Trial Outcomes & Findings for Influence of Nocturnal Light Exposure on the Impairment of Glucose Tolerance Induced by Chronic Sleep Restriction (NCT NCT04868539)
NCT ID: NCT04868539
Last Updated: 2025-10-14
Results Overview
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.
COMPLETED
NA
14 participants
Change between Study Day 7 vs. Study Day 15 and Study Day 24 vs. Study Day 32
2025-10-14
Participant Flow
Healthy volunteers were recruited through online advertisements between October 2021-December 2023.
Two participants were excluded prior to randomization; one was due to an undisclosed surgery that excluded them from the study, and the other was due to ending study enrollment before they were admitted.
Participant milestones
| Measure |
Sleep Restriction With ALAN, Then Sleep Restriction Without ALAN
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).
|
Sleep Restriction Without ALAN, Then Sleep Restriction With ALAN
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).
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|---|---|---|
|
Overall Study
STARTED
|
6
|
6
|
|
Overall Study
COMPLETED
|
5
|
5
|
|
Overall Study
NOT COMPLETED
|
1
|
1
|
Reasons for withdrawal
| Measure |
Sleep Restriction With ALAN, Then Sleep Restriction Without ALAN
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).
|
Sleep Restriction Without ALAN, Then Sleep Restriction With ALAN
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).
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|---|---|---|
|
Overall Study
Unable to complete study due to poor IV access
|
1
|
1
|
Baseline Characteristics
Influence of Nocturnal Light Exposure on the Impairment of Glucose Tolerance Induced by Chronic Sleep Restriction
Baseline characteristics by cohort
| Measure |
Sleep Restriction Without ALAN, Then Sleep Restriction With ALAN
n=5 Participants
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).
|
Sleep Restriction With ALAN, Then Sleep Restriction Without ALAN
n=5 Participants
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 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).
|
Total
n=10 Participants
Total of all reporting groups
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|---|---|---|---|
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Age, Categorical
<=18 years
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
5 Participants
n=99 Participants
|
5 Participants
n=107 Participants
|
10 Participants
n=206 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Sex: Female, Male
Female
|
2 Participants
n=99 Participants
|
2 Participants
n=107 Participants
|
4 Participants
n=206 Participants
|
|
Sex: Female, Male
Male
|
3 Participants
n=99 Participants
|
3 Participants
n=107 Participants
|
6 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
2 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
2 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
3 Participants
n=99 Participants
|
5 Participants
n=107 Participants
|
8 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Black or African American
|
1 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
2 Participants
n=206 Participants
|
|
Race (NIH/OMB)
White
|
3 Participants
n=99 Participants
|
3 Participants
n=107 Participants
|
6 Participants
n=206 Participants
|
|
Race (NIH/OMB)
More than one race
|
1 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Region of Enrollment
United States
|
5 Participants
n=99 Participants
|
5 Participants
n=107 Participants
|
10 Participants
n=206 Participants
|
PRIMARY outcome
Timeframe: Change between Study Day 7 vs. Study Day 15 and Study Day 24 vs. Study Day 32Population: One participant excluded from "Without ALAN" condition due to non-physiological assay results
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.
Outcome measures
| Measure |
ALAN
n=9 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=8 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Impairment of Insulin Sensitivity
|
-0.80 (mU/L)^-1 min^-1
Standard Deviation 1.63
|
0.55 (mU/L)^-1 min^-1
Standard Deviation 4.18
|
PRIMARY outcome
Timeframe: Change between Study Day 6 vs. Study Day 14 and Study Day 23 vs. Study Day 31Test 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
Outcome measures
| Measure |
ALAN
n=8 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=8 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Impairment of Glucose Tolerance
|
524.4 mg/dL*min
Standard Deviation 376.7
|
179.1 mg/dL*min
Standard Deviation 1121.6
|
PRIMARY outcome
Timeframe: Change between Study Day 14-15 (overnight) vs. Study Day 31-32 (overnight)Population: Unable to calculate melatonin duration for one participant under the Without ALAN condition due to IV sampling difficulties
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.
