Sleep
Conditions
Keywords
Sleep, Photoreceptor Cells, Vertebrate, Melatonin
Brief summary
The purpose of the study is to test the use of amber glasses at night as a method to block blue light from the eye, allowing the brain to produce a dim-light melatonin onset. The investigators hypothesize that blue-blocking will produce measurable benefits in subjectively and objectively rated sleep quality and mood as well as salivary melatonin levels during the night.
Detailed description
Participants will complete a self-report battery containing measures of sleep quality, morningness-eveningness chronotype, and mood. Participants will then wear a wrist-worn accelerometer for 14 days to objectively record activity level and sleep quality. Participants will also fill out a daily sleep log and short self-report measures assessing sleep and mood. On days 4-7 and 11-14 of the study the participants will wear either amber or placebo control lenses prior to sleep onset in a randomized crossover design (i.e., participants will be randomized to wear either amber lenses or placebo lenses for the first part of the protocol and then switch to wear the opposite lenses for the second part of the protocol). Participants will spend nights 7 and 14 of the study in a sleep laboratory in order to obtain hourly melatonin samples and wear a wrist sleep monitor to non-invasively and objectively measure sleep state and quality using peripheral arterial tone and oxygen perfusion.
Interventions
OTHERAmber Lenses
Glasses fitted with amber lenses that block the blue spectrum of light (\ 470 nm) to be worn prior to desired sleep onset time.
OTHERPlacebo Lenses
Glasses fitted with placebo lenses that allow all visible spectrum of light to be worn prior to desired sleep onset time.
Sponsors
University of North Carolina, Chapel Hill
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Good physical health * Proficiency in written and spoken English * Reported average total sleep time \<9 hours (so nights spent in sleep lab will not result in sleep deprivation)
Exclusion criteria
* Taking regular medication affecting sleep and/or mood * Travel across more than two time zones within the past month * Smoke \> 5 cigarettes per day * Excessive caffeine use (\>2 cups at one time or \>500 mg daily) * No current Axis I Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Disorder * No current use of street drugs * No history of sleep disorder/bipolar disorder/psychosis/seizure disorder/chronic medical condition * Night shift work within the past 2 months
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Increase dim-light melatonin production | 4 days | Hourly saliva samples will be collected from participants at the end of each 4 night interval in order to measure levels of melatonin production. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Improved subjective self-reported mood | 4 days | Participants will complete the Positive and Negative Affect Scale (PANAS) on a daily basis to measure self-reported mood. |
| Improved objective measures of sleep | 4 days | Participants will complete nights in the sleep lab while wearing a watch device to measure arterial tone in order to objectively measure time spent in different sleep stages. |
| Improved subjective self-reported sleep quality | 4 days | Participants will complete the Leeds Sleep Evaluation in order to assess self-report of sleep quality. |
Countries
United States
Outcome results
None listed