"People who reported high levels of anger and anxiety after performing a laboratory-based stress task showed greater increases in a marker of inflammation, than those who remained relatively calm," said Dr Judith Carroll, who conducted the study at the University of Pittsburgh. "This could help explain why some people with high levels of stress experience chronic health problems," she added.
The investigators asked healthy middle-aged individuals to complete a speech in the laboratory in front of video camera and a panel of judges. During the speech, they monitored the physical responses to the task and then afterwards asked them about the emotions that they had experienced.
"Most people show increases in heart rate and blood pressure when they complete a stressful task," explained Dr Carroll, "but some also show increases in a circulating marker of inflammation known as interleukin-6. Our study shows that the people who have the biggest increases in this marker are the ones who show the greatest emotional responses to the task."
"Our results raise the possibility that individuals who become angry or anxious when confronting relatively minor challenges in their lives are prone to increases in inflammation," explained lead author Dr Anna Marsland, an Associate Professor of Psychology and Nursing at the University of Pittsburgh. "Over time, this may render these emotionally-reactive individuals more vulnerable to inflammatory diseases, such as cardiovascular disease," she said.
The research, funded by the National Institute of Nursing Research, is part of a burgeoning field, known as Psychoneuroimmunology, which investigates the interactions between psychological processes and health. "This paper addresses a key question in psychoneuroimmunology -- what explains individual differences in the inflammatory response to stress," said Dr Margaret Kemeny, a Professor at the University of California, San Francisco. "These findings suggest that the specific nature of the emotional response to the task may be a key predictive factor and set the stage for future work defining these pathways and addressing their clinical implications," she added.