Abstract
| - The present study was aimed at examining the effects of awareness of hypertension on blood pressure and sympathetic responses to the cold pressor test. Nineteen-year-old men with similarly elevated mean blood pressure at a medical screening, but without knowledge of this, were randomized into two groups. The first group (n = 16) was sent a letter saying that their pressure was too high, and the second (n = 13) was sent a neutral letter. Information increased mean blood pressure both after 15 min sitting, by an average of 11.5 mm Hg (P< .01), and after 30 min supine rest, by an average of 4.5 mm Hg (P< .05). Changes in heart rate (8.4 ± 2.4 v 1.9 ± 1.7 beats/min) and plasma epinephrine (0.11 ± 0.04 v 0.01 ± 0.03 nmol/L) during execution of a cold pressor test were significantly greater in the informed group (P< .05). Plasma dopamine was lower in the informed group (P< .05). Thus, psychological stress caused by the awareness of hypertension may increase blood pressure and sympathetic responses to a provocative maneuver. Ideally, studies on sympathetic function in essential hypertension should be undertaken on subjects unaware of their blood pressure status. Am J Hypertens 1990;3:912-917
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