Sleep Apnea and Heart Disease

angiopoietin-2 blood vessels cardiovascular health coronary artery disease cpap heart attack heart disease high blood pressure hypoxia inflammation obstructive sleep apnea oxidative stress sleep apnea snoring sympathetic nervous system Oct 12, 2024

In the U.S., an estimated 39 million adults — about one-tenth of the population — suffer from a disorder called sleep apnea. Here’s the catch: Up to 90 percent of people with sleep apnea don’t know they have it.^1,2

Another prevalent condition is heart disease, which has been diagnosed in 11 percent of American adults. Heart disease also happens to be the leading cause of death in the country — it kills 1 in every 4 Americans — and in the world.^3,4

Studies show that sleep apnea raises your risk of heart disease by 30 percent. What’s more, 70 percent of people hospitalized for heart disease were found to have obstructive sleep apnea (OSA).^5,6 Given these statistics, it’s worth examining the relationship between the two conditions — and that’s what we’ll do in this article:

What is sleep apnea?
What is heart disease?
The effects of sleep apnea on your heart and blood vessels
Does CPAP help with heart disease?

But first, is sleep apnea the same as OSA? Let’s address this and other basic points before delving deeper.

What is sleep apnea?

Sleep apnea is a condition in which you frequently stop and restart breathing while you’re sleeping.⁷

OSA — the more common of two types of sleep apnea — stems from the physical obstruction of airflow through your upper airway. You’re at risk of OSA if you’re obese or have large tonsils. Changes in your hormones are another risk factor.^7,8

You may miss your symptoms of sleep apnea, especially if you’re unaware of your condition. But your bed partner may notice that you pause your breathing repeatedly, wake up often, and snore.⁸

Because sleep apnea disrupts your sleep cycle, it makes you tired and sleepy during the day despite a full night in bed. Over time, sleep apnea can lead to headaches and mood swings. You can have trouble remembering things and concentrating too.⁸

Let’s now shift our focus to heart disease.

What is heart disease?

“Heart disease” is an umbrella term for various conditions affecting the structure and function of your heart. But when people say “heart disease,” they likely mean coronary heart disease (CHD). CHD — the most common type of heart disease — is also known as coronary artery disease (CAD), ischemic heart disease, or myocardial ischemia.^9,10

CHD develops slowly over time as plaque — a mix of fat, cholesterol, and other substances in your blood — accumulates in the blood vessels called arteries. Plaque impedes the flow of oxygen-rich blood to your heart and may lead to other heart problems.⁹

Common symptoms of CHD are palpitations, sweating, or shortness of breath. Lightheadedness or dizziness are also likely. So are pain or discomfort in your neck, chest, and/or upper body. You may experience nausea or vomiting, heartburn, or indigestion too.¹¹

But it’s also possible not to have any symptoms of CHD. In some instances, you may not know you have it until you have a complication like a heart attack.¹²

The effects of sleep apnea on your heart and blood vessels

Sleep is a crucial time for your body to recover and recharge. When you sleep, your heart rate slows, your blood pressure falls, and your breathing stabilizes. These events allow your heart to recuperate from the strain it experienced while you were awake.¹³

With sleep apnea though, your sleep is constantly interrupted. This means your heart and blood vessels don’t get enough recovery time, making you more prone to heart disease.¹⁴

Even brief pauses in your breathing during sleep make your blood oxygen fall and carbon dioxide level rise. This condition marked by repeatedly low blood oxygen levels is called intermittent hypoxia (IH). IH triggers your sympathetic nervous system (SNS), driving the release of stress hormones like adrenaline into your blood. Stress hormones cause your heart rate and blood pressure to go up. These temporary physical reactions are good for dealing with stressful or dangerous situations. But when medical conditions like sleep apnea keep your SNS constantly activated, your blood pressure remains elevated. High blood pressure, in turn, is an established risk factor for heart disease.¹⁴

OSA-induced IH also leads to oxidative stress — an imbalance between harmful molecules called reactive oxygen species (ROS) and helpful substances called antioxidants. Oxidative stress can drive inflammation in the lining of your blood vessels. Over time, this inflammation damages your blood vessels and eventually your heart.^14,15,16

On top of that, having OSA means you take in air against a blocked upper airway. Forced and unsuccessful inhalations drive considerable pressure changes within your chest cavity. In the long term, these frequent pressure swings can also contribute to damaging your heart.¹⁴

Does CPAP help with heart disease?

Continuous positive airway pressure, or CPAP for short, is the “gold standard” medical treatment for sleep apnea. A CPAP machine sends a steady stream of air through your mouth, nose, or both. By doing so, the device aims to keep your airways open while you’re asleep.^17,18

Because CPAP stabilizes your breathing — and thus, prevents IH — during sleep, researchers thought that the treatment would lower your risk of heart disease. But studies show that despite reducing IH, the levels of angiopoietin-2 (Ang-2) — a pro-inflammatory protein — remained high in OSA patients using CPAP. High levels of Ang-2 increase your risk of heart and blood vessel disease.¹⁹

In fact, continued use of CPAP over a 12-month period increased Ang-2 levels in OSA patients with CAD. What’s more, the higher the CPAP pressure used by the patients, the higher their Ang-2 levels. It’s thought that the rise in Ang-2 occurs because CPAP increases your lung volume. This means that CPAP stretches the cells in the interior lining of your lungs. The stretched cells, in turn, are believed to secrete additional Ang-2. This manner in which CPAP promotes inflammation of the lungs is similar to the way ventilators induce lung injury.²⁰

Conclusion

Sleep apnea, or OSA, contributes to hypertension, intermittent hypoxia, and oxidative stress — all of which make you more prone to heart disease.

Perhaps surprisingly, CPAP — the treatment that doctors usually recommend for OSA — doesn’t help with heart disease. Just the opposite: CPAP use has been found to increase Ang-2, which promotes inflammation and raises your heart-disease risk.

If you want to beat sleep apnea for good, you’ll need to address its root cause. Want to know more about what drives sleep apnea and how you can get rid of it naturally? The answers are within your reach — click here to sign up for the Snoring Diet Solution.

References

Sleep Apnea and Heart Disease

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