Study shows link between minor stress, early signs of coronary artery disease Our everyday reactions are found to have effect

December 16, 1997|By Diana K. Sugg | Diana K. Sugg,SUN STAFF

In a reminder that heart disease starts developing years before symptoms show, Johns Hopkins researchers have uncovered a connection between apparently healthy people who are stressed and early signs of trouble in their hearts.

The finding, published today in the journal Circulation, focused on adults with siblings who suffered from heart disease before age 60. But experts say its relevance is much broader, for it helps explain the role of stress in the development of coronary artery disease.

"This suggests that ongoing, more minor stress, the way we react to our everyday environment on a regular basis, can ultimately have an effect," said Dr. Peter Kaufman of the Behavioral Medicine Research Group at the National Heart, Lung and Blood Institute in Bethesda.

Added Dr. Michael Gold, director of cardiac electrophysiology at the University of Maryland Medical Center: "We can't wait until patients develop angina or have heart attacks, since we now know that the changes in their arteries are occurring years earlier."

Many people are familiar with the link between stress and heart disease, one of the country's leading killers. But those studies have concentrated on people who are already sick. The new study is the first ever to look at people before they've suffered heart trouble, said the report's principal investigator, Dr. Diane Becker, director of the Center for Health Promotion at the Johns Hopkins University School of Medicine.

Becker and her colleagues didn't have trouble interpreting the data, because the findings were dramatic. They found that siblings who had ischemia -- decreased blood flow -- to the heart during a treadmill test were 21 times more likely to get stressed by the computer test.

Of the 152 brothers and sisters ages 30 to 59 in the experiment, roughly 10 percent were labeled "hot responders" during the mental test and then found to have hidden heart disease during an exercise test. This group's blood pressure increased from 8 to 23 millimeters in the computer test, compared with the normal group, whose blood pressure increased by only 8 to 14 millimeters.

Interestingly, the brothers and sisters often believed that they felt one way, only to discover, through these biological measurements, that their body felt another way. Many of the test-takers were sweating. Others were fiercely holding onto a computer button. Some described themselves as frustrated and angry, while their blood pressure and pulse rates showed calmness.

This is a key difficulty with stress -- and with heart disease. Often, you can't tell you have it.

"We're actually trying to look at more biological mechanisms," said Brian G. Kral, the study's lead author and a Hopkins graduate student. "We're trying to identify possible mechanisms of why."

Their hypothesis about what is happening in the body is straightforward. Each day, when someone is stressed, his blood pressure goes up and down, and that causes injury to blood vessel walls, making the walls constrict and function abnormally. Over time, Becker said researchers believe, this leads to heart disease.

The recent experiment is part of a larger, 15-year-long Hopkins study of 850 people from all over the country. Researchers are looking at the siblings of people who have premature heart disease, meaning between the ages of 30 and 59, trying to figure out why some will develop heart problems and others won't.

Stress has implications for other aspects of a person's health.

At Ohio State University, Dr. Ronald Glaser, an immunologist, and his wife, Janice Kiecolt-Glaser, a psychologist, found that the stressed caregivers for Alzheimer's disease patients took nine days longer to heal from a small biopsy than another group of people matched in every other way.

Another recent study, from the University of Michigan School of Medicine, found that men who get angry are almost twice as likely to have a stroke as those who are better at diffusing their anger. But experts said this doesn't mean people should suppress anger -- something that has been linked to high blood pressure.

Physicians said the entire field needs to be explored more.

"This is one of the weaknesses in our knowledge base," said Kaufman, of the NIH. "Even if we were able to detect when stress is having a physiological effect, we don't have a systematic way at this time to counteract it."

For the Hopkins' group, the next question for study will be whether the stressed-out siblings go on to have heart attacks.

Becker's group plans to continue monitoring them during the coming years. They've made treatment recommendations to the participants who showed heart disease, as well as their physicians. But researchers have seen that these people don't get into treatment.

"They are great deniers," Becker said. "They'll come up with these explanations. My father had the heart problem, but I look like my mother."

Pub Date: 12/16/97

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