Poor sleep linked to cortical amyloid burden

MINNEAPOLIS – People who report feeling more sleepy and less rested have elevated levels of amyloid in regions of the brain commonly involved in Alzheimer’s disease, according to a cohort study presented at the annual meeting of the Associated Professional Sleep Societies.

Researchers studied 98 asymptomatic, cognitively healthy late- to middle-age adults from the WRAP (Wisconsin Registry for Alzheimer’s Prevention) program, the majority of whom were at elevated risk for the disease because of family history.

Self-reported somnolence, poorer sleep quality, and sleep problems were significantly correlated with higher levels of amyloid deposition in the cortex overall and in four subregions typically affected in Alzheimer’s disease.

"It does appear that there is an association between amyloid burden and sleepiness, and that relationship is present in adults who are cognitively healthy but who are at risk of developing Alzheimer’s disease in the future. They are fairly young in terms of amyloid pathology," said first author Kate Sprecher, a PhD candidate in the neuroscience training program at the University of Wisconsin–Madison. She acknowledged that the findings may differ in a cohort not enriched for people at elevated risk.

"We can’t say from these data whether sleep is driving amyloid deposition or whether amyloid deposition is disrupting sleep," she said. "Nonetheless, it’s kind of tantalizing that sleep may be a tool that we can use to prevent or delay Alzheimer’s pathology. We may be able to intervene early in the disease, when people are actually able to respond to treatment, because typically, current drugs are targeting later disease, when a great deal of neurodegeneration has already taken place. So sleep may be something that we can target really early."