Clinical Trial: Body Weight Regulation in Patients With Narcolepsy

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: The Role of the Orexin System in Body Weight Regulation: Patients With Narcolepsy

Brief Summary:

This study will measure energy expenditure (the rate at which the body burns calories), physical activity and caloric intake in people with narcolepsy to learn more about how the risk of becoming overweight or diabetic may be affected.

Healthy control subjects and people with narcolepsy between 18 and 55 years of age may be eligible for this study. Participants are withdrawn from their narcolepsy medication and undergo the following tests and procedures over 5 weeks before resuming medications.

  • Blood draw for genetic studies.
  • Collection of a cerebrospinal fluid sample.
  • Diet to keep subjects' weight constant.
  • Activity watch, using a device worn on the wrist to measure amount of movement, and an activity monitor worn at the waist to measure physical activity and caloric expenditure.
  • Questionnaires about sleepiness, symptoms, food intake, exercise and mood.
  • 24-hour urine collection and 24-hour blood draw to measure hormones.
  • Glucose tolerance test. The subject drinks a sugar solution and blood samples are collected through a catheter before drinking the solution and 30 minutes, 1, 2 and 3 hours after drinking it.
  • Startle reflex test. Subjects hear a loud noise through headphones and are asked to look at pictures.
  • Sleep study to evaluate sleep-related breathing disturbances and record information about sleep stages.
  • Indirect calorimetry test to measure how fast the body uses calories. A plastic canopy is placed over the face for several minutes to capture the air exhaled to analyze oxyg

    Detailed Summary:

    BACKGROUND: Several cross-sectional studies have suggested that subjects with narcolepsy have increased body mass index (BMI) and insulin resistance. These subjects exhibit a decrease in cerebrospinal fluid (CSF) orexin levels, which has been causally linked to the clinical manifestations of this disease. Orexins are peptides expressed in a brain region, the lateral hypothalamic area, which stimulate appetite and modulate sleep. Low CSF orexin levels provoke narcolepsy-like behavior, such as excessive daytime sleepiness and a sudden loss of muscle tone known as cataplexy.

    OBJECTIVES: The primary objective of this study is to determine whether subjects with narcolepsy have lower energy expenditure compared to healthy matched controls. In addition, we will assess food intake, physical activity, and other relevant parameters.

    STUDY POPULATION: 18 to 55 year old men and premenopausal women with narcolepsy and healthy matched controls

    DESIGN: This is a cross-sectional, case-controlled study of subjects with narcolepsy matched on a one-to-one basis with healthy, non-narcoleptic control subjects.

    OUTCOME PARAMETERS: We will assess metabolic, hormonal, and energy expenditure parameters in subjects with narcolepsy. Outcomes: energy expenditure by various methods (indirect calorimetry, metabolic chamber, doubly-labeled water method); leptin circadian levels (frequent 24h sampling); physical activity, characterization of the main endocrine axes, and other relevant parameters.


    Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

    Current Primary Outcome:

    Original Primary Outcome:

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    Original Secondary Outcome:

    Information By: National Institutes of Health Clinical Center (CC)

    Dates:
    Date Received: January 29, 2006
    Date Started: January 20, 2006
    Date Completion: June 19, 2013
    Last Updated: April 19, 2017
    Last Verified: June 19, 2013