It has been known for awhile that poor sleep may increase people’s risk of Alzheimer’s disease, and that as the brain ages, it cannot precisely coordinate slow wave sleep spindles as well.
New research adds to the growing body of evidence on sleep disturbances and cognitive impairment with the discovery of significant links between three measures of sleep disturbance and the risk of developing dementia over a 10-year period. The findings link sleep-initiation insomnia (difficulty falling asleep within 30 minutes) and sleep medication use to an increased risk of dementia.
The researchers also discovered that people with sleep-maintenance insomnia (difficulty falling back to sleep after waking) had a lower risk of developing dementia over the course of the study.
“We expected sleep-initiation insomnia and sleep medication usage to increase dementia risk, but we were surprised to find sleep-maintenance insomnia decreased dementia risk,”
said lead investigator Roger Wong, Ph.D., MPH, MSW.
Long-term Sleep Disturbance and Dementia Risk
The inspiration for this study came from a personal experience. Dr. Wong’s father has had chronic sleep disturbances since the COVID-19 pandemic began, and he was worried about how this would affect his cognition in the future. After reading the existing literature and being surprised by the mixed findings, Wong decided to investigate the sleep-dementia relationship.
This study is unique because it is the first to examine how long-term sleep disturbance measures are related to dementia risk in a nationally representative US older adult sample.
Previous research has linked cognitive decline to REM sleep behaviour, sleep deprivation (less than five hours of sleep), and the use of short-acting benzodiazepines. Their findings for sleep-maintenance insomnia back up the findings of other recent studies that used smaller, separate data samples.
This study utilized prospective data from the National Health and Aging Trends Study (NHATS), a longitudinal panel study that surveys a nationally representative sample of Medicare beneficiaries aged 65 and older in the United States, from 2011 to 2020. This study included only participants without dementia at baseline in 2011.
Sleep Disturbance in Older Adults
There is currently no known cure for dementia, and recent pharmaceutical treatments have met with mixed results, underscoring the significance of dementia prevention strategies. While the exact cause of the lower risk of dementia in people with sleep-maintenance insomnia is still unknown, the researchers hypothesize that a lower risk of dementia may result from greater participation in activities that support or enhance cognitive reserve.
According to recent research, older adults have a higher prevalence of sleep disturbances than other age groups. This could be due to several factors, including concern about the COVID-19 pandemic or warmer nights due to climate change.
It is not just yourself that stands to suffer from poor sleep. A study recently found that children whose mothers experience insomnia symptoms tend to go to bed later, get less sleep, and spend less time in deep sleep, which may impact their mental health.
A wide range of issues is keeping older adults awake at night. More research is needed to better understand its causes and manifestations, as well as to limit its long-term effects.
“Our findings highlight the importance of considering sleep disturbance history when assessing the dementia risk profile for older adults. Future research is needed to examine other sleep disturbance measures using a national longitudinal sample, whether these sleep-dementia findings hold true for specific dementia subtypes, and how certain sociodemographic characteristics may interact with sleep disturbances to influence dementia risk,”
added Dr. Wong.
Reference:
- Roger Wong et al. Sleep Disturbances and Dementia Risk in Older Adults: Findings From 10 Years of National U.S. Prospective Data. American Journal of Preventive Medicine (2023). DOI: 10.1016/j.amepre.2023.01.008
Last Updated on November 29, 2023