Abdominal Body Composition, Inflammation and Cardiovascular Diseaase

描述(申请人提供)：肥胖是一个新兴的公共卫生问题，这种情况的比率因年龄、性别和种族而异。腹部脂肪的分布也因种族而异。例如，与非西班牙裔白人相比，非裔美国人的内脏脂肪水平较低，而体重指数和腰围较高。这些差异对于解释腹部身体成分、炎症和心血管疾病事件之间的种族特定关系具有重要意义。值得注意的是，体重指数的标准人体测量方法不能区分构成体重的不同组织类型或不同比例。因此，我们建议评估基线年龄在45-84岁的1,970名男性和女性的腹部容积身体成分，他们正在接受计算机断层扫描(CT)腹主动脉钙(AAC)的动脉粥样硬化(MESA)多种族研究的辅助研究。MESA有一个关于每个参与者的生物标记物和亚临床心血管疾病测量的广泛数据库，他们也被追踪事件心血管事件。我们建议从CT扫描中测量和计算腹体成分的5个离散体积指标：皮下脂肪、内脏脂肪、肌内脂肪、内脏脂肪与内脏腔的比率和瘦肌肉与内脏脂肪的比率。我们还将对炎症的几个相关指标进行分析。利用这一数据和现有的MESA数据，我们计划检验这一假设，即腹部身体成分的测量将与发生的冠状动脉和心血管疾病事件显著相关，独立于传统的心血管疾病危险因素、炎症和亚临床心血管疾病。我们将根据年龄、性别和种族来确定这种联系是否存在差异，并确定选定的饮食和体力活动变量的影响。此外，扩大的MESA数据集的丰富性将使我们有机会辨别身体成分的5种不同CT测量方法是否比传统的BMI和WC测量方法具有明显的优势。这将为干预措施的潜在治疗靶点提供重要的生理学和临床相关信息，旨在通过改变包括骨骼肌在内的不同部位的脂肪组成来降低心血管疾病风险。我们不知道有任何其他以人口为基础的研究像这样全面地研究所述的目标。

DESCRIPTION (provided by applicant): Obesity is a burgeoning public health problem with the rates of this condition differing by age, sex and ethnicity. The distribution of abdominal fat also differs by ethnic group. For example, compared to non-Hispanic Whites, African Americans have lower levels of visceral fat while having higher body mass index and waist circumference. These differences have important implications for the interpretation of the ethnic-specific relationships between abdominal body composition, inflammation and incident cardiovascular disease events. Notably, the standard anthropometric measure of body mass index cannot discriminate between different kinds or ratios of tissue types comprising the body weight. Accordingly, we propose to evaluate volumetric abdominal body composition in 1,970 men and women aged 45-84 at baseline, who are being studied in an ancillary study to the Multi-Ethnic Study of Atherosclerosis (MESA) for abdominal aortic calcium (AAC) by computed tomography (CT). The MESA has an extensive database of biomarkers and subclinical CVD measures on each participant, who are also being followed for incident CVD events. We propose to measure and calculate 5 discrete volumetric measures of abdominal body composition from the CT scans: subcutaneous fat, visceral fat, intramuscular fat, the visceral fat to visceral cavity ratio and the lean muscle to visceral fat ratio. We will also perform assays for several pertinent measures of inflammation. Using this and existing MESA data, we plan to test the hypothesis that measures of abdominal body composition will be significantly associated with incident coronary and cardiovascular disease events, independent of traditional CVD risk factors, inflammation and subclinical CVD. We will determine if there are differences in this association by age, sex and ethnicity and will also ascertain the influence of selected dietary and physical activity variables. Furthermore, the richness of the augmented MESA dataset will afford the opportunity to discern whether there is clear advantage afforded by the 5 distinct CT measures of body composition over the traditional measures of BMI and WC. This will provide important physiologic and clinically relevant information on the potential therapeutic targets for interventions aimed at reducing CVD risk by altering the composition of fat in different compartments, including skeletal muscle. We are unaware of any other population-based study that is as comprehensive as this to study the stated aims.