Long sleep duration and dementia: Could obstructive sleep apnea be responsible for neurodegeneration?
ClaudioLiguori, MD, PhD student, University Hospital of Rome "Tor Vergata"dott.claudioliguori@yahoo.it
Francesca Izzi, Nicola B. Mercuri, Fabio Placidi, Rome
Submitted April 05, 2017
Westwood et al. demonstrated that long sleep duration could represent a marker of early neurodegeneration leading to dementia. [1] There is evidence of an interplay between sleep and cognition. [2] In particular, sleep disturbances are related to the occurrence of dementia by altering brain processes active during sleep. [2] The observation by Westwood et al. adds to the literature on sleep and neurodegeneration. [3] However, the absence of polysomnographic recordings leaves an unresolved question: why are neurodegenerative processes promoted by long sleep duration?
We recently documented that obstructive sleep apnea (OSA) is frequent in patients affected by subjective cognitive impairment, thus inducing Alzheimer disease (AD) biomarkers. [4] Accordingly, OSA altering sleep quality and continuity, and producing nighttime intermittent hypoxia, promotes AD neurodegenerative changes. [4] Therefore, OSA may be the main candidate in prolonging sleep time since it alters sleep efficiency. [4] Since OSA increases in midlife to older-age populations, it could be responsible for the relationship between prolonged sleep and neurodegeneration. Further studies are needed to explore the interplay among sleep, OSA, and neurodegeneneration.
1. Westwood AJ, Beiser A, Jain N, et al. Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia. Neurology Epub 2017 Feb 22.
2. Daulatzai MA. Evidence of neurodegeneration in obstructive sleep apnea: Relationship between obstructive sleep apnea and cognitive dysfunction in the elderly. J Neurosci Res 2015;93:1778-1794.
Westwood et al. demonstrated that long sleep duration could represent a marker of early neurodegeneration leading to dementia. [1] There is evidence of an interplay between sleep and cognition. [2] In particular, sleep disturbances are related to the occurrence of dementia by altering brain processes active during sleep. [2] The observation by Westwood et al. adds to the literature on sleep and neurodegeneration. [3] However, the absence of polysomnographic recordings leaves an unresolved question: why are neurodegenerative processes promoted by long sleep duration?
We recently documented that obstructive sleep apnea (OSA) is frequent in patients affected by subjective cognitive impairment, thus inducing Alzheimer disease (AD) biomarkers. [4] Accordingly, OSA altering sleep quality and continuity, and producing nighttime intermittent hypoxia, promotes AD neurodegenerative changes. [4] Therefore, OSA may be the main candidate in prolonging sleep time since it alters sleep efficiency. [4] Since OSA increases in midlife to older-age populations, it could be responsible for the relationship between prolonged sleep and neurodegeneration. Further studies are needed to explore the interplay among sleep, OSA, and neurodegeneneration.
1. Westwood AJ, Beiser A, Jain N, et al. Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia. Neurology Epub 2017 Feb 22.
2. Daulatzai MA. Evidence of neurodegeneration in obstructive sleep apnea: Relationship between obstructive sleep apnea and cognitive dysfunction in the elderly. J Neurosci Res 2015;93:1778-1794.
3. Musiek ES, Holtzman DM. Mechanisms linking circadian clocks, sleep, and neurodegeneration. Science 2016;354:1004-1008.
4. Liguori C, Mercuri NB, Izzi F, et al. Obstructive sleep apnea is associated with early, but possibly modifiable, Alzheimer's Disease biomarkers changes. Sleep (in-press 2017).
For disclosures, please contact the editorial office at journal@neurology.org.