Sex differences in the association between sleep duration and frailty in older adults: evidence from the KNHANES study.

ABSTRACT

BACKGROUND: Frailty is a pervasive clinical syndrome among the older population. It is associated with an increased risk of diverse adverse health outcomes including death. The association between sleep duration and frailty remains unclear. Therefore, the aim of this study was to investigate the relationship between sleep duration and frailty in community-dwelling Korean older adults and to determine whether this relationship is sex-dependent. METHODS: Data on 3,953 older adults aged ≥ 65 years were obtained from the 7th (2016-2018) Korea National Health and Nutrition Examination Survey (KNHANES). Frailty was defined using the Fried phenotype with criteria customized for the KNHANES dataset. Self-reported sleep duration was classified as short sleep duration (≤ 6 h), middle sleep duration (6.1-8.9 h), and long sleep duration (≥ 9 h). Complex samples multivariate logistic regression analysis was conducted to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The percentage of male participants with short, middle, and long sleep durations was 34.9%, 62.1%, and 16.8%, respectively, while that of female participants was 26.1%, 59.2%, and 14.7%. The prevalence of frailty in the middle sleep duration group was lower than that in the short and long sleep duration groups in both men (short, 14.7%; middle, 14.2%; long, 24.5%; p < 0.001) and women (short, 42.9%; middle, 27.6%; long, 48.6%; p < 0.001). Both short (OR = 2.61, 95% CI = 1.91 - 4.83) and long (OR = 2.57, 95% CI = 1.36 - 3.88) sleep duration groups had a significantly higher OR for frailty than the middle sleep duration group even after adjusting for confounding variables among women, but not among men. CONCLUSION: Short and long sleep durations were independently associated with frailty in community-dwelling Korean older adult women. Managing sleep problems among women should be prioritized, and effective interventions to prevent frailty should be developed accordingly.