Brainwaves During Sleep Could Be a Useful Biomarker of Alzheimer’s Disease

By Erik MacLaren

DENVER -- June 20, 2016 -- It may be possible to use very low frequency slow wave activity during non-REM sleep (<1 Hz NREM SWA) as a surrogate biomarker to screen for β-amyloid (Aβ) burden levels in patients, and even predict future risk of Alzheimer’s disease (AD), according to a study presented here at SLEEP 2016, the 30th Annual Meeting of the Associated Professional Sleep Societies (APSS).

Previous research has suggested a relationship between sleep and cognitive decline, and Aβ accumulation in the brain has been associated with sleep disruption.

Bryce A. Mander, PhD, University of California, Berkeley, Berkeley, California, and colleagues sought to determine whether <1 Hz NREM SWA could be used to identify patients with Aβ pathology and predict future Aβ accumulation.

The benefit of this measure as a potential biomarker include that it is non-invasive, safe, inexpensive, and suitable for community screening.

The researchers assessed Aβ accumulation in the brains of 26 adults aged 71 to 78 years using 11C-Pittsburgh Compound B (PIB) and positron emission tomography (PET), and rescanned 13 of these individuals 3 to 5 years later. All study participants also underwent baseline sleep recordings.

Recordings of <1 Hz NREM SWA was able to correctly categorise the study participants into Aβ-positive and Aβ-negative groups in 20 out of 26 cases (75% sensitivity, 79% specificity) -- levels similar to those achieved through using apolipoprotein E (APOE) genotyping.

Lower <1 Hz NREM SWA increased Aβ-positive risk by 30%, while higher <1 Hz NREM SWA reduced risk by 27%.

In addition, <1 Hz NREM SWA not only predicted the severity of Aβ burden at baseline (P = .009), but also 3 to 5 years later (P = .011) and the 3- to 5-year change in Aβ accumulation (P - .084).

“This measure appears to be useful for early detection of AD and targeted interventions, but there are limitations to this study,” noted Dr. Mander.

In order to address these limitations, the authors plan to increase the sample size tested, compare and combine <1 Hz NREM SWA with other candidate biomarkers, examine longitudinal changes in this marker, and replicate these results in an independent study cohort.

[Presentation title: NREM Slow Wave Activity <1 Hz as a Biomarker and Long-Term Predictor of β-Amyloid Burden in Older Adults. Abstract 0969]
Log in to post comments

Tell us what you think of DG News

Click to like Click to dislike