A study found that having a better sleep health composite score was associated with a lower risk of physical frailty, with men and women possessing different risk factors.
The study took place in Taiwan and data were obtained from the Taiwan Longitudinal Study on Aging (TLSA), which includes patients 60 years and older. Patients who were younger than 65 years and/or were living 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 under the Fried criteria were used for this study. Sleep measures were self-reported using the 5 sleep health dimensions in the SATED model: sleep satisfaction, daytime alertness, sleep timing, sleep efficiency, and sleep duration. Physical activity was assessed by frequency of engaging in gardening, walks, bicycling, jogging, hiking, and other outdoor physical exercise.
There were 2015 participants for this study, of whom 9% were considered frail. The mean sleep health composite score was 2.51; the most prevalent good sleep health dimension was daytime alertness (91%) and least prevalent was sleep efficiency (11%).
Participants who were frail scored significantly lower on the sleep health composite compared with participants who were not frail, and significantly fewer frail participants indicated satisfaction with sleep, being alert during the daytime, and having adequate sleep duration.
The adjusted logistic regression analysis demonstrated a significant association between frailty and the multidimensional sleep health composite (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 the sleep health measure were approximately 22% less likely to be frail.
The multidimensional sleep health composite effect on frailty was significant in both female (OR, 0.59; 95% CI, 0.48-0.72) and male (OR, 0.54; 95% CI, 0.39-0.75) participants. A significant effect was only observed in women (OR, 0.79; 95% CI, 0.63-0.98) after adjusting for comorbidities.
The 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 as 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 adding health and risk behaviors 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 alertness remained significant after adding health and risk behaviors to the model.
There were some limitations to the study. The cross-sectional design of this study could cause reverse causality. The investigators used self-reported responses to construct an adopted frailty index due to constraints of archival data. Napping, which is often associated with frailty, was not found in the TLSA data set, and therefore couldn’t be tested. Sleep disorders can also increase the risks of frailty but were not available in the TLSA data set.
The researchers concluded that the first empirical evidence of sleep health being an early risk factor of frailty was demonstrated in the study.
Chen TY, Lee S, Buxton OM. Multidimensional sleep health is associated with physical frailty in a national sample of Taiwanese community-dwelling older adults: sex matters. Sleep Health. Published online July 3, 2022. doi:10.1016/j.sleh.2022.05.003