Types of Sleep Apnea

There are two main types of sleep apnea: obstructive sleep apnea (OSA), which Cory has, and central sleep apnea (CSA). OSA is more common by far, affecting about 30 million people in the United States — yet only about six million are diagnosed with the condition, according to the American Medical Association, most likely due to lack of awareness.

Mixed sleep apnea. also called complex sleep apnea, is a less common type of apnea that combines OSA with CSA.

The severity of sleep apnea is classified by the Apnea Hypopnea Index (AHI). The AHI is a value between 0 and 10 that indicates the number of apneas and hypopneas (sudden pauses in breathing) per hour of sleep

Heart Connections

Much research has shown that OSA, in particular, takes a heavy toll on the heart. In 2021, the American Heart Association (AHA) issued a scientific statement emphasizing how sleep apnea worsens heart disease, and why increased awareness on the part of physicians and patients is so important. Among the highlights:

• Between 40% and 80% of people in the US with cardiovascular disease also have OSA, yet it is underrecognized and undertreated by doctors.
• In general, about 34% of middle-aged men and 17% of middle-aged women meet the criteria for OSA.
• Sleep apnea can cause a negative feedback loop whereby it worsens cardiovascular conditions, which in turn worsen sleep apnea.
• OSA affects 30% to 50% of people with high blood pressure and is a risk factor for atrial fibrillation.
• OSA is also associated with Type 2 diabetes, worse outcomes from heart failure, and even sudden cardiac death.
• People with cardiovascular risk factors or conditions should be screened for OSA, and treated appropriately. This may include continuous positive airway pressure (CPAP), oral appliances, modifying lifestyle behaviors and weight loss.
• Risk factors for OSA include obesity, large neck circumference, craniofacial abnormalities, smoking, family history, and nighttime nasal congestion.
• OSA is associated with several cardiovascular complications, as detailed in the statement:
• High blood pressure – OSA is present in 30%-50% of people with high blood pressure, and up to 80% of those who have resistant, or hard-to-treat high blood pressure;
• Heart rhythm disorders such as atrial fibrillation and sudden cardiac death;
• Stroke;
• Worsening heart failure;
• Worsening coronary artery disease and risk of heart attack;
• Pulmonary hypertension (PH) – as many as 80% of people with PH have OSA; and
• Metabolic syndrome and Type 2 diabetes.

While there’s no consensus that screening for OSA alters clinical outcomes, the high prevalence of OSA among people with heart disease, along with evidence that OSA treatment improves quality of life, are reasons to screen and provide treatment, according to the statement.

If you suspect you have sleep apnea, see your doctor and/or a sleep specialist as soon as possible. The good news is, treating OSA can improve heart problems and help prevent them.

Talk with your doctor about these suggestions from the AHA statement authors:

• Be screened for OSA if you have resistant or difficult to control hypertension, pulmonary hypertension and atrial fibrillation that recurs despite treatment.
• Be screened for OSA via a sleep study if you have heart failure, especially if sleep-disordered breathing or excessive daytime sleepiness are suspected.
• If you are diagnosed with OSA, get treated with available therapies, potentially including lifestyle and behavior modifications and weight loss.
• If you have severe OSA, get treated with a CPAP device when possible.
• If you have mild-to-moderate OSA, get treated with oral appliances that adjust the jaw and tongue placement during sleep to prevent obstructed breathing.
• Have routine follow-up, including overnight sleep testing to confirm if treatment is effective.

Other OSA Consequences

OSA does not just affect the heart. Research shows connections with:

Memory and cognition. A number of studies connect OSA with cognitive problems and memory loss. One recent study found that OSA interferes with your ability to recall specific details of events that happened in your own life. The authors discovered that brain scans of people with OSA showed a significant loss of grey matter in the brain in regions that overlap with biographical memory.

Brain damage. According to the American Academy of Sleep Medicine, the breathing pauses that occur during OSA can prevent your body from supplying enough oxygen to the brain. In severe cases, this can lead to a significant reduction in the brain’s white matter, leading to difficulty concentrating and moodiness, as well as memory problems. However, the damage was reversible with CPAP therapy.

Asthma. A recent review article revealed that undiagnosed or inadequately treated OSA adversely affects asthma control, and that asthma and the medications that treat it predispose to OSA.

Weaker bones and teeth. A recent study has found a connection between sleep apnea and low bone-mineral density, suggesting that OSA can lead to increased fractures, loose teeth and failed dental implants.

Road traffic accidents. The first nationwide study to estimate the risk of all road traffic accidents in individuals with OSA was conducted using data from Denmark. The researchers found the risk of having a motor vehicle accident was significantly higher among those with OSA and that accidents were more severe among those with OSA compared with similar individuals who did not have OSA. That study also found that OSA did not increase the risk of pedestrian or biking accidents.

