Today's prolonged stress may predict tomorrow's heart problems

People whose stress hormones reach high levels are at greater risk for developing high blood pressure or having a heart attack or stroke down the road, according to a new study.

Published Monday in the American Heart Association journal Hypertension, the research analyzed levels of norepinephrine, epinephrine, dopamine and cortisol – hormones that respond to stress levels – in urine samples.

The work builds on previous studies showing cumulative exposure to daily stress, as well as exposure to traumatic stress, can increase cardiovascular disease risk. A growing body of research suggests a connection between mind, heart and body – that a person's psychological health can influence heart and brain health.

And while previous studies focused on the impact of stress levels in people who already had hypertension, there was a lack of research in adults who didn't have high blood pressure, study author Dr. Kosuke Inoue said in a news release.

"It is important to examine the impact of stress on adults in the general population because it provides new information about whether routine measurement of stress hormones needs to be considered to prevent hypertension and (cardiovascular disease) events," said Inoue, an assistant professor of social epidemiology at Kyoto University in Japan who also is affiliated with the department of epidemiology at the University of California, Los Angeles Fielding School of Public Health.

He and his team measured the four stress hormones in 412 Hispanic, Black and white adults from New York and Los Angeles. Three of the hormones – norepinephrine, epinephrine and dopamine – are known as catecholamines and help regulate involuntary body functions such as heart rate, blood pressure and breathing. The fourth, cortisol, is a steroid hormone released during stress.

"Although all of these hormones are produced in the adrenal gland, they have different roles and mechanisms to influence the cardiovascular system, so it is important to study their relationship with hypertension and cardiovascular events individually," Inoue said.

Participants, who had normal blood pressure and were 48 to 87 years old at the start of the study, were followed for more than a decade. After about seven years, every time a person's levels of all four stress hormones doubled, the risk for developing high blood pressure rose 21% to 31%.

After 11 years of follow-up, each time cortisol levels doubled, researchers found a 90% increased risk in cardiovascular events such as chest pain, the need for an artery-opening procedure, a heart attack or a stroke. No connection was found between the other three stress hormones and cardiovascular problems during the longer follow-up.

"The next key research question is whether and in which populations increased testing of stress hormones could be helpful," Inoue said. "Currently, these hormones are measured only when hypertension with an underlying cause or other related diseases are suspected. However, if additional screening could help prevent hypertension and cardiovascular events, we may want to measure these hormone levels more frequently."

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