Poor Sleep Might Indicate Preclinical Alzheimer’s Disease
Sleep disturbances may be one of the first clues that Alzheimer’s disease is developing in people who appear cognitively normal, according to a study published in the online March 11 JAMA Neurology.
Investigators used actigraphy to objectively measure sleep quality and quantity in a sample of 145 cognitively normal participants in longitudinal studies of memory and aging. Most participants were from the Adult Children Study, in which half of adults ages 45 to 75 have a parent with late-onset Alzheimer’s disease.
Amyloid deposition, a sign of preclinical Alzheimer’s disease, was measured through cerebrospinal fluid Aβ42 levels. Thirty-two participants (22.5%) showed amyloid deposition, reported Yo-El S. Ju, MD, of Washington University in Saint Louis, Missouri, and colleagues.
Those with amyloid deposition had worse sleep quality than those without amyloid deposition, though sleep quantity was mostly similar between the two groups of participants, the study authors noted.
“When we looked specifically at the worst sleepers, those with a sleep efficiency lower than 75%, they were more than five times more likely to have preclinical Alzheimer’s disease than good sleepers,” said Dr. Ju.
In addition, participants who napped during three or more days per week were more likely to show amyloid deposition.
“Our data provide the impetus for important future studies,” the researchers wrote. They added, “If sleep disruption increases risk of future Alzheimer’s disease, then this provides an even stronger motivation to identify and treat individuals with sleep disorders.”
2. Sleep loss precedes Alzheimer’s symptoms [press release]. Birmingham, AL: Newswise; March 11, 2013.