SRU students research blood pressure difference
SLIPPERY ROCK — When freshmen arrive at Slippery Rock University, it's only natural that they have questions. But it was one question asked more than three years ago that has led to an elaborate study at SRU involving 100 participants and more than $10,000 in combined grants.
It started when then-freshman Melanie Clarke, now a senior exercise science major from Pipersville, asked her professor and adviser, Michael Holmstrup, assistant professor of exercise and rehabilitative sciences, a simple question: “Which arm do you use to measure blood pressure?”
Holmstrup explained it's mostly based on convenience, but he had read research that if there is a significant difference in the blood pressure between arms that it could be a marker of health risks.
Clarke continued to ask more questions, especially when she discovered that none of the research to date had considered blood pressure difference during exercise.
“That was our eureka moment when we came up with it,” said Clarke, who came to SRU as an aspiring physical therapist before finding a new ambition: becoming a research professor.
“It completely changed my college experience. Getting involved with research, I started rethinking everything about my education and what I want to do, ” she said.
After conducting a pilot study two years ago, Clarke and Holmstrup are continuing the research this summer as part of a study in the University's Exercise and Rehabilitative Sciences Department.
The pair are measuring the effects of exercise duration on inter-arm systolic blood pressure difference, or ISBPD.
Clarke received a $725 Summer Undergraduate Research Experience grant to examine the response to exercise with people who don't have ISBPD at rest, while Maureen Walsh, a senior exercise science major from Hermitage, received a separate $725 SURE grant to study the response to exercise for people who have ISBPD at rest.
The research also was funded by faculty student research grants, state grants and a technology grant through SRU's College of Health, Environment and Science.
A person is considered to have ISBPD when there is a 10-millimeter difference between arm readings in their systolic blood pressure, which is the amount of pressure in the arteries during contraction of the heart muscle, identified in the top number in a blood pressure reading.
For example, ISBPD exists if a subject's blood pressure is 120 over 80 in the left arm and 130 over 80 in the right arm. Studies have shown this difference may lead to arterial stiffness or other vascular conditions.
“People with this difference have been associated with a higher risk of death from cardiovascular disease,” Holmstrup said. “That's one of the reasons we think it's such a vital sign to look at.”
By studying individuals through different “mechanisms,” such as vital signs at rest or during exercise, fluctuations of ISBPD can be further identified and characterized.
Having additional indicators can lead to additional research, new methods for taking blood pressure, doctors seeking more screening for their patients and, ultimately, early detection of cardiovascular disease.
“During our original study, we saw that the difference grew larger during periods of exercise,” Clarke said. “By conducting all these measurements we are trying to figure out more mechanisms that go into that difference. It's cool because we are branching out into a lot more diverse measurements.”
“We don't yet know what causes ISBPD,” Walsh said, “but there are certain things that it's linked to, like arterial stiffness. There's no better way to investigate it than to test it out.”
The ISBPD study requires extensive time in the lab. The research team plans to test 30 participants this summer and up to 100 participants overall by next spring.
