Men who tend to be hostile and have frequent, intense feelings of anger and depression may be at higher risk for immune system dysfunction and cardiovascular conditions including coronary heart disease, hypertension, and type 2 diabetes, according to an article in the August issue of Brain, behavior, and Immunity.

Steven Boyle, PhD, of Duke University Medical Center and colleagues studied 313 male Vietnam veterans who were part of a larger 20-year study on the effects of Agent Orange.

For the study, participants underwent a standard psychological test used to assess hostility, depression and anger.

The men had a series of blood tests taken on three occasions over 10 years (1992 to 2002). Researchers measured the two immune system proteins and inflammatory markers C3 and C4. Changes in C3 and C4 levels are associated with a number of diseases, including diabetes.

Men whose psychological screening showed the highest level of hostility, depressive symptoms and anger had a 7.1 percent increase in their C3 levels, while men with low levels of these personality attributes showed no change over the 10-year study period.

The researchers factored in other risk factors for higher C3 levels such as smoking, age, race, alcohol use and body mass index. They also could find no known influence of Agent Orange exposure on the increased C3 levels.

“We showed positive associations between psychological attributes and 10-year changes in C3 among initially healthy middle-aged males,” the researchers wrote. Neither group showed significant increases in C4 levels.

“Hostile, depressed and angry people see the world around them in a different way, and sometimes they see it as them against the world,” said study co-author Edward Suarez, PhD. “That kind of lifestyle often leads to greater stress and possibly changes in the way the body functions that could lead to disease.”