Effectiveness of Combining Light and Non-Light Treatments for Jet Lag and Sleep Disorders

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified August 2009 by National Heart, Lung, and Blood Institute (NHLBI).
Recruitment status was:  Recruiting
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
First received: October 11, 2006
Last updated: August 24, 2009
Last verified: August 2009
Jet lag and some sleep disorders are caused by a disruption in an individual's "internal clock." Understanding the most effective way to quickly re-adjust the body's internal clock will be beneficial for treating individuals with these conditions. This study will evaluate the combined effectiveness of light and non-light therapies at regulating sleep cycles and improving sleep quality.

Condition Intervention
Sleep Disorders, Circadian Rhythm
Drug: Melatonin
Drug: Methylxanthine
Procedure: Light Therapy

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
Official Title: Circadian Integration of Photic and Non-photic Stimuli

Resource links provided by NLM:

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Primary Outcome Measures:
  • Circadian phase, as measured by the shift of the endogenous melatonin rhythm (measured during each inpatient visit) [ Time Frame: 24 hour ]

Secondary Outcome Measures:
  • Circadian phase, as measured by the shift of the endogenous temperature rhythm [ Time Frame: 24 hour ]
  • Sleep quality, as measured by wakefulness after sleep onset (electroencephalogram [EEG] defined wakefulness after 10 minutes of consecutive sleep) and number of awakenings [ Time Frame: overnight ]
  • Cognitive function, as measured by daytime sleepiness, reaction time, and mood and well being (all measured during each inpatient visit) [ Time Frame: 24 h and daytime ]

Estimated Enrollment: 48
Study Start Date: October 2006
Estimated Study Completion Date: March 2010
Estimated Primary Completion Date: March 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Dim Light Melatonin and/or methylxanthine
Dim Light Melatonin and/or methylxanthine
Drug: Melatonin
5mg, pill, once
Other Name: Life Extension Melatonin 5 mg
Drug: Methylxanthine
2.9 mg/kg, pill, once
Experimental: Placebo and Dim Light or bright light
Placebo and Dim Light or bright light
Procedure: Light Therapy
Bright light exposure
Experimental: Bright light melatonin and/or methylxanthine
Bright light, melatonin, and/or methylxanthine
Drug: Melatonin
5mg, pill, once
Other Name: Life Extension Melatonin 5 mg
Drug: Methylxanthine
2.9 mg/kg, pill, once
Procedure: Light Therapy
Bright light exposure

Detailed Description:

Circadian rhythm disorders are disruptions in an individual's circadian rhythm, or "internal body clock." This internal clock regulates the 24-hour cycle of biological processes in the body, including sleep and hormone production. Jet lag, delayed sleep phase syndrome, in which individuals fall asleep and wake up later than desired, and advanced sleep phase syndrome, in which individuals fall asleep and wake up earlier than desired, are all examples of circadian rhythm disorders. Because of the disruptive nature of these conditions, it is important to identify the quickest and most effective method for regulating the body and reestablishing normal sleep patterns. Light therapy, in which individuals are exposed to bright, artificial light, is currently used to treat these disorders. Melatonin, a hormone that regulates circadian rhythms, and methylxanthines, a class of stimulant medications, are other common non-light treatments. While each of these individual treatments has been proven effective, little is known about the combined effect of light and non-light treatments. The purpose of this study is to evaluate the safety and effectiveness of light therapy, melatonin, and methylxanthine, alone and in combination, at regulating circadian rhythms and improving sleep quality and cognitive function.

This study will enroll healthy individuals. Participants will first attend two screening visits, which will include a review of medical, psychiatric, and sleep histories; vital sign measurements; blood and urine collection; a physical examination; and an electrocardiogram. For 1 week, participants will record sleep habits in a diary and by telephone. They will also wear a device that monitors activity and light exposure levels. Eligible participants will then attend four 5-day inpatient visits at the Sleep and Chronobiology Laboratory at the University of Colorado at Boulder. During each of the four visits, participants will be randomly assigned to one of the following four treatments:

  • Dim light therapy and placebo
  • Bright light therapy and placebo
  • Dim light therapy, melatonin, and methylxanthines
  • Bright light therapy, melatonin, and methylxanthines

At each visit, participants will receive a different treatment. During these visits, participants will remain awake for up to 40 hours at a time, while their eye movements, and brain, muscle, heart, and breathing activity are monitored. Urine and saliva will be collected, and participants will undergo various cognitive performance testing measures. At 3-week intervals between each visit, participants will record sleep habits and will wear the activity and light exposure monitoring device. A sleep diary will also be maintained by participants for 3 weeks following the end of the last visit.


Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • In good general health, as determined by blood chemistries, urine toxicology, physical examination, and medical and psychiatric history

Exclusion Criteria:

  • History of any current or chronic disease, including any of the following:

    1. Chronobiologic disorders
    2. Sleep disorders
    3. Cardiovascular disorders
    4. Respiratory disorders
    5. Kidney and urinary tract disorders
    6. Infectious diseases
    7. Gastrointestinal disorders
    8. Immune system disorders
    9. Connective tissue and joint disorders
    10. Hematopoietic disorders
    11. Neoplastic diseases
    12. Endocrine and metabolic diseases
    13. Neurologic disorders
  • Current or past history of drug abuse
  • Pregnant or breastfeeding
  • Current oral contraceptive use
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00387179

United States, Colorado
Sleep and Chronobiology Laboratory
Boulder, Colorado, United States, 80309
Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Kenneth P. Wright, PhD University of Colorado at Boulder
  More Information

Additional Information:

Responsible Party: Kenneth P. Wright Jr., Ph.D., Associate Professor, University of Colorado
ClinicalTrials.gov Identifier: NCT00387179     History of Changes
Other Study ID Numbers: 406  M01RR000051  R01HL081761 
Study First Received: October 11, 2006
Last Updated: August 24, 2009

Keywords provided by National Heart, Lung, and Blood Institute (NHLBI):
Circadian Rhythm Sleep Disorders

Additional relevant MeSH terms:
Sleep Wake Disorders
Sleep Disorders, Circadian Rhythm
Nervous System Diseases
Neurologic Manifestations
Signs and Symptoms
Mental Disorders
Chronobiology Disorders
Occupational Diseases
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs
Central Nervous System Depressants

ClinicalTrials.gov processed this record on January 19, 2017