Circulatory and plasma catecholamine responses to mental stress in young subjects with two different types of hypertension.

To determine whether any differences exist between young male subjects with elevated diastolic and systolic blood pressure (BP) and those with only an elevated systolic BP, the responses of BP and plasma catecholamines to a mental arithmetic test were studied in 11 young men (mean age of nineteen years) with BP of > or = 140/90 mm Hg at a routine health check-up (group I-hypertension [HT]), 26 age-matched men with only elevated systolic BP (> or = 140 mm Hg) (group II-HT), and 12 age-matched normotensive (NT) men (< 140/90 mm Hg). During an arithmetic test, group I-HT showed a significantly higher increment of systolic BP (+14.5-18.0%) than group II-HT (+9.3-10.2%) and NT controls (+6.4-8.2%). However, no significant difference in BP response was seen between group II-HT and NT controls. Plasma norepinephrine in group I-HT showed a significant increase after the test, (171 +/- 23-->202 +/- 27 pg/mL), whereas group II-HT and NT controls showed no change. No significant difference occurred in epinephrine response among the three groups. These results suggest that the young male subjects with screening BP above 140/90 mm Hg are hyperreactive to a mental stress as compared with subjects with only elevated systolic BP or NT controls.