There are a number of known risk factors for ischemic heart disease that have been very well characterized and studied. These risk factors include high blood pressure, diabetes mellitus, hypercholesterolemia, tobacco smoking, as well as others. More recently, homocysteine and C-reactive protein have been found to be independent risk factors for ischemic heart disease. Other indirect risk factors include lack of exercise, increased stress, obesity, and high saturated fat diet. Medical researchers have now found that observed hostility is associated with increased risk of ischemic heart disease. The results of the research were published online in the Journal of the American College of Cardiology. The investigators performed a large, prospective observational study using 1,749 adults included in the Canadian Nova Scotia Health Survey. The study participants did not have ischemic heart disease at the start of the study and were assessed for hostility using the observed hostility subscale of the Expanded Structured Interview (ESI). The ESI consists of a stressful 12-minute interview that categorized the participants into groups with varying degrees of hostility. During a 10-year follow up period, there were 149 incident ischemic heart disease events. The investigators found that participants with any observed hostility had a greater risk of incident ischemic heart disease that those participants without observed hostility. There was no relationship found between patient reported hostility and ischemic heart disease. After adjusting for cardiovascular risk factors and psychosocial risk factors, the researchers found a 2 fold increased risk for developing incident ischemic heart disease among the study participant that exhibited any degree of observed hostility. The authors wrote, “We found that the presence of any observed hostility was associated with a 2-fold elevated risk of [ischemic heart disease] over 10 years of follow-up, independent of other psychosocial and cardiovascular risk factors. Moreover, our findings suggest that observed hostility does not predict [ischemic heart disease] in a strictly linear fashion; rather, the presence of any hostility confers the majority of the [ischemic heart disease] risk…Confirmatory studies are needed before hostility should be routinely assessed in clinical practice. Although there is evidence to support psychological interventions for the management of hostility in the prevention of future [ischemic heart disease] events, further research is needed on the efficacy of psychological interventions to reduce cardiovascular risk”. The researchers cautioned against assuming any causality as these results were obtained through an observational study. In addition, the mechanism that contributes to this association is unclear but may involved increased catecolamines with higher sympathetic activation. Future studies will focus on elucidating the exact mechanism and further characterizing this observed relationship.
Jonathan D. Newman et al. “Observed Hostility and the Risk of Incident Ischemic Heart Disease: A Prospective Population Study From the 1995 Canadian Nova Scotia Health Survey” J Am Coll Cardiol, 2011; 58:1222-1228, doi:10.1016/j.jacc.2011.04.044