Influence of Nocturnal Light Exposure on the Impairment of Glucose Tolerance Induced by Chronic Sleep Restriction

NCT04868539 | Completed Results

• 1 other identifier: 2021P000961
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 1

Brief Summary

This project is designed to test for the first time whether glucose metabolism is differentially impaired by sleep restriction with and without additional exposure to artificial light at night (ALAN).

Conditions

Glucose Intolerance; Sleep Deprivation; Sleep

Keywords

Chronic Sleep Restriction; Artificial Light At Night; Glucose Intolerance; Melatonin; Sleep

Outcome Measures

Primary Outcomes (3)

• Impairment of Insulin Sensitivity

  Insulin sensitivity (Si) is assessed via minimal model analysis, a mathematical model developed by Bergman and colleagues. Higher values represent better insulin sensitivity and lower values represent impaired insulin sensitivity. The mean change in Si between exposure and baseline is reported for each arm.

  Change between Study Day 7 vs. Study Day 15 and Study Day 24 vs. Study Day 32

• Impairment of Glucose Tolerance

  Test the hypothesis that exposure to one week of sleep restriction with concurrent exposure to extended duration ALAN (LD 19:5) will induce greater impairment of glucose tolerance than exposure to one week of sleep restriction without extended duration ALAN (LD 14:10). Glucose tolerance will be calculated as the area under the curve from minutes 0-120 following a mixed meal tolerance test

  Change between Study Day 6 vs. Study Day 14 and Study Day 23 vs. Study Day 31

• Duration of Nocturnal Melatonin Secretion

  Test the hypothesis that exposure to one week of sleep restriction with concurrent exposure to extended duration ALAN (LD 19:5) will acutely reduce the duration of nocturnal melatonin secretion as compared to baseline more than exposure to one week of sleep restriction without extended duration ALAN (LD 14:10). Duration of nocturnal melatonin secretion will be determined by the duration of time at which melatonin levels are above a threshold calculated as 25% of peak-to-trough amplitude at baseline in dim light.

  Change between Study Day 14-15 (overnight) vs. Study Day 31-32 (overnight)

Secondary Outcomes (4)

• Acute Insulin Response to Glucose

  Change from study day 7 to 15 compared to change from study day 24 to 32

• Glucose Effectiveness

  Change from study day 7 to 15 vs change from study day 24 to 32

• Insulin Area-under-the-curve

  Change between Study Day 6 vs. Study Day 14 and Study Day 23 vs. Study Day 31

• Duration of Endogenous Melatonin Secretory Profile

  Study Day 15-16 vs Study Day 32-33

Study Arms (2)

Sleep Restriction with ALAN, then Sleep Restriction without ALAN

EXPERIMENTAL

Participants first received Sleep Restriction with extended duration Artificial Light At Night (ALAN), during which sleep episodes were shortened to 5 hours and participants remained in room lighting for the full wake episode (19h room light, 5h darkness). After a washout of 10 days, participants received Sleep Restriction without ALAN, during which sleep episodes were shortened to 5 hours but participants were kept in dim light for the extra time awake (14h room light, 5h dim light, 5h darkness).

Other: Sleep Restriction with ALAN first, then Sleep Restriction without ALAN

Sleep Restriction without ALAN, then Sleep Restriction with ALAN

EXPERIMENTAL

Participants first received Sleep Restriction without extended duration Artificial Light At Night (ALAN), during which sleep episodes were shortened to 5 hours but participants were kept in dim light for the extra time awake (14h room light, 5h dim light, 5h darkness). After a washout of 10 days, participants received Sleep Restriction with extended duration ALAN, during which sleep episodes were shortened to 5 hours and participants remained in room lighting for the full wake episode (19h room light, 5h darkness).

Other: Sleep Restriction without ALAN first, then sleep restriction with ALAN

Interventions

Sleep Restriction with ALAN first, then Sleep Restriction without ALAN OTHER

Sleep restriction with 90 lux lighting for 19hr/day first, followed by Sleep restriction with 90 lux lighting for 14hr/day

Also known as: ALAN first

Sleep Restriction with ALAN, then Sleep Restriction without ALAN

Sleep Restriction without ALAN first, then sleep restriction with ALAN OTHER

Sleep restriction with 90 lux lighting for 14hr/day first, followed by Sleep restriction with 90 lux lighting for 19hr/day

Also known as: ALAN second

Sleep Restriction without ALAN, then Sleep Restriction with ALAN

Eligibility Criteria

• Age: 20 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy adults with conventional and regular sleep-wake timing
• Non-smokers
• Completion of medical, psychological, and sleep screening tests
• Able to spend 33 consecutive days/nights in the laboratory
• Normal color vision

You may not qualify if:

• History of neurological or psychiatric disorder
• History of sleep disorder or regular use of sleep-promoting medication
• Current prescription, herbal, or over-the-counter medication use
• Traveling across 2 or more time zones within past 3 months
• Donating blood within past 8 weeks
• Worked night or rotating shift work within past 3 years
• Hearing impairment, visual impairment
• History of eye trauma or surgery
• Drug or alcohol dependency

Sponsors & Collaborators

• Brigham and Women's Hospital: lead

Study Sites (1)

Brigham and Women's Hospital

Boston, Massachusetts, 02115, United States

Location

MeSH Terms

Conditions

Glucose Intolerance; Sleep Deprivation

Condition Hierarchy (Ancestors)

Hyperglycemia; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Mental Disorders

Limitations and Caveats

Study enrollment was ended early due to budgetary reasons, so we were unable to study the total number of participants planned. Thus, we may have limited statistical power to interpret the results.

Results Point of Contact

• Title: Dr. Charles Czeisler, Ph.D., M.D.
• Organization: Brigham and Women's Hospital

cacadmin@partners.org

617-732-4013

Study Officials

• Charles A Czeisler, PhD, MD

  Brigham and Women's Hospital

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: The order in which subjects undergo the two sleep interventions will be randomized.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: This study uses a within-subjects randomized crossover design to compare the effects of sleep restriction with and without ALAN on glucose metabolism. The order in which subjects undergo the two sleep interventions will be randomized.

Study Record Dates

• First Submitted: April 20, 2021
• First Posted: May 3, 2021
• Study Start: March 15, 2022
• Primary Completion: February 20, 2024
• Study Completion: May 30, 2024
• Last Updated: October 14, 2025
• Results First Posted: October 14, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)