The Connection between Sleep Apnea and Alzheimer's Risk

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Got a loud snorer with sleep apnea next to you in bed? If so, recent research concludes he or she may have an increased risk of memory problems such as mild cognitive impairment and Alzheimer's disease. Don't despair, however; this research study also suggests a way to minimize the risk.

The Research

The research, published in the journal Neurology and conducted at the New York University School of Medicine, outlines a study conducted with more than 2000 participants.

After reviewing the sleeping patterns and cognitive functioning of these participants, the researchers reached the following conclusions:

  • Persons with sleep apnea developed mild cognitive impairment about 10 years earlier in life than those without sleep apnea.
  • Sleep apnea was correlated with the presence of Alzheimer's at a younger age- age 83 compared to age 88 in those without sleep apnea.
  • Here's the good news: In the study, people who were treating their sleep apnea by using CPAP machines gained about 10 years of cognitive functioning. They developed mild cognitive impairment (MCI) at about age 82, while those who did not treat their sleep apnea developed MCI at approximately age 72.

What's the Difference between Mild Cognitive Impairment and Alzheimer's Disease?

Mild cognitive impairment is a condition where there's some difficulty with functions like memory, decision-making and communication, but day-to-day functioning remains fairly intact.

Mild cognitive impairment places people at a higher risk of developing Alzheimer's disease, although not everyone who has MCI will progress to Alzheimer's disease. Some people have MCI for many years and remain stable, while others develop increased problems with thinking and functioning and are eventually diagnosed with Alzheimer's or another type of dementia.

What Are CPAP Machines?

CPAP machines treat sleep apnea by placing pressurized air in your mouth to keep your airway open.

Other Research Studies

Several other researchers have studied the relationship between cognition and sleep apnea. They reached the following conclusions in their respective studies:

  • One study found that sleep apnea was correlated with a decrease in hippocampal volume and increases in white matter lesions in the brain- changes that are often consistent with cognitive problems such as Alzheimer's disease.
  • A second study determined that people with sleep apnea who had seemingly normal cognitive functioning displayed decreased delayed recall and a decline in executive functioning when tested with the Trail Making Test. (The Trail Making Test is one of many cognitive screening tests.)
  • A third study that consisted of over 400 female participants found that those with sleep apnea had a higher likelihood of cognitive problems, including dementia.
  • One other study identified deficits in attention, executive functioning, visual-spatial ability and delayed memory in participants with sleep apnea, but also found that CPAP treatment improved those symptoms.

    More about Sleep Apnea

    Sleep apnea is a condition where you stop breathing when you sleep. According to's Sleep Disorders Expert, Dr. Brandon Peters, you might hold your breath for 10 seconds, begin breathing again, and then repeat this more than 100 times a night.

    For more information, review the definition and symptoms of obstructive sleep apnea and consult your physician if you're concerned you may be experiencing sleep apnea.

    Related Reading


    The Journal of the American Medical Association. August 10, 2011, Vol 306, No. 6. Sleep-Disordered Breathing, Hypoxia, and Risk of Mild Cognitive Impairment and Dementia in Older Women.

    Journal of the American Geriatric Society. 2012 Jun;60(6):1099-103. doi: 10.1111/j.1532-5415.2012.03961.x. Epub 2012 May 30. Effects of sleep apnea syndrome on delayed memory and executive function in elderly adults.

    La Revue de Medicine' Interne. 2014 Oct;35(10):664-9. doi: 10.1016/j.revmed.2014.02.005. Epub 2014 Mar 12. [Obstructive sleep apnea syndrome: a cause of cognitive disorders in the elderly?].

    Neurology. 2015 Apr 15. Sleep-disordered breathing advances cognitive decline in the elderly.

    Zhonghua Yi Xue Za Zhi. 2014 Dec 2;94(44):3483-7. [Association between inflammation and cognitive function and effects of continuous positive airway pressure treatment in obstructive sleep apnea hypopnea syndrome].

    Zhonghua Yi Xue Za Zhi. 2014 Mar 18;94(10):724-8. [Correlation between cognitive function and hippocampal atrophy and cerebral white matter lesions in patients with obstructive sleep apnea hypopnea syndrome].

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