BACKGROUND/AIMS: In patients with cirrhosis, the systemic circulation is hyperdynamic with low arterial blood pressure and reduced systemic vascular resistance. The present study was undertaken to estimate the compliance of the arterial tree in relation to severity of cirrhosis, circulating level of the vasodilator, calcitonin gene-related peptide (CGRP) and mean arterial blood pressure (MAP). METHODS: Arterial compliance (COMPart=deltaV/deltaP) was determined as the stroke volume relative to pulse pressure (i.e. systolic minus diastolic blood pressure) during a haemodynamic evaluation of portal hypertension in patients with biopsy-verified cirrhosis (Child-Turcotte classes A/B/C=10/15/6). RESULTS: COMPart was significantly higher in cirrhotic patients (n=31) than in controls (n=10) (1.44 vs 1.00 x 10(-3) l/mmHg, p<0.01). It increased significantly through the Child-Turcotte classes A, B, and C (1.02, 1.47, and 2.1 x 10(-3) l/mmHg, respectively, p=0.03). The stroke volume did not change significantly with the severity of the disease, but pulse pressure decreased through class A, B, and C (79, 65, and 50 mmHg, respectively, p<0.01). COMPart was slightly, but significantly correlated to the circulating level of CGRP (r=0.34, p<0.05), and a substantial but inverse correlation was present to MAP (r= -0.63, p<0.002). CONCLUSIONS: Elevated arterial compliance in cirrhosis is directly related to the severity of the disease and to the elevated level of circulating vasodilator peptide CGRP, and inversely related to the level of arterial blood pressure. The altered static and dynamic functions of the arterial wall in cirrhosis may have implications for the circulatory and homoeostatic derangement, and potentially for therapy with vasoactive drugs.