Ignite Creation Date:
2024-05-06 @ 3:46 PM
Last Modification Date:
2024-10-26 @ 1:56 PM
Study NCT ID:
NCT04753190
Status:
RECRUITING
Last Update Posted:
2023-11-13
First Post:
2021-02-08
Brief Title:
Light Timing Study
Sponsor:
Rush University Medical Center
Organization:
Rush University Medical Center
Study Overview
Official Title:
Adolescent Circadian Phase Shifts Novel Time-of-day Targets for Bright Light
Status:
RECRUITING
Status Verified Date:
2024-09
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
ALT
Brief Summary:
Chronic circadian misalignment and sleep restriction peak during late adolescence and are associated with morning daytime sleepiness poor academic performance conduct problems depressed mood suicidal ideation substance use insulin resistance and obesity Bright light exposure from light boxes can shift rhythms earlier phase advance to facilitate earlier sleep onset and reduce morning circadian misalignment and the associated risks To phase advance circadian rhythms the investigators PRCs showed that the ideal time to begin light exposure was slightly before wake-up time and light should be avoided around bedtime because this is when light produces maximum phase delay shifts An unexpected finding from these results however was a second advancing region in the afternoon 6 to 9 h after habitual wake-up time suggesting that afternoon light may have more circadian phase advancing ability than traditionally thought The overall goal of this mechanistic study is to follow-up on the unexpected PRC findings and test whether individually-timed afternoon light alone and in combination with morning bright light can shift circadian rhythms earlier in older adolescents Four groups will be compared in a randomized parallel group design afternoon bright light morning bright light morning afternoon bright light and a dim room light control Adolescents will complete a 2-week protocol After a baseline week with a stable sleep schedule adolescents will live in the laboratory for 7 days Sleepdark and the time of bright light exposure will gradually shift earlier Bright light 5000 lux will be timed individually based on hisher stable baseline sleep schedule The first 3-h morning bright light exposure will begin 1 h before wake on the first morning The first 3-h afternoon bright light exposure will begin 5 h after wake The morning afternoon exposures will begin at the same times but each exposure will be 15 h so that a total of 3 h of bright light per day will be given to each group except the dim light control group Phase shifts of the circadian clocks marked by the dim light melatonin onset DLMO is the main outcome Investigators hypothesize that afternoon bright light will work synergistically with morning bright light to produce larger shifts than morning or afternoon bright light alone These data could challenge the current understanding of how to use bright light to shift circadian rhythms earlier
Detailed Description:
Participants will complete a 14-day protocol On days 1-7 participants will sleep at home on a stable sleep schedule that requires 9 h of time in bed in the dark This will ensure that participants are not sleep deprived before beginning the lab sessions Wake time will be the average of the self-reported wake-up time 15 mins before the study begins measured from pre-study sleep logs collected for a week or more Bedtime will be 9 h before wake-up time A device worn on the wrist that measures activity actigraph sleep diaries and daily telephone messages will monitor compliance to the sleep schedule Participants will visit the lab at least once during this week to download and review their data If participants are not compliant to the sleep schedule they will be dropped from the study
On days 8-13 participants will live in the laboratory for seven days On day 8 participants will arrive at the laboratory in the afternoon and shortly after will begin a baseline circadian phase assessment to determine baseline dim light melatonin onset DLMO a reliable marker of the circadian timing system On day 9 participants will sleep on their stable 9-h sleep schedule in the laboratory Their 9-h fixed sleep schedule will be shifted by 1 h per day over 3 days Participants will sleep in dark bedrooms in the lab During scheduled wake participants will remain awake in normal dim room light except during bright light sessions when light will range from 5000 to 7000 lux Study groups will differ by the light exposure they receive during the lab sessions In the afternoon bright light ABL group participants will be exposed to 3 h of bright light on 3 consecutive afternoons On the first day day 10 light boxes will be turned on 5 h after fixed wake-up time Then the start of the light exposure will move 1 h earlier each day In the morning bright light MBL group participants will be exposed to 3 consecutive mornings of 3 h of bright light On the morning of day 11 the 3-h bright light exposure will begin 1 h before their stable wake-up time In the morning afternoon bright light MBL ABL group bright light will begin at the same times as the ABL and MBL groups and participants will received the same duration of bright light per day 3 h as the ABL and MBL groups because the duration of each exposure will be 15 h instead of 3 h Both bright light exposures will move 1 h earlier on subsequent days In the room light control group participants will complete the same 7-day lab session except remain in dim room lighting All participants will complete a final circadian phase assessment at the end of the 7-day lab session day 13
On days 8-13 participants will live in the laboratory for seven days On day 8 participants will arrive at the laboratory in the afternoon and shortly after will begin a baseline circadian phase assessment to determine baseline dim light melatonin onset DLMO a reliable marker of the circadian timing system On day 9 participants will sleep on their stable 9-h sleep schedule in the laboratory Their 9-h fixed sleep schedule will be shifted by 1 h per day over 3 days Participants will sleep in dark bedrooms in the lab During scheduled wake participants will remain awake in normal dim room light except during bright light sessions when light will range from 5000 to 7000 lux Study groups will differ by the light exposure they receive during the lab sessions In the afternoon bright light ABL group participants will be exposed to 3 h of bright light on 3 consecutive afternoons On the first day day 10 light boxes will be turned on 5 h after fixed wake-up time Then the start of the light exposure will move 1 h earlier each day In the morning bright light MBL group participants will be exposed to 3 consecutive mornings of 3 h of bright light On the morning of day 11 the 3-h bright light exposure will begin 1 h before their stable wake-up time In the morning afternoon bright light MBL ABL group bright light will begin at the same times as the ABL and MBL groups and participants will received the same duration of bright light per day 3 h as the ABL and MBL groups because the duration of each exposure will be 15 h instead of 3 h Both bright light exposures will move 1 h earlier on subsequent days In the room light control group participants will complete the same 7-day lab session except remain in dim room lighting All participants will complete a final circadian phase assessment at the end of the 7-day lab session day 13
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None