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Examining the Biological Factors That Affect Sleep Duration

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00607204
Recruitment Status : Completed
First Posted : February 5, 2008
Last Update Posted : July 31, 2013
National Heart, Lung, and Blood Institute (NHLBI)
National Center for Research Resources (NCRR)
Information provided by (Responsible Party):
Daniel Aeschbach, Brigham and Women's Hospital

Brief Summary:
Sleep is necessary for healthy functioning, and people who sleep too little or too much may have an increased risk of developing health problems. This study will examine people who regularly sleep for short or long amounts of time to understand the biological factors that determine how much sleep a person needs.

Condition or disease
Sleep Circadian Rhythm Cognitive Performance

Detailed Description:

The amount of sleep people require depends on many factors, including age, but experts agree that most adults need 7 to 8 hours of sleep a night. People who sleep for shorter or longer amounts of time may be at risk of developing memory problems, heart disease, obesity, and diabetes. The duration and timing of sleep are regulated by an interaction between the circadian pacemaker, or biological clock, and the sleep homeostat, which is an internal account of the amount of sleep a person has received recently. It is unknown whether there is a biological or genetic basis for the amount of sleep a person needs. This inpatient study will examine two extreme sleep groups: short sleepers who sleep 6.5 or less hours a night and long sleepers who sleep 9 or more hours a night. Participants will be exposed to identical sleep opportunities and living conditions. Using hormone analysis to examine participants' circadian rhythms, researchers will evaluate the biological differences that people undergo during the sleep process. Results from this study may help researchers understand whether sleep duration and sleep needs differ among people because of biological and genetic variations.

Over a period of 4 to 6 weeks, potential study participants will attend 4 to 6 screening visits, which will include a medical history review, physical exam, blood and urine collection, electrocardiogram (EKG) to measure electrical activity of the heart, a psychological assessment, and an overnight stay in a sleep laboratory. For 3 weeks, potential participants will also wear an activity monitor, and they will record sleep habits electronically and in a daily diary.

Participants who are eligible for the study will spend 28 days in the Intensive Physiological Monitoring Unit of the Clinical and Translational Sciences Center at the Brigham and Women's Hospital. Participants will not have access to a clock, radio, television, or computer, and they will not be allowed any outside contact. Most days participants will remain in bed for 10 to 14 hours; however, at selected times during the study, participants will remain inactive for periods of 32 to 64 hours and will stay awake for 32 to 40 hours. Throughout the study, participants' sleep patterns will be monitored continuously by a wrist activity recorder. Heart rhythms, brain electrical activity, eye movements, and temperature will also be measured continuously. At different times throughout the study, participants will undergo urine, saliva, and blood collection; alertness, mood, and performance evaluations; and blood pressure measurements. Upon release from the research center, participants will maintain a sleep diary for 3 weeks.

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Study Type : Observational
Actual Enrollment : 119 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Neurobiology of Individual Differences in Sleep Duration
Study Start Date : October 2005
Actual Primary Completion Date : November 2011
Actual Study Completion Date : November 2011

Primary Outcome Measures :
  1. Circadian rhythm assessment based on plasma melatonin and other hormones; sleep and EEG analysis; measurements of cognitive performance, alertness, and mood [ Time Frame: Measured during the 4-week inpatient stay ]

Biospecimen Retention:   Samples Without DNA
Plasma samples

Information from the National Library of Medicine

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, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Participants will include healthy people who are catagorized as either short sleepers or long sleepers.

Inclusion Criteria:

  • Routinely sleeps 6.5 hours or less a night, or routinely sleeps 9 hours or more a night
  • In good health

Exclusion Criteria:

  • Diagnosed with a sleep disorder
  • Currently uses medications
  • Performed night shift work in the 3 years before study entry
  • History of psychiatric illness

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00607204

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United States, Massachusetts
Brigham & Women's Hospital
Boston, Massachusetts, United States, 02115
Sponsors and Collaborators
Brigham and Women's Hospital
National Heart, Lung, and Blood Institute (NHLBI)
National Center for Research Resources (NCRR)
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Principal Investigator: Daniel Aeschbach, PhD Brigham & Women's Hospital, Boston, MA
Additional Information:
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Responsible Party: Daniel Aeschbach, Associate Neuroscientist, Brigham and Women's Hospital Identifier: NCT00607204    
Other Study ID Numbers: 559
R01HL077399 ( U.S. NIH Grant/Contract )
First Posted: February 5, 2008    Key Record Dates
Last Update Posted: July 31, 2013
Last Verified: July 2013
Keywords provided by Daniel Aeschbach, Brigham and Women's Hospital:
Basic Research
Individual Sleep Duration