New research reported at the Alzheimer's Association International Conference (AAIC) 2019 evaluates drug and non-drug treatments to improve sleep patterns in persons with Alzheimer's disease or other dementias. Sleep disruption is a common behavioral challenge that significantly reduces quality of life for people with dementia and their caregivers/family members.

Sleep disturbances are common among people with Alzheimer's and other dementias, including changes in sleep schedule and restlessness/wandering during the night. It has been reported that up to 45% of people with dementia may have sleep problems. Many people with Alzheimer's wake up more often and stay awake longer during the night. Those who cannot sleep may wander, be unable to lie still, or yell or call out, disrupting the sleep of their caregivers. Experts estimate that in late stages of Alzheimer's, individuals spend about 40% of their time in bed at night awake and a significant part of their daytime sleeping.

Disruption in the body's sleep-wake cycle can lead to more behavioral problems, though effective coping strategies exist. At the same time, research suggests that poor sleep habits in mid- and late-life may increase the risk for developing dementia.

In a study from the University of California, San Francisco, researchers found that more frequent use of sleep medications may be associated with higher risk of dementia, especially in older white adults compared to older black adults who experienced reduced risk. Whether the change in risk is due to the medications or sleep problems is not yet known.

The research, overseen by Kristine Yaffe, MD, professor of psychiatry, neurology and epidemiology, evaluated data of 3,068 black and white (45% of women and 33% of men, African American) community-dwelling older adults age 70–79 at baseline without dementia who were enrolled in the Health, Aging and Body Composition study. The study participants were followed to see if they would develop dementia over 15 years using an algorithm that incorporates medical records, information on medication use and assessment of cognition.

A total of 147 (4.8%) participants reported taking sleep medications "sometimes"; 172 (5.6%) reported "often" or "almost always." Thirty-four (34, 2.7%) blacks and 138 (7.7%) whites reported taking sleep medications "often" or "almost always."
The researchers found that study participants who reported taking sleep medications "often" or "almost always" were 43% more likely to develop dementia compared to those who reported "never or rarely" taking sleep medications. Increased risk for dementia among frequent sleeping medication users was only observed among white adults in the study.

No increased risk was found for people taking sleep medications "sometimes." There was no difference reported in men versus women.

"Based on our findings, we recommend that clinicians make more effort to be aware of their patients' sleep problems including use of sleep aids," said lead study author Yue Leng, PhD, University of California, San Francisco. "In particular, clinicians may need to be more cautious about prescribing sleep medications to older adults who are at high risk for dementia. There are non-pharmacological sleep treatment options that should be considered."

The research was funded by the U.S. National Institute on Aging, Global Brain Health Institute, Global Brain Health Institute, Alzheimer's Association and the Alzheimer's Society.

Other researchers reported results from an observational study of 3,656 adults 65 and older (57.8% female) from the Cache County Study on Memory and Aging (CCSMA) evaluated if use of sleep medications was associated with an increased risk of developing Alzheimer's, and whether risk differed between men and women. 

The study found that men who reported use of sleep medication had a 3.6 times increased risk of developing Alzheimer's disease compared to those who did not use sleep medications. In women, the risk varied by whether or not they experienced sleep disturbances. Women who used sleep medications but did not report sleep disturbances were at nearly four times greater risk for developing Alzheimer's. Women who said they had sleep disturbances and used sleep medications were at a 35.2% reduced risk of developing Alzheimer's.

"More research is needed to determine and understand the mechanisms underlying the differences between men and women, and the cognitive impact of using sleep medications," said Elizabeth Vernon, MS, Utah State University, who presented the data at AAIC 2019.

This work was funded by the U.S. National Institute on Aging.

"Research has shown us that not getting enough sleep because of insomnia or sleep apnea may result in problems with memory and thinking and increase the risk for Alzheimer's-related brain changes," said Maria C. Carrillo, PhD, Alzheimer's Association chief science officer. "The new findings reported at AAIC 2019 are important because disrupted sleep patterns not only put the overall health of people with dementia at further risk, they may also worsen their memory loss and disrupted thinking."