Effects of Body Composition on Vascular Health in Females with a Healthy Body Weight

Overview

Most of the time, body weight is evaluated by looking at the ratio of your weight to your height. This measurement is called body mass index or BMI. However, BMI does not account for what your body is actually made up of (e.g., body fat versus muscle), which may be more important for determining cardiovascular disease risk. The investigators aim to understand vascular health in females with a "healthy" BMI with differing amounts of body fat and muscle mass. We will have participants come to the lab for two different study visits. At one visit, participants will eat a meal high in fat, and at the other visit, participants will undergo a stress task.

The investigators will recruit females with a BMI in the normal (18.5-24.9 kg/m2) from the Ball State University campus and surrounding communities. Each participant will complete a meal trial and a stress trial in a randomized crossover design. At the meal trial, an intravenous catheter will be inserted and baseline blood sample collected. Then vascular measurements (i.e., flow-mediated dilation, pulse wave analysis, pulse wave velocity) will be performed. Each time vascular measurements are performed, the participants will lie in a quiet area to acclimate prior to beginning. Next, participants will consume a high-fat, Western style meal consisting of two Jimmy Deans Breakfast Bowls (sausage; 68 g fat; 880 kcal). Following completion of the meal, blood samples will also be collected 1, 2, 3, and 4 hours after the meal. Vascular measurements will be repeated 2 and 4 hours after the meal. Blood will be collected and stored as serum in order to measure triglycerides, HDL-C, and intestinal permeability (e.g., lipopolysaccharide binding protein) using commercially available ELISAs. At the stress trial, an intravenous catheter will be inserted and baseline blood sample collected. Then vascular measurements (i.e., flow-mediated dilation, pulse wave analysis, pulse wave velocity) will be performed. Each time vascular measurements are performed, the participants will lie in a quiet area to acclimate prior to beginning. Next, participants will undergo the stress task. Then, blood samples will be collected at 10, 60, and 90 minutes after the stress task. Blood will be collected and stored as serum in order to measure epinephrine and inflammatory markers. Vascular measurements will also be repeated 10 and 90 minutes after the stress task.