Sutin and colleagues found that agreeableness scores were significantly associated with initial arterial thickness and with changes during the three-year follow-up. The specific traits of straightforwardness and compliance were most strongly associated with the arterial thickness.
On the other hand, when the researchers looked at the risk of being in the top quartile of arterial thickness, high agreeableness scores did not appear to have a protective effect in participants from either gender.
Dr. Redford Williams of Duke University in Durham, N.C., who was not involved with the study, commented that the findings highlight the largely unappreciated role of psychological factors in cardiovascular disease risk.
"Psychological and social factors are just as strong, as this study clearly documented, in putting people at higher risk of heart disease and other health problems," he said in an interview.
Williams noted the degree of cardiovascular event risk suggested by the study findings as associated with antagonistic personality traits was comparable to that of high LDL cholesterol, hypertension, or smoking.
"We really need, in this country and around the world, to begin to focus on ameliorating the effect of psychosocial risk factors just as we are on the physical risk factors," he said.
He suggested that patients with these traits should consider anger-management training, though he cautioned that cardiovascular benefits remain uncertain.
"I think we need the clinical trials -- carefully done, randomized clinical trials -- to make sure the kinds of anger-management training we might employ really are not only reducing anger, but reducing the rate of disease development. That's the gold standard we have to hit," Williams said.
But he adds, "It's certainly not going to hurt you to learn how to manage anger better."