Anger expression and incident stroke: Prospective evidence from the Kuopio Ischemic Heart Disease study

Background and Purpose - High levels of anger are associated with an increased risk of coronary heart disease and hypertension, but little is known about the role of anger in stroke risk. Methods - Anger expression style and risk of incident stroke were examined in 2074 men (mean age, 53.0±5.2 years) from a population-based, longitudinal study of risk factors for ischemic heart disease and related outcomes in eastern Finland. Self- reported style of anger expression was assessed by questionnaire at baseline. Linkage to the FINMONICA stroke and national hospital discharge registers identified 64 first strokes (50 ischemic) through 1996. Average follow-up time was 8.3±0.9 (mean±SD) years. Results - Men who reported the highest level of expressed anger were at twice the risk of stroke (relative hazard, 2.03; 95% CI, 1.05 to 3.94) of men who reported the lowest level of anger, after adjustments for age, resting blood pressure, smoking, alcohol consumption, body mass index, low-density and high-density lipoprotein cholesterol, fibrinogen, socioeconomic status, history of diabetes, and use of antihypertensive medications. Additional analysis showed that these associations were evident only in men with a history of ischemic heart disease (n=481), among whom high levels of outwardly expressed anger (high anger-out) predicted >6-fold increased risk of stroke after risk factor adjustment (relative hazard, 6.87; 95% CI, 1.50 to 31.4). Suppressed anger (anger-in) and controlled anger (anger-control) were not consistently related to stroke risk. Conclusions - This is the first population-based study to show a significant relationship between high levels of expressed anger and incident stroke. Additional research is necessary to explore the mechanisms that underlie this association.