Objectively Measured Sedentary Behavior and Physical Activity in PREVENTABLE Study

久坐行为（大部分清醒时间处于坐姿/卧位）和缺乏身体活动 (lack实现每周适度/剧烈体力活动目标）是不可互换的术语， 代表不同的领域;一个人可以进行身体活动，并实现每周150分钟的目标， 但是在醒着的其余时间里仍然久坐不动。技术进步导致了 发展加速度计，以客观地测量姿势，持续时间和强度的身体 活动"老年人降脂事件和益处的实用评估（可预防）" 试验是一项由NIA资助的正在进行的随机对照试验，评价他汀类药物对认知功能的影响 和老年人（年龄≥ 75岁）的身体残疾结局。试验处于招募阶段， 2万的N。我们建议善用家长研究的资源， 辅助研究，客观地测量久坐，站立和踏步的持续时间以及 步/天与经验证的加速度计检查两个不同的问题的公共卫生的重要性。 首先，较高水平的中度/剧烈体力活动与较低的风险有关。 发展阿尔茨海默病或相关痴呆症（ADRD）。然而，缺乏身体活动和久坐不动 行为是不同的领域。关于久坐行为与肥胖风险的前瞻性纵向研究 ADRD缺乏。因此，在第一个具体目标中，在纵向的、前瞻性的分析中，我们将研究 假设久坐时间较长会增加轻度认知障碍（MCI）的风险/可能 ADRD;然而，久坐持续时间与步行持续时间的权衡与这些风险的降低相关 结果。 其次，关于他汀类药物与身体残疾/身体活动的关联存在相互矛盾的数据。 预防是检查阿托伐他汀在预防残疾（但不是体力活动）的可能作用。 我们建议增加对身体活动的客观衡量。在第二个目标中，我们将检验假设 随机接受阿托伐他汀治疗后， 与安慰剂相比，将导致更高的体力活动水平和更短的久坐时间。 这个多学科小组的调查人员拥有开展以下各方面工作的经验和专业知识： 该项目拟议的辅助研究将很好地融入母试验的务实设计， 对受试者和家长研究人员的负担最小。通过增加严格的久坐措施 行为和身体活动，这项辅助研究将与母公司试验产生协同作用，以提高科学性 通过解决母公司研究中的一个重要缺口来提高产量。如果久坐行为与MCI事件相关， ADRD在老年人中，目前的研究结果将有助于未来RCT的设计，以检查 久坐行为干预对预防老年人ADRD的影响。

Sedentary behavior (spending most of the awake time in sitting/ recumbent posture) and physical inactivity (lack of achieving weekly moderate/ vigorous physical activity goals) are not interchangeable terms but represent distinct domains; one could be physically active and achieve the weekly goal of 150 min/week of MVPA but still spend the rest of the awake hours sedentary. Technological advances have led to the development of accelerometers for objectively measuring the posture, duration and intensity of physical activities. “Pragmatic Evaluation of Events And Benefits of Lipid-lowering in older adults (PREVENTABLE)” Trial is a NIA funded ongoing randomized controlled trial evaluating the effects of a statin on cognitive function and physical disability outcomes in older adults (age ≥ 75 years). The trial is in recruitment phase with a target N of 20,000. Leveraging the resources of the parent study, we propose to recruit 2,500 participants in this ancillary study and objectively measure sedentary, standing and stepping durations and the number of steps/day with a validated accelerometer to examine two distinct questions of public health importance. First, higher levels of moderate/ vigorous physical activities have been associated with lower risk of developing Alzheimer’s disease or related dementias (ADRD). However, physical inactivity and sedentary behavior are distinct domains. Prospective longitudinal studies relating sedentary behavior with the risk of ADRD are lacking. Hence, in the first specific aim, in a longitudinal, prospective analysis, we will examine the hypothesis that longer sedentary duration increases risk of incident mild cognitive impairment (MCI)/ probable ADRD; whereas, trade-off of sedentary duration for stepping duration is associated with lower risk of these outcomes. Second, there are conflicting data on the associations of statins with physical disability/ physical activity. PREVENTABLE is examining the possible role of atorvastatin in preventing disability (but not physical activity). We propose to add objective measures of physical activity. In the second aim, we will examine the hypothesis that decrease in physical disability and preservation of functional ability with randomization to atorvastatin compared to placebo will result in higher physical activity levels and lower sedentary duration. The investigators on this multi-disciplinary team have the experience and expertise to carry out all aspects of the project. The proposed ancillary study will be well integrated into the pragmatic design of the parent trial and place minimal burden on participants and parent study staff. By adding rigorous measures of sedentary behavior and physical activity, this ancillary study will create synergy with the parent trial to enhance scientific yield by addressing an important gap in the parent study. If sedentary behavior is associated with incident MCI/ ADRD in older adults, the results of the current study will aid in the design of a future RCT to examine the effect of a sedentary behavior intervention to prevent ADRD in older adults.