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

Official Title: “Circadian Integration of Photic and Non-photic Stimuli”

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.

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.

Intervention(s) in this Clinical Trial

• Drug: Melatonin
  • 5mg, pill, once
• Drug: Methylxanthine
  • 2.9 mg/kg, pill, once
• Procedure: Light Therapy
  • Bright light exposure

Arms, Groups and Cohorts in this Clinical Trial

• Experimental: Dim Light Melatonin and/or methylxanthine
  • Dim Light Melatonin and/or methylxanthine
• Experimental: Placebo and Dim Light or bright light
  • Placebo and Dim Light or bright light
• Experimental: Bright light melatonin and/or methylxanthine
  • Bright light, melatonin, and/or methylxanthine

Primary Measures

• Circadian phase, as measured by the shift of the endogenous melatonin rhythm (measured during each inpatient visit)
  • Time Frame: 24 hour
    Safety Issue?: No

Secondary Measures

• Circadian phase, as measured by the shift of the endogenous temperature rhythm
  • Time Frame: 24 hour
    Safety Issue?: No
• 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
    Safety Issue?: No
• 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
    Safety Issue?: No

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

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: 40 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: Accepts Healthy Volunteers

Lead Investigator: National Heart, Lung, and Blood Institute (NHLBI) NIH

Overall Clinical Trial Officials and Contacts

Kenneth P. Wright, PhD Principal Investigator University of Colorado at Boulder  

Overall Contact: Gayle Wright, MS 303-735-1923 Sleep.Study@colorado.edu

Information obtained from ClinicalTrials.gov on February 12, 2012

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00387179

Study ID Number: 406

ClinicalTrials.gov Identifier: NCT00387179

Health Authority: United States: Food and Drug Administration

Click here for the University of Colorado at Boulder Sleep and Chronobiology Laboratory web site