Effect of Diet on Vascular Disease in Pre-Menopausal Women

African Americans have a higher prevalence of vascular disease than Caucasians. Vascular disease can lead to heart attacks, strokes and even amputations. Insulin, a hormone which is secreted by the pancreas, affects not only glucose and fat metabolism but also vascular disease. Impairment of insulin s ability to remove glucose from the circulation is known as insulin resistance. To overcome insulin resistance the pancreas secretes extra insulin. These high levels of insulin affect circulating triglyceride levels by both promoting production of triglyceride by the liver and interfering with clearance of triglyceride from the circulation. Triglyceride in turn contributes to the development of vascular disease by causing both inflammation and hypercoagulability. Surprisingly African Americans are more insulin resistant and have a higher rate of vascular disease than Caucasians but have lower triglyceride levels. Because of the high rate of vascular diseases in African Americans, our aim is to determine if the adverse effects of triglyceride occur at a lower level in African Americans than Caucasians. To achieve this goal we will determine if there are differences in the effect of a meal on triglyceride levels and vascular function in a representative cohort of African American and Caucasian women. For this study we will enroll 96 women (48 African American and 48 Caucasian women). We are recruiting women because ethnic differences in triglyceride are even greater in women than men. We are enrolling women between the ages of 18 and 65 years. The study will involve several outpatient visits to the NIH Clinical Center. The first visit will be a screening to determine eligibility. At the second visit a test to measure insulin resistance will be performed. This test is called a frequently sampled intravenous glucose tolerance test. The third visit will be for the test meal. Before and at 2, 4 and 6 hours after the meal, blood will be drawn and vascular function measured.