Cardiometabolic Outcomes With Light Exposure During Sleep

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

Study Overview

• Status: Completed
• Conditions: Light
• Intervention / Treatment: Behavioral: room light

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: room light; 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; 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.
No Intervention: dim light; The dim light condition (n=10) included two consecutive nights of sleep in dim light.

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Melatonin	pg/ml	Day 2
Melatonin	pg/ml	Day 3
subjective sleepiness	sleepiness level	Day 2
subjective sleepiness	sleepiness level	Day 3
hunger	hunger level	Day 2
hunger	hunger level	Day 3

Collaborators and Investigators

• Sponsor: Northwestern University

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2014
• Primary Completion (Actual): January 1, 2018
• Study Completion (Actual): July 1, 2018

Study Registration Dates

• First Submitted: December 9, 2021
• First Submitted That Met QC Criteria: March 30, 2022
• First Posted (Actual): April 8, 2022

Study Record Updates

• Last Update Posted (Actual): April 8, 2022
• Last Update Submitted That Met QC Criteria: March 30, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: sleep; insulin resistance; metabolism; light; sympathetic nervous system
• Other Study ID Numbers: STU00094737

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified data to support the findings of the study are available in Arch, the open access Northwestern University Institutional Repository (https://doi.org/10.21985/n2-9zrx-ev05)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No