Raised circulating levels of atrial natriuretic peptides in essential hypertension.

Plasma levels (mean +/- SD) of immunoreactive atrial natriuretic peptides (ANP) were significantly higher in 28 hypertensive subjects (17.1 +/- 13.8 pg/ml) than in 24 normotensive subjects (8.4 +/- 3.7 pg/ml) matched as far as possible for age, sex, and race. All subjects were studied on their normal dietary sodium intake. In the normotensive subjects ANP levels were significantly correlated with age but not with blood pressure, whereas in the hypertensive subjects ANP levels were significantly correlated with systolic blood pressure but not with age. These findings may indicate a compensatory reaction to a diminished renal capacity for sodium excretion, in response to increasing age in normotensive subjects and to higher blood pressure in hypertensive subjects.