Cardiometabolic Outcomes With Light Exposure During Sleep

Study Overview
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Brief Summary
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This study tested the hypothesis that acute exposure to light during nighttime sleep adversely affects cardiometabolic function.

Detailed Description
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This study tested the hypothesis that acute exposure to light during sleep adversely affects next morning glucose homeostasis and whether this effect occurs via reduced sleep quality, melatonin suppression, or sympathetic nervous system (SNS) activation during sleep. Twenty young adults participated in this parallel-group study design. The room light condition (n=10) included one night of sleep in dim light (< 3 lux) followed by one night of sleep with overhead room lighting (100 lux). The dim light condition (n=10) included two consecutive nights of sleep in dim light.

Official Title
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Cardiometabolic Outcomes With Light Exposure During Sleep

Conditions
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Light

Intervention / Treatment
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* Behavioral: room light


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy adults ages 18-40 years habitual sleep duration of 6.5-8.5 hours habitual sleep onset of 9:00 pm-1:00 am Exclusion Criteria: any sleep disorder as assessed by history and screening questionnaires for obstructive sleep apnea (Berlin) and excessive daytime sleepiness (ESS >12), and by PSG to exclude sleep apnea (apnea hypopnea index ≥ 15), periodic leg movements (movement arousal index ≥ 15), or REM sleep behavior disorder; history of a cognitive or neurological disorder; history of a major psychiatric disorder, including but not limited to mood/anxiety, eating, and alcohol/substance abuse disorders; depressed mood (Beck Depression Inventory II score ≥ 20); diabetes or other endocrine disorders; any gastrointestinal disease requiring dietary adjustment; blindness or significant vision loss; any unstable or serious medical conditions; current or recent (within the past month) of psychoactive, hypnotic, stimulant or analgesic medications; shift work or other types of self-imposed irregular sleep schedules; obesity (body mass index > 30 kg/m2); history of habitual smoking (6 or more cigarettes per week) or drinking (7 or more alcoholic beverages per week) or caffeine consumption greater than 300 mg per day; current use of light therapy; use of any other legal or illicit substance that may affect sleep and/or appetite; allergy to heparin. Due to the metabolic stress associated with pregnancy and breastfeeding, patients who were pregnant or breastfeeding were also excluded.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: room light<br>The room light condition (n=10) included one night of sleep in dim light (< 3 lux) followed by one night of sleep with overhead room lighting (100 lux). | Behavioral: room light<br>* The room light condition (n=10) included one night of sleep in dim light (< 3 lux) followed by one night of sleep with overhead room lighting (100 lux). The dim light condition (n=10) included two consecutive nights of sleep in dim light.<br>|
| No Intervention: dim light<br>The dim light condition (n=10) included two consecutive nights of sleep in dim light. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Matsuda Index | OGTT | Day 2 | 
| Matsuda Index | OGTT | Day 3 | 
| HOMA-IR | Fasting | Day 2 | 
| HOMA-IR | Fasting | Day 3 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleep Stages | Stage N1, N2, N3 | Night 1 | 
| Sleep Stages | Stage N1, N2, N3 | Night 2 | 
| Sleep Stages | Stage N1, N2, N3 | Night 3 | 
| Heart Rate | beat to beat | Night 2 | 
| Heart Rate | beat to beat | Night 3 | 
| Blood pressure | diastolic/systolic | Day 2 | 
| Blood pressure | diastolic/systolic | Day 3 | 
| Slow Wave Activity | Spectral power in the Slow Wave Activity (0.5 to 4 Hz) | Night 1 | 
| Slow Wave Activity | Spectral power in the Slow Wave Activity (0.5 to 4 Hz) | Night 2 | 
| Slow Wave Activity | Spectral power in the Slow Wave Activity (0.5 to 4 Hz) | Night 3 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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light, sleep, metabolism, sympathetic nervous system, insulin resistance