Outcome measures
| Measure |
ALAN
n=10 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=9 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Duration of Nocturnal Melatonin Secretion
|
432.9 minutes
Standard Deviation 90.3
|
579.6 minutes
Standard Deviation 44.8
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SECONDARY outcome
Timeframe: Change from study day 7 to 15 compared to change from study day 24 to 32Acute Insulin Response as calculated with minimal model analysis, a mathematical model developed by Bergman and colleagues, and represents early insulin release in the body to manage blood glucose levels. Higher values represent a better response and lower values represent a worse response. The mean change in AIRg between exposure and baseline is reported for each arm.
Outcome measures
| Measure |
ALAN
n=9 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=9 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Acute Insulin Response to Glucose
|
-110.41 (mU/L)^-1 min^-1
Standard Deviation 472.51
|
-37.04 (mU/L)^-1 min^-1
Standard Deviation 203.45
|
SECONDARY outcome
Timeframe: Change from study day 7 to 15 vs change from study day 24 to 32Glucose Effectiveness as calculated using minimal model analysis, a mathematical model developed by Bergman and colleagues. It represents how well the body can normalize blood glucose independent of insulin. Higher glucose effectiveness (Sg) is generally associated with better metabolic health outcomes.
Outcome measures
| Measure |
ALAN
n=9 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=9 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Glucose Effectiveness
|
-0.00049 min^-1
Standard Deviation 0.0051
|
-0.0012 min^-1
Standard Deviation 0.0073
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SECONDARY outcome
Timeframe: Change between Study Day 6 vs. Study Day 14 and Study Day 23 vs. Study Day 31Population: We were unable to obtain meal response data for 2 participants due to IV access issues.
Insulin area under the curve (AUC) as calculated with trapezoidal method between 0-120min following mixed meal tolerance test.
Outcome measures
| Measure |
ALAN
n=8 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=8 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Insulin Area-under-the-curve
|
663.4 uIu/mL*min
Standard Deviation 917.7
|
-71.6 uIu/mL*min
Standard Deviation 702.5
|
SECONDARY outcome
Timeframe: Study Day 15-16 vs Study Day 32-33Test the hypothesis that exposure to one week of sleep restriction with concurrent exposure to extended duration ALAN (LD 19:5) will reduce the duration of the endogenous melatonin secretory profile 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.
Outcome measures
| Measure |
ALAN
n=10 Participants
Participants exposed to sleep restriction with extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
Without ALAN
n=10 Participants
Participants exposed to sleep restriction without extended duration artificial light at night (ALAN) during study days 8-14 or 25-31
|
|---|---|---|
|
Duration of Endogenous Melatonin Secretory Profile
|
581.7 minutes
Standard Deviation 51.1
|
609.6 minutes
Standard Deviation 66.1
|
Adverse Events
Sleep Restriction With ALAN
Sleep Restriction Without ALAN
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Sleep Restriction With ALAN
n=12 participants at risk
Participants 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).
|
Sleep Restriction Without ALAN
n=12 participants at risk
Participants 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).
|
|---|---|---|
|
General disorders
Headache
|
8.3%
1/12 • Number of events 2 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
16.7%
1/6 • Number of events 5 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
|
General disorders
Lightheadedness
|
0.00%
0/12 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
16.7%
2/12 • Number of events 2 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
|
General disorders
Nausea
|
0.00%
0/12 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
8.3%
1/12 • Number of events 2 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
|
General disorders
Bruising/petechiae on arm
|
0.00%
0/12 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
8.3%
1/12 • Number of events 1 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
|
General disorders
Chest pressure
|
8.3%
1/12 • Number of events 2 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
0.00%
0/12 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
|
General disorders
Stomach pain
|
0.00%
0/12 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
8.3%
1/12 • Number of events 2 • From admission to inpatient study until the participant's last inpatient day (up to 33 days)
|
Additional Information
Dr. Charles Czeisler, Ph.D., M.D.
Brigham and Women's Hospital
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place