Is Poor Sleep Associated with Lower Physical Function in Older Adults?

Introduction & Purpose Poor sleep is a major contributor to mortality and many diseases. Epidemiological data suggests that sleep disturbances affect overall health and physical function [1] and growing evidence points to an association of sleep quality with muscle health and body composition across the lifespan [2]. Effective prevention and treatment programs rely on understanding the role of sleep in the development of sarcopenia and obesity. This project investigated the association of sleep quality with BMI and muscle function in older adults in Austria. Methods For this cross-sectional study, older adults aged 65+ were recruited across Austria to complete an online survey and self-measurements. We collected personal information, sleep quality via the Pittsburgh Sleep Quality Index (PSQI), habitual physical activity with the International Physical Activity Questionnaire: Short Form (IPAQ), and the risk of sarcopenia via SARC-F score. BMI was derived from self-measured body height and mass. Muscle function was assessed using a self-administered 30s chair rise test (CRT30) with detailed video-based instructions. Multiple linear regression models were calculated in a hierarchical manner to predict the number of repetitions in the CRT30, the SARC-F score and the BMI. Confounding variables were added to the unadjusted models (only PSQI) in blocks. Results 203 participants (96 female; age: 74.0±8.3years; BMI:26.0±3.4kg*m2) fulfilled the inclusion criteria. They performed 9.40±4.07 repetitions in the CRT30, had a mean PSQI of 6.47±3.17, and a median SARC-F score of 2 [IQR: 3]. To predict CRT30, the final model included PSQI, age and sex (F(3,198) = 38.68, p < .001; R2adj. = 0.360). Adding further confounders did not significantly improve the model. PSQI (β = –0.244, p < 0.001) and age (β = –0.492, p < 0.001) were significant predictors of CRT30, while sex was not (β = –0.075, p = 0.188). The same variables were included in the final model to predict the SARC-F score (F(3,198) = 94.11, p < 0.001; R2adj. = 0.582), with no improvement when adding more confounders. PSQI (β = –0.231, p < 0.001) and age (β = –0.671, p < 0.001) were significant predictors of SARC-F score, but sex was not (β = –0.050, p < 0.279). No significant association was found between PSQI and BMI. No significant predictive power of physical activity on CRT30 was found in a subsample. Discussion Low self-reported sleep quality was independently associated with low objective physical function (30CRT) and low self-reported function (SARC-F). This is in agreement with previous results, although sex differences reported earlier [3] were not observed. No association of sleep quality with BMI was found. As only a small fraction of participants was obese or underweight, our sample may not have been diverse enough to detect the previously reported association. If improving sleep hygiene in older adults can mitigate the risk of sarcopenia needs to be investigated. Conclusion Poor sleep quality is independently associated with low muscle function but not BMI in a sample of predominantly non-obese Austrian older adults. The potential role of sleep health in sarcopenia prevention warrants further investigation. References [1] Stone, K. L., & Xiao, Q. (2018). Impact of Poor Sleep on Physical and Mental Health in Older Women. Sleep Medicine Clinics, 13(3), 457–465. https://doi.org/10.1016/j.jsmc.2018.04.012 [2] Chien, M.-Y., Wang, L.-Y., & Chen, H.-C. (2015). The Relationship of Sleep Duration with Obesity and Sarcopenia in Community-Dwelling Older Adults. Gerontology, 61(5), 399–406. https://doi.org/10.1159/000371847 [3] Denison, H. J., Jameson, K. A., Sayer, A. A., Patel, H. P., Edwards, M. H., Arora, T., Dennison, E. M., Cooper, C., & Baird, J. (2021). Poor sleep quality and physical performance in older adults. Sleep Health, 7(2), 205–211. https://doi.org/10.1016/j.sleh.2020.10.002