It's an interesting time in the world of sleep apnea research, a disorder in which a person has periods of slow or paused breathing during sleep. It seems that every month there is a new study showing yet another link between sleep apnea and sleep-disordered breathing (snoring, paused breathing, etc.), and its negative effects on health.
Recent studies have linked obstructive sleep apnea (OSA) to depression, silent strokes and small brain lesions, abnormalities in the blood vessels, high blood pressure, heart disease and strokes, even sudden hearing loss. And women take note: Sleep apnea has been linked to dementia in older women, and another observational study found that women with untreated severe OSA are 3.5 times more likely to die from cardiovascular disease than women without OSA!
Clearly, the link between OSA and an increased risk of stroke has been medically established. But what effect does OSA have on the brain vessels and cerebral circulation? Researchers at the Baylor College of Medicine in Houston, Texas developed a way to find out.
In late April, a study entitled, "Cerebrovascular Consequences of Obstructive Sleep Apnea" was presented and discussed at the Experimental Biology 2012 meeting at the San Diego Convention Center. The researchers described how they developed a new way to induce the effects of obstructive sleep apnea in mice -- specifically, the closure of the airway that results in paused breathing and the physiological side effects of OSA. The new testing model enabled the researchers to mimic the symptoms and effects of OSA in humans, and thus study the results in a controlled environment.
For the study, the researchers induced sleep apnea in the mice while they slept. Surprisingly, they found that after just one month of induced repeated apneas, the mice's "cerebral vessel dilatory function" was reduced by as much as 22 percent, and the mice's cerebrovascular function did not function as normal, before the apneas.
In other words, after just one month of repeated apneas, the blood vessels in the mice's brains did not work as well as they once did.
What are the implications of this study? According to the researchers, one is that the new method of testing provides researchers with a more accurate and complete way to study the effects of sleep apnea on people. The other, which I find compelling, is that only one month of moderate, repeated sleep apnea caused a change in cerebrovascular function, which could result in a stroke. It is important to note that the results of the study correlate with other studies that show similar cell dysfunction in arteries, which has caused an increased risk of stroke in OSA patients.
This just reinforces the speed in which sleep apnea can damage the body, and the importance of getting diagnosed and treated as quickly as possible. The results are also a wake-up call to physicians that damage to the vascular wall in brain arteries could be a factor predisposing an individual with OSA to stroke.
Again, it is in interesting time for sleep apnea research. And I hope and encourage researchers to continue studying and publishing their results so we can all better understand the symptoms and treatments of this disorder. I believe the need for treatment will only increase with time. As obesity, hypertension and other related conditions continue to plague this country, and as the general population ages, we will see an increase in OSA cases. It is no longer a male condition -- women, non-obese people and even children can have OSA.
An estimated 18 million Americans have sleep apnea, including one in four women over 65, according to the National Sleep Foundation. While apnea is more common in men, it increases in women after age 50. And some researchers estimate that up to 85 percent of people with clinically significant sleep apnea have not even been diagnosed yet.
Sleep apnea and other sleep-related disorders are prevalent in our society, and people need to wake up to the symptoms and risks associated with them. (I am on a personal mission to educate people about this, and my blog is one of the ways in which I do so.)
So how do you know if you have sleep apnea? The first step is to become aware of some common symptoms, including trouble falling asleep at night, waking throughout the night, chronic snoring, morning headaches, poor memory, daytime sleepiness/falling asleep during the day, bad moods and irritability, increased depression and trouble concentrating, driving, and making decisions.
If you have any of the symptoms mentioned above, and suspect that you may have sleep apnea, please get checked out by a doctor who specializes in sleep disorders. Be specific about the symptoms you are experiencing. Many times, sleep apnea can be misdiagnosed as chronic fatigue, insomnia, depression, or some other non-specific condition. Also, some doctors are too quick to prescribe a medication, rather than do a full sleep disorder work up. To try and avoid misdiagnosis, go to a qualified sleep specialist and be specific about your symptoms. Don't wait -- it could save your life, not to mention help your bedmate keep his or her sanity.
For more by David Volpi, M.D., P.C., F.A.C.S., click here.
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