Activity Levels, Myosteatosis and Insulin Resistance/Diabetes Mellitus

摘要 肌脂肪变性是衡量身体组成的指标，它衡量脂肪浸润的存在和程度 进入肌肉隔室以包括肌肉纤维/束周围的沉积，以及进入肌肉隔室以包括肌肉纤维/束周围的沉积。 肌肉组织本身。我们对异位脂肪测量的研究表明， 与血糖调节措施显著相关，独立于内脏和肝脏肥胖。 鉴于葡萄糖调节异常（即代谢综合征和/或糖尿病）之间的密切联系， 和动脉僵硬度，以及左心室结构和功能， 可能是心力衰竭的决定因素。与非西班牙裔白人相比， 西班牙裔/拉丁裔美国人的肥胖率、心脏代谢风险因素和2型糖尿病的发生率显著较高。 糖尿病（T2 DM），导致心力衰竭风险增加。评估不同的风险因素， 在这个迅速增长的人口中，美国国立卫生研究院委托西班牙裔社区健康 研究-拉丁美洲人的研究（HCHS-SOL）。2007年，这项研究开始在四个不同的现场中心招募 招募了16,000多名来自不同背景传统群体的西班牙裔/拉丁裔美国人。HCHS- SOL现已完成两次门诊访视，计划于2019年12月开始入组访视3。在 本次访视时，研究将更新病史，获取空腹血样，用于测量 葡萄糖、胰岛素和血红蛋白A1 C，并将进行2小时葡萄糖耐量试验。此外，该研究 将对返回的参与者进行以下评估：1）客观测量的身体活动 和久坐行为; 2）踝和趾肱指数以及多普勒外周动脉疾病 波形和脉搏容积记录; 3）颈动脉股动脉脉搏波速度的动脉硬度和4） 心脏结构和功能的磁共振成像。可以利用该测量集合 评估从体力活动/久坐行为到身体成分到心脏代谢风险的途径， 动脉硬化对心脏结构和功能的影响。因此，我们建议利用现有的HCHS-SOL 基础设施，并增加新的腹部和大腿中部计算机断层扫描的采集， 获得肌肉脂肪变性和骨骼肌质量以及皮下、内脏和肝脏的测量结果 肥胖症本项目的目标是确定适用性的肌肉脂肪变性，以上述 来自不同背景遗产的西班牙裔/拉丁裔美国人之间的途径，独立于其他 身体成分的测量。

ABSTRACT Myosteatosis is a measure of body composition, which measures the presence and degree of fatty infiltration into the muscle compartment to include deposition around the muscle fibers/bundles, as well as into the muscle tissue itself. Our work on this measure of ectopic fat has shown myosteatosis to be strongly and significantly associated with measures of glucose regulation, independent of visceral and hepatic adiposity. Given the strong links between the glucose dysregulation (i.e. metabolic syndrome and/or diabetes mellitus) and arterial stiffness, as well as left ventricular structure and function, we believe the study of myosteatosis may be particularly relevant as a determinant of heart failure. Compared to non-Hispanic Whites, Hispanic/Latino Americans have significantly higher rates of obesity, cardiometabolic risk factors and type 2 diabetes mellitus (T2DM), resulting in an increased risk for heart failure. To assess the risk factors for different chronic diseases in this burgeoning population, the NIH commissioned the Hispanic Communities Health Study – Study of Latinos (HCHS-SOL). In 2007, this study began recruitment at four different field centers and enrolled over 16,000 Hispanic/Latino Americans from diverse background heritage groups. The HCHS- SOL has now completed two clinic visits and is scheduled to begin enrollment for visit 3 in December 2019. At this visit, the study will update the medical history, obtain fasting blood samples that will be used to measure glucose, insulin and hemoglobin A1C, and will acquire a 2-hour glucose tolerance test. Additionally, the study will conduct the following assessments on the returning participants: 1) objectively measured physical activity and sedentary behavior; 2) peripheral arterial disease by the ankle and toe brachial indices, as well as Doppler waveforms and pulse volume recordings; 3) arterial stiffness by carotid femoral pulse wave velocity and 4) cardiac structure and function by magnetic resonance imaging. This ensemble of measurements can be utilized to assess the pathway from physical activity/sedentary behavior to body composition to cardiometabolic risk to arterial stiffness to cardiac structure and function. Given this, we propose to leverage the existing HCHS-SOL infrastructure and add the acquisition of new computed tomography scans of the abdomen and mid-thigh to obtain measurements of myosteatosis and skeletal muscle mass, as well as subcutaneous, visceral and hepatic adiposity. The goal of this project is to determine the applicability of myosteatosis to the aforementioned pathway among Hispanic/Latino Americans from diverse background heritages, independent of other measures of body composition.