ECU researcher to link aging, bloodflow

GREENVILLE, NC   (July 19, 2004)   —   Aging and its effects on muscle stress and capillary growth will be the focus of a new study conducted by an East Carolina University physiologist.

Tim Gavin, ECU professor of exercise and sport science and physiology, received a $132,000 grant from the American Heart Association to determine why aging lowers the capacity of skeletal muscle to adapt to stress.

“What we set out to find in this study is, does aging impair the ability to make new capillaries?” Gavin said.

The study involves as many as 50 participants in two different age groups. By sampling leg muscle tissue before and after the study, Gavin hopes to compare between the two groups how capillary growth and overall muscle composition is affected by regular exercise over an eight-week period.

“Exercise presents a signal. It puts stress on the muscle. But what demands signals to occur? Which ones are important?” he said. “So the question is, is the response we see similar or slower in older folks as we see in younger folks?”

The slowed capillary development in older people is significant, Gavin said, because it could affect how muscles adapt to exercise and its ability to deliver oxygen and blood. Increased blood supply to a working muscle is a generally benefit of exercise training, Gavin said. But muscles that have difficulty adapting to the demands of exercise could also hinder the body’s ability to respond to the hardening of arteries.

“Without the ability to make new capillaries, in the legs or core arteries, there can be a hardening, which brings less bloodflow to the tissue,” said Gavin. “Aged muscles may not respond as well and that may be why we see poor prognoses in older individuals. If you look at age, it’s the number one risk factor for cardiovascular disease.”

Because heart and skeletal muscles are structurally similar, the questions Gavin poses through the two-year American Heart Association grant will resonate with how aging and strain could affect the function of heart muscles.