IMPACT OF TOTAL BODY FAT IN SEDENTARY HISPANIC ADOLESCENTS WITH NORMAL BMI

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 摘要 国家健康和营养检查调查(NHANES II和III)报告称，儿童超重和肥胖以及肥胖相关疾病的患病率不断上升。这是一个严重的公共卫生问题，需要进行研究，以确定哪些因素会导致肥胖，哪些策略可以用来预防和治疗肥胖及其后果。为解决这些问题而进行的大多数研究都需要对肥胖和瘦的受试者进行比较。为了提供准确的结论，“瘦”和“胖”的定义必须绝对明确。区分瘦身和肥胖者最常用的标准是身体质量指数(BMI)，即体重(公斤)/身高(平方米)。然而，BMI在正常年龄范围内可能会导致不同的群体，包括低和高体脂百分比的受试者，低和高内脏脂肪的受试者，以及低和高肝脏脂肪含量的受试者。所有这些因素都可能混淆结果和结论。 在这个方案中，我们将探索体重指数正常的青少年(低于第85个百分位数，即计划年龄组的25 kg/m2)的体脂百分比(通过DXA测量)、内脏脂肪含量(通过MRI测量)、肝脏脂肪含量(通过MRI测量)和胰岛素敏感性(通过空腹胰岛素和口服葡萄糖耐量试验(OGTT)进行评估)与体脂百分比等于或大于27%的女孩和25%的男孩之间是否存在相关性。这些结果将与我们正在进行的研究(H-11954)的结果进行比较，这些研究包括严格瘦的和肥胖的受试者。来自该拟议方案和正在进行的研究的信息将使我们能够确定体重指数、体脂百分比和脂肪分布对青少年胰岛素敏感性和葡萄糖稳态的影响，这将反过来为肥胖研究中优化筛查方法提供指导。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. ABSTRACT The National Health and Nutrition Examination Surveys, NHANES II and III, report an increasing prevalence of overweight and obesity as well as of obesity related diseases in children. This is a serious public health problem necessitating research to determine which factors lead to obesity and which strategies could be used to prevent and treat obesity and its consequences. Most of the research conducted to address these issues requires comparison between obese and lean subjects. In order to provide accurate conclusions, the definition of "lean" and "obese" must be absolutely clear. The most routinely used criteria to distinguish lean from obese subjects is body mass index (BMI) i.e. weight in kg/ height in m2. However, a BMI within the normal range for age might result in heterogeneous groups, including subjects with both low and high body fat percentage, low and high visceral fat and low and high hepatic fat content. All of these factors might confound results and conclusions. In this protocol we will explore whether there is a correlation between body fat percentage (measured by DXA), visceral adiposity (measured by MRI), hepatic fat content (measured by MRI) and insulin sensitivity (assessed by fasting insulin and an Oral Glucose Tolerance Test (OGTT)) in adolescents with normal BMI (below the 85th percentile i.e. 25 kg/m2 in the planned age group) and body fat percentage equal to or above 27% in girls and 25% in boys. These results will be compared with those of our ongoing study (H-11954) including strictly lean and obese subjects Collectively the information from this proposed protocol and the ongoing study, will enable us to define the influence of BMI, body fat percentage and fat distribution on insulin sensitivity and glucose homeostasis in adolescents, which will in turn provide guidelines for optimizing screening methods in studies on obesity.