Background Self-reported low physical activity is a defining feature of phenotypic frailty but does not adequately capture physical activity performed throughout the day. This study examined associations between accelerometer-derived patterns of routine daily physical activity and frailty. Methods Wrist accelerometer and frailty data from 638 participants (mean age 77 [SD = 5.5] years; 44% women) were used to derive 5 physical activity metrics: active minutes/day, sedentary minutes/day, total activity counts/day, activity fragmentation (reciprocal of the average active bout length), and sedentary fragmentation (reciprocal of the average sedentary bout length). Robust, prefrail, and frail statuses were identified using the physical frailty phenotype defined as having 0, 1–2, or ≥3 of the following criterion: weight loss, exhaustion, slowness, self-reported low activity, and weakness. Frailty was collapsed into not frail (robust and prefrail) and frail, and each frailty criteria was dichotomized. Multiple logistic regression was used to model each accelerometer metric. Separate frailty criteria and interactions with age and sex were also examined. Results With higher amounts and intensity of daily activity (more active minutes, fewer sedentary minutes, higher activity counts) and lower activity fragmentation, the odds of frailty were lower compared to robust/prefrail states (p < .02 for all). For interactions, only an age by sedentary fragmentation interaction on the odds of frailty was observed (p = .01). For each separate criteria, accelerometer metrics were associated with odds of slowness, low activity, and weakness. Conclusion Less favorable patterns of objectively measured daily physical activity are associated with frailty and the components of slowness, low self-reported activity, and weakness.

中文翻译：

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日常体力活动和表型虚弱的客观测量模式

背景自我报告的低体力活动是表型虚弱的一个决定性特征，但不能充分捕捉全天进行的体力活动。这项研究检查了加速度计衍生的日常身体活动模式与虚弱之间的关联。方法 使用来自 638 名参与者（平均年龄 77 [SD = 5.5] 岁；44% 女性）的腕部加速度计和虚弱数据得出 5 个身体活动指标：活动分钟/天、久坐时间/天、总活动计数/天、活动碎片（平均活动回合长度的倒数）和久坐碎片（平均久坐回合长度的倒数）。使用定义为具有以下标准的 0、1-2 或 ≥3 的身体虚弱表型来确定强健、体弱前和虚弱状态：体重减轻、疲惫、缓慢、自我报告的低活动和虚弱。脆弱被分解为不脆弱（健壮和前脆弱）和脆弱，每个脆弱标准都被二分法。多元逻辑回归用于对每个加速度计指标进行建模。还检查了单独的虚弱标准以及与年龄和性别的相互作用。结果 随着日常活动量和强度的增加（更多的活动时间，更少的久坐时间，更多的活动计数）和更少的活动碎片，与健壮/衰弱状态相比，衰弱的几率更低（p <.02）。对于交互作用，仅观察到久坐碎片交互作用对虚弱几率的影响（p = .01）。对于每个单独的标准，加速度计指标与缓慢、低活动和虚弱的几率相关联。