Longer, More Frequent Daytime Naps May Predict Alzheimer Dementia

Taking longer and more frequent naps during the day may predict an increased risk of incident Alzheimer dementia among community-based older adults, according to new study findings presented at the SLEEP 2020 Virtual Annual Meeting.

The authors of the study arrived at their conclusion after evaluating 1180 older adults (mean age 81 years) without dementia at baseline, of whom 264 had mild cognitive impairment. Participants in the present study were part of the Rush Memory and Aging Project and had 14 years of available follow-up data.

The authors objectively examined napping characteristics by recording up to 10 days of motor activities at baseline. Daytime napping episodes were defined as segments of motor activity that occurred between 10:00 am and 7:00 pm with continued zero-activity for at least 10 minutes, but less than 1 hour, which the authors noted was to avoid off-wrist periods. Segments that were separated by less than 5 minutes were combined.

Criteria set forth by the National Institute of Neurological and Communicative Disorders and Strone and the Alzheimer’s Disease and Related Disorders Association were used to identify Alzheimer dementia diagnoses. The associations between duration and frequency of daily naps and incident Alzheimer dementia were assessed via Cox proportional hazards models.

The results of the study indicated that 277 of 1180 participants had developed Alzheimer dementia within 5.74 years. Among the study population, naps occurred an average 1.56 times per day and lasted an average 38.3 minutes. Following adjustment for sex, age, and education, findings indicated that each additional 30 minutes spent napping each day was associated with a 20% increase in incident Alzheimer dementia risk. Each additional nap per day was associated with a 19% increase in Alzheimer dementia risk. These associations remained significant following adjustment for total sleep time.

“Future studies are needed to examine specific underlying mechanisms,” the authors concluded.

—Christina Vogt

Reference:
Liao W, Lin S, Meng N, Tin H, Tsai S, Huang Y. Longer and more frequent naps predict incident Alzheimer dementia in community-based older adults. SLEEP. 2020;43 (Suppl). https://www.sleepmeeting.org/wp-content/uploads/2020/06/34th_Annual_Meeting_of_the_Associated_Professional_Sleep_Societies_Abstract_Book_-_2020.pdf