Upper Airway Resistance Syndrome vs. Obstructive Sleep Apnea

UARS vs OSA

Upper airway resistance syndrome (UARS) and obstructive sleep apnea (OSA) are both sleep-breathing disorders that cause excessive daytime fatigue and unrefreshing sleep.

While their symptoms may be almost indistinguishable, how each condition is caused, diagnosed, and treated have a few key differences.

The main difference between UARS and OSA is how the airflow is being restricted. In sleep apnea, the airway is completely cut off (apnea) or partially cut off (hypopnea). In UARS, the airway is narrow enough to cause sleep issues, but not severe enough to meet the official diagnostic criteria for obstructive sleep apnea.

In a way, UARS is like a Sleep Apnea Lite. But don't quote me on that.

Symptoms

The symptoms of UARS and OSA are nearly identical, but there are a few that are specific to each.

If you suspect you are suffering from some a sleep-breathing disorder such as UARS or OSA, there are a few warning signs unique to each illness that might be indicative of one disorder.

UARS

Surprisingly, studies have shown that UARS patients have worse sleep quality, more fatigue, and worse ADHD-like symptoms than those with mild sleep apnea.

Symptoms specific to UARS are...

• Chronic insomnia
• Being a "light sleeper"
• Low blood pressure, especially when standing up
• TMJ (temporomandibular joint) issues
• Recurrent sinus infections, pain, or pressure
• Fibromyalgia-like symptoms^fibro

This same study also states that UARS patients scored worse in almost every metric measurable. To list a few, general productivity, social outcome, activity level, and vigilance.

OSA

One of the most textbook symptom of obstructive sleep apnea is an audible/visible pause in breathing during the sleep. These events are typically only noticed by someone such as a spouse, roommate, or parent.

Risk Factors

UARS

• Nasal congestion
• Narrow nasal passageways
• Deviated septum
• Small and crowded jaws
• Anything else that can contribute to narrowing of the airways

Click here to see a complete list of UARS risk factors.

OSA

These are the most common risk factors of obstructive sleep apnea:

• Loud or frequent snoring
• Middle aged
• Male gender
• High blood pressure
• Excess weight and obesity
• Narrow throat, thick neck, and round head
• Hypothyroidism
• Use of growth hormone
• Smoking and/or excessive alcohol use

Diagnosis

Both UARS and OSA require you to undergo a sleep study to be diagnosed. There are at-home studies as well as overnight, in-lab studies at a sleep center.

UARS

When assessing a patient for UARS, sleep technicians will look for a numeric variable called the RDI, which stands for respiratory distress index. This metric includes RERAs (respiratory-effort related arousals) in addition to your typical apnea events.

RERAs, or Respiratory Effort Related Arousals, are event of increased respiratory effort for at least 10 seconds that causes one to wake up.

An AHI less than 5 and an RDI greater than or equal to 5 is indicative of a UARS diagnosis.

OSA

OSA is diagnosed by calculating a number called the AHI, or Apnea-Hypopnea Index. This index represents the average number of 10-second+ apnea and hypopnea events-per-hour throughout the duration of the study. An apnea event is when airflow is fully cut off, and a hypopnea event is when airflow partially cut off.

An AHI greater than or equal to 5 is indicative of an OSA diagnosis.

Treatment

As you could expect, UARS and OSA are treated the same way for the most part: a CPAP machine.

UARS Treatment

OSA

As sleep apnea is much more common for overweight people than UARS, losing weight is considered a pretty solid method to treat OSA when combined with a CPAP or oral appliance. Unfortunately, this doesn't really apply to UARS, as most people with UARS are skinny/normal body weight.