Sleep apnea sufferers who spend less time in deep sleep may have a higher risk of Alzheimer’s according to researchers.
The American Academy of Neurology’s medical journal, Neurology, published research on Wednesday that examined sleep factors and biomarkers of brain health.
Sleep Apnea’s Impact on White Matter Damage
According to estimates, 936 million adults aged 30 to 69 worldwide may suffer from sleep apnea, with many cases going undiagnosed. Severe and untreated sleep apnea is associated with a threefold increased risk of mortality from any cause.
A study found that individuals with severe sleep apnea who spend less time in deep, slow-wave sleep had more damage to the white matter of the brain, which forms connections between brain cells and the nervous system.
White matter hyperintensities, small white spots that show the extent of the damage when the brain is scanned, were more prevalent in individuals with less slow-wave sleep.
For every 10% decrease in slow-wave sleep, the brain showed an increase in white matter hyperintensities similar to aging 2.3 years, according to Dr. Diego Carvalho, a neurologist at the Mayo Clinic and coauthor of the study.
The brain’s processing ability can be slowed down by having an increased number of white matter hyperintensities.
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Physiological Consequences
In the study, around 34% of participants had mild sleep apnea, 32% had moderate, and 34% had severe sleep apnea.
Sleep apnea can cause a drop in oxygen levels, as well as increased carbon dioxide levels, blood pressure, and heart rate.
The study controlled for factors such as age, high blood pressure, and cholesterol that could affect brain changes and found that each 10% decrease in slow-wave sleep was equivalent to three years of aging as measured by genu FA.
While some level of white matter damage is normal in midlife due to environmental challenges like pollution and stress, it has been linked to an increased risk for cognitive decline, Alzheimer’s disease, and other forms of dementia.