Plasma atrial natriuretic peptide in juvenile essential hypertension: Comparison with young normotensive subjects with or without a family history of hypertension

Plasma atrial natriuretic peptide (ANP) was studied in 26 young hypertensives and in 34 young normotensives (13 of whom had a family history of hypertension) under normal sodium intake (120 mEq of sodium/daily). In the hypertensives, ANP was 44.5 ± 19.4 pg/ml after a night's sleep and 24.1 ± 11.6 pg/ml after one hour of deambulation (orthostatic position). In normotensives without hypertensive heredity ANP was 38.3 ± 19.4 pg/ml after a night's sleep and 19.9 ± 10.6 pg/ml after one hour of deambulation, while in normotensives with hypertensive heredity, ANP was 41.4 ± 16.3 pg/ml and 22.3 ± 9.9 respectively. In the hypertensive group plasma levels of ANP were higher than in the normotensive group, with a percentage difference of 13.8% after a night's sleep and 17.4% after one hour of deambulation. Furthermore, normotensives with hypertensive heredity appeared to have mean plasma levels of ANP slightly higher than normotensives with heredity, with a percentage difference of 7.4% after a night's sleep and 10% after one hour of deambulation. In the hypertensive group, ANP was inversely correlated with plasma aldosterone (after a night's sleep, r = -.44, P < 0.05; after one hour of deambulation, r = -.66, P < 0.001) and with renin activity (after one hour of deambulation, r = -.64, P < 0.001). In the same group ANP was positively correlated with systolic blood pressure (r = -.64, P < 0.001). In the normotensive group, ANP was inversely correlated only with aldosterone, and only after one hour of deambulation (r = -.42, P 0.05). This finding appeared independent of the presence of a family history of hypertension. In conclusion, our data indicate that ANP is elevated in young hypertensives, showing an inverse correlation with the renin-aldosterone axis. Furthermore, normotensives with a family history of hypertension showed slightly higher levels of ANP than normotensives without such a family history.