An Objective Measure of Physical Activity in the DPPOS: the Accelerometry Ancilla

描述(由申请人提供)：DPPOS中体力活动的客观测量：加速计量学辅助研究摘要生活方式干预预防2型糖尿病的有效性最近已在包括糖尿病预防计划(DPP)在内的五项临床试验中得到证明。所有这些试验的结果都支持一种生活方式方法(包括体力活动)来预防那些最初处于糖尿病高危人群中的2型糖尿病。民进党的独特之处在于，它在招募的参与者中具有显著的多样性(族裔/种族、年龄和地理)。所有这五项临床试验都使用主观测量来评估各自预防工作中的体力活动水平。在最初的研究结束时，DPP中的体力活动水平在随机分组之间显示出统计学上的差异。通过活动问卷评估的基线活动水平的部分相关性与空腹和75克口服葡萄糖耐量胰岛素(空腹和30分钟后负荷)、空腹血浆胰岛素原和糖化血红蛋白呈显著负相关。然而，由这些问卷确定的生活方式组从基线到第二年的体力活动水平的变化与调整体重变化后的糖尿病发病率没有显著关系。这些发现的一个潜在原因可能部分是由于体力活动问卷本身的测量误差。由于干预导致的体力活动水平的适度变化可能无法使用主观测量来检测。体力活动问卷在评估低强度和无结构的体力活动方面存在局限性，这些活动现在已成为当前干预建议的重点之一。此外，随着活动处方变得更加灵活，允许个人将活动拆分成更小的部分，回忆变得更加困难，因此对身体活动的主观评估也变得更加困难。最后，样本的多样性也使对27个地点的准确评估成为一个挑战。出于这些原因，在DPP中，为了全面捕捉体力活动变化及其影响，可能需要使用更准确的客观体力活动衡量标准。活动监测器，更具体地说是加速计，已经被成功地用来客观地记录几项干预努力中的体力活动变化。加速计是一种小型活动监测器，通常戴在臀部，配备了一个电子传感器，可以测量运动的数量和强度，从而收集和存储日常身体活动的模式。由于由加速度计测量的体力活动可以划分为不同强度级别的活动回合，因此可以确定在总运动中花费的时间量和在特定强度上花费的时间量。我们最近分析了来自国家数据集(NHANES)的体力活动数据，其中我们证明，根据使用的活动评估，可以得出关于种族群体活动排名的两个非常不同的结论。尽管活动问卷的数据表明拉美裔男性和女性是最不活跃的群体，但大约在同一时间收集的加速计数据发现，拉美裔男性和女性都是最活跃的群体。此外，通过问卷调查发现，空腹血糖和胰岛素与加速计活动计数显著相关，但与每日总活动量无关。这表明有必要用加速度计观察民进党的活动。由于干预导致的活动变化很可能是微妙的，反映了难以通过问卷确定的生活方式的变化，而且由于民进党人口在种族/种族、年龄和地理位置方面非常不同，体力活动水平可能过于复杂，无法通过回忆来评估。这项辅助研究的目的是使用加速计客观地评估所有选择参加下一周期DPP后续研究且尚未转为糖尿病的DPP参与者的体力活动水平。尽管自最初的试验结束以来，干预的影响似乎有所减弱，但与其他两组相比，生活方式组的糖尿病发病率以及心血管疾病和代谢综合征的风险因素仍然更好。合理的假设是，这些群体之间的体力活动水平也可能存在差异，这可能是导致这种更好的健康状况的部分原因。此外，在我们确定了加速度计数据与MAQ活动问卷所报告的体力活动之间的关系后，我们将能够使用这些信息来指导涉及MAQ测量的活动水平的DPP和DPPOS数据分析(自最初的DPP临床试验基线以来一直使用该数据)。这项申请取决于第二个D级后续行动周期的未来供资情况。公共卫生相关性：这项应用旨在通过使用加速计客观地评估所有选择参与下一轮DPP后续研究且尚未转为糖尿病的DPP参与者的体力活动水平。所有五项使用生活方式干预方法预防2型糖尿病的临床试验都使用了主观测量来评估各自努力中的体力活动水平。我们很可能再也没有机会在糖尿病预防的随机临床试验中研究这个问题了。因此，我们召集了一组调查人员来开展这一独特的项目。

DESCRIPTION (provided by applicant): An Objective Measure of Physical Activity in the DPPOS: The Accelerometry Ancillary Study Abstract The effectiveness of lifestyle intervention for the prevention of Type2 diabetes has been recently demonstrated in five clinical trials including the Diabetes Prevention Program (DPP). The results of all of these trials support a lifestyle approach (which includes physical activity) to the prevention of Type2 diabetes in individuals that were initially at high risk for diabetes. The uniqueness of the DPP was that it had significant diversity (ethnicity/race, age and geography) among the participants recruited. All of these five clinical trials used a subjective measure to assess physical activity levels in their respective prevention efforts. Physical activity levels in the DPP were shown to be statistically different at the end of the original study between the randomized groups. Partial correlations of activity levels as assessed at baseline by the activity questionnaires were significantly and inversely associated with fasting and 75- g oral glucose tolerance measures of insulin (fasting and 30 minute postload), fasting plasma proinsulin, and HbA1c. Yet, change in physical activity level from baseline to year 2 in the lifestyle arm as determined by theses questionnaires was not significantly related to diabetes incidence after adjustment for weight change. A potential reason for these findings is likely due, in part, to the measurement error of the physical activity questionnaire itself. Modest changes in physical activity levels due to the intervention may not feasibly be detected using subjective measures. Physical activity questionnaires have limitations in assessing low-intensity and unstructured physical activity which have now become part of the focus of current intervention recommendations. Also, as the activity prescription has become more flexible, allowing individuals to split up their activity bouts into smaller pieces, the recall and therefore subjective assessment of physical activity becomes more difficult. Finally, the diversity of the sample