Sleep Apnea and High Blood Pressure

adrenaline cpap elimination diet high blood pressure hypoxia nitric oxide obstructive sleep apnea oxidative stress renin-angiotensin-aldosterone system sleep apnea snoring sympathetic nervous system Oct 05, 2024

The image on the left shows a man wearing a CPAP mask while sleeping. The image on the right shows a digital blood pressure monitor indicating a high-blood pressure reading of 160 over 73.

Around 6 million adults have been diagnosed with sleep apnea in the U.S. In reality though, an estimated 39 million Americans have this sleep disorder.¹

A more prevalent condition is high blood pressure (hypertension), which affects almost 50 percent of American adults. But most of these people are unaware of their condition, which seldom causes symptoms on its own — the reason why high blood pressure is called the “silent killer.”²

Here’s the thing: Studies show that half of people with obstructive sleep apnea (OSA) have high blood pressure too.³ What gives? That’s what this article is about, and more:

What is sleep apnea?
What is high blood pressure?
The link between high blood pressure and sleep apnea
Benefits and drawbacks of CPAP for sleep apnea and high blood pressure

Let’s start by defining sleep apnea. We’ll describe its two types and identify its symptoms.

What is sleep apnea?

Sleep apnea is a condition in which your breathing often stops and restarts during sleep.⁴

There are two types of sleep apnea. Obstructive sleep apnea (OSA), the more common type, happens because of a physical blockage of the airflow through your upper airway. Obesity, large tonsils, and hormone changes are among the risk factors for OSA.^4,5

The other, less common type of sleep apnea is called central apnea. Central apnea occurs when your brain doesn’t send the signals you need to breathe. You’re more likely to develop this condition if you’re over age 60. If you take opioid pain meds, suffer from a heart problem, or live at a high altitude, you’re more prone to having central apnea as well.^4,5,6

When breathing is interrupted during sleep, the shortage of oxygen triggers a survival reflex that wakes you just enough to resume breathing. Although this reflex keeps you alive, it also disrupts your sleep cycle. The result is a lack of restful sleep and a host of other unpleasant effects, including potentially deadly stress on your heart.⁵

Sometimes people aren’t aware of their own sleep apnea, but your spouse or partner may notice your symptoms. These include pauses in your breathing, waking up frequently, and snoring.⁵

Waking up tired even after a full night in bed and feeling sleepy during the day are other common symptoms of sleep apnea. Plus, over time the condition may cause headaches, mood changes, memory loss, and concentration issues.⁵

Now, let’s switch gears and think about high blood pressure.

What is high blood pressure?

Blood pressure is a measure of the force of blood flowing through your arteries. Arteries are the blood vessels that carry oxygen-rich blood from your heart to the other parts of your body. Arteries are distinguished from veins, which carry the blood back to your heart.^7,8

Two numbers make up a blood-pressure reading. The first number, the systolic blood pressure, measures the force in your arteries when your heart beats. The second number is the diastolic blood pressure. This number corresponds with the force in your arteries while your heart rests between beats.⁷

For example, a blood-pressure reading of 120/80 mm Hg means “120 systolic and 80 diastolic.” Or you can just say “120 over 80.”⁹

Throughout the day, your blood pressure changes depending on your activities. But if your reading is constantly at least 130 systolic or at least 80 diastolic, you’ll be diagnosed with high blood pressure.¹⁰

Your genes, existing health issues, and lifestyle all affect your risk of high blood pressure. You’re more prone to this condition if your family members have it, or if you’re African American. Your risk also increases if you’re obese, have high cholesterol, or are diabetic. Smoking, lack of exercise, and taking birth-control pills are risk factors too. So is sodium-potassium imbalance in your body — a common situation due to the wide availability of chemically preserved processed foods today.⁷

The link between sleep apnea and high blood pressure

Sleep apnea can lead to high blood pressure in multiple ways.

Every time you stop breathing, even for a moment, your blood oxygen level drops, while your carbon dioxide level rises. These changes activate your sympathetic nervous system (SNS), making your body release catecholamines into your blood. Catecholamines are stress hormones that include adrenaline. They prompt your heart to beat faster and your blood pressure to increase. These and other temporary physical reactions are designed to help you respond to stressful situations. But when your SNS is activated too frequently — as is the case with sleep apnea — consistently high blood pressure can be the result.^11,12

What’s more, the drop in oxygen levels in OSA drives an increase in harmful molecules called reactive oxygen species (ROS). When there is an imbalance between ROS and antioxidants (substances that help fight cell damage), oxidative stress happens. Oxidative stress impairs the activity of nitric oxide (NO), a molecule that widens your blood vessels. Plus, oxidative stress causes smooth muscle cells to multiply in the interior lining of your arteries. This combination of effects means that your arteries become narrower, and your blood must flow through tighter spaces, thus increasing your blood pressure.^13,14

Also, sleep disruptions due to OSA may activate your renin-angiotensin-aldosterone system (RAAS). Your RAAS is a complex system of enzymes, proteins, and hormones that helps control your blood pressure by affecting the balance of sodium and potassium in your body. When the RAAS is triggered, it makes your body secrete more aldosterone. This hormone prompts your kidneys to retain sodium and release potassium. Elevated sodium levels lead to water retention, which raises your blood volume and your blood pressure.^15,16

Benefits and drawbacks of CPAP for sleep apnea and high blood pressure

Research indicates that treating sleep apnea can help lower your blood pressure.

The standard medical treatment for sleep apnea is CPAP, which stands for “continuous positive airway pressure.” A CPAP machine keeps your airways open during sleep by continuously delivering air through your mouth and/or nose.^11,17

In a study, 918 OSA patients had CPAP therapy for up to 24 months. Patients who stuck to their treatment for the whole 24-month period showed significant reductions in their blood pressure.¹⁸

But in another study, patients failed to see significant changes in their blood pressure after 3 months of CPAP.¹⁹

The above results are consistent with the findings of several other studies — that is, it may take longer than a few months for people with OSA to lower their blood pressure through CPAP therapy.¹⁹

OSA patients with hypertension may shy away from CPAP therapy for reasons besides the long treatment period. For one, you often have to join a sleep study before you can get a prescription for a CPAP machine.²⁰

Cost is another deterrent: CPAP machines, especially those with advanced features, can be expensive.²¹

The machines are also complex to use and prone to air leaks. Moreover, they can be uncomfortable to wear and can cause side effects. Some of the least annoying side effects are sores on your face, nosebleeds, a stuffy nose, and a dry mouth.^21,22

And for OSA sufferers and their bed partners who just want to sleep in a quiet room, the motor noise made by CPAP machines can be an issue.²²

Conclusion

Sleep apnea is a disorder in which your breathing starts and restarts many times while you’re sleeping.

This condition can drive high blood pressure in several ways: by activating your SNS, by promoting oxidative stress, and by triggering your RAAS.

Studies indicate that treating sleep apnea can help reduce blood pressure in OSA patients with hypertension. For these patients, CPAP is the most commonly recommended treatment.

But research also shows that long therapy periods are required for CPAP to be effective in lowering blood pressure. In addition, patients may avoid CPAP for various reasons, including cost, discomfort, and side effects.

Fortunately, there’s another way to beat sleep apnea — and hypertension — without the drawbacks of CPAP. Even better, this all-natural method addresses the root cause of sleep apnea, allowing for a permanent solution to the problem. Sign up for the Snoring Diet Solution to learn more.

References

Sleep Apnea and High Blood Pressure

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