Over the past couple of years, I have seen more patients coming to me, indicating that they have been “diagnosed” with upper airway resistance syndrome (UARS) by so-called sleep experts. I have to stop myself from shaking my head, not knowing whether I should laugh or cry. The problem has become particularly noticeable over the last few months, where more patients are coming to me with this misleading diagnosis. I am writing this blog entry to demystify UARS.

I will start by stating the obvious: UARS is not a real diagnosis because it is actually obstructive sleep apnea. Those who suggest otherwise are either:

• not up on developments in the field of sleep medicine going back to at least 2022;
• pretending to know more than others do by resurrecting a diagnosis that no longer exists;
• ensuring that someone will get a UARS diagnosis that guarantees no medical insurance coverage for their condition (insurance does not cover treatment of UARS), which seems to be a disservice to patients; or
• minimizing a patient’s condition by relegating to a less-important or less-recognized entity.

It all begins and ends with how you define hypopneas

Obstructive sleep apnea is diagnosed with sleep studies that measure breathing patterns. The two types of sleep apnea events are apneas (no airflow for at least 10 seconds) or hypopneas (decreases in airflow associated with drops in oxygen levels and/or awakenings from sleep). While defining apneas is relatively straightforward, there have been various definitions of hypopneas that are used widely. Traditional definitions of hypopneas are focused on drops in oxygen levels in the bloodstream (oxygen desaturations), counting events only if these desaturations occur. Because younger, healthier patients will wake themselves up from sleep when they have blockage in breathing, often before their oxygen levels drop, some of the real pioneers in sleep medicine created the UARS term to capture those with sleep apnea-type events with awakenings (arousals) from sleep without the same drops in oxygen levels. Importantly, these patients responded well to sleep apnea treatment (CPAP, surgery, or oral appliances).

Starting in 2022, the American Academy of Sleep Medicine has recommended use of a definition of hypopnea (called H3A) based on a decrease in airflow (at least 30% decrease in airflow over a period of at least 10 seconds) associated with at least a 3% oxygen desaturation or arousal from sleep (even if there is no oxygen desaturation). The result is that patients who were considered to have UARS for many years now have obstructive sleep apnea if this H3A definition of hypopnea is used to score the sleep studies.

The contrarian would say that we should not require someone to have a decrease in airflow, but then every arousal from sleep could be considered a sleep apnea event, ignoring the fact known to all in sleep medicine that there are many potential reasons for arousal from sleep. UARS was about more than just snoring before an arousal from sleep. The classic description of UARS included use of a tube placed through the nose into the esophagus (through the throat and towards the stomach) to monitor breathing effort. This could provide information about breathing effort, as many individuals with UARS would have breathing effort that increased over a few breaths until they woke up. In some cases, they kept a full amount of airflow the whole time, so it would suggest that you do not need to have a decrease in airflow to have UARS. However, these esophageal pressure catheters are not used anymore (I have had a sleep study with one and can attest that they are very uncomfortable). It is simply not correct to suggest that someone has UARS without decreased airflow without a sleep study using this catheter (that is no longer used in sleep studies)…another reason the UARS diagnosis should not be used anymore.

Don’t have surgery based on a diagnosis of UARS!

There is always some uncertainty associated with treatment of obstructive sleep apnea. In many cases, it is difficult to know if treatment will eliminate the sleep apnea. It also can be challenging to know what benefit a patient may experience. What is clear is that one should be cautious of anyone trying to encourage surgery for treatment of UARS, a diagnosis that should no longer be considered a real one!