Thursday, October 24, 2013
Poor Sleep and Alzheimer's Disease
Can poor sleep lead to Alzheimer’s disease? A new study published in the Journal of the American Medical Association – Neurology set out to track the association between self-reported sleep disturbance and amyloid-beta (Abeta) deposition in the brains of older adults. Adam P. Spira, PhD, of the Johns Hopkins Bloomberg School of Public Health, and colleagues found that those individuals reporting poor sleep also had a higher burden of Abeta.
In this cross-sectional study of 70 community-dwelling adults (76 years old, on average) from the neuroimaging substudy of the Baltimore Longitudinal Study of Aging, investigators conducted standardized interviews with participants to obtain the number of hours they slept per night during the previous month: “more than 7”; “more than 6, up to 7”; “more than 5, up to 6”; or “5 or fewer.” They then coded these responses from 0 to 3. The Abeta burden of these participants was measured in vivo with positron emission tomography (PET) with the tracer carbon 11–labeled Pittsburgh compound B (PiB).
What Dr. Spira and colleagues found, after adjusting for potential cofounders, was that less sleep was associated with greater Abeta burden. Overall, 24 participants (34%) had elevated PiB levels according to cortical distribution volume ratio (cDVR) and 16 (23%) had elevated PiB levels according to the precuneus DVR.
After removing the 4 participants with mild cognitive impairment or dementia, they still found a significant association between shorter sleep duration and cDVR (P = .02) and precuneus DVR (P = .02).
“Our results may have significant public health implications. Alzheimer disease is the most common form of dementing illness, and almost half of older adults report insomnia symptoms. Because late-life sleep disturbance can be treated, interventions to improve sleep or maintain healthy sleep among older adults may help prevent or slow AD to the extent that poor sleep promotes AD onset and progression,” the authors wrote. “As evidence of this association accumulates, intervention trials will be needed to determine whether optimizing sleep can prevent or slow AD progression.”
For Neurology Today’s previous coverage of Alzheimer’s and sleep, see our archives: http://bit.ly/1d2bwRc.