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.

我们发现我们的全室间接量热套件（2008 年 8 月投入使用）存在系统性问题。今年冬天，我们在所有三个腔室中检测到明显的伪影，导致性能不稳定。经过严格的测试，我们将问题追溯到建筑物供应空气的相对湿度极低，因为它在腔室和参考空气之间引入了高分压（水蒸气）。我们与建筑工程师以及设施管理办公室、研究设施办公室和临床中心的官员进行了接触。我们证实了低湿度的发现，目前正在努力采取三管齐下的方法来纠正该问题：(1) 对代谢单元供应空气进行更严格的湿度控制，以通过 OFM 提供更稳定的环境，(2) 使用临床中心医用空气作为量热套件的供应空气，(3) 改造量热空气样品和调节设备、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，我们在这些关键改造方面正在稳步取得进展。 研究结果：在 25 名体重正常的年轻健康志愿者中，Celi 博士和他的同事发现，12 小时的环境温度变化（从 24 摄氏度到 19 摄氏度）会使静息能量消耗增加 6%（根据我们的新陈代谢测量）套房。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，但甲状腺激素的影响较小。虽然正在进行扩大研究来研究肥胖和老年人，并通过 FDG-PET 成像进一步量化棕色脂肪组织的活性，但我们已经发表了当前的研究结果。 我们正在继续与范德比尔特大学的 Naji Abumrad 博士开展校内/校外合作项目，研究 Roux-en-Y 胃绕道手术前后能量代谢、蛋白质周转、胰岛素作用以及相关体重减轻的变化。范德比尔特大学的研究已经停止了新的招募，但我们对快速减肥过程中全身代谢研究的患者进行了追踪。我们最近在《肥胖》杂志上发表了一篇手稿。 提供的服务（2009 财年活动）：整个房间呼吸室的 24 小时能量消耗 (299)、代谢车的静息能量消耗 (364)、运动和身体功能测试 (144)、身体成分（581 Bod Pod 测量、388 iDXA 扫描）、客观身体活动监测（588）、食物阵列实验用餐（146）、肌肉活检（28）、皮下脂肪活检(79) 和健康与体检 (75)。尽管代谢室存在湿度问题，但所有活动均较 2008 财年显着增加。