0720 Daytime Napping and Cognition in Older Adults

Abstract

This study aimed to synthesize the current evidence on the association between daytime napping and cognition in older adults. Systematic searches were conducted on PubMed, Google Scholar, and PsycInfo using various combinations of keywords: (nap/ daytime sleep /siesta) and (cognition/cognitive function/memory/executive function/visual spatial/reaction time/attention) and (older adults/elders/elderly/seniors/aging). The searchers were limited to publications from January 1995 to November 2017. Reference lists of selected articles were examined to identify additional published studies. Twelve observational and thirteen intervention studies were included. Nap habits (duration/weekly frequency) were assessed in the observational studies. Four of the six nap duration studies found that naps limited to a certain duration (e.g. <60–90 minutes) were protective for cognition both cross-sectionally (1 study) and longitudinally at two to ten year’s follow-up (3 studies). Longer napping (e.g.>90–120 minutes) was associated with worse cognition in three nap-duration studies. One of the nap-frequency studies suggested that napping no more than 3 days/week had cognitive benefits, while the other two showed napping more than 3 days/week or a higher likelihood of napping was associated with decreased cognition Among the intervention studies, the length of interventions varied from one-day single session (7 studies) to 4 weeks (1 study). The nap opportunity ranged from 20 minutes (1 study) to 2 hours (2 studies). Positive cognitive effects were found in five of the seven single nap session studies. Two of the five studies applied slow oscillatory stimulation during napping and found improved memory in people with Alzheimer’s disease. Four of the five studies that applied 3–7 day nap interventions showed improvement in attention, alertness, and visual detection. One study with 4-week nap intervention found both 45 minutes and 2-hour nap opportunity in the afternoon improved logical reasoning, mathematical processing and memory. Nap within a certain duration/frequency may be protective for cognitive function. Overall, nap interventions demonstrated favorable cognitive effects. However, the findings must be interpreted with caution due to the differences in design, sample, intervention, cognitive assessment, and nap features. Future studies with rigorous design are needed. K99NR016484.