Breaking up Prolonged Sedentary Behavior to Improve Cardiometabolic Health: An Adaptive Dose-Finding Study

过度久坐行为在发达国家非常普遍，是心血管疾病的危险因素。 疾病（CVD）的发病率和死亡率。有证据表明，久坐不动的行为不仅仅是一种不活动的形式 这是一种积极的能量平衡。相反，久坐行为本身可能是有害的。因此，卫生机构 提供了“少坐多动”的一般性建议，穿插了短暂的活动时间。 然而，缺乏经验证据描述多久（例如，每30分钟，每60分钟）和多长时间 (e.g. 1分钟活动回合，5分钟活动回合）应中断久坐时间（“久坐休息”）， 生产健康效益排除了更多的量化，可操作的指导方针。到目前为止，严谨和有条不紊 尚未进行剂量递增实验来阐明有效和耐受的久坐休息 剂量没有向公众提供具体的目标;针对久坐行为的公共卫生倡议将 很可能效果甚微。严重，没有经过严格测试的剂量信息;随机对照 针对久坐行为的试验可能是徒劳的;承担无效或无法忍受剂量的风险。的 拟议研究的目的是确定两种药物的最低有效剂量（例如最小剂量）。 久坐休息的要素，频率和持续时间，可改善已确定的CVD风险 因素我们还将确定最大耐受剂量（例如，不会引起过度耐受的最高剂量）。 身体/心理困扰）的频率和持续时间久坐休息。为了实现我们的目标，我们 将在控制良好的实验室条件下，使用创新的 贝叶斯自适应随机化剂量确定方法以前从未应用于行为试验。这 方法将使我们能够有效地测试25种可能的频率/持续时间组合在一个单一的研究。我们 将招募324名成年人在实验室完成总共2个试验条件（每个条件8小时），即 久坐休息（活动）条件和不间断的坐着（对照）条件，以随机顺序。的 久坐休息条件将包括25种可能的频率/持续时间组合中的一种（例如，每30分钟 10分钟），根据自适应随机化方案选择。确定的CVD风险因素，包括 血压和葡萄糖，以及剂量耐受性的测量（身体疲惫/疲劳，影响）和 每次试验期间将对工作敬业度和绩效进行连续评估。我们把这个项目看作是 开创性的一步，为久坐行为制定循证指南， 成功的久坐行为干预开发过程可以扎根于此基础之上。通过 确定最低有效和最大耐受剂量组合的频率和持续时间， 久坐休息;这项研究将为未来III期研究的成功提供关键的基础证据 第四阶段随机试验和最终的公共卫生指南。

Excessive sedentary behavior is highly prevalent in developed nations and is a risk factor for cardiovascular disease (CVD) morbidity and mortality. Evidence suggests sedentary behavior is not simply a form of inactivity that elicits positive energy balance. Instead sedentary behavior itself may be harmful. As such, health agencies have provided general recommendations to “sit less, move more” by interspersing brief periods of activity. However, a lack of empirical evidence describing how often (e.g. every 30 min, every 60 min) and for how long (e.g. 1 min activity bouts, 5 min activity bouts) sedentary time should be interrupted (a “sedentary break”) to yield health benefit has precluded more quantitative, actionable guidelines. To date, rigorous and methodical dose escalation experiments have not been conducted to elucidate efficacious and tolerated sedentary break doses. Without specific targets to provide to the public; public health initiatives targeting sedentary behavior will likely have minimal effectiveness. Critically, without rigorously tested dosing information; randomized controlled trials targeting sedentary behavior may be fruitless; bearing risk of inefficacious or intolerable doses. The objective of the proposed study is to determine the minimally effective dose (e.g. the smallest dose) for two elements of a sedentary break, frequency and duration, that yields improvements in established CVD risk factors. We will also determine the maximally tolerated dose (e.g. the highest dose that does not cause undue physical/psychological distress) for both frequency and duration of sedentary breaks. To address our aims, we will conduct a state-of-the-art dose finding study under well controlled laboratory conditions using an innovative Bayesian adaptive randomization method for dose determination never before applied to behavioral trials. This method will enable us to efficiently test 25 possible frequency/duration combinations in just a single study. We will recruit 324 adults to complete a total of 2 trial conditions in the laboratory (8 hours each), namely a sedentary break (active) condition and an uninterrupted sitting (control) condition, in a randomized order. The sedentary break condition will consist of 1 of 25 possible frequency/duration combinations (e.g. every 30 min for 10 min), selected according to the adaptive randomization protocol. Established CVD risk factors, including blood pressure and glucose, as well as measures of dose tolerability (physical exhaustion/fatigue, affect) and work engagement and performance will be serially assessed during each trial. We view this project as a groundbreaking step towards developing evidence-based guidelines for sedentary behavior that will establish a foundation upon which a successful sedentary behavior intervention development process can be rooted. By identifying the minimally effective and maximally tolerated dose combinations for the frequency and duration of a sedentary break; this study will provide key foundational evidence critical to the success of future Phase III and Phase IV randomized trials and ultimately public health guidelines.