Physical Activity Energy Expenditure & Adolescent Obesit

描述（由申请人提供）： 体力活动消耗的能量（EEAcr）是能量平衡的主要因素。由于随着时间的推移，少量能量过剩（摄入>消耗）是人类体重增加和肥胖的最常见原因，因此测量EEACT的精度对于病因学和干预性研究至关重要。青少年肥胖的风险很高，但他们身体活动（PA）的间歇性和更高的代谢效率使测量EEAcr更具挑战性。现有的加速度测量技术局限于使用粗糙的时间平均信号和过度简化的线性回归算法，这导致EEAcr预测的不准确性。这些技术的先前验证研究通常具有不精确的EE测量，缺乏自发和较低强度的PA，并且样本量不足。在我们提出的研究中，我们将测试这一假设，即与目前用于青少年的现有设备和算法相比，测量来自不同身体部位的详细运动和姿势信号将显著改善我们对EEACr的预测。在具体目标1中，我们将获得与PA同步测量的金标准EE测量，使用当前可用的和定制设计的加速度计设备。我们将使用全房间间接热量计测量24小时内的每分钟EEACr，并使用便携式热量计测量3小时的自由生活时间。专门为这项研究开发的新加速度测量设备将以32个样本/秒、16个通道和10个不同的身体位置同步测量加速度。在具体目标2中，我们建议开发先进的建模方法来转换身体加速度和姿势以预测EEACr-我们将利用强大的人工神经网络和传统的生物统计方法进行建模。在具体目标3中，我们将使用无线设备和双标记水在自由生活的青少年中验证这些EE预测模型。然后，我们将在具体目标4中，定义PA在瘦，超重和肥胖青少年能量平衡中的作用。在这项研究中，我们将应用生物工程设备和分析模型的最新进展，在青少年肥胖的临床调查。这也将指导未来巴勒斯坦权力机构监测器的设计，以准确评估这一弱势群体的能源消耗。此外，我们将利用我们的综合测量来验证和提高现有的加速计预测青少年能量消耗的能力，从而为实地研究人员提供直接的好处。

DESCRIPTION (provided by applicant): The energy expended in physical activity (EEAcr) is a major factor in energy balance. Since small energy excess (intake>expenditure) over time is the most common cause for weight gain and obesity in humans, the precision in measuring EEACT is crucial for etiological and interventional studies. Adolescents are at high risk for obesity, yet the intermittent nature of their physical activity (PA) and their greater metabolic efficiency make measuring EEAcr more challenging. The existing technologies in accelerometry are restricted to using crude time-averaged signals and over-simplified linear regression algorithms, which lead to inaccuracies in EEAcr predictions. Previous validation studies of these technologies often had imprecise measures of EE, lacked spontaneous and lower intensity PA's, and suffered from insufficient sample sizes. In our proposed study, we will test this hypothesis that measurements of detailed motion and postural signals from different body segments will significantly improve our predictions of EEACr as compared to the existing devices and algorithms used currently for adolescents. In Specific Aim 1, we will obtain goldstandard EE measurements synchronously with PA measured using currently-available and custom designed accelerometry devices. We will measure minute-to-minute EEACr using a whole-room indirect calorimeter for a 24-hour period, and a portable calorimeter for a 3-hour free-living period. The new accelerometry device specifically developed for this study will synchronously measure accelerations at 32 samples/second, 16 channels, and 10 different body locations. In Specific Aim 2, we propose to develop advanced modeling approaches to transform body accelerations and postures to predict EEACr- We will utilize powerful Artificial Neural Network and traditional biostatistical approaches for modeling. In Specific Aim 3, we will validate these EE predictive models in free-living adolescents using wireless devices and doubly-labeled water. We will then, in Specific Aim 4, define the role of PA in energy balance for lean, overweight, and obese adolescents. In this study, we will apply the latest advances in bioengineering devices and analytical modeling in clinical investigations of adolescent obesity. This will also guide the design of future PA monitors targeting accurate energy expenditure assessments in this vulnerable population. Moreover, we will utilize our comprehensive measurements to validate and improve the ability of existing accelerometers to predict energy expenditure in adolescents, thus providing directly benefits to the field researchers.