Racial differences in cardiovascular reactivity to mental arithmetic.

One hypothesized mechanism for the higher rates and greater severity of essential hypertension among blacks is that this group is particularly susceptible to stress-induced beta-adrenergically mediated cardiovascular hyperreactivity. In this study, we compared the cardiovascular responses to mental arithmetic in 20 white and 17 black, young, normotensive males. Contrary to expectations, the black subjects exhibited significantly smaller changes in heart rate, and systolic and diastolic blood pressure. These findings suggest that cardiovascular reactivity to a mental stressor known to produce beta-adrenergically mediated responses may be lower in some normotensive blacks compared to their white counterparts.