Sedentary Behaviour Interrupted: Acute, medium and long-term effects on biomarkers of healthy aging, physical function and mortality

摘要 老年人努力从事健康促进体力活动（PA），每天花费长达11个小时 坐着特别是老年妇女，患慢性病和残疾的风险增加， 医疗资源的比例。改善这两种行为有希望改善几个突出的 老化的结果，但证据告知指导方针，如何最好地中断长期久坐不动的行为， (SB)缺乏。很少有基于实验室的试验包括70岁以上的成年人，主要集中在PA， 中断SB，并且没有测试老年人可能接受的站立休息。最近一次审查 表明，在真实的世界中，传统的PA干预措施不会对SB产生有意义的影响。相反， 专注于站立的干预措施可以减少SB，每天最多2小时。流行病学研究 显示自我报告的SB与死亡和代谢结果风险增加之间存在关联，但非常 一些前瞻性研究采用了SB的客观测量。虽然加速度计测量可以 指示运动的强度或缺乏运动，传统的分界点不能准确地对行为进行分类， 无论是坐着、站着还是走路。虽然试点干预研究，使用大腿磨损倾斜仪， 虽然研究表明SB可以大大降低，但没有在老年人中进行的具有健康结果的RCT。那里 我们对SB和健康老龄化的理解还有很大的改进空间。国家老龄化研究所 2013年举办了一系列夏季讲习班，以解决这一问题。因此，我们设计了一个方案， 项目-久坐时间和衰老研究（星星）-提供更严格和全面的 关于如何中断坐着的时间和健康老龄化的后果的证据。我们尤其 提出一种范式转变，从能源支出作为健康结果的主要机制， 调查一些行为，如从坐到站的短暂过渡，这种过渡消耗很少的能量，但会使肌肉活动， 改善姿势血流，并可能影响老年人的身体功能。此外，我们还将研究 比迄今为止研究的结果范围更广，包括重要的靶向新机制， 健康老龄化该星星计划将包括3个项目和2个核心的研究绝经后妇女在 慢性病的风险。星星包括实验室（N = 86）和真实的世界中的2项随机试验 （N = 592），重点是优化新的计算技术，以应用于现有的前瞻性 加速度计数据（n> 6000）。所有项目将调查长期坐着，站着，简短 从坐到站的转换和PA中断对健康衰老机制的影响，包括葡萄糖调节， 内皮功能和线粒体功能。我们还将调查身体功能，血液 在项目3中，5 - 7年死亡风险。所有项目都将比较不同年龄组的效果。Star 将提供一个全面的证据基础，可以为SB和衰老的公共卫生指南提供信息。我们将 与美国心脏协会新成立的SB和拉丁裔中心协调我们的努力。

Abstract Older adults struggle to engage in health enhancing physical activity (PA) and spend up to 11 hours a day sitting. Older women, in particular, are at increased risk of chronic disease and disability, and use a high proportion of healthcare resources. Improving both these behaviors has promise for improving several salient aging outcomes, but evidence to inform guidelines on how best to interrupt long periods of sedentary behavior (SB) are lacking. Few laboratory-based trials have included adults over 70 years old, have focused on PA to interrupt SB, and have not tested standing breaks that might be acceptable to older adults. A recent review showed that in the real world, traditional PA interventions do not meaningfully impact SB. In contrast, interventions that focus on standing can reduce SB, up to 2 hours per day. Epidemiological studies have shown associations between self-reported SB and increased risks of death and metabolic outcomes, but very few prospective studies have employed objective measures of SB. Although accelerometer measures can indicate the intensity of movement or lack of it, traditional cutpoints do not accurately classify behaviors such as sitting, standing or walking. While pilot intervention studies, using thigh worn inclinometers, have demonstrated that SB can be greatly reduced, there are no RCTs in older adults with health outcomes. There is much room for improvement in our understanding of SB and healthy aging. The National Institute on Aging conducted a summer workshop series to address this issue in 2013. We have therefore designed a Program project – Sedentary Time and Aging Research (STAR) – to provide more rigorous and comprehensive evidence on how to interrupt sitting time and the consequences for healthy aging. In particular, we are proposing a paradigm shift away from energy expenditure as the primary mechanism for health outcomes to investigating behaviors such as brief sit-to-stand transitions that expend little energy but engage muscles, improve postural blood flow, and may impact physical functioning in older adults. Further, we will study a broader range of outcomes than investigated to date, including targeted novel mechanisms important for healthy aging. The STAR program will include 3 Projects and 2 Cores for study of postmenopausal women at risk for chronic disease. STAR includes 2 randomized trials, in the laboratory (N=86) and in the real world (N=592), with focus on optimizing new computational techniques to apply to existing prospective accelerometer data (n>6000). All projects will investigate the consequences of extended sitting, standing, brief sit-to-stand transitions and PA breaks on mechanisms of healthy aging including glucose regulation, endothelial functioning, and mitochondrial functioning. We will also investigate physical functioning, blood pressure and in Project 3, 5-7 year mortality risk. All Projects will compare effects across age groups. STAR will provide a comprehensive evidence base that can inform public health guidelines on SB and aging. We will coordinate our efforts with a new American Heart Association Center on SB and Latinas.