Excessive daytime sleepiness linked to increase in Alzheimer’s biomarker

The prospective, longitudinal cohort analysis from Dr. Carvalho and his colleagues included 283 participants age 70 or older without a diagnosis of dementia who filled out a sleepiness assessment survey and underwent baseline and follow-up imaging studies as part of the Mayo Clinic Study of Aging.

All participants included in the analysis underwent at least two consecutive carbon 11–labeled Pittsburgh compound B PET (PiB-PET) scans. EDS, defined as a score of at least 10 on the Epworth Sleepiness Scale, was seen in 63 participants (22.3%), the researchers found.

At baseline, EDS was significantly associated with increased beta-amyloid accumulation in the anterior cingulate (P = .04), posterior cingulate-precuneus (P = .02), and parietal (P = .04) regions. The association between EDS and longitudinal beta-amyloid accumulation was most pronounced in participants who had global PiB positivity at baseline in anterior cingulate and cingulate-precuneus regions (P = .02 for both), they reported.

Findings of the study are consistent with a previous investigation of middle-aged participants without dementia, Dr. Carvalho and coauthors said in a discussion of the results. In that study, increased daytime somnolence was associated with increased beta-amyloid burden in regions including the precuneus and anterior cingulate. Daytime sleepiness in that study was measured using a different measure, the Sleep Scale, which was originally developed as part of the Medical Outcomes Study.