Metabolic Research Core: energy balance and obesity studies

代谢研究核心：能量平衡和肥胖研究

• 批准号: 8149685
• 负责人: Kong Chen
• 金额: $ 39.87万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8149685
• 关键词: Metabolic; Obesity; Research; energy balance

We discovered a systemic problem with our whole-room indirect calorimetry suites (commissioned in August 2008). During the winter of this year, we detected significant artifacts in all three chambers that lead to unstable performances. After rigorous testing, we traced the issue to extreme low relative humidity of the building supply air as it introduced high differential partial pressure (of water vapor) between the chamber and reference air. We engaged with building engineers and officials from Office of Facility Management, Office of Research Facilities, and the Clinical Center. We confirmed our findings of low humidity and are currently working towards a three-prong approach to rectify the issue: (1) tighter humidity control of the Metabolic Unit supply air to provide a more stable environment by the OFM, (2) use the Clinical Center medical air as supply air for the calorimetry suites, and (3) revamp the calorimetry air sample and condition equipment, calibration gas mixing, and analyzer upgrades. With the strong support from NIDDK leadership and Clinical Center, we are making steady progress in these critical renovations. Research findings: In 25 young and normal-weight healthy volunteers, Dr. Celi and his colleagues have found that a 12-hr environmental temperature change (from 24 to 19 C) produced a 6% increase in resting energy expenditure as measured by our metabolic suites. This increase was likely a result of the activation of brown adipose tissue via the sympathetic nervous system, but less of an influence by the thyroid hormone. While expanded studies are underway to study obese and elderly individuals and to further quantify the brown adipose tissue activity by FDG-PET imaging, we have published the current findings. We are continuing our intra/extramural collaboration project with Dr. Naji Abumrad from Vanderbilt University to study the changes in energy metabolism, protein turnover, insulin action, and associated weight loss before and after Roux-en-Y gastric bypass surgery. The Vanderbilt study has stopped new recruitment but we following up the patients that we studied on whole-body metabolism during rapid weight loss. We have published a manuscript in Obesity recently. Services rendered (FY09 activities): 24-hr energy expenditure by whole-room respiratory chambers (299), resting energy expenditure by metabolic carts (364), exercise and physical function testing (144), body composition (581 Bod Pod measurements, 388 iDXA scans), objective physical activity monitoring (588), food-array experimental dinning (146), muscle biopsies (28), subcutaneous fat biopsies (79), and Health and Physical Exams (75). All activities are significantly up from FY08, despite of the humidity issue with the metabolic chambers.

我们发现我们的整个房间间接测热套件（2008年8月投入使用）存在系统性问题。在今年冬天，我们在所有三个腔室中都检测到了导致性能不稳定的显著伪影。经过严格的测试，我们将问题追溯到建筑物供气的相对湿度极低，因为它在室内和参考空气之间引入了高的分压差（水蒸气）。我们与建筑工程师和设施管理办公室、研究设施办公室和临床中心的官员进行了接触。我们确认了我们的低湿度调查结果，目前正在努力采取三管齐下的方法来纠正这个问题：（1）通过OFM对代谢单元供气进行更严格的湿度控制，以提供更稳定的环境，（2）使用临床中心医用空气作为量热室的供气，以及（3）改造量热空气样本和条件设备，校准气体混合，和分析仪升级。在NIDDK领导层和临床中心的大力支持下，我们正在这些关键的翻新工作中取得稳步进展。 研究结果：Celi博士和他的同事们在25名年轻和正常体重的健康志愿者中发现，12小时的环境温度变化（从24到19 ℃）使静息能量消耗增加6%，这是由我们的代谢套件测量的。这种增加可能是通过交感神经系统激活棕色脂肪组织的结果，但受甲状腺激素的影响较小。虽然正在进行扩展研究，以研究肥胖和老年人，并通过FDG-PET成像进一步量化棕色脂肪组织的活动，我们已经发表了目前的研究结果。 我们正在继续与范德比尔特大学的Naji Abumrad博士进行校内/校外合作项目，研究Roux-en-Y胃旁路手术前后能量代谢、蛋白质周转、胰岛素作用和相关体重减轻的变化。范德比尔特的研究已经停止招募新的研究对象，但是我们对那些在快速减肥过程中进行全身代谢研究的患者进行了随访。我们最近在《肥胖》杂志上发表了一篇手稿。 提供服务（2009财年活动）：全室呼吸室24小时能量消耗（299），代谢推车静息能量消耗（364），运动和身体功能测试（144），身体成分（581次Bod Pod测量，388次iDXA扫描），客观身体活动监测（588次），食物阵列实验晚餐（146次），肌肉活检（28次），皮下脂肪活检（79），健康和体检（75）。尽管代谢室存在湿度问题，但所有活动均比2008财年显著增加。