Development of obesity and metabolic clinical research programs

对于第一个目标，我们继续改进三个大尺寸全室间接量热套件(2008年投入使用)。除了可靠的24小时能量消耗和常量营养素氧化测量外，我们还使用基于小波的去噪算法在测量精度和灵敏度方面进行了相当大的改进。我们还为所有三个套件设计并实施了新的采样、过滤和校准系统，以延长系统寿命、减少测量误差和伪影，并提高操作效率。这些都是我们从2008财年开始要完成的工作。对于自由生活活动评估，我们成功地开发了一种基于便携式加速度计的体力活动监测器的通用台式校准器。有了这个仪器，我们可以全面研究不同尺寸、灵敏度、精度和范围的监视器之间和内部的变异性。 对于第二个目标，我们开发了一种新的临床方案，名为饮食诱导人类肥胖抵抗表型，目的是识别对高热量饮食具有抵抗力的健康瘦身受试者，并研究他们在4周过度喂养(+1000千卡/天超重平衡饮食)下实现能量和体重平衡的独特补偿机制。该方案于2009年8月获得IRB批准，并将于2009年10月开始招募研究参与者。我们还在2009年3月启动了年龄、基因/环境易感性-雷克雅未克研究(AGEs-Reykjavik Study，由NIA赞助)的自由生活体力活动和睡眠评估辅助研究。使用我们在实验室中优化的100个复杂的3D加速计，我们正在收集1000名冰岛老年人一周的活动模式。我们预计，加速计测量的活动特征将补充对这一独特人群中心血管健康、骨骼和肌肉、新陈代谢和认知功能的关注。

For the first aim, we continue to refine the three large-size whole-room indirect calorimetry suites (commissioned in 2008). In addition to robust 24-hr energy expenditure and macronutrient oxidation measurements, we made considerable improvements in measurement accuracy and sensitivity using a wavelet-based de-noising algorithm. We also designed and implemented new sampling, filtering, and calibration systems for all three suites to prolong system longevity, reduce measurement errors and artifacts, and improve operational efficiency. These were the work we laid out to accomplish from FY2008. For free-living activity assessments, we successfully developed a universal bench-top calibrator for portable accelerometry-based physical activity monitors. With this apparatus, we can comprehensively study the variability between and within monitors of various size, sensitivity, accuracy, and ranges. For the second aim, we developed a new clinical protocol titled Diet-Induced-Obesity Resistant Phenotypes in Humans, with the goal of identifying healthy lean subjects who are resistant to hypercaloric diets and studying their unique compensatory mechanisms for achieving energy and weight balance under 4 weeks of overfeeding (+1000 kcal/day over weight balanced diets). This protocol was approved by the IRB in August 2009 and will start accruing study participants in Oct 2009. We also launched a free-living physical activity and sleep assessment ancillary study to the Age, Gene/Environment Susceptibility-Reykjavik Study (AGES-Reykjavik Study, sponsored by NIA) in March 2009. Using 100 sophisticated 3D accelerometers that we optimized in the lab, we are in the process to collect one week of activity patterns in 1000 Icelandic elderly individuals. We expected that the activity characteristics measured by the accelerometers would complement the focus on cardiovascular health, bone and muscle, metabolism, and cognitive function in this unique population.