man in bed unable to sleepWhat actually causes Obstructive Sleep Apnea (OSA) and why is it left undiagnosed so often? There are a multitude of reasons, but the most common remains that people are unaware they have a sleep problem. OSA is not always obvious (like a broken bone) and people don’t always know how to address the problem. And despite all of the advancements in the healthcare industry regarding OSA, 70–80% of those affected remain undiagnosed.

Dentists and Orthodontists are usually the first to notice the signs and symptoms of OSA (wear of tooth enamel, scalloped tongue, limited airway based on tonsil size, and small palates). Secondary to the dental field would be an ENT specialist or your PCP. Once the symptoms are noticed, referral to a sleep specialist is the proper course of action.

Let’s talk about the causes of OSA. There are 2 types of causes, direct and indirect.

Direct Causes:

1. Body Weight – Obesity is determined by calculating BMI (Body mass index), which is a measurement of body fat. BMI is your weight (in kilograms) over your height squared (in centimeters). A BMI greater than 30 = obese, while a BMI of 25-29.9 = overweight. Obesity is present in more than 60% of people diagnosed with OSA, and overweight people have a 6 times higher risk of developing moderate to severe obstructive sleep apnea (compared to normal BMI). If you are overweight, your windpipe may become narrow from the extra soft fat tissue, making it harder for it to stay open overnight.
2. Age – As we age, sleep-related disorders become more common (difficulty falling asleep and staying asleep, night-time awakenings, amount of quality sleep obtained, etc.). Studies show that more than 50% of adults over the age of 65 have a sleep-related disorder. Age-related loss of muscle tone in the throat muscles and increased fat deposits in the oropharyngeal area can cause your airway to become narrow or weak, creating tendency to collapse. Lengthening of the soft palate and structural changes in the area around the pharynx can also occur. Additionally, the aging process impairs your brain’s ability to keep your throat muscles stiff during sleep, also leading to airway collapse.
3. Sex – Studies have shown that men are more susceptible to developing OSA than women. The average ratio of male patients vs. female patients referred for clinical evaluation is between 5-8:1. The male predisposition for OSA can be attributed to both anatomical and functional traits of the upper airway, hormonal influences and respiratory responses to arousals. While women also suffer from OSA, they tend to report different symptoms than men. Rather than the typical loud snoring and gasping for breath (stereotype of a man’s sleep profile), women usually report fatigue and lack of energy during the day (things men do not typically want to admit). Furthermore, female bed partners of men with undiagnosed OSA tend to report the symptoms more often than male bed partners of females with undiagnosed OSA.
4. Anatomy – A deviated septum, enlarged nasal turbinates, thickened soft palate, enlarged uvula, large tongue, tonsillar hypertrophy, retrognathia, inferiorly positioned hyoid bone, or maxillary and/or mandibular retroposition can all cause airway restriction. Additionally, your risk of OSA increases if your neck circumference is larger than 17” for males and 15” for females. If your airway is blocked, then your lungs won’t get enough airflow, which results in loud snoring and a drop in blood oxygen levels. When your oxygen drops to an unsafe level, your brain is triggered to disrupt your sleep. This disruption opens up your windpipe again and allows normal breathing to restart (often accompanied by a choking noise).

Indirect Causes:

1. Use of alcohol or sedatives – Sedation can interfere with the ability to awaken from sleep. It can also lengthen periods of apnea (no breathing), with potentially fatal consequences. Alcohol can tamper with hormones you can consume supplements to help keep your health in the best shape.  Alcohol and sedatives can cause the throat muscles to become too relaxed, resulting in OSA.
2. Smoking – Smokers are 3 times more likely to have OSA than non-smokers. Smoking irritates the upper airway tissues, leading to inflammation. The inflammation then reduces the space for airflow, causing eventual obstruction. Smoking has been linked to frequent awakenings and sleep deprivation, contributing to poor sleep quality. Smoking has also been associated with longer apneic episodes and greater levels of oxygen deprivation.
3. Asthma – Studies have shown that people with asthma have a significantly higher risk of developing OSA. This link is even higher for people who were diagnosed with asthma as children. People with asthma suffer from breathlessness, nighttime coughing and wheezing, which disrupts the sleep cycle. The airway becomes inflamed, constricting the airflow and therefore breathing becomes difficult.
4. Nasal congestion – Whether you are suffering from seasonal allergies, a cold or a sinus infection, nasal congestion increases your risk of developing OSA. Your body naturally tries to breathe through your nose while you sleep, so when that isn’t possible, it forces mouth breathing. Mouth breathing then creates a negative pressure behind the uvula, causing noise and vibration between the uvula and soft palate. This sound is known more commonly as snoring.
5. Sleep position – Typically, OSA is worse when you sleep on your back (supine position). OSA can occur in other positions, but the most common complaints from bed partners are when their partner is supine. Additionally, you are more likely to snore while supine, as the tissues in your upper airway can crowd the back of the throat and block airflow. If you phase into REM sleep while supine, apnea may worsen, as your upper airway has no muscle tone during this stage of sleep.

At Michigan Head & Neck Institute, we exclusively offer treatment of sleep apnea that consists of creating a custom-fit oral appliance (mouthpiece) which is comfortable and can be adjusted to meet the requirements of each patient. Even though males who are overweight are at higher risk for OSA, females who are not overweight are also at risk. Each patient is treated with a customized oral appliance that is specific to his or her needs. Dr. Klein works with each patient to provide the best options for their specific treatment.
Please contact our office at (586) 573-0438 if you would like to learn more about the causes of OSA and possible treatment options.

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