Association of Type 2 Diabetes with Liver and Muscle Adiposity in Black Men

描述(申请人提供)：肥胖和2型糖尿病(T2D)正在以惊人的速度上升，对黑人个人的影响不成比例。在黑人中观察到的高T2D率不能用肥胖或其他既定的风险因素来解释。新的证据表明，脂肪在非脂肪组织(异位脂肪)中的积累，如骨骼肌和肝脏，有助于T2D的发展，而不是肥胖。然而，目前仍不清楚这些脂肪库是否以及如何影响T2D，特别是在高危黑人人群中。仍然有必要更好地了解异位脂肪在T2D中的作用，特别是在黑人人群中。通过职业发展奖(K01-DK083029)，申请人目前正在调查“多巴哥健康研究”中一个特征明确的黑人男性队列中骨骼肌脂肪渗透的流行病学情况。这一队列为研究黑人人口提供了一个独特的机会，这些人口中非非洲人混杂很少，总肥胖率很低，潜在混杂变量的患病率很低，但T2D的患病率很高，特别是在非肥胖男性中。在现有的骨骼肌脂肪渗透研究的基础上，我们建议进行一项试点研究，通过计算机断层扫描(CT)对来自多巴哥健康研究的300名黑人男性(150名患有T2D，150名不患有T2D)增加腹部内脏、皮下、肌肉和肝脏脂肪积累的关键指标，年龄在40-80岁之间。这些新收集的数据将使我们能够检验这样的假设：与没有T2D的黑人男性相比，T2D的黑人男性有更多的脂肪渗透：1)骨骼肌，2)肝脏，与内脏、皮下和全身脂肪无关。这项拟议的先导性研究将对糖尿病高危黑人人群的内脏、肌肉和肝脏脂肪渗透及其与T2D的个体和集体关系提供重要的新见解。它还将产生必要的初步数据，以支持更大规模的异位脂肪渗透到骨骼肌和肝脏的提议。这也将为未来对异位脂肪库随年龄的变化以及这些变化与T2D风险的关系的纵向研究奠定基础。最后，这项拟议的研究将是申请人长期目标的重要一步，即确定异位脂肪的流行病学特征，并调查其在黑人人群T2D中的作用。

DESCRIPTION (provided by applicant): Obesity and type 2 diabetes (T2D) are escalating at alarming rates and disproportionately affect black individuals. High T2D rates observed among blacks cannot be explained by obesity or other established risk factors. Emerging evidence indicates that accumulation of fat in non-adipose tissues (ectopic fat), such as in skeletal muscle and liver, contributes to the development of T2D, independent of obesity. However, it is still unclear if and how these fat depots influence T2D, particularly among high-risk black populations. There remains a need to better understand the role of ectopic fat in T2D especially in black populations. Through the Career Development Award (K01-DK083029) the applicant is currently investigating the epidemiology of skeletal muscle fat infiltration in a well-characterized cohort of black men from the Tobago Health Study. This cohort offers a unique opportunity to study a black population with very little non-African admixture, low levels of total adiposity, low prevalence of potential confounding variables, but with a high prevalence of T2D, especially among non-obese men. Building on this existing study of skeletal muscle fat infiltration, we are proposing a pilot study to add critical measures of abdominal visceral, subcutaneous, muscle, and hepatic fat accumulation by computed tomography (CT) in 300 black men (150 with and 150 without T2D) from the Tobago Health Study, aged 40-80 years. These newly collected data will enable us to test the hypotheses that compared to black men without T2D, black men with T2D have greater fat infiltration 1) in skeletal muscle, and, 2) in liver, independent of visceral, subcutaneous and total body fat. The proposed pilot study will provide important new insight on visceral, muscular, and hepatic fat infiltration and their individual and collective relationship with T2D in a black population at high risk of diabetes. It will also generate essential preliminary data to support a larger scale proposal of ectopic fat infiltration in skeletal muscle and liver. It will also lay the foundation for a future longitudinal study of changes in ectopic fat depots with aging and the relationships of these changes to T2D risk. Finally, the proposed research will be an important step in the applicant's long-term goal to characterize the epidemiology of ectopic fat and to investigate its role in T2D in black populations.