The following is an in-depth look at upper airway resistance syndrome.  Those who want a more superficial overview of this common disorder should go to the UARS section of this website.  

 

From this clinician’s perspective, upper airway resistance syndrome (UARS) is the neglected stepchild of sleep medicine.  It is very clear to me that UARS is significantly under diagnosed and under managed. This lack of diagnosis and management has significant effects on the lives of those who unknowingly live with this disorder.  At The Center for Sound Sleep, we are accumulating quite a long list of patients who have gone to a sleep lab for a sleep evaluation, were told that they snored (sometimes very loudly), but had no problem of clinical significance. These patients ended up at our office for treatment of their bothersome snoring to please their bed partners, were fitted with an oral appliance to stop the snoring, and ended up noticing significant relief of physical symptoms.

 

 

Some of the patients that we have treated who have upper airway resistance syndrome are shown in this slide from my lecture series.  The one thing that all of these patients have in common is that they had all had hospital sleep studies and were all told that while they snored, they had no problem. Since people experience the effects of poor sleep differently, their stories are different, but many of these people complain of restless sleep, waking up during the night frequently and most wake up feeling groggy or unrefreshed after a night’s sleep. Some of them have significant daytime sleepiness and fatigue like Featured Patient #102, while others have absolutely no symptoms after they finally awaken from their groggy state and start their day as with the patient shown in the video below who was immensely helped with her oral appliance.

 

 

Others have upper airway resistance syndrome brought about by pregnancy as did Featured Patient #108 and the young woman shown in the video below. This patient was a subject in a clinical trial that I am doing on the efficacy of oral appliance therapy used to help sleep breathing during the latter stages of pregnancy.

While sleep-related breathing disorders, particularly upper airway resistance syndrome, are not uncommon during pregnancy, any sleep lab technician will tell you that the presence of a woman in pregnancy coming to a sleep lab for a sleep study is an extremely rare event.

One of the factors that is NEVER considered when a sleep study is done on a patient suspected of having a sleep-related breathing disorder is night to night variability of sleep. In the chart below I show an important slide from my lecture series. This slide addresses the night to night sleep variability that patients have and shows that 34% of patients with milder sleep apnea fail to get a diagnosis because on the night that they happened to have their sleep study, they failed to have enough respiratory events.

This clinician has made a bold statement that UARS is under-diagnosed in sleep labs and, if diagnosed, under-managed by physicians.  It is logical to ask the question, “How could this be?”   Perhaps this answer to this question starts by observing that this disorder has not found its way into the International Classification of Sleep Disorders Diagnostic and Coding Manual.  In other words, there is no code available to submit for medical insurance reimbursement for the management of this disorder. Since the medical profession is at the largely at the mercy of the insurance industry, a significant percentage of the medical community has developed the mindset that no treatment is offered that is not reimbursable by medical insurance.  In other words, much of the medical community assumes that patients will not accept any treatment that is not paid for by medical insurance.  This attitude deprives patients of the option of making choices.

 

 

 

It also must be understood that UARS is a disorder that is rarely studied in relationship to other diseases. The chart at right shows the number of studies that were published from the beginning of January to the end of August in 2008.  Notice the sparse number of studies on obstructive sleep apnea compared to the number of studies on cardiovascular disease and diabetes.  This is in spite of the knowledge that obstructive sleep apnea is a known independent risk factor for both cardiovascular disease and diabetes.

 
 

 

 

 

 

 

 

 

Making matters more ridiculous, the number of studies on upper airway resistance syndrome pales in comparison to the number of studies on obstructive sleep apnea during this same period of time as seen in the chart shown at right.

 

 

 

As Medical Advisor to the Indiana Society of Sleep Professionals, a professional association of sleep lab technicians, I am privileged to know a large number of sleep lab technicians throughout the state of Indiana.  As a result of this, I am aware that many sleep labs recognize UARS as a problem for patients and are able to score enough respiratory effort related arousals throughout the night to eek out a diagnosis for obstructive sleep apnea.  They are able to do this even though UARS patients do not stop breathing enough per hour through the night for their apnea/hypopnea index to be 5 or above (see Sleep Medicine Basics) nor do their oxygen levels drop significantly.  However, many sleep labs do not have equipment that is sensitive enough to measure upper airway resistance while others that do have this sensitive equipment do not have the software that allows them to record the events.  So there is a vast disparity from one lab to another as to how this disorder is diagnosed, if it is diagnosed at all.

 

 

Adding to this conundrum, physicians vary as to how they deal with this disorder if it is diagnosed.  I recently had a long conversation with a well respected, board certified, sleep physician about this disorder and how he managed it.  He replied that he manages this disorder by having patients start with “the easy things”, loosing weight and refraining from sleeping on their back.  There is no question that his recommendations can help since any fatty tissue accumulation in the area of the upper airway causes airway restriction and people who sleep on their back tend to snore more.  However, let’s stop and think about this recommendation!  Easy things! If loosing weight was easy, obesity would not be an issue in our country!  And I routinely see sleep studies on patients who swear that they do not sleep on their back while the sleep study clearly shows them sleeping on their back.  Overcoming a life time of sleeping posture habit is not easy.

 

The complete opposite of starting with “the easy things” is manifested by those physicians who put UARS patients on CPAP.  They do this is spite of a large number of studies showing that CPAP compliance decreases with the severity of the disorder.  UARS patients clearly are the least severe of the sleep-disordered breathing spectrum so CPAP compliance for these patients is very low.  In spite of this, my informal survey of sleep lab technicians throughout the state shows that if UARS is managed by sleep physicians, it is done by CPAP.  Almost never is oral appliance therapy suggested as a therapy even though oral appliance therapy used with UARS patients is highly predictable.  

 

 

The lack of referral of UARS patients for oral appliance therapy may be a result of ignorance, bias or lack of a trusted dental professional to refer to who is knowledgeable in sleep medicine.  It is the assertion of this clinician that, since UARS is rarely managed successfully by sleep physicians, these physicians are not always aware of the more wide reaching effects of UARS symptoms and that dentists who routinely manage these patients have the ability observe the sometimes subtle physical ramifications of UARS management.  Every patient who has received a diagnosis of severe sleep apnea at one time passed through the threshold of upper airway resistance on their way to this diagnosis. It is logical that an early intervention could halt this devastating progression.