Epidemiology and Genetics of Skeletal Muscle Composition

描述（由申请人提供）： 骨骼肌脂肪堆积，独立于全身脂肪，可能导致高血糖症和胰岛素抵抗，这些疾病在非洲裔人群中非常普遍。一些主要在女性或小样本中进行的研究也表明，与高加索人相比，非洲血统的个体可能增加了骨骼肌脂肪，与整体体脂无关。然而，骨骼肌组成的流行病学及其与代谢紊乱的关系，特别是在非洲血统的人群中，仍有许多需要了解的。拟议的应用程序的目标是表征异位骨骼肌脂肪的流行病学。将通过现有的定量计算机断层扫描（pQCT）扫描测量2200名白人和非洲裔男性的骨骼肌组成成分，包括肌肉横截面积、总脂肪组织面积、皮下脂肪组织面积和肌间脂肪组织面积以及骨骼肌密度。具体目标是：（1）确定骨骼肌脂肪分布是否存在种族差异;（2）评估脂肪酸结合蛋白4基因的遗传变异是否有助于非洲和高加索血统男性的骨骼肌组成;（3）检验骨骼肌脂肪随年龄增长而增加的假设。候选人的目标是：（1）获得骨骼肌组成定量计算机断层扫描成像的新技能;（2）精通高通量基因分型和DMA序列分析;（3）获得进行骨骼肌组成纵向研究的现场经验。 公共卫生相关性：这些目标的实现将大大提高我们对骨骼肌异位脂肪浸润的流行病学和遗传学及其与糖尿病关系的理解。

DESCRIPTION (provided by applicant): Skeletal muscle fat accumulation, independent of overall body fat, may contribute to hyperglycemia and insulin resistance, disorders that are highly prevalent in populations of African origin. A few studies conducted mainly in women or in small samples, also suggest that individuals of African ancestry may have increased skeletal muscle fat compared to Caucasians, independent of overall body fat. However, much remains to be learned about the epidemiology of skeletal muscle composition and its relationship to metabolic disorders, particularly in populations of African ancestry. The goal of the proposed application is to characterize the epidemiology of ectopic skeletal muscle fat. Components of skeletal muscle composition including muscle cross-sectional area, total, subcutaneous, and intermuscular adipose tissue areas, and skeletal muscle density will be measured from existing quantitative computed tomography (pQCT) scans in 2200 men of Caucasian and African descent. The specific aims are to: (1) determine if there are ethnic differences in the distribution of skeletal muscle fat; (2) evaluate if genetic variations in the fatty-acid binding protein 4 gene contribute to skeletal muscle composition in men of African and Caucasian ancestry; and (3) to test the hypothesis that skeletal muscle fat increases with advancing age. The candidate's goals are to: (1) acquire new skills in quantitative computed tomography imaging of skeletal muscle composition; (2) become proficient in high-throughput genotyping and DMA sequence analysis; (3) obtain field experience in conducting longitudinal studies of skeletal muscle composition. PUBLIC HEALTH RELEVANCE: The accomplishment of the proposed aims will greatly enhance our understanding of the epidemiology and genetics of ectopic fat infiltration in skeletal muscle and its relationship to diabetes.