Effects of Napping in Sleep-Restricted Adolescents

Sleep Clinical Trial

Official title:

Effectiveness of a Daytime Nap on Alleviating Cognitive Impairment Due to Short Sleep in Adolescents

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02838095
• Other study ID #: NFS2
• Status: Completed
• Phase: N/A
• First received: June 15, 2016
• Last updated: July 15, 2016
• Start date: August 2015
• Est. completion date: December 2015

Study information

• Verified date: July 2016
• Source: Duke-NUS Graduate Medical School
• Contact: n/a
• Is FDA regulated: No
• Health authority: Singapore: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

To examine the neurobehavioural responses to two successive cycles of sleep restriction and recovery in adolescents, and to determine the benefits of napping on cognitive performance, alertness, and mood. 57 participants, aged 15 to 19 years old, were divided into nap and no-nap groups. Both groups underwent two cycles of sleep restriction and recovery over 15 days. The nap group received an afternoon sleep opportunity lasting 1 hour.

Description:

57 participants (aged 15 to 19 years old) were grouped into nap and no nap groups. Both groups took part in a 15-day protocol that started with 2 9-hour adaptation and baseline nights, followed by two successive cycles of sleep restriction (5-h time-in-bed [TIB]; 01:00-06:00) and recovery (9-h TIB; 23:00-08:00) intended to simulate the weekday sleep loss and weekend attempt to 'catch up' that are familiar to high school students. The nap group received a 1-hour nap opportunity at 14:00 following each sleep-restricted night, while participants in the no nap group watched a documentary. Sleep was monitored with polysomnography on 9 selected nights. Cognitive performance, subjective sleepiness, and mood were assessed 3 times daily (10:00, 15:45, and 20:00).

All participants stayed in air-conditioned, twin-share bedrooms with en-suite bathrooms. Bedroom windows were fitted with blackout panels to ensure participants were not woken up prematurely by sunlight. Earplugs were also provided, and participants were allowed to adjust the temperature of their bedrooms to their personal comfort. 3 main meals were served each day, with snacks being provided for upon request. Caffeinated drinks, unscheduled sleep, and strenuous physical activities were prohibited.

Outside of scheduled sleep, meal, and cognitive testing times, participants spent the majority of their free time in a common room that was illuminated by natural and artificial lighting. They were allowed to read, play non-physically exerting games, watch videos, and interact with research staff and other participants. Participants were under constant supervision by the research staff.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 57
• Est. completion date: December 2015
• Est. primary completion date: December 2015
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 15 Years to 19 Years

Eligibility

Inclusion Criteria:

• healthy

• no sleep disorder

• body mass index not greater than 30

Exclusion Criteria:

• 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

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Sleep
• Sleep Deprivation

Intervention

Behavioral:
• Nap
A 1-hour daytime nap opportunity

Locations

Country	Name	City	State
Singapore	Duke-NUS Medical School	Singapore

Sponsors (2)

Lead Sponsor	Collaborator
Duke-NUS Graduate Medical School	National Medical Research Council (NMRC), Singapore

Country where clinical trial is conducted

Singapore, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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)	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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)	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Primary	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	3 times daily (10:00, 15:45, and 20:00) for 15 days	No
Secondary	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 third nights) and changes in the first sleep restriction period (fourth, sixth and eighth night), the first recovery period (ninth night), the second sleep restriction period (eleventh and thirteenth night), and the second recovery period (fourteenth night).	Nocturnal sleep on nights 1 & 3 (baseline), 4, 6 & 8 (first sleep restriction period), 9 (first recovery period), 11 & 13 (second sleep restriction period), & 14 (second recovery period)	No
Secondary	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 third nights) and changes in the first sleep restriction period (fourth, sixth and eighth night), the first recovery period (ninth night), the second sleep restriction period (eleventh and thirteenth night), and the second recovery period (fourteenth night).	Nocturnal sleep on nights 1 & 3 (baseline), 4, 6 & 8 (first sleep restriction period), 9 (first recovery period), 11 & 13 (second sleep restriction period), & 14 (second recovery period)	No
Secondary	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 third nights) and changes in the first sleep restriction period (fourth, sixth and eighth night), the first recovery period (ninth night), the second sleep restriction period (eleventh and thirteenth night), and the second recovery period (fourteenth night).	Nocturnal sleep on nights 1 & 3 (baseline), 4, 6 & 8 (first sleep restriction period), 9 (first recovery period), 11 & 13 (second sleep restriction period), & 14 (second recovery period)	No
Secondary	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 third nights) and changes in the first sleep restriction period (fourth, sixth and eighth night), the first recovery period (ninth night), the second sleep restriction period (eleventh and thirteenth night), and the second recovery period (fourteenth night).	Nocturnal sleep on nights 1 & 3 (baseline), 4, 6 & 8 (first sleep restriction period), 9 (first recovery period), 11 & 13 (second sleep restriction period), & 14 (second recovery period)	No
Secondary	Change in 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 third nights) and changes in the first sleep restriction period (fourth, sixth and eighth night), the first recovery period (ninth night), the second sleep restriction period (eleventh and thirteenth night), and the second recovery period (fourteenth night).	Nocturnal sleep on nights 1 & 3 (baseline), 4, 6 & 8 (first sleep restriction period), 9 (first recovery period), 11 & 13 (second sleep restriction period), & 14 (second recovery period)	No
Secondary	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 (fourth, sixth and eighth day) to the second sleep restriction period (eleventh and thirteenth day).	Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period)	No
Secondary	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 (fourth, sixth and eighth day) to the second sleep restriction period (eleventh and thirteenth day).	Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period)	No
Secondary	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 (fourth, sixth and eighth day) to the second sleep restriction period (eleventh and thirteenth day).	Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period)	No
Secondary	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 (fourth, sixth and eighth day) to the second sleep restriction period (eleventh and thirteenth day).	Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period)	No
Secondary	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 (fourth, sixth and eighth day) to the second sleep restriction period (eleventh and thirteenth day).	Afternoon naps on days 4, 6 & 8 (first sleep restriction period), 11 & 13 (second sleep restriction period)	No