GENUD Toledo Research Group, University of Castilla-La Mancha, Spain.
CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.
J Gerontol A Biol Sci Med Sci. 2021 Apr 30;76(5):893-900. doi: 10.1093/gerona/glaa159.
Cross-sectional evidence exists on the beneficial effects of breaks in sedentary time (BST) on frailty in older adults. Nonetheless, the longitudinal nature of these associations is unknown. This study aimed to investigate the direction and temporal order of the association between accelerometer-derived BST and frailty over time in older adults.
This longitudinal study analyzed a total of 186 older adults aged 67-90 (76.7 ± 3.9 years; 52.7% females) from the Toledo Study for Healthy Aging over a 4-year period. Number of daily BST was measured by accelerometry. Frailty was assessed with the Frailty Trait Scale. Multiple cross-lagged panel models were used to test the temporal and reciprocal relationship between BST and frailty.
For those physically inactive (n = 126), our analyses revealed a reciprocal inverse relationship between BST and frailty, such as higher initial BST predicted lower levels of later frailty (standardized regression coefficient [β] = -0.150, 95% confidence interval [CI] = -0.281, -0.018; p < .05); as well as initial lower frailty levels predicted higher future BST (β = -0.161, 95% CI = -0.310, -0.011; p < .05). Conversely, no significant pathway was found in the active participants (n = 60).
In physically inactive older adults, the relationship between BST and frailty is bidirectional, while in active individuals no associations were found. This investigation provides preliminary longitudinal evidence that breaking-up sedentary time more often reduces frailty in those older adults who do not meet physical activity recommendations. Targeting frequent BST may bring a feasible approach to decrease the burden of frailty among more at-risk inactive older adults.
已有横断面研究表明，久坐时间（BST）中断对老年人虚弱有有益影响。然而，这些关联的纵向性质尚不清楚。本研究旨在探讨老年人中 BST 与虚弱之间的关联在时间上的方向和先后顺序。
这项纵向研究分析了来自托莱多健康老龄化研究的总共 186 名年龄在 67-90 岁（76.7±3.9 岁；52.7%为女性）的老年人，随访时间为 4 年。每天 BST 的数量通过加速度计测量。虚弱程度使用虚弱特征量表评估。采用多交叉滞后面板模型来测试 BST 和虚弱之间的时间和相互关系。
对于那些不活跃的参与者（n=126），我们的分析显示 BST 和虚弱之间存在一种相互反向的关系，例如，较高的初始 BST 预示着较低的后续虚弱程度（标准化回归系数[β] = -0.150，95%置信区间[CI] = -0.281，-0.018；p <.05）；以及初始较低的虚弱程度预示着未来更高的 BST（β = -0.161，95%CI = -0.310，-0.011；p <.05）。相反，在活跃的参与者（n=60）中没有发现显著的途径。
在不活跃的老年人中，BST 和虚弱之间的关系是双向的，而在活跃的个体中则没有发现关联。这项研究提供了初步的纵向证据，表明更频繁地打破久坐时间可以降低不符合身体活动建议的老年人的虚弱程度。针对频繁的 BST 可能为减少更多高风险不活跃的老年人体弱提供一种可行的方法。
