Plasma atrial natriuretic peptide in young essential hypertensive patients

Plasma atrial natriuretic peptide (ANP) was studied in 26 young hypertensives and in 21 young normotensives with normal sodium intake (120 mEq of sodium daily). In the hypertensives ANP was 44.5 ± 19.4 pg/ml after a night's bed rest and 24.1 ± 11.6 pg/ml after one hour of deambulation. In normotensives ANP was 38.3 ± 19.4 pg/ml after a night's bed rest and 19.9 ± 10.6 pg/ml after one hour of deambulation. In the hypertensive group ANP plasma levels were higher than in the normotensive group, with a percentage difference of +13.8% after a night's bed rest and +17.4% after one hour of deambulation. In the hypertensive group, ANP was inversely correlated with plasma aldosterone (after a night's bed rest, r = -0.44, P<0.05; after one hour of deambulation, r = -0.66, P<0.001) and renin activity (after 1 hour of deambulation, r = -0.64, P<0.001). In the same group ANP was positively correlated with systolic blood pressure (r = +0.64, P<0.001). In the normotensive group, ANP was inversely correlated only with aldosterone and only after one hour of deambulation (r = -0.42, P<0.05). In conclusion, our data indicate that ANP is elevated in young hypertensives, showing an inverse correlation with the renin axis.