THE ROLE OF FATTY ACID COMPOSITION IN RACIAL AND ETHNIC DIFFERENCES IN DM2

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 这项研究建议探索一种假设，即非裔美国人患2型糖尿病(DM2)的风险增加在一定程度上与对饮食碳水化合物的代谢反应的差异有关，从而导致易感个体的饱和脂肪酸(SFA)产生增加。 以下假设将肥胖和胰岛素抵抗联系在一起：氧化不良的SFA在对胰岛素敏感的组织中积聚，并削弱胰岛素的作用。SFA可以来自内源性合成，也可以来自饮食。多年来，膳食脂肪和糖耐量受损之间的联系已经为人所知，支持脂肪酸组成在糖耐量中发挥重要作用的长期论点的证据正在积累。 在人类中的流行病学研究已经确定了高脂肪饮食和葡萄糖耐量异常与DM2之间的联系，其中饱和脂肪酸的联系最密切。饮食脂肪似乎不能解释非裔美国人(AA)患糖尿病的更大风险。在大多数研究中，与高加索人(C)相比，AA患者对膳食脂肪的习惯性消耗要么相同，要么减少。碳水化合物摄入在糖尿病风险中的作用是有争议的。膳食纤维和血糖负荷的差异已经被观察到，它们可以预测患DM2的风险。然而，大多数研究了碳水化合物摄入量与糖尿病风险之间的关系的研究得出结论，碳水化合物摄入量的增加(和脂肪的减少)与更高的胰岛素敏感性有关。将高风险再生障碍性贫血患者纳入拟议的研究将增强我们发现种族差异的能力，这可能是他们患糖尿病风险增加的原因。 年龄在18岁到55岁之间的肥胖非裔美国人和高加索女性将被招募参加拟议的研究。种族和民族分类将通过自我报告来确定。受试者将接受以下检查：葡萄糖耐量测试、身体成分测量、皮下脂肪组织的针吸活组织检查和饮食评估。然后将进行新陈代谢研究。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study proposes to explore the hypothesis that the increased risk for diabetes mellitus 2 (DM2) in African Americans is related in part to differences in the metabolic response to dietary carbohydrate, resulting in increased saturated fatty acid (SFA) production in susceptible individuals. The following hypothesis links obesity and insulin resistance: poorly oxidized SFA accumulate within insulin sensitive tissues and impair insulin action. The SFA may be derived from either endogenous synthesis or diet. Links between dietary fat and impaired glucose tolerance have been known for many years and evidence supporting the long-held contention that fatty acid composition plays an important role in glucose tolerance is now accumulating. Epidemiologic studies in man have established the association between a diet high in fat and glucose intolerance and DM2, with saturated fatty acids most closely linked. Dietary fat does not appear to explain the greater risk for diabetes in African American (AA) individuals. In most studies, habitual consumption of dietary fat is either the same or decreased in AA compared to Caucasian (C) individuals. The role of carbohydrate intake in diabetes risk is controversial. Differences in dietary fiber and glycemic load have been observed which predict risk for DM2. However, most but not all studies which have examined the relationship between carbohydrate intake and risk for diabetes conclude that increased carbohydrate (and decreased fat) intake is associated with greater insulin sensitivity. The inclusion of high risk AA individuals in the proposed study will enhance our ability to detect ethnic differences which may explain their increased risk for diabetes mellitus. Obese African American and Caucasian women between the ages of 18 and 55 will be recruited for the proposed studies in equal numbers. Racial and ethnic classification will be defined by self-report. Subjects will undergo the following: a glucose tolerance test, body composition measurements, a needle biopsy of subcutaneous adipose tissue, and a dietary assessment. Metabolic studies will then be performed.