Excessive ‍Daytime Sleepiness ⁣Doubles Dementia ⁢Risk in ⁢Older Women

⁣ ⁣ Updated June 20, 2025
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Women ⁤in their 80s ‌who experience increasing daytime sleepiness ‍may ‌face twice the risk ⁣of developing dementia, according to research published in Neurology. The study,⁣ while⁢ revealing an association, does not establish a ​direct cause-and-effect relationship between daytime sleepiness and dementia.

Yue Leng, of the University ‌of California, San Francisco, emphasized the importance of sleep for cognitive function. She noted that changes in sleep patterns‌ and their connection to cognitive decline remain largely unexplored, especially concerning dementia risk in older⁢ women. Leng said their⁤ findings suggest ⁤sleep disturbances could be an early​ indicator or risk factor for dementia⁣ in this demographic.

The study involved 733 women, ⁤averaging ‌83 years old, without cognitive impairment or dementia at the outset. Researchers monitored ‍the participants over a five-year period.

During the⁢ study, 22% of participants (164 women) developed ‍mild cognitive impairment, while 13% (93 women) developed dementia.

Participants wore wrist devices to monitor their sleep and circadian rhythms for three days at both the beginning and end of the ⁢five-year study.

The research team analyzed⁢ changes in nighttime sleep duration‍ and quality, daytime napping habits, and circadian rhythm patterns.

After five years, significant ⁤shifts in sleep patterns were observed in more than ‍half (56%) of the participants.

The⁣ study identified three⁢ distinct groups: those ‍with stable sleep patterns or slight improvements (44%),those with declining nighttime sleep (35%),and those with increasing sleepiness (21%). The declining nighttime sleep ⁢group experienced reduced sleep quality and⁤ duration,increased napping,and worsening circadian rhythms. The increasing ⁢sleepiness‌ group showed increases in both daytime ⁣and nighttime‍ sleep, ‍along with disrupted ‌circadian rhythms.

Researchers then examined the correlation between these changes ⁢and dementia risk.

Of the stable sleep group, 8% (25 ‌women) developed dementia. In the declining nighttime sleep group, 15% (39 women) ‌developed dementia. Among the increasing sleepiness group, 19% (29 women) developed dementia.

After accounting for factors⁣ like age, education,⁣ race, diabetes, and high blood pressure, the study found that women in the increasing sleepiness group had double⁢ the risk of dementia compared to ‌the stable sleep ‌group. No such association ⁣was found for the ⁤declining nighttime sleep group.

Leng noted the rapid changes ⁤in sleeping, napping, and circadian rhythms observed in women⁣ in their 80s over just five years. She said this underscores the need for further research into all aspects of daily sleep patterns to better understand their⁢ link​ to dementia risk.

The study’s primary limitation is its focus on predominantly ​white participants, ​which ‍restricts the generalizability of the findings to more diverse populations.

The National Institutes of Health and the National Institute on‍ Aging provided funding for this research.

What’s next

Future research should focus on diverse populations and explore the multifaceted aspects of daily sleep patterns to gain a more extensive⁣ understanding ⁤of the connection between sleep and dementia risk.