Epidemiology and Genetics of Skeletal Muscle Composition

描述(由申请人提供)： 骨骼肌脂肪积累与全身脂肪无关，可能会导致高血糖和胰岛素抵抗，这两种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，非洲血统的人骨骼肌脂肪可能增加了，与整体身体脂肪无关。然而，关于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。建议应用的目的是描述异位骨骼肌脂肪的流行病学特征。骨骼肌组成的组成部分，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肉间脂肪组织面积，以及骨骼肌密度，将根据现有的定量计算机断层扫描(PQCT)对2200名高加索和非洲裔男性进行测量。其具体目的是：(1)确定骨骼肌脂肪的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；以及(3)检验骨骼肌脂肪随年龄增长而增加的假设。应聘者的目标是：(1)获得骨骼肌成分定量计算机断层成像的新技能；(2)熟练掌握高通量基因分型和DMA序列分析；(3)在进行骨骼肌组成的纵向研究方面获得现场经验。 公共卫生相关性：这些建议目标的实现将极大地提高我们对骨骼肌异位脂肪渗透的流行病学和遗传学及其与糖尿病的关系的理解。

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.