"Anger seems to predict an increased risk of heart disease in initially healthy individuals, and several studies have shown that," said study author Edward Suarez, an associate professor of psychiatry and behavioral sciences at Duke University. However, until now, no one had studied links between anger and inflammation. "This is the first step to link the behavior to this [heart disease] mechanism - one that's garnering a lot of attention" among cardiologists, he said.

The findings appear in the September issue of Psychosomatic Medicine.

In the study, Suarez tested C-reactive protein (CRP) blood levels in 121 healthy, nonsmoking men and women between 18 and 65 years of age. On the same day, he also measured each participant's level of anger, hostility and depression using a series of standard psychological tests. He found that - in the absence of heart disease risk factors such as smoking, obesity and high blood pressure - high levels of these negative emotional states "significantly predicted the blood level of CRP." Those who were prone to anger, hostility or depression had two to three times higher CRP levels than their more mellow peers, the researchers said.

It's not yet clear why this association exists, but studies are under way to shed light on pathways by which anger or depression might encourage inflammation. In one study, Suarez plans to track patients for two years, to see if hotheaded individuals are any more likely to develop elevated CRP levels over time.

Other studies are planned that focus on anger's effect on stress hormones such as noradrenaline and norepinephrine. The latter hormone, in particular, works on a second chemical, nuclear factor-kappa B, "as a kind of 'off/on' switch" for inflammation," Suarez said. "When that switch is turned on, it begins a cascade of events that leads to the promotion or release of inflammatory proteins."

In the meantime, people concerned about their heart health might want to just "cool it" when tempers flare. "It's very important to pay attention to how we can change these behaviors," Suarez said. "I know it isn't easy, though."
"It's difficult to change patterns of behavior that are intrinsic to who we are as individuals, so it's not going to be an overnight thing," he added. "But we can start by saying, 'What gets me angry?' and 'If I get angry, do I start to feel depressed and withdrawn from my social network?' " Also, take a stress break. "If a walk around the park can calm you down, do it," Suarez said.