Extreme Phenotypes and Obstructive Sleep Apnea

Site Image

Study Overview

The purpose of this study is to understand the relationship between obesity and obstructive sleep apnea. Obstructive sleep apnea typically causes daytime sleepiness and fragmented (broken up) sleep. Obesity is thought to be the most important risk factor for sleep apnea, yet we currently do not understand how obesity increases the likelihood of having sleep apnea. Some people who have obstructive sleep apnea are obese, and some people who have it are not obese. Also, some people who are not obese have obstructive sleep apnea. We are enrolling some people in this study who are obese and some who are not to compare differences in the anatomy between people with and without sleep apnea. Please complete this survey to determine your eligibility: https://redcap.med.upenn.edu/surveys/?s=MJLADC4AL9

Study Description

Depending on whether or not you have had a previous sleep study, you may be asked to complete a baseline home sleep study. The other parts of the study consist of an office visit, MRI, and Overnight Sleep Study. 

1. Office visit: Ultrasound, Saliva sample, Airway digital pictures, Tongue force measurements 

2. MRI scan: The MRI is a test that takes pictures of your upper airway (mouth and throat), and of your abdomen (belly area). This procedure is not invasive and does not involve radiation. There is no contrast with the MRI. The test will involve wearing a helmet-like device called a head coil to give us detailed pictures of your brain. Your face will not be covered by the head coil. The MRI scan will take about one hour. 

3. Overnight sleep study to measure the causes of sleep apnea: If you use CPAP at home, we will ask you not to use it for 2 nights before the study. You will be asked to come to the Sleep Laboratory about 2 hours before your bedtime. A technician will prepare you for the sleep study. Sensors are pasted or taped to your scalp, face, and body. They monitor your sleep and breathing. Breathing effort is measured with belts that are put around your chest and stomach. Your oxygen level is recorded using an oximeter. This sensor clips to your index finger and shines light through it. A device (similar to a large watch) will be strapped to your wrist to measure sleep signals and body position, and will be attached to sensors. A thimble-like sensor will be attached to your finger, and sensors will also be placed on your chest and forehead. There is little risk in any of these tests, but applying and wearing the sensors can be a little uncomfortable. On the night of the study, after the sensors are applied, you can watch TV, read or sit quietly until bedtime. The study lasts all night. If at any time you need help, you will be instructed how to call the technician into your room. You will wear a nasal CPAP (Continuous positive airway pressure) mask during the study. Before the mask is placed over your nose, we will numb one of your nostrils and the back of your throat with a nasal spray (lidocaine, local anesthetic). Once the nostril is numb, a thin tube (catheter) will be inserted through your nostril, until it sits in your esophagus (as far as the top of your stomach). This will allow us to monitor your effort to breathe. If your nostrils are congested, we will first apply a decongestant medicine (Afrin) into both of your nostrils to clear them before using the numbing spray. The tube will be taped to your nose to make sure it does not move. Finally, we will place a mask over your nose and hold it in place with Velcro straps. The mask will be attached to a modified CPAP machine that blows or sucks constant levels of air through the mask. During the night we will change CPAP levels while you sleep depending on your breathing pattern. 
                        • If you have sleep apnea we will monitor spontaneous changes in your breathing and ventilatory effort without CPAP pressure.
                        • If you do not have sleep apnea, we will provide low-level negative CPAP to challenge your throat muscles, and monitor spontaneous changes in your breathing. If you wake up during the test, any negative pressure will be removed until you fall back asleep. We will gently remove all sensors in the morning.

Additional Information:

You will be paid $100 each for completing the overnight sleep study to measure airway collapse and the MRI, and $50 for completing the home sleep study, for a total of $250. The only exception to this is if your baseline sleep study is done clinically through the Penn Sleep Center- then you will not be paid $50 for the sleep study. If you travel to the University of Pennsylvania for a study visit you may receive travel reimbursement up to $25. Please note: In order to be compensated for your participation in this study, you must provide your Social Security Number. Additionally, please note that the University of Pennsylvania is required to report to the IRS any cumulative payments for participation in research studies that exceed a total of $600 in a calendar year.

  • Study Identifier: 823038

Recruitment Status


Check to see if you pre-qualify for the study.

Volunteer Sign up

Volunteer Sign-up

Participate in medical studies to develop new diagnostic and clinical treatments and improve current standards of care.

Sign Up Now!

If you need assistance finding a non-cancer study or if you have any questions, please email psom-ocr@pobox.upenn.edu