How Does Sleep Apnea Affect You?

In OSA, breathing is interrupted when the upper airway is blocked by the soft tissue in the back of the mouth collapsing during sleep. The effect is like trying to drink through a wet paper straw: You suck on it, but nothing gets through. Someone with OSA can have 5-100 apneas (breathing stoppages) per hour, totaling hundreds during the night. The cutoff of air may lead to low levels of oxygen and increased levels of carbon dioxide in the blood; you get less deep sleep, and the sleep you do get is interrupted. You may awaken suddenly, gasping for breath. The frequent awakenings keep you from getting deep, restorative sleep, and also set the stage for hypersomnia.

With CSA, you regularly stop breathing because your brain doesn’t tell your muscles to take in air, not because something physically blocks your airway. CSA often happens after a serious illness and is more common in people over age 65, who may have health conditions such as congestive heart failure, kidney failure or a neurological disease. Evidence suggests that these conditions may set the stage for sleep apnea and, conversely, sleep apnea makes these conditions worse.

Mixed sleep apnea, sometimes complex sleep apnea syndrome cannot be readily treated by CPAP alone. For sleep specialists, this is a controversial diagnosis, and some maintain that mixed sleep apnea is really a form of CSA. As of now, more research is needed to better understand the disorder and identify treatment options.

Diagnosing OSA

If you have a bedmate, that person my be the first to spot that you have a problem, often evidenced by your loud snoring, or when you gasp for breath repeatedly through the night. If this happens, see your doctor, who may in turn, refer you to a sleep specialist.

The latest guidelines from the American Academy of Sleep Medicine (AASM) recommend a series of diagnostic tools and steps. Overall, a definitive diagnosis usually is made by a sleep specialist in a laboratory-based or in-home sleep study.

Lab-based sleep study (Polysomnography). For this test, you’ll likely spend the night in a sleep lab for a study to assess the number and severity of your apneas. You’ll undergo a test that records a variety of bodily functions, including brain waves, muscle activity, eye movements, heart rate, breathing, air flow, and blood-oxygen levels. The test records the number of apneas and hypopneas per hour of sleep, and the degree of low blood oxygen and reduced airflow determine the diagnosis and severity of OSA.

Home sleep study

This system, which is not appropriate for everyone, is worn during sleep in your own bed. It consists of a small recording device, sensors, belts, and related cables and accessories. Adults between the ages of 18 and 65 who have a high probability of moderate-to-severe OSA and no other medical conditions are most likely to benefit from the home test, according to the AASM.

In the future, it may be easier to make a diagnosis of OSA. Emerging research shows that analyzing a person’s breathing sounds while awake may accurately screen for OSA.

Treatment Options

Management of both OSA and CSA is similar: The gold-standard treatment is nasal continuous positive airway pressure or CPAP. The CPAP device delivers air through a small mask that fits over your nose or through plastic nasal prongs. The device forces pressured air into your airway while you sleep, keeping it from closing. Some devices can vary the flow of air to match an individual’s specific breathing pattern, while others start out the night with a lower air pressure and builds as required.

CPAP is not a cure for OSA or CSA (neither condition is curable), but treatment may lower high blood pressure and reduce the risk of cardiovascular events such as heart attacks and cardiac deaths. It also helps reduce daytime sleepiness and depressive symptoms, which many people with OSA experience. Although some people struggle to sleep with a CPAP device, others adjust well. Your doctor can help you choose a mask, CPAP device, and pressure setting that is right for you.

If you have a CPAP device and are experiencing difficulty or require assistance in configuring or adjusting your CPAP device or mask, please contact ASAA at 888-293-3650.

Lifestyle changes can also help reduce OSA symptoms, particularly for mild cases, but should be undertaken regardless of OSA severity. These include:

• Regular physical activity, but not right before bed because that gets your adrenaline pumping and can keep you awake. Recent data suggest that sedentary behavior contributes to the development of OSA. Following a healthy diet, such as the Mediterranean diet, and achieving and maintaining a healthy weight.
• Limiting alcohol consumption to one drink per day for women and two drinks for men; too much alcohol interferes with sleep.
• Avoiding caffeine before bed.
• Developing a pre-bedtime routine such as taking a warm bath, dimming the lights or having some herbal tea.

Coming Up

Two drugs are being tested for the treatment of sleep apnea, and more are likely on the way. Eli Lilly has an ongoing phase III trial of tirzepatide in OSA patients who are unwilling or unable to use a CPAP device.

In addition, Bayer recently reported on its first small, placebo-controlled trial of a novel potassium channel antagonist called BAY2586116 delivered via a nasal spray, that shows promise in treating OSA symptoms.

We will be providing more information on these trials, and are keeping an eye out for other emerging OSA treatments.