also makes accurate assessment across the 27 sites a challenge. For these reasons, in the DPP, to capture the full extent of the physical activity change and its impact, one will likely need to utilize more precise objective measures of physical activity. Activity monitors, more specifically accelerometers, have been successfully used to objectively document physical activity changes in several intervention efforts. The accelerometer is a small activity monitor, typically worn on the hip and is equipped with an electronic sensor that measures both quantity and intensity of movement, resulting in the collection and storage of daily patterns of physical activity. Since physical activity measured by the accelerometer can be partitioned into activity bouts of varying levels of intensity, both the amount of time spent in total movement and the amount of time spent in specific intensities can be determined. We recently analyzed the physical activity data from a national data set (NHANES) in which we demonstrated that two very different conclusions can be drawn in regards to activity ranking of the ethnic groups, depending on which activity assessment is used. Although data from the activity questionnaire identified Hispanic men and women to be among the least active groups, accelerometer data collected around the same time found both Hispanic men and women to be among the most active. In addition, fasting glucose and insulin was shown to be significantly related to accelerometer activity counts but not to total daily activity as assessed by questionnaire. This demonstrates the need to look at activity in the DPP by accelerometer. Since the changes in activity due to the intervention were likely subtle and reflect lifestyle changes hard to determine by questionnaire, and since the DPP population was very diverse in regards to ethnicity/race, age and geographic location, physical activity levels may be too complex to assess by recall. The purpose of this ancillary study is to objectively assess physical activity levels with the use of an accelerometer in all DPP participants that have chosen to participate in the next cycle of the DPP follow-up study and have not yet converted to diabetes. Even though the impact of the intervention appears to have weakened since the end of the original trial, diabetes incidence and cardiovascular disease and metabolic syndrome risk factors continue to be better in the lifestyle group compare to the other two groups. It is reasonable to hypothesize that differences in physical activity levels among the groups may also exist that could be partially responsible for this better health profile. In addition, after we determine the relationship between accelerometer data and reported physical activity derived from the MAQ activity questionnaire, we would be able to use this information to direct DPP and DPPOS data analyses involving activity levels measured by the MAQ (which has been utilized since baseline of the original DPP clinical trial). This application is contingent on the future funding of the second cycle of the D follow-up. PUBLIC HEALTH RELEVANCE: This application aims to objectively assess physical activity levels with the use of an accelerometer in all DPP participants that have chosen to participate in the next cycle of the DPP follow-up study, and have not yet converted to diabetes. All five clinical trials that utilized a lifestyle intervention approach in the prevention of Type 2 diabetes used a subjective measure to assess physical activity levels in their respective efforts. We will likely never have the opportunity to investigate this question in a randomized clinical trial of diabetes prevention again. Therefore, we have convened a team of investigators to carry out this unique project.