Frailty is associated with poor bone health and osteoporosis, and physical activity (PA) is one of the best treatments for both pathologies in older adults. Nonetheless, because daily time is limited, how the time is distributed during the waking hours is critical. The waking hours are spent according to different movement behaviors: sedentary behaviors (SB), light physical activity (LPA), and moderate‐to‐vigorous physical activity (MVPA). The aim of this study was to use compositional data analyses to examine the effects of the change in movement behaviors on bone health during aging in older people, related to the changes in their frailty levels. We analyzed 227 older people aged 65 to 94 (125 women and 102 men) over a 4‐year period. Movement behaviors were assessed using accelerometry. Both bone mineral density (BMD) and bone mineral content (BMC) were determined using bone densitometry. The Frailty Trait Scale was used to divide the sample by frailty level evolution during aging. The R statistical system was used for the compositional data analysis and, in addition, all models were adjusted for several covariates. The changes in the distribution of all movement behaviors within a waking hour period were significantly associated with spine and femoral neck BMD changes in the subgroup with a positive change in frailty level and spine BMC in the subgroup with no change in frailty level (p  ≤ .05). Likewise, MVPA relative to the change in other movement behaviors was also associated in both subgroups with higher BMD and BMC, respectively, in the same body areas (p  ≤ .05). No significant associations were found in the negative change in frailty level subgroup. Older people who achieved a positive change in frailty level during a 4‐year period showed higher BMD changes compared to those with no changes or increases in their frailty level. Therefore, increasing MVPA relative to the change in the other movement behaviors during a 4‐year period could perhaps produce bone health improvements in the elderly that do not worsen their frailty level. © 2020 American Society for Bone and Mineral Research.

中文翻译：

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运动能力分布的前瞻性变化与老年人骨骼健康的脆弱性水平有关。

身体虚弱与骨骼健康不佳和骨质疏松症有关，而体育锻炼（PA）是老年人针对这两种疾病的最佳治疗方法之一。但是，由于每天的时间有限，因此在清醒时间内如何分配时间至关重要。醒来时间是根据不同的运动行为而花费的：久坐行为（SB），轻微身体活动（LPA）和中度至剧烈身体活动（MVPA）。这项研究的目的是使用成分数据分析来检查运动行为变化对老年人衰老期间骨骼健康的影响，这与他们的脆弱水平的变化有关。我们在4年期间分析了227位年龄在65-94岁之间的老年人（125位女性和102位男性）。使用加速度计评估运动行为。使用骨密度测定法确定骨矿物质密度（BMD）和骨矿物质含量（BMC）。衰老特质量表用于根据衰老过程中衰弱程度的演变来划分样本。R统计系统用于成分数据分析，此外，所有模型都针对多个协变量进行了调整。在一个清醒时段内，所有运动行为分布的变化与该组的脊柱和股骨颈BMD变化显着相关，而脆弱水平为正变化，而该组的脊柱BMC变化不显着（所有模型都针对几个协变量进行了调整。在一个清醒时段内，所有运动行为分布的变化与该组的脊柱和股骨颈BMD变化显着相关，而脆弱水平为正变化，而该组的脊柱BMC变化不显着（所有模型都针对几个协变量进行了调整。在一个清醒时段内，所有运动行为分布的变化与该组的脊柱和股骨颈BMD变化显着相关，而脆弱水平为正变化，而该组的脊柱BMC变化不显着（p  ≤0.05）。同样地，相对于在其他运动行为的变化MVPA分别与更高的BMD和BMC，这两个亚组也被相关联，在相同的身体区域（p  ≤0.05）。在脆弱水平亚组的负变化中未发现显着关联。在4年内，脆弱性水平出现正向变化的老年人的BMD变化高于无变化或脆弱性水平升高的老年人。因此，相对于其他运动行为在4年内的变化而言，增加MVPA可能会使老年人的骨骼健康得到改善，而又不会使他们的虚弱程度恶化。©2020美国骨骼和矿物质研究学会。