Introduction:
Decompensated liver cirrhosis is associated with hemodynamic changes including arterial blood pressure alterations. The aim of the study was to investigate the circadian rhythm variability of arterial blood pressure in relation to reninemia and aldosteronemia in cirrhotic patients with ascites, before and after paracentesis.

Material and methods:
The study was performed in 22 normotensive cirrhotics with ascites and 19 healthy controls. Ambulatory arterial blood pressure monitoring was conducted for 24 hours, cardiac output and systemic vascular resistance were determined and circulating renin and aldosterone concentrations were measured. In cirrhotics, the tests were repeated 24 hours after paracentesis.

Results:
It was demonstrated that as a consequence of paracentesis, the mesor values of systolic and diastolic blood pressure and heart rate decreased, whereas the amplitudes did not change in the cirrhotics. Moreover, in the cirrhotics' acrophases of blood pressure occurred earlier than in the controls. The day-night differences of mean pressure values were smaller in the cirrhotics than in the controls. The patients before paracentesis demonstrated higher cardiac output and lower systemic vascular resistance than healthy subjects. In cirrhotic patients the renin and aldosterone concentrations were higher and the aldosterone/renin ratio was lower than in the controls.

Conclusions:
Arterial blood pressure circadian rhythm in normotensive patients with decompensated cirrhosis of the liver with ascites is characterized by a lowered decrease at nighttime that suggests the occurrence of non-dipping phenomenon. The reduction of ascites in patients with decompensated liver cirrhosis leads to a reduction in arterial blood pressure and does not eliminate the non-dipping phenomenon in its day-night rhythm. In normotensive cirrhotic patients with ascites before and after single paracentesis, a dissociation of the renin-aldosterone nexus occurs.