Intramyocellular Lipid: Effects of Race and Diet

肌细胞内脂质：种族和饮食的影响

• 批准号: 7094293
• 负责人: JEANINE B ALBU
• 金额: $ 16.14万
• 依托单位: ST. LUKE'S-ROOSEVELT INST FOR HLTH SCIS
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7094293
• 关键词: African American; caucasian American; cell morphology; clinical research; diabetes risk; dietary lipid; female; glucose tolerance test; human subject; insulin sensitivity /resistance; lipids; magnetic resonance imaging; muscle cells; nutrition related tag; obesity; racial /ethnic difference

DESCRIPTION (provided by applicant): Obesity and its co-morbidities continue to be a growing problem in this country. This is particularly so in African Americans and within this group, in women. Insulin resistance is one co-morbidity associated with obesity and is found to a greater degree in African Americans compared to Caucasians. Intramyocellular Lipids (IMCL- the fat within the myocytes) have been shown to be inversely related to a person's insulin sensitivity (SI). To date, it is not known if racial differences exist in IMCL content or whether it plays a role in the increased insulin resistance in African Americans. We have shown that African American women have increased skeletal muscle volume. The skeletal muscle in African American women may have a greater amount of IMCL, which can explain the greater degree of insulin resistance. We propose to explore aspects of muscle physiology and metabolism to identify if racial differences exist 1) in IMCL content and how this relates to SI; 2) in IMCL content and SI response to manipulations of fat and carbohydrate content of eucaloric diets. To answer these questions we propose to study lean and obese, pre-menopausal, non- diabetic African Americans and Caucasians women using 1) proton magnetic resonance spectroscopy (1H MRS) at baseline and after low and high fat diets, 2) frequently sampled intravenous glucose tolerance test at baseline and 3) hyperinsulinemic-euglycemic clamps after low and high fat diets. These studies will help in the understanding of the mechanisms of increased insulin resistance in the African American population. This is an important public health problem and results arising from the proposed studies may to lead to the development of new approaches for the treatment of this condition and prevention of related illnesses such as type 2 diabetes in African Americans. In this regard these studies may help to identify mechanisms for race-ethnic disparities in the incidence of type 2 diabetes mellitus and therefore respond to the NIH PA number 04-074.

描述（由申请人提供）：肥胖及其合并症继续成为这个国家日益严重的问题。这在非裔美国人和这一群体中的妇女中尤其如此。胰岛素抵抗是一种与肥胖相关的并发症，与高加索人相比，在非洲裔美国人中发现的程度更高。肌细胞内脂质（IMCL-肌细胞内的脂肪）已被证明与一个人的胰岛素敏感性（SI）呈负相关。到目前为止，尚不清楚IMCL含量是否存在种族差异，或者它是否在非洲裔美国人的胰岛素抵抗增加中发挥作用。我们已经表明，非洲裔美国妇女增加了骨骼肌体积。非洲裔美国妇女的骨骼肌可能有更大量的IMCL，这可以解释更大程度的胰岛素抵抗。我们建议探索肌肉生理学和代谢方面，以确定是否存在种族差异1）IMCL含量及其与SI的关系; 2）IMCL含量和SI对正常热量饮食中脂肪和碳水化合物含量的操纵的反应。为了回答这些问题，我们建议使用1）基线时和低脂肪和高脂肪饮食后的质子磁共振波谱（1H MRS），2）基线时频繁采样的静脉内葡萄糖耐量试验和3）低脂肪和高脂肪饮食后的高胰岛素-正常血糖钳夹试验，研究瘦型和肥胖型、绝经前、非糖尿病的非裔美国人和白人女性。这些研究将有助于了解非洲裔美国人胰岛素抵抗增加的机制。这是一个重要的公共卫生问题，拟议研究的结果可能会导致开发治疗这种疾病和预防相关疾病（如非裔美国人的2型糖尿病）的新方法。在这方面，这些研究可能有助于确定2型糖尿病发病率种族-民族差异的机制，因此对NIH PA编号04-074作出回应。