American Heart Association funds UMass Boston professor's study of how blood vessels respond to exercise training

Assistant Professor of Exercise and Health Sciences Huimin Yan has received a two-year, $154,000 American Heart Association Institutional Research Enhancement Award for her research of vascular health, the health of the blood vessels that provide blood to your tissues. Yan says if your blood vessels aren’t healthy, you’re more likely to develop cardiovascular diseases like heart disease, which remains the number one killer of both women and men in the United States.

“I’m looking at how well they can dilate–[how well] they can increase their diameter. The blood vessels, if they are healthy, they will be able to increase their diameter in response to a stimulus, like exercise or stress,” Yan said. “If they are stressed, they will open up to accommodate more blood flow. If a blood vessel is very stiff, they are reflecting a lot more blood back to your heart, so increasing pressure. It’s more likely that you’re going to get hypertension—high blood pressure—and all the related cardiovascular diseases.”

The AIREA grant will fund Yan’s study, “Effect of Exercise Training on Microvascular Function and Sympathetic Reactivity in African American and Caucasian Women.” She is particularly focused on African American women because after diagnostic guidelines were streamlined last year, the American Heart Association reported that 46 percent of African American women had high blood pressure, a major risk factor for stroke and cardiovascular disease.

Blood vessels have two layers. Yan says think of it like a tube: the smooth muscle layer wraps around the endothelium layer, which wraps around the blood. Yan says little is known about how the smooth muscle layer contributes to vascular health in African Americans, which is why her study is focused on how it reacts to exercise training.

One of the goals of the grant is to expose students to research. Yan and the undergraduate and graduate students in the Cardiovascular Exercise Physiology Lab will study a mix of 48 African American and Caucasian women over the course of eight weeks. At the beginning and end of each session, Yan and her team will insert probes into the thigh of their research participants, which will allow a dye–an ethanol marker with a vasoactive reagent that stimulates the smooth muscle layer of the blood vessel–to get into their skin. Yan will be able to see how the blood flows by looking at the concentration of the ethanol left behind—a higher concentration will indicate poorer vascular health. During the bulk of the session, research participants will engage in high-intensity interval training, meaning they will run on the treadmill for three to four minutes, walk for the same amount of time, and then repeat the process.

“For you to spend the same amount of energy, if you’re doing continuous, moderate-intensity exercise, it might take you 45 or 50 minutes. The high intensity interval training takes about 35 to 40 minutes to complete a session,” Yan said.

This is a collaborative project in UMass Boston’s College of Nursing and Health Sciences. Nursing professors Laura Hayman and Ling Shi are helping out with the project, providing support and training students.