Race/Ethnic Specific Association Between Anthropometry, Liver Fat and Incident Type 2 Diabetes: Evidence from The Multi-Ethnic Study of Atherosclerosis

项目摘要 在美国，七分之一的成年人患有2型糖尿病（T2 D），如果目前的趋势继续下去，预计T2 D 到2050年，感染率可能高达三分之一。此外，这种健康的负担 这种情况不成比例地影响美国少数民族;而目前的T2 D患病率为11%， 在白人中，黑人和西班牙裔中的比例为22%。肥胖是T2 D的一个强风险因素，这种影响的一部分是 假设是由于非酒精性脂肪肝（NAFLD）的发展。然而，程度 肥胖通过肝脏脂肪对T2 D的发展起作用是未知的。当前种族/族裔特异性 制定了使用人体测量学（如体重指数）识别肥胖症的指南， 白色和亚洲人群。然而，缺乏针对美国黑人和西班牙裔的种族/民族特定指南 这主要是因为证据仅限于横断面研究的结果。我们提出 为了检验肥胖-T2 D关系在不同的临床相关性下将是明显的假设， 与白人相比，黑人和西班牙裔的人体测量值。此外，我们建议估计 肝脏脂肪对人体测量学和T2 D之间关联的介导作用。 拟议的调查利用了来自多民族动脉粥样硬化研究的丰富纵向数据 （梅萨），一项对6，814名白色、黑人、西班牙裔和中国成年人进行的队列研究， 在2000年基线数据将使用几种人体测量方法来识别肥胖，并确定肥胖的程度。 脂肪肝的诊断方法。在随后的四个研究中， 后续检查访问。比例风险回归将用于估计种族特异性关联 人体测量与T2 D事件之间的关系;将使用多变量线性回归分析评价人种- 人体测量和基线肝脏脂肪之间的特定关联;我们将使用逆 概率加权比例风险回归估计肥胖对T2 D的介导作用， 肝脏脂肪 先前关于黑人和西班牙裔人群中人体测量指标与T2 D相关性的研究是 受其横断面研究设计的限制，或缺乏多种族群体来评价T2 D的异质性 种族/民族之间的风险。相比之下，我们的建议是创新的，通过在一个大的， 多种族/族裔群体的充分表征的前瞻性队列。提案的意义体现在 在未充分研究的黑人和西班牙裔人群中，T2 D的患病率要高得多。 跨学科的培训环境，肥胖和T2 D流行病学领域的专家指导， 健康差异和流行病学方法，将为申请人提供一个平台，他可以加强 他的培训目标，并有助于慢性病领域作为未来的独立研究人员在T2 D 预防流行病学。 !

Project Summary In the US, one in seven adults has type 2 diabetes (T2D), and if current trends continue, it is projected that T2D prevalence can rise to as high as one in three adults by the year 2050. Furthermore, the burden of this health condition disproportionately affects US ethnic minorities; whereas the current T2D prevalence is 11% among Whites, it is 22% among Blacks and Hispanics. Obesity is a strong risk factor for T2D and part of this effect is hypothesized to be due to the development of non-alcoholic fatty liver disease (NAFLD). However, the extent to which adiposity acts on the development of T2D through liver fat is unknown. Current race/ethnic-specific guidelines for the identification of obesity using body anthropometry (e.g. body mass index) are established for White and Asian populations. However, race/ethnic-specific guidelines are lacking for US Black and Hispanic populations, primarily because evidence has been limited to findings from cross-sectional studies. We propose to test the hypothesis that the obesity-T2D relationship will be evident at different clinically relevant anthropometric values among Blacks and Hispanics compared to Whites. In addition, we propose to estimate the mediating effect of liver fat on the association between anthropometry and T2D. The proposed investigation leverages the rich longitudinal data from the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study of 6,814 White, Black, Hispanic and Chinese adults that have been followed since the year 2000. Baseline data will identify obesity using several anthropometric measures, and to identify the degree of fatty liver using Computed Tomography scans. Individuals were followed for incident T2D in four subsequent follow-up exam visits. Proportional hazards regression will be used to estimate race-specific associations between anthropometry and incident T2D; multivariable linear regression analyses will be used to evaluate race- specific associations between anthropometric measurements and liver fat at baseline; and we will use inverse probability weighted proportional hazards regression to estimate the mediating effect of obesity on T2D through liver fat. Prior studies of the association of anthropometric measures and T2D in Black and Hispanic populations were limited by their cross-sectional study design, or lacked multi-ethnic groups to evaluate heterogeneity of the T2D risk between race/ethnic groups. In contrast, our proposal is innovative by evaluating this association in a large, well-characterized prospective cohort of multi-racial/ethnic groups. The significance of the proposal is reflected in the much higher prevalence of T2D in the understudied Black and Hispanic populations. The interdisciplinary training environment, expert mentorship in the fields of obesity and T2D epidemiology, health disparities and epidemiologic methods, will provide the applicant a platform in which he can strengthen his training goals and contribute to the field of chronic disease as a future independent researcher in T2D prevention epidemiology. !