Race differences in stress-induced reactivity in young adults.

The cardiovascular response to the stress of mental arithmetic was studied in young Black and White adults. Stress-induced reactivity was studied before and following 14 days of oral sodium loading (10 gm NaCl per day). Marginal hypertensives, both Black and White, had greater systolic blood pressure (SBP) levels (p less than 0.001) and greater diastolic blood pressure (DBP) levels (p less than 0.01) in response to stress. Whites had a greater SBP level during mental stress than Blacks (p = 0.008) and greater reactivity (change from baseline; p less than 0.001). The prevalence of sodium sensitivity was greater in Blacks (37.3%) than in Whites (18.4%). Sodium loading did not augment the BP reactivity to the mental stress in any of the racial or BP groups. These data demonstrate racial variation in the cardiovascular response to centrally mediated adrenergic stimuli. The results also suggest that mild BP elevation in Blacks may be regulated through changes in vascular resistance.