Personality type and neural circulatory control

Psychosocial factors, including type A personality, anger, hostility, and a nxiety, 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 hypoth esis that in normal humans, type A personality characteristics are associat ed with exaggerated heart rate, presser, and sympathetic nerve responses to mental and physical stress. We measured heart rate, blood pressure, and mu scle sympathetic nerve activity (obtained with direct intraneural recording s) at rest and during stress in 45 healthy subjects (19 men and 26 women, a ge 29.2+/-8.7 years) who had no chronic diseases and were taking no medicat ions. Subjects were divided into tertiles based on type A scores. There wer e no significant differences in sympathetic or hemodynamic reactivity among the 3 different intensity levels of type A characteristics. Baseline measu res and responses to stress tests were similar across the 3 groups. Sympath etic and hemodynamic changes during stress tests were also similar in subje ct groups stratified according to anger scale and cynicism scale. Sympathet ic nerve and hemodynamic measurements at rest and during stress were not di fferent in normal subjects with type A characteristics. Abnormalities in sy mpathetic or cardiovascular reactivity are unlikely to be implicated in any excess of cardiovascular disease in people with type A personality charact eristics.