Obstructive sleep apnea (OSA) is a common disorder in which the throat narrows abnormally or even collapses fully during sleep. The narrowing leads to sleep disruption and increases the risk of many chronic health conditions. We do not understand why the throat narrows in some people during sleep but not in others. While being overweight or obese increases a person's risk of OSA, it is only one part of the problem. Some thin adults and children have OSA, and many overweight or obese people do not have OSA. In addition, many people with OSA struggle to benefit from current OSA treatments like continuous positive airway pressure (CPAP), which uses air pressure to hold the airway open during sleep. We need improved understanding of OSA in order to improve treatment of it.
The throat is used for swallowing as well as for breathing. Hence it should not be surprising if a throat that has trouble staying open during sleep might also have some abnormalities during swallowing. Indeed, some research has shown subtle abnormalities in swallowing in people who have snoring or OSA compared to people who don't snore at all. We would like to further develop this line of research.
This study has two arms: an observational arm to look for differences in swallowing, and an interventional arm to see if swallowing exercises can improve people's ability to use CPAP.
The purpose of the observational arm is to look for differences in swallowing between healthy people and people who have obstructive sleep apnea (OSA) using a variety of measurement techniques, some of which have not been done in the past. Understanding the differences in swallowing may help us to develop new treatments for OSA. It may also help us to figure out how to prevent OSA from developing in the first place. We are also looking to see if there are swallowing differences between people with OSA who don't tolerate CPAP compared to people who do well with CPAP. If there are differences, these differences may help us better understand why some people do not tolerate CPAP, and may lead to the development of novel treatments such as exercise therapies to help them do better with CPAP.
The interventional arm will test exercise therapies to see if they will help people who struggle with CPAP. The goal is not to cure OSA, but to help people be able to use CPAP better so that they can sleep better. Participants who have abnormalities in their swallowing study will get exercises from speech language pathologists (SLP, also known as speech therapists) aimed at trying to correct those abnormalities. Participants will then try to use CPAP again. Participants who still can't sleep well with CPAP after those exercises, or who don't have abnormalities on the swallowing study, will get another type of exercise therapy based on an exercise technique called orofacial myofunctional therapy (OMT). This therapy aims to train exclusive nasal breathing and correct variations in the swallow. This sort of exercise technique has had some success in improving CPAP use as well as in reducing the severity of OSA. We have created a streamlined exercise protocol based on these techniques that we hope will provide better results in a shorter period of time. At the end of the exercise interventions, the participants will repeat the investigations that were done at the beginning of the study.
Investigations will include home sleep testing, CPAP trials (only for participants with OSA and CPAP intolerance), a modified barium swallow study (MBS), a measurement visit, and questionnaires. During the measurement visit, there will be assessments of the strength of the tongue, lips, and cheeks, assessment of nasal airflow, respiratory muscle strength, restrictions in tongue mobility (tongue tie), posture, dental and facial form, and eating and drinking. The modified barium swallow study uses x-rays; the amount of radiation from the procedure is about what a person would receive from about 4.5 months of background radiation. It is a little bit more radiation than what a person would receive from a mammogram, but much less than what a person would receive from a CT scan.
