Zhang Li, Liu Shuqin, Li Yujie, Li Suyun, Wu Yili
Department of Epidemiology and Health Statistics, Public Health College, Qingdao University, Qingdao, China.
Department of Emergency, The Affiliated Hospital of Qingdao University, Qingdao, China.
Gerontology. 2022;68(1):1-7. doi: 10.1159/000514894. Epub 2021 Apr 23.
Although previous studies have reported the significant associations of sleep quality with gait speed and falls, the mechanisms underlying these associations are unclear. We aimed to examine the gender-specific associations of sleep quality with gait speed and falls among older adults and to explore the possible mediating effect of muscle strength on these relationships.
Data were taken from wave 6 (2012-2013) of the English Longitudinal Study of Aging (ELSA), including 7,664 participants aged 60 years and older. Sleep quality and falls were assessed by self-report. Gait speed was measured by the "timed walking test" and then adjusted by height. As an indicator of overall muscle strength, grip strength was measured by using the Smedley dynamometer. Baron and Kenny's causal steps and the Karlson/Holm/Breen method were used to examine the mediating effect.
Higher sleep quality was associated with the higher level of gait speed (β = 0.008, p = 0.031 in men; β = 0.008, p = 0.017 in women) and with lower prevalence of falls (OR = 0.878, 95% CI: 0.773, 0.998 in men; OR = 0.874, 95% CI: 0.792, 0.965 in women). Grip strength mediated these associations in men but not in women, and the mediating effects of grip strength can explain 23.74 and 11.01% of the total effect of sleep quality on gait speed and falls, respectively.
Our findings help explain the mechanism underlying the associations of sleep quality with gait speed and falls. Effort to maintain the mobility of the older men should focus on improving both sleep quality and muscle strength.
尽管先前的研究报告了睡眠质量与步速和跌倒之间存在显著关联，但这些关联背后的机制尚不清楚。我们旨在研究老年人睡眠质量与步速和跌倒之间的性别特异性关联，并探讨肌肉力量在这些关系中可能起到的中介作用。
数据取自英国老龄化纵向研究（ELSA）的第6波（2012 - 2013年），包括7664名60岁及以上的参与者。睡眠质量和跌倒情况通过自我报告进行评估。步速通过“定时步行测试”测量，然后根据身高进行调整。作为整体肌肉力量的指标，握力使用斯梅德利测力计进行测量。采用巴伦和肯尼的因果步骤法以及卡尔森/霍尔姆/布林方法来检验中介作用。
较高的睡眠质量与较高的步速水平相关（男性中β = 0.008，p = 0.031；女性中β = 0.008，p = 0.017），且与较低的跌倒发生率相关（男性中OR = 0.878，95%置信区间：0.773，0.998；女性中OR = 0.874，95%置信区间：0.792，0.965）。握力在男性中介导了这些关联，但在女性中未介导，握力的中介作用分别可解释睡眠质量对步速和跌倒总效应的23.74%和11.01%。
我们的研究结果有助于解释睡眠质量与步速和跌倒之间关联的潜在机制。努力维持老年男性的行动能力应侧重于改善睡眠质量和肌肉力量。
