EFFECT OF UPRIGHT POSTURE AND PHYSICAL EXERCISE ON ENDOGENOUS NEUROHORMONAL SYSTEMS IN CIRRHOTIC-PATIENTS WITH SODIUM RETENTION AND NORMAL SUPINE PLASMA-RENIN, ALDOSTERONE, AND NOREPINEPHRINE LEVELS

It is well known that sodium retention occurs in a significant proport ion of patients with cirrhosis despite normal supine plasma levels of renin, aldosterone (AI;DO), and norepinephrine (NE). The current study was performed to assess whether this subset of patients also present normal activity of the renin-aldosterone and sympathetic nervous syste ms during upright posture in sitting position and moderate physical ex ercise. Nine healthy controls, 14 patients with compensated cirrhosis and 10 patients with cirrhosis, ascites, sodium retention, and normal supine plasma renin activity (PRA) and ALDO and NE concentration were sequentially studied after 60 minutes in supine rest, 30 minutes in si tting position, and 30 minutes of cycloergometric exercise (3-METs). S itting position and exercise were associated with similar stimulation of the renin-aldosterone and sympathetic nervous systems in the three groups of subjects. Consequently, cirrhotic patients with ascites show ed values of PRA and plasma concentration of ALDO and NE similar to he althy subjects and patients with compensated cirrhosis during supine r est (renin: 1.4 +/- 0.3, 0.8 +/- 0.2, and 0.8 +/- 0.3 ng/mL.hr; aldost erone: 24.3 +/- 4.7, 20.2 +/- 3.9 and 21.4 +/- 3.4 ng/dL; norepinephri ne: 252 +/- 23, 250 +/- 16, and 255 +/- 23 pg/mL), sitting position (r enin: 2.1 +/- 0.5, 1.1 +/- 0.3, and 1.6 +/- 0.4; aldosterone: 32.2 +/- 7.3, 23.7 +/- 5.3, and 26.2 +/- 4.5; norepinephrine: 356 +/- 38, 401 +/- 63, and 420 +/- 35), and exercise (renin: 2.9 +/- 0.8, 1.6 +/- 0.4 , and 2.2 +/- 0.5; aldosterone: 43 +/- 6.4, 34.9 +/- 8.5, and 38.2 +/- 5.3; norepinephrine: 481 +/- 35, 499 +/- 54, and 534 +/- 48). Plasma atrial natriuretic peptide concentration was significantly (P < .05) h igher in cirrhotic patients with ascites than in healthy subjects duri ng supine rest (5.63 +/- 1.1 vs. 21.0 +/- 3.3 fmol/L) and exercise (9. 1 +/- 2.2 vs. 28.3 +/- 6.6). These results indicate that sodium retent ion in cirrhosis may occur in the setting of a normal activity of the endogenous,neurohormonal antinatriuretic systems and high plasma level s of ANP.