Sleep Duration and Excessive Daytime Sleepiness Are Associated With Incidence of Disability in Community-Dwelling Older Adults.

OBJECTIVE: Although sleep disturbances are associated with disability among older adults, no longitudinal study has examined the impact of sleep assessed based on both sleep quality and quantity on incident disability. This study examined whether sleep duration and excessive daytime sleepiness were associated with incidence of disability in community-dwelling older adults.

METHODS: A total of 4756 older adults (53.3% women, mean age 71.9 years) met the entry criteria for this study. We measured monthly incident disability, defined as the onset of being certified for personal support or care as required by Japanese public long-term care insurance during the preceding 24 months. Sleep duration, excessive daytime sleepiness (EDS), and demographic factors were assessed at baseline. Cox's proportional hazard regression analysis estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of incidence of disability according to the 3 categories of sleep duration (short: ≤6.0 hours, mid: 6.1 to 8.9 hours, long: ≥9.0 hours), and we used mid duration sleepers as the reference group.

RESULTS: Long sleep duration (HR 1.43, 95% CI 1.04-1.97) and presence of EDS (HR 1.41, 95% CI 1.01-1.98) were associated with higher rates of incident disability. Furthermore, a combination of sleep duration and EDS was associated with a higher rate of incident disability than the mid and no EDS group (HR 2.25, 95% CI 1.36-3.70).

CONCLUSION: Long sleep duration and EDS affected the incident of disability; thus, older adults with both sleep patterns may require an intervention to alter their sleep habit.