC, Ang JWA, Koa TB, Ong JL, Lim J. Predicting vigilance vulnerability during 1 and 2 weeks of sleep restriction with baseline performance metrics. Sleep Adv. 2022 Oct 25;3(1):zpac040. doi: 10.1093/sleepadvances/zpac040. eCollection 2022.
- Derived from this study: PubMed 35089345Lo JC, Koa TB, Ong JL, Gooley JJ, Chee MWL. Staying vigilant during recurrent sleep restriction: dose-response effects of time-in-bed and benefits of daytime napping. Sleep. 2022 Apr 11;45(4):zsac023. doi: 10.1093/sleep/zsac023.
- Derived from this study: PubMed 31538605Lee XK, Chee NIYN, Ong JL, Teo TB, van Rijn E, Lo JC, Chee MWL. Validation of a Consumer Sleep Wearable Device With Actigraphy and Polysomnography in Adolescents Across Sleep Opportunity Manipulations. J Clin Sleep Med. 2019 Sep 15;15(9):1337-1346. doi: 10.5664/jcsm.7932.
- Derived from this study: PubMed 30753648Lo JC, Twan DCK, Karamchedu S, Lee XK, Ong JL, Van Rijn E, Gooley JJ, Chee MWL. Differential effects of split and continuous sleep on neurobehavioral function and glucose tolerance in sleep-restricted adolescents. Sleep. 2019 May 1;42(5):zsz037. doi: 10.1093/sleep/zsz037.
- 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.
Michael WL Chee, MBBS principal investigator
Duke-NUS Graduate Medical School
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nap in people with Sleep and Sleep Restriction, run by Duke-NUS Graduate Medical School 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 3 inclusion and 5 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 1 Feb 2018. 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: 3 times daily (10:00, 16:15, and 20:00) for 15 days). The study lists 23 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 NCT03333512, which also lists 5 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 1 Feb 2018.