A study published in Sleep health found a relationship between sound sleep in multiple dimensions and the risk of frailty. The risk is different for men and women.
The study was conducted in Taiwan and obtained data from the Taiwan Longitudinal Study of Aging (TLSA), which included patients aged 60 years and older. Patients who were younger than 65 years of age and/or lived in a long-term care facility were excluded from this study. Patients with missing information or other covariates were also excluded.
Modified definitions of frailty according to Fried’s criteria were used for this study. Sleep measures were self-reported using the 5 dimensions of sleep health in the SATED model: sleep satisfaction, daytime alertness, time to sleep, sleep efficiency, and sleep duration. Physical activity was assessed by the frequency of gardening, walking, cycling, jogging, hiking and other outdoor physical activities.
There were 2,015 participants in this study, of which 9% were considered lean. The mean sleep health composite score was 2.51; the most common dimension of good sleep health is daytime alertness (91%), and the least common is sleep efficiency (11%).
Participants who were frail scored significantly lower on overall sleep health compared to participants who were not frail, and significantly less frail participants reported sleep satisfaction, being alert during the day, and having adequate sleep duration.
Adjusted logistic regression analysis demonstrated a significant association between frailty and the multidimensional composite of sleep health (odds ratio [OR]0.57; 95% CI, 0.49-0.68). The effect remained significant after adding comorbidity, cognitive function, pain, depressive symptoms, drinking, smoking, and exercise to the model (OR, 0.78; 95% CI, 0.64-0.94). Individuals who scored 1 point higher on healthy sleep were approximately 22% less likely to be thin.
The multivariate composite effect of sleep health status on frailty was significant in both women (OR, 0.59; 95% CI, 0.48-0.72) and men (OR, 0.54; 95% CI, 0.39-0.75) participants. A significant effect was observed only in women (OR, 0.79; 95% CI, 0.63-0.98) after adjustment for comorbidities.
Adjusted logistic regression analysis found that sleep satisfaction (OR, 0.34; 95% CI, 0.24-0.48), daytime alertness (OR, 0.21; 95% CI, 0.14-0, 31) and sleep duration (OR, 0.50; 95% CI , 0.34-0.74) were associated with frailty. When considering individuals’ health, only daytime alertness remained a significant association (OR, 0.46; 95% CI, 0.29-0.75).
Sleep satisfaction (OR, 0.29; 95% CI, 0.19-0.44), daytime alertness (OR, 0.29; 95% CI, 0.18-0.47), and sleep duration ( OR, 0.48; 95% CI, 0.30-0.78) were associated with frailty in women but were no longer significant when health and risk behaviors were added to the model. Sleep satisfaction (OR, 0.47; 95% CI, 0.24-0.94) and daytime alertness (OR, 0.10; 95% CI, 0.05-0.21) were associated with frailty in men, although only daytime vigilance remained significant after adding health and risk behaviors to the model.
There were some limitations of the study. The cross-sectional design of this study may cause reverse causation. Researchers used self-reported responses to construct a perceived frailty index due to the limitations of archival data. Napping, which is often associated with frailty, was not found in the TLSA dataset and therefore could not be tested. Sleep disturbances may also increase frailty risks, but were not available in the TLSA dataset.
The researchers conclude that the first empirical evidence that sleep health is an early risk factor for frailty is demonstrated in the study.
Chen TY, Lee S, Buxton OM. Multidimensional sleep health is associated with physical frailty in a national sample of community-dwelling older adults in Taiwan: sex matters. Sleep health. Published online July 3, 2022. doi:10.1016/j.sleh.2022.05.003