“Laugh and the world laughs with you, snore and you sleep alone.” This quip by author Anthony Burgess is funny, but snoring is a symptom of sleep apnea—and sleep apnea is no laughing matter.
When you snore, the soft tissues in the back of your throat rattle around, partially blocking your airway. If the airway is completely blocked, as it periodically is if you have sleep apnea, breathing stops altogether. Levels of oxygen in the blood fall and carbon dioxide levels rise, signaling your brain to rouse you just enough to take a breath.
Although you may be unaware of these episodes, they can last 10–20 seconds or longer and occur hundreds of times a night, resulting in oxygen deprivation and sleep interruptions that seriously impact your health.
How Sleep Apnea Affects Your Brain
You know how you can feel tired, grumpy, unfocused, and forgetful when you don't get enough sleep. If you think you’re chalking up eight hours a night but still experience these symptoms, you may have sleep apnea.
Every time your airway is blocked, and you are forced to catch your breath, you are nudged out of whatever stage of sleep you’re in. Unfortunately, many apnea episodes take place during REM sleep, a stage involved in dreaming, the regulation of emotions, and the consolidation of memories. Disruptions in REM sleep night after night take a toll.
The inevitable drop in blood oxygen that occurs during these lapses in breathing also impacts the brain and, in severe cases, can cause inadequate levels of oxygen in tissues and organs (hypoxia). Sleep apnea-related hypoxia is associated with metabolic abnormalities, structural changes, and dysfunction of the brain and other organs. To make matters worse, people with sleep apnea often have coexisting conditions that also adversely affect the brain, including diabetes, obesity, hypertension, and cardiovascular disease.
Mood & Memory
It’s easy to see why sleep apnea causes daytime sleepiness, irritability, and poor concentration, but did you know it is also linked with more serious mood and memory problems?
- Depression: A study published in Sleep Medicine reported that 23% of patients with sleep apnea also had depression. This isn’t surprising, since sleep apnea and depression share several of the same symptoms (fatigue, low energy, lack of focus, weight gain, etc.). Plus, REM sleep disturbances of any kind can cause mood disorders.
- Anxiety: A large national survey revealed that people who have sleep apnea are nearly four times more likely to suffer with anxiety. One reason is high levels of cortisol, the primary stress hormone, is elevated in both anxiety and sleep apnea.
- Alzheimer’s: Sleep apnea and other sleep disorders are now recognized as a risk factor for Alzheimer's. Sleep is crucial for brain health because metabolic wastes and other toxins are cleared out of the brain while we sleep. PET scans reveal higher levels of beta-amyloid, a protein associated with Alzheimer’s, in individuals with sleep apnea.
On the positive side, treatment with CPAP (continuous positive airway pressure), which keeps the airway open during sleep, has been shown to improve symptoms of depression and anxiety. Although no one can claim CPAP as a cure for Alzheimer's, studies suggest it may help reduce the risk of developing dementia and slow its progression.
Sleep Apnea & Heart Disease
Untreated sleep apnea also increases the risk of hypertension, atrial fibrillation, heart failure, stroke, and other cardiovascular disorders. Frequent interruptions in the deepest stages of sleep—when your heartbeat and breathing rate slow, your blood pressure decreases, and your body is in recovery and repair mode—increase the burden of heart problems.
The low concentration of oxygen in the blood characteristic of sleep apnea is another contributor. In addition to promoting chronic inflammation, which is a central feature of heart disease, it also activates the sympathetic nervous system and triggers the production of cortisol to wake you enough to start breathing again. But these hormones do more than remind you to breathe. They also increase your heart rate and blood pressure and signal the release of glucose and fatty acids. Elevations in all of these are related to cardiovascular disease.
Furthermore, sleep apnea is closely linked to obesity, diabetes, and metabolic syndrome, which are major risk factors for heart disease. An estimated 25%–30% of individuals with sleep apnea have diabetes, and the vast majority are obese.
CPAP Can Help
Now for the good news. Treatment with CPAP can reduce some of these risk factors. In a study by Johns Hopkins researchers, patients with moderate to severe sleep apnea spent two nights in a sleep lab hooked up to all kinds of monitors—one night while using CPAP and the other without it.
The researchers reported that on the nights CPAP was not used, there were more sleep disturbances, greater elevations in heart rate and blood pressure, and steeper declines in blood oxygen levels. There were also higher levels of free fatty acids, glucose, and cortisol during the night. Patients with the most severe sleep apnea had the greatest increases in these cardiovascular/diabetes risk factors.
This underscores the importance of getting tested and treated for sleep apnea. It might even save your life. A JAMA study involving men and women with severe sleep apnea found that those who had been prescribed CPAP had a 62% lower risk of death from all causes during 11 years of follow-up.
Other Common Problems
The adverse consequences of sleep apnea affect nearly every organ and system in your body.
There are overlaps with chronic obstructive pulmonary disease (COPD) and asthma, with more flare-ups and greater drops in oxygen levels in individuals who also have sleep apnea. Erectile dysfunction is more common, likely because of the circulation problems and lower testosterone levels associated with sleep apnea.
Time to Get Serious About Sleep Apnea
I hope this article will encourage you to get serious about sleep apnea because it is taken far too lightly.
If you have symptoms such as heavy snoring, gasping for breath during sleep, or daytime drowsiness—or risk factors like obesity, excess weight in the neck, or diabetes—do yourself and your loved ones a tremendous favor and get tested.
As for treatment, losing weight, changing sleeping positions, and some oral/dental appliances may help, but using a CPAP machine is the gold standard for sleep apnea. I understand the idea of wearing a face mask to bed isn’t appealing, but I will tell you from personal experience that you’ll get used to it—and the difference it can make in your quality of life will amaze you.
I used to snore at an Olympic-caliber volume. My wife finally convinced me to get tested, and sure enough, I was diagnosed with sleep apnea. I have been using a CPAP machine every night since, and I sleep like a baby—no snoring or starting and snorting to catch my breath. Best of all, I wake up refreshed, rejuvenated, and full of energy.