Correlates of plasma atrial natriuretic factor in health and hypertension

Abstract

Plasma concentrations of atrial natriuretic factor (ANF) were compared in normotensive subjects and subjects with untreated, uncomplicated essential hypertension (n=21 pairs) matched for age, sex, and race. Plasma peptide values were slightly greater (45±3 vs 36±3 pg/ml; p<0.05) in the hypertensive group. On univariate analysis, age (r=0.52, n=47, p<0.001) and creatinine clearance (r=-0.30, n=47, p<0.05) were significantly related to plasma ANF concentrations, but arterial pressure was not (r=0.14, n=47), in an extended group of normal subjects. In contrast, plasma ANF values were related to arterial pressure in both an extended group of subjects with untreated essential hypertension (r=0.54, n=38, p<0.001) and in our total heterogeneous pool of hypertensive patients (r=0.46, n=79, p<0.001), but weak positive associations with age and inverse relationships with creatinine clearance were not statistically significant in either hypertensive group. Similar weak inverse relationships between plasma ANF values and renin-angiotensin-aldosterone system activity were found in both normal and hypertensive subjects. Plasma ANF concentration was related to electrocardiographic scores for left ventricular hypertrophy and to radiological cardiothoracic ratio in subjects with untreated essential hypertension (r=0.53, n=34, p<0.01 and r=0.35, n=32, p<0.05, respectively) and for all hypertensive subjects combined (r=0.35, n=59, p<0.02 for cardiothoracic ratio and r=0.47, n=69, p<0.001 for hypertrophy scores). Seventy percent of subjects with left ventricular hypertrophy had plasma ANF values beyond the normal range for our laboratory. Comparison of hypertensive subjects with and without hypertrophy, closely matched for age and arterial pressure (n=13 pairs), revealed clearly elevated values of plasma ANF in the hypertrophy group (133 ± 24 vs 46 ± 5 pg/ml; p<0.01).