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

久坐过多的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)发病率和死亡率。有证据表明，久坐不动不仅仅是不活动的一种形式 这会产生正能量平衡。相反，久坐行为本身可能是有害的。因此，卫生机构 提出了“少坐多动”的一般性建议，建议在短时间的活动中穿插。 然而，缺乏描述频率(例如每30分钟、每60分钟)和持续多长时间的经验证据 (例如，1分钟活动，5分钟活动)应中断久坐时间(“久坐休息”)以 收益健康效益排除了更多量化的、可操作的指导方针。迄今为止，严谨而有条不紊 目前还没有进行剂量递增实验来阐明久坐休息的有效性和耐受性。 剂量。如果没有具体的目标提供给公众；针对久坐行为的公共卫生倡议将 效果很可能微乎其微。关键的，没有经过严格测试的剂量信息；随机控制 针对久坐行为的试验可能是徒劳的；承担着无效或无法忍受剂量的风险。这个 拟议研究的目的是确定两种药物的最小有效剂量(例如最小剂量) 久坐休息的要素、频率和持续时间，从而改善已建立的心血管疾病风险 各种因素。我们还将确定最大耐受剂量(例如，不会导致不适当的最高剂量 身体/心理痛苦)对久坐休息的频率和持续时间都有影响。为了实现我们的目标，我们 将在受控良好的实验室条件下使用创新的 用于确定剂量的贝叶斯自适应随机化方法以前从未应用于行为试验。这 该方法将使我们能够在一次研究中有效地测试25种可能的频率/持续时间组合。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8小时)，即 静坐休息(活动)状态和不间断静坐(控制)状态，按随机顺序排列。这个 久坐休息条件将由25个可能的频率/持续时间组合中的一个组成(例如，每30分钟 10分钟)，根据自适应随机化协议选择。已确定的心血管疾病风险因素，包括 血压和血糖，以及剂量耐受性的测量(体力衰竭/疲劳，影响)和 在每一次试验期间，将对工作敬业度和表现进行连续评估。我们将这个项目视为 朝着开发基于证据的久坐行为指南迈出了开创性的一步，这将建立一个 一个成功的久坐行为干预发展过程可以扎根的基础。通过 确定最低有效剂量和最大耐受剂量组合的频率和持续时间 久坐休息；这项研究将提供对未来第三阶段成功至关重要的关键基础证据 以及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.