Researchers said the findings reflect the largest brain imaging study to date of cardiovascular stress physiology.
“What we found is that you have to step back and see the whole brain. It’s not like there’s only one part of the brain that you can say, ‘Ah ha! This is the spot that predicts cardiovascular stress reactions,’” said Gianaros, a psychology and psychiatry professor at the University of Pittsburgh.
But some parts of the brain – including portions of the frontal lobe and the amygdala, which governs fear, stress and emotion – contributed more than others within the pattern. Those areas were consistent with similar past research that has been conducted on animals, Gianaros said.
The brain pattern, however, was only able to predict about 9 percent of the differences between people in terms of how their blood pressure increased with stress. “This means that there is a lot left to be learned about what accounts for the effects of stress on blood pressure in the moment,” Gianaros said.
“It’s statistically significant, but how this might be helpful from a patient’s standpoint is far from clear,” said Larry B. Goldstein, M.D., professor and chairman of the University of Kentucky’s neurology department.
Still, the study provides additional insight into the brain’s response to stress and its relationship to risk factors for stroke, heart attacks and other vascular illnesses, he said.
“It is another step in trying to understand what may be an underlying mechanism of this exaggerated blood pressure response.”
Goldstein, who also co-directs the Kentucky Neuroscience Institute, said the study’s findings don’t entirely establish causality. He said people who experience short-term blood pressure increases from stress “may have had this exaggerated response their entire lives, and we know that changes in the body can cause functional alterations in the brain, so it’s a ‘which came first – the chicken or the egg?’”
As an example, he noted that the amputation of a person’s arm or leg will change the way that individual’s brain responds to where the limb used to be.
“It’s the brain responding to peripheral stimuli as opposed to the brain causing a peripheral, secondary response,” he said.
Goldstein noted scientists are “just beginning” to probe the link between brain activity and heart disease and stroke.
Gianaros agreed. He said his study “opens the door” for additional brain imaging research that can help understand the mind’s link to cardiovascular disease risk. It also complements another study released earlier this year that found people with heightened activity in the amygdala may be at higher risk for heart disease and stroke.
“That work and our work point to the possible future integration of brain imaging methods into cardiovascular disease research,” Gianaros said.
“You can envision a future, if this work plays out, where when you go and get your blood work done, and you can image your vessels. Then, you might have brain scans that could add to determining your risk profile, which may help you manage your health.”
