Chronobiological Evaluation of Sympathoadrenergic Function in Cirrhosis

Intraday activity of the adrenergic system was investigated in 7 heaIthy controls and in cirrhotic patients without ascites (group 1, 7 cases) and with ascites [group 2, 9 cases) by determining the urinary norepinephrine and vaniIIyImandeIic acid excretions at 4-h intervals for 24 h. Mean arterial pressure and heart rate were also recorded. In controls, the statistical evaluation by the cosinor method showed a circadian rhythm of such variables, with zenith in the morning and nadir at night. Intraday changes of urinary excretion of norepinephrine were closely related to arterial pressure and heart rate in most subjects. The most important change in cirrhotic patients was the achronia [no detection of a statistically significant (p > 0.05) rhythm] in urinary excretion of norepinephrine and arterial pressure. This occurred not only in group 2 patients, who had lower arterial pressure and higher NE mesors than controls (p < O&5), but also in group 1 patients, whose mesors were comparable to controls. The statistical significance of heart rate rhythmicity was preserved in patients, but its zenith was progressively displaced toward evening [group I) and night hours (group 2, whose mesor was increased). Changes in urinary excretion of VaniIIyImandeIic acid roughIy paralleled those of norepinephrine both in controls and patients, but they did not signi