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Light Sensitization Study

Primary Purpose

Chronobiology Disorders, Circadian Rhythm Disorders, Sleep Disorders, Circadian Rhythm

Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
light exposure
Sponsored by
Brigham and Women's Hospital
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Chronobiology Disorders focused on measuring light, melatonin, circadian, delayed sleep phase disorder, circadian light sensitivity, circadian timing system

Eligibility Criteria

21 Years - 30 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • healthy adults with conventional and regular sleep-wake timing
  • non-smokers
  • completion of medical, psychological, ophthalmological, and sleep screening tests
  • able to spend 13 consecutive days/nights in the laboratory

Exclusion Criteria:

  • history of neurological or psychiatric disorder
  • history of eye injury, eye surgery, or visual disorder (corrective lenses are acceptable)
  • history of sleep disorder or regular use of sleep-promoting medication
  • current prescription, herbal, or over-the-counter medication use (oral contraceptives are acceptable)

Sites / Locations

  • Brigham and Women's Hospital

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm 4

Arm Type

Experimental

Experimental

Experimental

Experimental

Arm Label

sensitization duration 1.375h

sensitization duration 5.5h

sensitization duration 22h

sensitization duration 0.33h

Arm Description

This group will experience a 1.375h sensitization duration prior to the 12h light exposure

This group will experience a 5.5h sensitization duration prior to the 12h light exposure

This group will experience a 22h sensitization duration prior to the 12h light exposure

This group will experience a 0.33h sensitization duration prior to the 12h light exposure

Outcomes

Primary Outcome Measures

circadian phase timing
timing of circadian phase as assessed using melatonin and temperature data

Secondary Outcome Measures

melatonin suppression
percent of melatonin suppression

Full Information

First Posted
March 30, 2011
Last Updated
June 29, 2021
Sponsor
Brigham and Women's Hospital
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
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1. Study Identification

Unique Protocol Identification Number
NCT01327040
Brief Title
Light Sensitization Study
Official Title
Sensitization of Human Circadian Responses to Light
Study Type
Interventional

2. Study Status

Record Verification Date
June 2021
Overall Recruitment Status
Completed
Study Start Date
October 2010 (undefined)
Primary Completion Date
December 2015 (Actual)
Study Completion Date
December 2020 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Brigham and Women's Hospital
Collaborators
National Heart, Lung, and Blood Institute (NHLBI)

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief Summary
Circadian rhythm disorders are a class of sleep disorders characterized by misalignment between the timing of sleep and the timing of rhythms driven by the biological clock. Light therapy can effectively treat these disorders, but the intensity and duration of light exposure required to do so has limited its practical use. In this study the investigators will test whether pre-exposure to dim light may enhance the response of the circadian system to light therapy. If so, this could result in shorter treatments that would have greater practical applications.
Detailed Description
Sleep disorders affect 35-40% of adults, resulting in diminished quality of life, and increased morbidity, mortality, and risk of automobile and occupational accidents. Circadian rhythm sleep disorders form a distinct class of sleep disorders characterized by misalignment between the timing of sleep and the circadian pacemaker. While light therapy can be an effective treatment of circadian rhythm sleep disorders, there are numerous practical limitations. Light is the most powerful signal from the environment that influences and regulates daily biological rhythms. It is well-established that the irradiance, duration, and timing of light exposure all affect the response of the circadian system. While it was once thought that these responses were mediated through the visual system, it is now known that there is a network of intrinsically photosensitive retinal ganglion cells (ipRGCs) that mediate circadian responses to light. Other new studies have demonstrated that recent light exposure history affects the circadian response to light in humans. These recent findings have important implications for the use of light to treat circadian rhythm disorders, including delayed and advanced sleep phase disorders, shift work sleep disorder, and jet lag, and they may also have relevance for the use of light to treat seasonal affective disorder. Up to now, little attention has been paid to the duration or intensity of light exposure prior to such light treatments. The investigators now have evidence that the human circadian system can become desensitized to light during long exposures and evidence that it can be sensitized to light by prior exposure to dim light. These recent findings suggest that light treatment protocols that sensitize the circadian system prior to the light treatment will be more effective than those currently in use. The 13-day inpatient studies the investigators propose will examine the effect on the human circadian system of different durations of dim-light sensitization prior to a standardized light treatment. These results will be compared within subjects in a randomized cross-over design study in which each subject will receive a control treatment and a light treatment with prior dim-light sensitization. The investigators will also include circadian phase disorder patients to test these mechanisms in the target patient population. Our findings will provide an important step in understanding how new knowledge about the circadian photoreceptive system can be used to refine and provide better treatment options for circadian rhythm disorders.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Chronobiology Disorders, Circadian Rhythm Disorders, Sleep Disorders, Circadian Rhythm
Keywords
light, melatonin, circadian, delayed sleep phase disorder, circadian light sensitivity, circadian timing system

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Crossover Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
32 (Actual)

8. Arms, Groups, and Interventions

Arm Title
sensitization duration 1.375h
Arm Type
Experimental
Arm Description
This group will experience a 1.375h sensitization duration prior to the 12h light exposure
Arm Title
sensitization duration 5.5h
Arm Type
Experimental
Arm Description
This group will experience a 5.5h sensitization duration prior to the 12h light exposure
Arm Title
sensitization duration 22h
Arm Type
Experimental
Arm Description
This group will experience a 22h sensitization duration prior to the 12h light exposure
Arm Title
sensitization duration 0.33h
Arm Type
Experimental
Arm Description
This group will experience a 0.33h sensitization duration prior to the 12h light exposure
Intervention Type
Other
Intervention Name(s)
light exposure
Intervention Description
12-hour light exposure of approximately 200 lux
Primary Outcome Measure Information:
Title
circadian phase timing
Description
timing of circadian phase as assessed using melatonin and temperature data
Time Frame
During inpatient study, on days 6-7 and 11-12
Secondary Outcome Measure Information:
Title
melatonin suppression
Description
percent of melatonin suppression
Time Frame
During inpatient study, on days 6-7 and 11-12

10. Eligibility

Sex
All
Minimum Age & Unit of Time
21 Years
Maximum Age & Unit of Time
30 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: healthy adults with conventional and regular sleep-wake timing non-smokers completion of medical, psychological, ophthalmological, and sleep screening tests able to spend 13 consecutive days/nights in the laboratory Exclusion Criteria: history of neurological or psychiatric disorder history of eye injury, eye surgery, or visual disorder (corrective lenses are acceptable) history of sleep disorder or regular use of sleep-promoting medication current prescription, herbal, or over-the-counter medication use (oral contraceptives are acceptable)
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Charles A Czeisler, PhD, MD
Organizational Affiliation
Brigham and Women's Hospital
Official's Role
Principal Investigator
First Name & Middle Initial & Last Name & Degree
Jeanne F Duffy, PhD
Organizational Affiliation
Brigham and Women's Hospital
Official's Role
Study Director
Facility Information:
Facility Name
Brigham and Women's Hospital
City
Boston
State/Province
Massachusetts
ZIP/Postal Code
02115
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
No

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Light Sensitization Study

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