Rest-activity rhythms associated with aging traits in the elderly.

许多生物功能受到昼夜节律的控制，包括荷尔蒙和 神经肽、温度、血压和心率、骨重建、肌肉再生、突触 可塑性、睡眠和活动周期。我们之前报道过，老年社区居住的男性和女性 昼夜节律较弱，死亡风险较高，更有可能发展为轻度认知能力。 损伤和痴呆症。然而，关于与年龄相关的昼夜节律变化的原因，我们知之甚少。 老年人的活动模式以及这些变化如何独立于 衰老的其他特征。为了促进关于客观测量的作用的当前知识 衰老中的昼夜活动节律，我们建议(1)推导出一组新的活动节律参数来 补充我们当前的传统活动节律变量以(2)检查这些节律是如何关联的 运动、力量和认知的纵向变化，以及(3)检查节奏是否能识别出年龄 有更大风险发生事故或残疾恶化的成年人，以及这些关系是否 独立于机动性、力量和认知的同时变化。这些分析将被执行 使用来自两个大型(N&>；6,000)、基于人口的纵向队列的现有数据，这些队列具有多天 在两个时间点测量的动作图。 我们提出了三个研究目标，这将促进目前对昼夜节律作用的了解。 衰老中的活动节律。对于我们的第一个特定目标，我们将使用Function 主成分分析(FPCA)来补充现有的传统(余弦)活动节律变量 在骨质疏松性骨折(SOF)和男性骨质疏松(MRO)队列研究中。我们的第二个目标是 我将研究传统的和新的fPCA衍生的活动节律如何与纵向变化相关联 在行走速度、力量和认知功能方面。对于我们的第三个目标，我们将测试老年男性和女性 随着昼夜休息-活动节律的打乱，随着时间的推移，发生事件或恶化残疾的风险更大 这些关联是否独立于行走速度、力量和认知能力的同步变化 功能以及合并症，以及炎症和代谢生物标志物。 活动节律是潜在的可改变的行为，可以更好地理解 活动节律与随后与年龄相关的活动、力量和认知变化之间的关系 功能和意外残疾可能导致新的干预措施，以改善健康和福祉在 老年人。此外，考虑到用于跟踪活动的基于消费者的设备的快速增长，研究结果可能证明 在确定老年人作为干预目标方面很有用。

Many biological functions are under circadian control, including release of hormones and neuropeptides, temperature, blood pressure and heart rate, bone remodeling, muscle regeneration, synaptic plasticity, sleep and activity cycles. We previously reported that older community dwelling men and women with weak circadian activity rhythms have a higher mortality risk and are more likely to develop mild cognitive impairment and dementia. However, little is known concerning the causes of age-related changes in circadian activity patterns in older adults and how these changes directly influence physiologic decline independent of other features of aging. In order to advance current knowledge regarding the role of objectively measured circadian activity rhythms in aging, we propose to (1) derive a novel set of activity rhythm parameters to complement our current traditional activity rhythm variables to (2) examine how these rhythms are associated with longitudinal changes in mobility, strength, and cognition, and (3) examine whether rhythms identify older adults at greater risk of incident or worsening disability, and furthermore whether these relationships are independent of concurrent changes in mobility, strength, and cognition. These analyses will be performed using existing data from two large (n>6,000), population-based, longitudinal cohorts with multiple-day actigraphy measured at two time points. We propose three study aims that will advance current knowledge regarding the role of circadian activity rhythms in aging. For our first specific aim we will derive a novel set of activity patterns using functional principle components analysis (fPCA) to complement the existing traditional (cosinor) activity rhythm variables in the Study of Osteoporotic Fractures (SOF) and Osteoporosis in Men (MrOS) cohorts. In our second aim we will examine how traditional and novel fPCA-derived activity rhythms are associated with longitudinal changes in walking speed, strength, and cognitive function. For our third aim we will test whether older men and women with disrupted circadian rest-activity rhythms are at greater risk of incident or worsening disability over time and whether these associations are independent of concurrent changes in walking speed, strength and cognitive function as well as comorbidities, and inflammatory and metabolic biomarkers. Activity rhythms are potentially modifiable behaviors and gaining a better understanding of the relationship between activity rhythms and subsequent age-related changes in mobility, strength, and cognitive function as well as incident disability may lead to novel interventions that improve health and well-being in the elderly. Furthermore, given the rapid growth of consumer-based devices to track activity, findings may prove useful in identifying older adults to target for intervention.