Personality type and neural circulatory control.

Psychosocial factors, including type A personality, anger, hostility, and anxiety, have been implicated in the pathogenesis of cardiovascular disease. Abnormal sympathetic responses to stress may help explain the link between certain behavior patterns and cardiovascular disease. We tested the hypothesis that in normal humans, type A personality characteristics are associated with exaggerated heart rate, pressor, and sympathetic nerve responses to mental and physical stress. We measured heart rate, blood pressure, and muscle sympathetic nerve activity (obtained with direct intraneural recordings) at rest and during stress in 45 healthy subjects (19 men and 26 women, age 29.2+/-8.7 years) who had no chronic diseases and were taking no medications. Subjects were divided into tertiles based on type A scores. There were no significant differences in sympathetic or hemodynamic reactivity among the 3 different intensity levels of type A characteristics. Baseline measures and responses to stress tests were similar across the 3 groups. Sympathetic and hemodynamic changes during stress tests were also similar in subject groups stratified according to anger scale and cynicism scale. Sympathetic nerve and hemodynamic measurements at rest and during stress were not different in normal subjects with type A characteristics. Abnormalities in sympathetic or cardiovascular reactivity are unlikely to be implicated in any excess of cardiovascular disease in people with type A personality characteristics.