Modeling the epidemiologic transition: Energy expenditure, obesity and diabetes

描述(申请人提供)：世界各地的人口正在经历肥胖症和糖尿病患病率的快速增长。到目前为止，公共卫生对新出现的肥胖流行病的反应几乎完全无效。专业团体和政府发布了预防指南，所有指南都包括关于体力活动水平的建议。然而，目前还不清楚目前增加体力活动的建议是否会扭转与年龄相关的体重增加的趋势。事实上，对于肥胖症流行是否主要或部分是由全社会习惯性体力活动减少造成的问题，几乎没有直接的证据可以证明。我们这个项目的目标是在2500个不同的样本中检查一个人的活动能量消耗(AEE)量是否与肥胖和肥胖/糖尿病相关激素有关，并测试生态假说，即AEE水平的下降是目前许多社会中肥胖增加的重要原因。我们的目标是使用双标记水和/或加速计来客观地测量来自肥胖风险范围内的五个成年人的社区样本中的活动能量消耗。每个地点，即尼日利亚、南非、塞舌尔、牙买加和美国，将招募500名黑人成年人。在所有参与者中，将使用加速计测量AEE，在每个站点75个子集中，也将使用双标记水来测量AEE。双标记水样将被用来确认特定地点与加速度计测量的一致性，并估计人群平均AEE水平。此外，还将评估身体成分、饮食摄入量、空腹血糖、胰岛素、脂联素、瘦素和胃促生长素。将使用双标记水和加速计检查每个人群内部和之间在活动中消耗的卡路里与身体组成、饮食摄入量、葡萄糖、激素和脂肪细胞因子之间的关系。体重将在12个月和24个月时测量，加速度计将在2年后再次评估AEE，以及AEE变化与评估的体重变化之间的关系。我们提议的项目的中心目的是测试AEE或AEE的变化是否可以被确定为人口范围内体重增加的贡献机制，如果是，则量化其重要性。此外，我们试图了解脂肪细胞因子和激素Ghrelin和胰岛素之间的相互关系，以及EE在这五个群体代表的BMI连续体中调节体重的相互关系。与公共健康相关的可预防肥胖的体力活动量指南已具有相当大的公共健康重要性。然而，到目前为止，对体力活动的衡量一直非常粗糙。我们建议进行一项大型国际研究，以确定日常活动水平对体重增加和肥胖风险的影响。

DESCRIPTION (provided by applicant): Populations all over the world are experiencing rapid increases in the prevalence of obesity and diabetes. To date, the public health response to the emerging obesity epidemic has been almost totally ineffective. Professional bodies and governments have issued prevention guidelines, all of which include recommendations on levels of physical activity. However, it is not clear that the current recommendations to increase physical activity would reverse the trend in age-related weight gain. In fact, there is virtually no direct evidence that can be brought to bear on the question of whether the obesity epidemic has resulted primarily or even partially from society-wide declines in habitual physical activity. Our objectives with this project are to examine whether an individuals' amount of activity energy expenditure (AEE) is related to adiposity and adiposity/diabetes-related hormones in a diverse sample of 2500, and to test the ecological hypothesis that a decline in levels of AEE is an important cause of the increases in obesity that are currently taking place in many societies. Our aim is to use doubly labeled water and/or accelerometers to objectively measure activity energy expenditure in community samples from five adult populations across the spectrum of obesity risk. From each site, i.e., Nigeria, South Africa, Seychelles, Jamaica and the US, 500 black adults will be recruited. In all participants, AEE will be measured using accelerometers and in a subset of 75 per site, AEE will also be measured by doubly labeled water. The doubly labeled water sample will be used to confirm site-specific concordance with the accelerometer measurements and to estimate population mean levels of AEE. In addition, body composition, dietary intake, fasting glucose, insulin, adiponectin, leptin and ghrelin will assessed. The relationships between calories expended in activity and body composition, dietary intake, glucose, hormones and adipocytokines, both within and between each population using doubly labeled water and accelerometers will be examined. Weight will be measured at 12 and 24-months and AEE by accelerometer will be assessed again at 2-years of follow-up and associations between change in AEE and change in weight assessed. The central purpose of our proposed project is to test whether AEE or change in AEE can be identified as a contributory mechanism to population- wide weight gain and, if so, to quantify its importance. In addition, we seek to understand the interrelationships between the adipocytokines and the hormones ghrelin and insulin, and EE in the regulation of body weight across the continuum of BMI represented by these five populations. PUBLIC HEALTH RELEVANCE Guidelines for the amount of physical activity that might prevent obesity have taken on considerable public health importance. To date, however, measurement of physical activity has been very crude. We propose to conduct a large international study to define the impact of daily activity level on the risk of weight gain and obesity.