Accumulation of the protein ?-amyloid (??) manifests early in the preclinical stages of Alzheimer’s disease and is an important biomarker of the disease. Sleep may help to clear soluble ?? and disturbed sleep may aid in its accumulation. Disrupted sleep can also increase synaptic activity in the brain, which may contribute to ?? accumulation.

A study published in JAMA Neurology found that excessive daytime sleepiness in a group of older adults without dementia was associated with increased accumulation of ?? protein. This information may be important in developing interventions.

The participants were 283 adults 70 or older without dementia from the Mayo Clinic Study of Aging who completed surveys assessing sleepiness at baseline and had at least two consecutive imaging scans of their brains from 2009 to 2016. This was an observational study. Researchers were not intervening for purposes of the study and cannot control for all the natural differences that could explain the study results.

Sixty-three participants (22.3%) had excessive daytime sleepiness at baseline; excessive daytime sleepiness was associated with increased ?? accumulation in susceptible regions of the brain.