Adding to the growing body of evidence on sleep disturbance and cognitive impairment, new research finds significant links between three measures of sleep disturbance and the risk of developing dementia over a 10-year period. The results, reported in the American Journal of Preventive Medicine, published by Elsevier, links sleep onset insomnia (difficulty falling asleep within 30 minutes) and the use of sleeping pills with a higher risk of developing dementia. Investigators also found that people who reported having sleep maintenance insomnia (difficulty falling back to sleep after waking up) were less likely to develop dementia during the study.
This research is novel because it is the first to examine how measures of long-term sleep disturbance are associated with dementia risk using a nationally representative sample of older American adults. Previous research has linked REM sleep behavior, sleep deprivation (less than five hours of sleep), and short-acting benzodiazepine use to cognitive decline. Their results for sleep maintenance insomnia support other recent studies using smaller, separate data samples.
This study used 10 annual waves (2011-2020) of 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 UNITED STATES. This study only included people without dementia at baseline in 2011.
There is no cure for dementia and recent pharmaceutical approaches to treating dementia have had limited success, highlighting the importance of preventive approaches to dementia. “By focusing on variations in sleep disturbances, our findings may help shed light on lifestyle changes that may reduce dementia risk,” explained co-investigator Margaret Anne Lovier, MPH, Department of Public Health and of Preventive Medicine, SUNY Upstate Medical University, Syracuse, NY, USA.
Although the mechanism of decreased dementia risk in people with sleep maintenance insomnia is still unknown, researchers hypothesize that greater engagement in activities that preserve or increase cognitive reserve may thereby reduce the risk of dementia.
Recent data indicate that the prevalence of sleep disorders is higher in the elderly than in other age groups. This could be attributed to a variety of factors, including anxiety over the COVID-19 pandemic or warmer nights due to climate change.
“Older people lose sleep due to a wide variety of problems. Further research is needed to better understand its causes and manifestations and limit the long-term consequences,” added Dr. Wong. “Our results underscore the importance of considering a history of sleep disturbance when assessing the risk profile for dementia in older adults. Future research is needed to examine other measures of sleep disturbance in the 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 disturbance to influence dementia risk.”