What is Obstructive Sleep-Disordered Breathing?
Obstructive sleep-disordered breathing (SDB) is a sleeping issue where the airways don’t operate as they should. This leads to snoring and/or breathing difficulties during sleep due to increased resistance and the potential for the throat to collapse. One common type of SDB is Obstructive Sleep Apnea (OSA). This is a condition where breathing stops or becomes notably shallow, despite the person still trying to breathe.
* Apnea is when breathing stops completely for 10 seconds or more.
* Hypopnea is when there is a temporary and noticeable decrease in breathing, but not a complete stop, for 10 seconds or more.
The Apnea–hypopnea index (AHI) measures the severity of SDB, which is a common term used in sleep studies.
“Obstructive SDB” is the phrase used to describe symptoms of intermittent blocking of the throat during sleep. This term is used even when the severity of the blockage has not yet been measured through objective tests like sleep studies.
Obstructive Sleep Apnea is generally characterized by increased risk of the throat collapsing during sleep. This results in extremely decreased (hypopnea) or no (apnea) airflow through the nose and/or mouth. This usually results in low levels of oxygen in the blood and is typically ended by a brief awakening.
Repeated episodes of apnea can lead to sustained low oxygen levels in the blood and disrupted sleep with less deep sleep (slow-wave) and dream sleep (rapid eye movement or REM).
What Causes Obstructive Sleep-Disordered Breathing?
Being overweight is a major risk factor for sleep apnea, accounting for 58% of moderate to severe cases. Sleep apnea can be caused by both physical traits and non-physical factors, including genetics.
Physical traits that may lead to sleep apnea include irregularities in the facial bone structure that can cause airway collapse during sleep. This includes:
* Having a small, set-back jaw or a small lower jaw
* Underdeveloped upper and lower jaw
* Enlarged tonsils or adenoids, particularly in children and young adults
* A high, arched roof of the mouth (especially commonly seen in women)
Sleep apnea can also be influenced by non-physical factors such as:
* Being overweight
* Having fat mainly in the upper body
* Being male
* Getting older
* Being postmenopausal
* Drinking alcohol
* Using sedatives
* Smoking
Certain health conditions like underactive thyroid, stroke and a condition called acromegaly can also lead to sleep apnea.
Even though the evidence is limited, especially for women, smoking and drinking alcohol are considered possible risk factors for sleep apnea. It is known that drinking alcohol before bed can make sleep apnea worse in men, and that smoking can cause snoring in both men and women.
One study showed that in Japanese women, drinking more than 23 grams of alcohol a day was linked to lower oxygen levels during sleep and snoring.
Risk Factors and Frequency for Obstructive Sleep-Disordered Breathing
Obstructive Sleep Apnoea (OSA), once considered a very rare disorder, has seen a significant increase in reported cases in recent years. The frequency of Obstructive Sleep Apnoea Syndrome (OSAS) can range dramatically, from a minor 0.1% to as high as 13%. However, most studies usually find a prevalence of between 1% and 4%.
- This condition is especially common among middle-aged men and women, with up to 50% of men and 25% of women experiencing moderate to severe OSA.
- This increased severity is defined by an Apnea-Hypopnea Index (AHI) equal to or greater than 15.
- Dramatically rising levels of obesity over the past 30 years partially explain the increased prevalence of OSA.
Signs and Symptoms of Obstructive Sleep-Disordered Breathing
Obstructive Sleep Apnea (OSA) is a condition that affects a person’s sleep and can take years to diagnose. People with OSA often show a variety of symptoms during both day and night, and the condition can even be recognized through various physical signs.
OSA symptoms that come up during the night can include:
- Loud and frequent snoring
- Sudden pauses in breathing while asleep (referred to as ‘apneas’)
- Restless sleep
- Frequent nighttime urination
- Mouth breathing during sleep
These symptoms could indicate that a person has sleep-disordered breathing (SDB), a group of disorders characterized by abnormal respiratory patterns during sleep, of which OSA is a part.
During the daytime, a person with OSA might experience:
- A feeling of not having got enough sleep even after a full night’s rest
- Morning headaches or a sore, dry throat
- A tendency to feel sleepy during quiet activities
- Fatigue or tiredness throughout the day
- Difficulties with memory and intellectual abilities
- Changes in sexual function, such as erectile dysfunction or a reduced sex drive
A history of disruptive snoring, or disruptive snoring accompanied by witnessed apneas, is often a good indicator of SDB.
Physical signs of OSA can include:
- Obesity – Body mass index (BMI) greater than 30 kg/m
- A large neck size – More than 43 cm (17 in) in men and 37 cm (15 in) in women
- Enlarged tonsils
- Abnormalities in the shape or size of the jaw or tongue
- Extreme overbite
- High-arched hard palate (the top part of the inside of the mouth)
- High blood pressure, which is present in about half of the people with OSA
It’s important to remember that just because you have one or two of these symptoms doesn’t necessarily mean you have sleep apnea. Other conditions can also cause similar symptoms. For example, nighttime shortness of breath can be due to asthma, acid reflux, or even panic disorder. Similarly, daytime sleepiness can result from poor sleep habits, substance abuse, depression, or narcolepsy. And frequent nighttime urination can be caused by different factors, ranging from bladder or prostate problems to diabetes, heart failure, kidney issues, or certain medications. So, before labelling one’s condition as sleep apnea, all these other possibilities should be checked out.
