Sleep as a potential biomarker of tau and β-amyloid burden in the human brain

[BrianR]

http://www.jneurosci.org/content/early/ ... 03-19.2019
paywalled

Sleep as a potential biomarker of tau and β-amyloid burden in the human brain
Joseph R. Winer, Bryce A. Mander, Randolph F. Helfrich, Anne Maass, Theresa M. Harrison, Suzanne L. Baker, Robert T. Knight, William J. Jagust and Matthew P. Walker
Journal of Neuroscience 17 June 2019, 0503-19; DOI: https://doi.org/10.1523/JNEUROSCI.0503-19.2019

A new paper from Matthew Walker et al.

Science Daily has a longish discussion/summary of this paper that might be a good substitute for actually reading it: https://www.sciencedaily.com/releases/2 ... 114105.htm

Here's the summary from the Journal of Neuroscience link:

Abstract
Recent proposals suggest that sleep may be a factor associated with accumulation of two core pathological features of Alzheimer's disease (AD): tau and β-amyloid (Aβ). Here we combined positron emission tomography measures of Aβ and tau, electroencephalogram sleep recordings, and retrospective sleep evaluations to investigate the potential utility of sleep measures in predicting in vivo AD pathology in male and female older adults. Regression analyses revealed that the severity of impaired slow oscillation-sleep spindle coupling predicted greater medial temporal lobe tau burden. Aβ burden was not associated with coupling impairment, but instead predicted the diminished amplitude of <1Hz slow-wave-activity—results that were statistically dissociable from each other. Additionally, comparisons of AD pathology and retrospective, self-reported changes in sleep duration demonstrated that changes in sleep across the lifespan can predict late-life Aβ and tau burden. Thus, quantitative and qualitative features of human sleep represent potential non-invasive, cost-effective and scalable biomarkers (current and future-forecasting) of AD pathology, and carry both therapeutic and public-health implications.

SIGNIFICANCE STATEMENT

Several studies have linked sleep disruption to the progression of Alzheimer's disease (AD). Tau and β-amyloid (Aβ), the primary pathological features of AD, are associated with both objective and subjective changes in sleep. However it remains unknown whether late life tau and Aβ burden are associated with distinct impairments in sleep physiology or changes in sleep across the lifespan. Using polysomnography, retrospective questionnaires, and tau- and Aβ-specific positron emission tomography, the present study reveals human sleep signatures which dissociably predict levels of brain tau and Aβ in older adults. These results suggest that a night of polysomnography may aid in evaluating tau and Aβ burden, and that treating sleep deficiencies within decade-specific time windows may serve in delaying AD progression.

I wonder if "retrospective sleep evaluations" are more trustworthy than the somewhat discredited diet questionnaires that nutritional epidemiologists use.

[frankiesfriend]

In a typical polysomnography used to evaluate sleep apnea or other sleep disorders, do they look at spindle coupling and amplitude which is indicated in this paper to correlate to tau and amyloid accumulation? I am interested in obtaining a sleep study due to a recent history (five years) of poor sleep efficiency and my concern about the potential for development of AD pathology. However, where I live there are no study centers looking specifically at sleep profiles and AD pathology. Further, I have pretty much followed every recommendation for good sleep hygiene. This has helped some, but I am still a sufferer of disrupted sleep, and it has been a cause for some worry, as I am not sure that I can "treat" my sleep deficiency as recommended in the last sentence of the article.

[JJ 007]

I know that Dr Rhonda recently said that deep sleep is the one which helps clear out the AB. (sorry if you knew that already).
Does anyone wear a fitbit? if so, how much DEEP sleep do you get each night?

I get around 1.5 hours. (deep) and lots of REM sometimes, 2-3 hours on a good day!
would be keen to see what others get for Deep. I dont feel like mine is a lot.
Thanks

[xactly]

Does anyone wear a fitbit? if so, how much DEEP sleep do you get each night?

I wear an Oura ring, and it tells me I average 58 minutes of deep sleep. However, all of the commercially available sleep trackers are only about 50-60% correlated with polysomnography, which is what is used in sleep labs. (And only 83% of polysomnography findings can be correlated across labs and scorers, so even this method has room for error.)

The measurements of sleep stages are particularly suspect among personal trackers, so I use the assessments as relative findings rather than as the absolute truth. In other words, I look at trends about whether my deep or REM sleep is increasing or decreasing, rather than accept that the amount shown by the tracker is an accurate value.

[JJ 007]

Thank you for the reply. That sounds like a sensible method.
J

[cdamaden]

Does anyone wear a fitbit? if so, how much DEEP sleep do you get each night?

J. I recently bought an Oura ring and have been comparing it to my Fitbit. I haven't done a full excel spreadsheet comparison, but over the last five nights they show my deep sleep as:
Saturday 31 min (FB) 80 min (O), ratio (FB/O) 0.39
Sunday 69 min (FB) 107 min (O), ratio 0.64
Monday 49 min (FB) 80 min (O), ratio 0.61
Tuesday 66 min (FB) 121 min (O), ratio 0.55
Wednesday 57 min (FB) 79 min (O), ratio 0.73
As you can see, they trend together (ups and downs) but aren't linearly related. I hope the Oura ring is more accurate for me! Overall, the Oura ring shows much less awake time (during my sleep) than my fitbit does.
Chris

[JJ 007]

Hey,

Hopefully the higher reading is true.

It’s funny as I get a really high amount of R.E.M. sometimes like 2.5 hours but only an hour of deep.

Really interesting to see how much deep sleep others are getting and especially pointing out how inaccurate the readings are.

Thanks