Angry Cynics Risk Heart Disease

Researchers found that those who scored high on this hostility measure were more likely to suffer from exercise- induced ischemia, which can be a precursor to heart disease.

"Aggressive responding may be a behavioral marker that could provide early identification of people who are at risk of heart disease but who don't yet have damage to the heart," said Tilmer Engebretson, co-author of the study and an assistant professor of psychiatry at Ohio State University.

Engebretson is a member of Ohio State's new Institute for Behavioral Medicine Research, and presented this study March 14 at the International Congress of Behavioral Medicine, hosted by the Society of Behavioral Medicine in Washington, D.C.

The study involved 39 middle-aged men and women with no history of heart disease who were undergoing an initial evaluation for coronary problems.

The subjects were given a thallium exercise stress test in which they ran on a treadmill for 6 to 12 minutes. They were then injected with a radioactive dye and images were taken that identifies exercise-induced ischemia, a condition in which the heart cannot get enough oxygen during stress caused by heavy physical exertion. This may suggest the beginning of heart disease.

The subjects were also given paper-and-pencil questionnaires that measured several different aspects of hostility including anger and cynicism. But only aggressive responding was related to ischemia, Engebretson said.

"A lot of studies have examined the connection between hostility and heart disease, but they have produced mixed results," he said. "One problem may have been that these studies lump a lot of aspects of hostility together. Our results suggest that hostility has many different dimensions, and these different dimensions may not all have the same relationship with heart disease."

The results showed that aggressive responding was related to ischemia even after taking into account demographic factors such as age and sex, and health factors such as cigarette, coffee and alcohol use.

It's too early to say for sure why aggressive responding may be linked to heart disease, Engebretson said. But other researchers have shown that hostile people have higher levels of cardiovascular reactivity: in other words, their cardiovascular system shows greater response during times of stress. One hypothesis is that greater reactivity may facilitate and accelerate the atherosclerosis process in coronary arteries.

In a separate but related analysis, Engebretson and his colleagues analyzed which hostility measures best predicted those people in the study who already had myocardial infarcts -- areas of dead tissue in the heart. The researchers found that cynical hostility best predicted those with infarcts. As the name implies, people who score high on the cynical hostility measure show a great deal of cynicism. They agree, for example, with statements that "most people would lie to get ahead" and that "people seek friends who are likely to be useful to them."

Engebretson said more research needs to be done to figure out why different hostility measures were needed to predict those who had existing infarcts and those who had exercise-induced ischemia. But the results of both analyses suggest that not all hostility measures are equal in predicting the risk of heart disease.