People do not wake up one morning suddenly afflicted with obstructive sleep apnea. Rather, obstructive sleep apnea (OSA) is believed to be a progressive disorder that lies on the extreme end of a spectrum of sleep disordered breathing.
At the other end of the spectrum is benign snoring–snoring that has no impact on sleep health other than possibly disrupting one's bed partner's sleep. When the causes of snoring begin to progress from relatively harmless noise-making to the harmful sleep disorder of sleep apnea, it often first develops into upper airway resistance syndrome (UARS).
But what exactly is UARS? How does it differ from OSA? And what treatments are available to keep it from developing into OSA? Here we hope to answer these questions and more.
What is Upper Airway Resistance Syndrome?
First we will need a brief recap of what snoring is, as UARS is a progression towards OSA from snoring.
Snoring is the sound created when air flows past loose or relaxed tissues in the throat, which causes the tissues to vibrate and thus creates an irritating sound.
Snoring is an indication that some type of resistance is occurring in the upper respiratory system. The greater the resistance, the greater the breathing effort needed to get past the resistance.
Upper airway resistance syndrome occurs when that breathing effort crosses over from just being harmless snoring to a possibly troublesome disorder.
Causes of UARS
Causes of UARS are similar to OSA. It can be caused by a naturally narrowed air passage, loose fatty tissues of the throat collapsing back into the airway, or the position of the tongue (falling back) during sleep.
Patients with UARS require a greater effort in breathing to get past obstructions. Not all patients with UARS snore, and their symptoms may sound more like heavy, labored breathing during sleep. Sufferers of UARS often describe their breathing effort as "trying to breathe through a straw."
Similar to OSA, the brain has to arouse itself from deeper stages of sleep to increase respiratory effort. When the brain is constantly being aroused from the deeper stages of sleep, it's not able to perform other important tasks that it needs to complete so that you can feel refreshed in the morning. This can lead to symptoms of chronic fatigue and excessive daytime sleepiness, which are also present in obstructive sleep apnea.
Patients can move from snoring to UARS as a result of aging (as muscle tone decreases in the throat) and weight gain (increase of fatty tissues in the throat, which can increase material resistant to airflow). Women in their third trimester of pregnancy are also more likely to develop UARS as a result of weight gain.
Consequences of UARS
Frequent nocturnal awakenings
Difficulty going to sleep/maintaining sleep
Excessive daytime sleepiness
What is the difference between UARS and OSA?
One of the key differences between upper airway resistance syndrome and obstructive sleep apnea is that apneas (pauses in breathing) and hypopneas (decreases in breathing) are either absent or very low in patients with UARS.
Patients with OSA are often overweight or obese (although they can be of normal weight), whereas patients with UARS are often of average weight.
OSA is twice as likely to affect men as women, while UARS can affect men and women equally.
Obstructive sleep apnea is related to many more long-term health conditions as a result of apneas and hypopneas due to the decrease in blood pressure during apnea/hypopnea events, which can lead to increased risk of high blood pressure, heart disease, heart arrhythmias, stroke, and heart failure.
Patients who fail to treat UARS can end up developing OSA and find themselves at risk for many of these health problems.
Treatments for UARS are often similar to the treatments of OSA. However, CPAP therapy may be a last resort treatment option for UARS, rather than the "go-to" treatment that it is for OSA.
Behavior and Lifestyle treatments. This can include practicing good sleep hygiene, making quality sleep a priority, getting adequate exercise and eating right to avoid weight gain, avoiding alcohol and sedatives before bedtime, and changing sleep position (avoiding sleeping on back where gravity aids in creating obstructions).
Oral/Dental Appliances. Dental appliances are often used to treat mild to moderate OSA by themselves, or used with along with CPAP to lower pressure settings for OSA patients. Dental appliances are often the first option for treating UARS. Dental appliances look like sports mouthguards and help move the jaw forward or hold the tongue in place to reduce obstructions.
CPAP Therapy. While CPAP therapy is the most common treatment for sleep apnea, it can also be used in treating UARS. CPAP works by using air pressure via mask to stent open the airways, preventing obstructions.
If you believe your snoring may be becoming a cause for concern, or if you think you may have upper airway resistance syndrome or even obstructive sleep apnea, contact The Alaska Sleep Clinic to receive a free 10-minute phone consultation with a sleep educator who can help you determine if a sleep study may be necessary to diagnose and treat your disorder.