Association between sleep health and intrinsic capacity among older adults in Taiwan

Although the association between poor sleep quality and frailty has been previously reported, the relationship between sleep health and intrinsic capacity (IC) remains largely unknown. We aimed to examine the association between sleep health and IC among older adults. This was a cross-sectional study, and 1268 eligible participants completed a questionnaire collecting information on demographic, socioeconomic, lifestyle, sleep health, and IC. Sleep health was measured by the RU-SATED V2.0 scale. High, moderate, and low levels of IC were defined using the Integrated Care for Older People Screening Tool for Taiwanese. The ordinal logistic regression model estimated the odds ratio and corresponding 95% confidence interval. Low IC was significantly associated with age of 80 years or above, female, currently unmarried, uneducated, currently not working, financially dependent, and having emotional disorders. A one-point increase in sleep health was significantly associated with a 9% reduction in the odds of poor IC. An increase in daytime alertness was related to the greatest reduction in poor IC (aOR, 0.64; 95% CI, 0.52–0.79). In addition, the subitems sleep regularity (aOR, 0.77; 95% CI, 0.60–0.99), sleep timing (aOR, 0.80; 95% CI, 0.65–0.99), and sleep duration (aOR, 0.77; 95% CI, 0.61–0.96) were associated with a reduced OR of poor IC but with marginal statistical significance. Our findings showed that sleep health across multiple dimensions is related to IC, particularly daytime alertness in older adults. We suggest developing interventions to improve sleep health and prevent IC decline, which is crucial in causing poor health outcomes.