Heart Disease Risk Factors In African Americans

肥胖、糖尿病和心脏病的特点是对胰岛素（一种血糖调节激素）的抵抗。非裔美国人，尤其是非裔美国妇女，在这三种情况下遭受的痛苦尤为严重。我们相信性别差异对胰岛素的敏感性？美国黑人女性抑制脂肪分解的能力加速了肥胖、糖尿病和心脏病的发展。本研究的假设是，非洲裔美国男性对作为血糖调节激素的胰岛素和作为脂肪调节激素的胰岛素有抵抗性。相比之下，非洲裔美国女性对作为血糖调节激素的胰岛素有抵抗性，但对作为脂肪调节激素的胰岛素敏感。频繁取样的静脉葡萄糖耐量试验用于测量胰岛素？作为血糖调节激素的作用。不幸的是没有胰岛素指数？S作为脂肪调节激素的作用。因此，我们正致力于通过在频繁取样的葡萄糖耐量试验中获得游离脂肪酸来开发这一指标。我们的目标是能够通过一次测试获得胰岛素两种作用的信息。然而，在频繁采样的静脉葡萄糖耐量试验中，游离脂肪酸对胰岛素敏感性指数的发展涉及复杂的数学模型，需要验证。

Obesity, diabetes and heart disease are characterized by resistance to insulin as a glucoregulatory hormone. African Americans, particularly African American women suffer disproportionately from these three conditions. We believe that sex differences in sensitivity to insulin?s ability to suppress lipolysis contribute to the accelerated development of obesity, diabetes and heart disease in African American women. The hypothesis of this research is that African American men are resistant to insulin as a glucoregulatory hormone and resistant to insulin as a fat regulatory hormone. In contrast, African American women are resistant to insulin as a glucoregulatory hormone but sensitive to insulin as a fat regulatory hormone. The frequently sampled intravenous glucose tolerance test is used to measure insulin?s action as a glucoregulatory hormone. Unfortunately there is no index of insulin?s action as a fat regulatory hormone. Hence we are working on the development of this index by obtaining free fatty acids during the frequently sampled glucose tolerance test. Our goal is be able to do one test to obtain information about both actions of insulin. However, the development of an index of free fatty acid sensitivity to insulin during the frequently sampled intravenous glucose tolerance test involves sophisticated mathematical modeling and will need to be validated. As we work towards developing this index, we have studied sex differences in body fat content and distribution in African Americans. The distribution of body fat has a major impact on the interaction between insulin and body fat. We determined using serial slice computerized tomographic scans and dual X-ray absorptiometry (DXA) that there are sex differences in central body fat distribution in African Americans. These findings will be published in the American Journal of Clinical Nutrition in November 2002. In addition, we have found that beta cell secretion of insulin is impaired in obese glucose intolerant African American women and this work was published in Diabetes Care in 2001. Now we are concentrating on sex differences in the free fatty acid profile during the frequently sampled intravenous glucose tolerance test. It is the intent that this free fatty acid work through the complicated process of modeling will lead to the development of an index of free fatty acid sensitivity to insulin. The development of this index is required so the research hypotheses can be fully tested.