Irregular Sleep Patterns tied to Alzheimer's Disease Biomarker

Getting a good night's rest is even more important for the elderly. Sleep is essential for the brain as it flushes out potentially harmful toxins, including those that have been implicated in Alzheimer's disease.

The researchers at the Johns Hopkins Bloomberg School of Public Health examined the association between sleep variables and a biomarker for Alzheimer's disease in older adults. They  found that reports of shorter sleep duration and poorer sleep quality were associated with a greater β-Amyloid burden, a hallmark of the disease. The results are featured online in the October issue of JAMA Neurology.

"Our study found that among older adults, reports of shorter sleep duration and poorer sleep quality were associated with higher levels of β-Amyloid measured by PET scans of the brain," said Adam Spira, PhD, lead author of the study and an assistant professor with the Bloomberg School's Department of Mental Health. "These results could have significant public health implications as Alzheimer's disease is the most common cause of dementia, and approximately half of older adults have insomnia symptoms."

Spira and his colleagues surveyed 70 adults, ages 53 to 91 years, on the amount of hours they slept each night and how often they woke up during the night or had otherwise disrupted sleep.

According to the study, the researchers then scanned each person's brain to look for clusters of beta-amyloid. The clumps of protein pieces were present in the brains of people with Alzheimer's disease in much higher quantities than among healthy people.

"The brain doesn't have a traditional lymphatic system, so this system carries all those functions," said Rashid Deane, one of the study's authors and a professor in the department of neurosurgery at URMC.

"These findings are important in part because sleep disturbances can be treated in older people. To the degree that poor sleep promotes the development of Alzheimer's disease, treatments for poor sleep or efforts to maintain healthy sleep patterns may help prevent or slow the progression of Alzheimer disease," added Spira.