Evaluating Standing as a Health Behavior to Promote Cardiovascular Risk Reduction in African Americans

美国成年人每天久坐约11-12小时，这极大地增加了心血管疾病(CVD)和 死亡风险。美国人的体育锻炼指南已经扩展到推广适度的- 剧烈的体力活动，现在也提倡减少久坐时间。相应地，有很强的 对阐明减少久坐时间的简单、经济有效的方法感兴趣。大众媒体和 寻求从健康趋势中获利的公司一直在延续这样一种观念，即仅仅是原地踏步 这是坐着的健康替代品。因此，站立式和坐立式办公桌是增长最快的 美国工作场所的员工福利。然而，很少有证据证明它对健康有好处。 站稳脚跟。因此，尽管公众认为站立是一种健康的选择，但它仍然没有出现在 体力活动指南，人们担心站着可能比坐着更有害。的目标是 建议的研究是综合评估声称的益处(心脏代谢)和风险(血管 腿部损伤，肌肉骨骼疼痛)，站立可能引起的及其在 美国风险最高的群体--生活在中风带的非裔美国人。未来两国之间的联系 客观测量的站立时间和心血管疾病综合风险评分(包括葡萄糖、 将评估(目标1)甘油三酯、胆固醇、血压、腰围。多部小说 将调查站立模式变量(例如，站立回合的分布、长度和规律性)以 确定立场的哪些方面与心血管疾病风险评分的两年变化最相关(目标2)。状态 分析技术将被用来评估从久坐到站立的重新分配时间是否会产生 降低心血管疾病风险分数(次要目标)。站立时间/模式与 踝臂指数(ABI，外周血管疾病指数)和肌肉骨骼的两年变化 还将检查疼痛症状和站立的横断面/前瞻性预测因素(探索性 目标)。为了实现我们的研究目标，我们将利用杰克逊心脏研究(JHS)的基础设施，以及 专门针对非裔美国人的队列研究。第四次JHS考试计划在2020-2022年进行， 将包括对心血管疾病风险因素的评估。对于这项辅助研究，我们建议增加一个7天加速度计 协议(包括姿势检测)、ABI评估和问卷调查，共有1,250名参与者参加。我们 此外，建议在两年后进行后续访问，以重新评估这些措施和心血管疾病风险因素。发现 将(1)告知与地位和健康结果有关的可能因果关系，(2)确定 应推广的最佳站立模式，(3)为未来的试验建立终点，促进 站立，以及(4)确定可以作为干预目标的站立的预测因素。我们将这个项目视为 关键的下一步，将提供对未来试验的成功至关重要的基础证据，并最终 针对非裔美国人和其他人口群体久坐行为的公共卫生努力。

US adults are sedentary for ~11-12 h/day - which greatly increases cardiovascular disease (CVD) and mortality risk. The Physical Activity Guidelines for Americans have expanded beyond promoting moderate- vigorous physical activity and now also advocate for reductions in sedentary time. Accordingly, there is strong interest in elucidating simple, cost-effective methods to reduce sedentary time. The popular press and corporations seeking to capitalize on health trends have perpetuated the notion that simply standing in place is a healthful alternative to sitting. Consequently, standing and sit-to-stand desks are the fastest growing employee benefit in US workplaces. However, there is a paucity of evidence documenting the health benefits of standing. As such, despite public perception that standing is a healthful alternative, it remains absent from physical activity guidelines, with concerns raised that standing could be more harmful then sitting. The goal of the proposed study is to comprehensively evaluate purported benefits (cardiometabolic) and risks (vascular damage to lower limbs, musculoskeletal pain) that may be incurred with standing and its accrual pattern in the highest risk group in the US - African Americans living in the stroke belt. The prospective association between objectively-measured standing time and the 2-year change in a composite CVD risk score (comprising glucose, triglycerides, cholesterol, blood pressure, waist circumference) will be evaluated (Aim 1). Multiple novel standing pattern variables (e.g. distribution, length, and regularity of standing bouts) will be investigated to identify which aspects of standing are most associated with the 2-year change in CVD risk score (Aim 2). State of the art analytic techniques will be used to evaluate if reallocating time from sedentary to standing would yield CVD risk score reductions (Secondary Aim). Prospective associations between standing time/patterns and the 2-year change in the ankle-brachial index (ABI, an index of peripheral vascular disease) and musculoskeletal pain symptoms, and the cross-sectional/prospective predictors of standing will also be examined (Exploratory Aims). To address our study aims, we will leverage the infrastructure of the Jackson Heart Study (JHS), an exclusively African American cohort study. A fourth JHS exam is scheduled to be conducted in 2020-2022 and will include assessment of CVD risk factors. For this ancillary study, we propose to add a 7-day accelerometer protocol (with posture detection), ABI assessment, and questionnaires to this exam for 1,250 participants. We furthermore propose a follow-up visit 2 years later to re-assess these measures and CVD risk factors. Findings will (1) inform probable cause and effect associations with respect to standing and health outcomes, (2) identify optimal patterns of standing that should be promoted, (3) establish endpoints for future trials promoting standing, and (4) identify predictors of standing that can serve as intervention targets. We view this project as a critical next step that will provide foundational evidence important for success of future trials and ultimately public health efforts targeting sedentary behavior in African Americans and other population groups.