Longer Naps Linked to Doubled dementia Risk in Women, New Study Finds
PARIS – Women who experience increased daytime sleepiness and take longer, more frequent naps face nearly double the risk of developing dementia, according to research published today in the journal neurology. The five-year study, tracking sleep-wake patterns in older women, reveals a significant correlation between changes in sleep habits and cognitive decline, offering a perhaps simple new method for early dementia risk assessment.
Researchers analyzed 24-hour sleep-wake activity data from a cohort of older women, finding that average nap duration increased by 33.1 minutes, with total sleep time rising by 18.7 minutes. However, sleep efficiency decreased by 6% across the group. Notably, 21.3% of participants reported “a sharp increase in the duration and quality of sleep” both during the day and at night, while 44% maintained stable sleep patterns.
The study revealed that 22.4% of the volunteers developed mild cognitive impairment (MCI) and 12.7% were diagnosed with dementia. Women whose daytime sleepiness increased - especially those with extended and frequent naps – were almost twice as likely to develop dementia compared to those with stable sleep habits. Reduced “quality sleep” time and increased insomnia were also associated with heightened dementia risk.
While the research doesn’t establish a causal link – whether sleep problems contribute to dementia or vice versa – it highlights the potential of 24-hour sleep-wake activity monitoring as a readily accessible tool for identifying individuals at risk.
Dementia is a growing global health crisis, affecting an estimated 57 million people worldwide in 2021, according to the World Health Association (OMS). Approximately 10 million new cases are diagnosed annually, making it the seventh leading cause of death and a major contributor to disability and dependency among the elderly. These findings suggest that monitoring sleep patterns could facilitate earlier intervention and improved care for those at risk.