Testing for Obstructive Sleep-Disordered Breathing
In diagnosing obstructive sleep apnea (OSA), which is a condition where your breath pauses while you’re asleep, doctors typically follow a three-step process. This includes an interview about your symptoms, a physical examination, and a series of tests during your sleep.
When you see your doctor, they will evaluate common risk factors and symptoms for OSA. Being overweight or obese is the most well-established risk factor.
Routine tests from a lab usually aren’t valuable in diagnosing OSA unless they have a special reason to consider them. For instance, a test for thyroid function, called a thyrotropin test, might be done if a patient is showing other signs of an underactive thyroid (hypothyroidism). This is particularly relevant in older people.
The gold standard for diagnosing OSA is polysomnography, which is a type of test administered during sleep. However, this test can be expensive and time-consuming.
Several different questionnaires have been developed to identify individuals who are at high risk for OSA. Two of these are the Berlin Questionnaire, which classifies around 82% of people as high risk, and the STOP-Bang questionnaire, which can stratify the risk of OSA. Of the five questionnaires analyzed, STOP-Bang and the Berlin questionnaire were found to be more sensitive, meaning they’re more likely to correctly identify people with OSA, while the Epworth Sleepiness Scale and a four-variable questionnaire showed more specificity, meaning they’re more likely to correctly identify people without OSA.
Polysomnography involves recording various physiological variables during sleep, like brain activity, eye movement, muscle activity in the chin, heart activity, respiratory effort, airflow and oxygen levels, ventilation, and snoring.
Polysomnography allows an accurate diagnosis of OSA and gives a measure of the benefit from treatment. The test should last at least six hours. In OSA, characteristic findings include episodes of apnea, or lack of breathing, occurring alongside respiratory muscle effort. If these episodes last 10 seconds or longer, they’re regarded as significant. Patients might mainly have either apnea or hypopnea, which is shallow or slow breathing, or a combination of the two.
The apnea-hypopnea index (AHI) is a measure of the severity of sleep apnea, calculated from the total number of apnea and hypopnea episodes divided by the total sleep time. If someone has between five and 15 episodes an hour, they have mild sleep apnea; 15 to 30 episodes an hour suggests moderate sleep apnea, and more than 30 episodes an hour indicates severe sleep apnea.
Excessive sleepiness during the day is also a key sign indicating the need for sleep apnea treatment.
Treatment Options for Obstructive Sleep-Disordered Breathing
If you have obstructive sleep apnea (OSA), it’s important to know about the benefits of treatment and the potential risks of ignoring the condition. Treatment options range from lifestyle changes and devices to medications and surgery, and the best course of treatment often depends on the severity of the sleep issues.
For mild sleep apnea, there are many treatment options, while for moderate to severe sleep apnea, doctors commonly recommend a treatment method called continuous positive airway pressure (CPAP). This involves wearing a mask over your nose while you sleep, which helps keep your airways open. CPAP is particularly beneficial for people experiencing a high number of sleep disruptions each hour, and also for those with certain cardiovascular diseases.
Regular use of CPAP is shown to considerably improve various sleep-related symptoms, including snoring, nightmares, and daytime sleepiness. It may also enhance overall quality of life. However, some patients reject or can’t tolerate nasal CPAP therapy. For them, alternatives like BiPAP or oral appliances may be considered.
Oral appliances, which include devices that move the lower jaw forward or hold the tongue in place, can help reduce sleep disruptions and daytime sleepiness, and improve quality of life. They are typically recommended for those suffering from mild to moderate sleep apnea.
Additional general measures include lifestyle modifications such as losing weight, avoiding alcohol before bedtime, and adopting certain sleep positions. Obesity, for instance, can considerably increase the risk of OSA, so losing weight can result in a significant reduction in sleep disturbances. To ensure a good quality sleep, it’s also advised to follow proper sleep hygiene instructions, such as avoiding caffeine after lunch, limiting alcohol and smoking especially close to bedtime, maintaining regular physical activity, ensuring a quiet and comfortable bedroom, and practicing good ventilation.
Some people with OSA may find relief from positional treatment, which involves avoiding sleeping on their back and instead adopting different positions. Various devices such as special straps, vests, or tennis balls attached to the back of a nightgown can train patients in maintaining recommended sleeping positions.
For those struggling with severe OSA or whose noninvasive treatments were unsuccessful, surgical options are available. These aim to permanently widen the airways to decrease throat resistance during sleep. Various surgical techniques are available depending on the patient’s specific needs.
Use of certain medications is also part of OSA treatment. Dronabinol and Modafinil, for instance, have shown promise in small studies, although more research is needed. Modafinil is just for patients still experiencing daytime sleepiness despite optimal use of CPAP.
In conclusion, OSA is a manageable condition, but it requires regular follow-up with a sleep specialist. The goal is to find an effective treatment and encourage its regular use while also addressing any problems leading to difficulties in adherence to the prescribed course of treatment.
What else can Obstructive Sleep-Disordered Breathing be?
There are several conditions that can be found in people including:
- Asthma
- Central sleep apnea syndromes
- Chronic Obstructive Pulmonary Disease (COPD)
- Depression
- Gastroesophageal reflux disease (a condition where stomach acid frequently flows back into the tube connecting your mouth and stomach)
- Underactive thyroid (Hypothyroidism)
- Narcolepsy (a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep)
- Obstructive sleep apnea (a potentially serious sleep disorder in which breathing repeatedly stops and starts)
- Periodic limb movement disorder (a condition that causes people to jerk and kick their legs while sleeping)
