0806 Sleep Inertia, Daytime Sleepiness, and Falls in Older Adults of the Wisconsin Sleep Cohort

Abstract Introduction Falls constitute a serious health concern in older adults, representing the leading cause of injury-related death. Identifying modifiable risk factors is key to mitigating and managing falls in older adults. Excessive sleep inertia (ESI) and daytime sleepiness (EDS) are known safety hazards that could plausibly heighten fall risk in older adults. However, sleep inertia and daytime sleepiness are understudied in the context of fall risk. This study examined the relationships between sleep inertia, daytime sleepiness, and falls in older adults of the Wisconsin Sleep Cohort (WSC). Methods Data from older adults without shift-worker history in the WSC were utilized. The Sleep Inertia Questionnaire (SIQ) and Epworth Sleepiness Scale (ESS) measured sleep inertia and daytime sleepiness severity, respectively. SIQ and ESS were dichotomized. ESI was defined by the upper quartile (SIQ > 36), while EDS was defined using an established severity threshold (ESS > 10). Participants self-reported the number of falls (Falls-Number) over the past year, and whether they experienced any fall-related injuries (Falls-Injury). Falls-Number (< 3 vs. 3+ falls) and Falls-Injury (no vs. yes) served as outcomes in analyses. Logistic regressions were performed, with adjusted models accounting for age, sex, body mass index, chronotype, habitual sleep duration, arthritis history, alcohol use, caffeine use, smoking history, depressive symptomatology, and anxiety symptomatology. Results 403 older adults (mean age = 74.4 ± 6.74 years; 44.4% female) comprised the analytic sample. In adjusted analyses, ESI, but not EDS, significantly associated with a higher likelihood of falls (Odds Ratio [OR] = 3.44, 95% Confidence Interval [CI] = [1.51, 7.86], p = 0.003). Both ESI (OR = 2.11, 95% CI = [1.12, 3.95], p = 0.02) and EDS (OR = 2.19, 95% CI = [1.13, 4.17], p = 0.02) significantly associated with a greater likelihood of having a fall-related injury in adjusted analyses. Conclusion ESI associated with increased likelihood of having more falls and fall-related injury, while EDS associated with increased likelihood of having a fall-related injury. Future research that uses objective measures to capture ESI and EDS is indicated. Support (if any) This study is supported by a US National Institutes of Health, National Institute on Aging grant (R01079352).