The Effects of Sleep Variability in Youth

Not Applicable

Completed

• Conditions: Sleep Variability
• Interventions: Behavioral: Irregular sleep

• Registration Number: NCT04263428
• Lead Sponsor: The University of Hong Kong

Brief Summary

Daily sleep variability is prevalent in the young populations, yet its effects remain less clear. The experimental study aims to examine the impacts of intraindividual daily sleep variability on sleep characteristics, cardiometabolic regulations and daytime functioning in college students.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-06-01
• Study First Submitted: 2019-06-15
• Study First Submitted QC: 2020-02-07
• Study First Posted: 2020-02-10
• Primary Completion: 2021-01-01
• Study Completion: 2021-01-01
• Status Verified: 2021-05
• Last Update Submitted: 2021-05-09
• Last Update Posted: 2021-05-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 41

Inclusion Criteria

• Habitual sleep duration > 7 h/day.

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Exclusion Criteria

• Extreme morning- nor extreme evening-chronotype
• With sleep problems
• With mood and anxiety problems
• With excessive daytime sleepiness
• Have history of any chronic medical condition and on regular medication.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Irregular sleep	Irregular sleep	Participants sleep in lab while being monitored with polysomnography for 8 consecutive nights, including an adaptation night and a baseline night of 7.5 h time in bed (0:00-7:30). Afterwards, they are instructed to sleep in bed on a schedule alternated between 6 h, i.e. 1:30-7:30, and 9 h, i.e. 22:30-7:30).

Primary Outcome Measures

Name	Time	Method
Cognitive functioning - Sustained attention	7 days (every morning and evening)	Sustained attention as measured by psychomotor vigilance task (PVT)
Cognitive functioning - inhibition	7 days	Inhibition as measured by stop-signal reaction time (SSRT)
Subjective sleepiness	7 days (every morning and evening)	As measured by the Stanford Sleepiness Scalen (SSS)
Mood	7 days (every morning and evening)	mood state as measured by the Positive and Negative Affect Scale (PANAS).
Cognitive functioning - processing speed	7 days	Processing speed as measured by Digit Symbol Substitution Test (DSST)
Cognitive functioning - working memory	7 days	working memory as measured by 2-back task

Secondary Outcome Measures

Name	Time	Method
Cortisol awakening response	baseline, post-intervention	Cortisol awakening response is assessed before and after the manipulation.
Sleep quality	7 days	Actual sleep time, sleep onset latency, wake after sleep onset and night time arousals as measured by actigraphy and PSG. Sleep satisfactory and dreams as measured by sleep diary.
Sleep architecture	7 days	Sleep stagings (e.g., SWS%, REM duration) and sleep EEG spectrums as analysed from PSG recordings.
Heart rate variability	7 days	Resting heart rate and heart rate variability are measured in the morning, evening and during the night.

Trial Locations

Locations (1)

Sleep Research Clinic & Laboratory, Department of Psychology, The University of Hong Kong; 🇭🇰 Hong Kong, Hong Kong