Body Weight Regulation in Patients With Narcolepsy

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

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 Participants are withdrawn from their narcolepsy medication and undergo the following tests and procedures over 5 weeks before resuming medications.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 oxygen use. To measure the energy associated with meals, the same measurements are taken after the subject eats lunch. * CT scan of the abdomen to see how much fat is deposited in the abdomen, and DEXA scan of the whole body to see the percentage of fat and muscle. * Plethysmography. Participants sit in an enclosed chamber while the mass and volume of the body are measured by changes in air pressure. * Neuropsychological testing to assess thought processes. * Continuous 24-hour heart rate measurement. * Metabolic chamber. Subjects spend 24 hours in a small room to measure the amount of oxygen inhaled and carbon dioxide exhaled. * Walking/running test to assess level of physical conditioning. * Dexamethasone CRH (corticotropin-releasing hormone) suppression test and CRH stimulation test. Subjects receive eight doses of 0.5 mg dexamethasone every 6 hours for a day and a half. After the last dose, two blood samples are drawn, then a dose of CRH is injected, and then six more blood samples are drawn over the next 3 hours. * TRH (thyrotropin-releasing hormone) stimulation test. Subjects are given TRH through a vein, and several blood samples are then drawn over the next 3 hours. * Doubly labeled water test. Subjects drink a dose of "heavy" water. Urine samples are collected at 2, 3 and 5 hours after drinking and again for two 4-hour collections a week later.

About this trial record page

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Public field values for ClinicalTrials.gov record NCT00283894, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.

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Last update posted Oct 5, 2017 · Synced Sep 11, 2026

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