A new study including work from UW-Madison researchers has established a link between lack of sleep and higher risk for developing Alzheimer’s disease.
The study was published online last week in Neurology, the medical journal of the American Academy of Neurology. The research team, led by UW-Madison scientists, found those getting less sleep in “late midlife” had more early indicators for the disease, such as amyloid plaque — clusters of proteins that lose their normal function and become harmful — as well as signs of inflammation and brain-cell injury.
“Our findings suggest that improving sleep during mid-life could potentially reduce a person’s risk of Alzheimer’s disease,” said Kate Sprecher, neuroscience researcher at UW and one of the leaders of the study. “While it’s not the case that everyone with sleep problems will develop Alzheimer’s disease, sleep disturbance is a common, treatable issue for many middle-aged Americans.”
The study focused on 101 volunteers between the ages of 57 and 69 with “normal” memory. Volunteers answered a questionnaire on sleep, and researchers also studied their cerebrospinal fluid — a clear fluid in the brain and spinal cord that performs several important functions like protecting from impacts and removing waste products from the brain.
Barbara Bendlin, an associate professor of medicine and an Alzheimer’s disease researcher at the UW School of Medicine and Public Health, says the study shows those with more reported sleep problems — like inadequate sleep and greater daytime sleepiness — had more fibrous deposits known as amyloids in their brains.
“Amyloid deposits in the brain are a hallmark of Alzheimer’s disease,” said Bendlin. “Dr. Sprecher also examined markers related to brain-cell injury and activity of cells that respond to injury, and these were also associated with subjective reports of sleep quality.”
In Wisconsin, more than 110,000 people aged 65 or older are estimated to have Alzheimer’s. That’s predicted to rise to 130,000 in less than 10 years by the Alzheimer’s Association. There were 1,671 deaths in 2013 from Alzheimer’s, making it the sixth leading cause of death in the state, per the association.
And the Medicaid costs for caring for Alzheimer’s patients was $706 million in the state, according to a fact sheet from the Alzheimer’s Association.
Though over 5 million Americans are living with the disease, Sprecher says sleep medicine might “represent a promising, untapped toolkit for preventing or delaying Alzheimer’s disease.”
As well as scientists from Wisconsin Alzheimer’s Disease Research Center and Wisconsin Alzheimer’s Institute at UW-Madison, the study team included researchers from the Geriatric Research Education and Clinical Center at William S. Middleton Memorial Veterans Hospital. Investigators from the University of Gothenburg in Molndal, Sweden and the University of California, Irvine, also played a role.
–By Alex Moe