Background & aims: In healthy subjects, exercise promotes marked hemodynamic and humoral changes characterized by an increase in cardiac output, a redistribution of blood flow to muscular territories under activity, and an increase in sympathoadrenergic activity. The aim of this study was to investigate the extent to which hemodynamic and humoral changes caused by exercise may influence portal and systemic hemodynamics in patients with cirrhosis.
Methods: In 8 patients with liver cirrhosis and portal hypertension, arterial pressure, cardiac output, portal pressure (as hepatic venous pressure gradient [HVPG]), and hepatic blood flow were measured before and at two steps of cycling exercise equivalent to 30% and 50% of their peak workload.
Results: Exercise (at 30% of peak work-load) significantly increased arterial pressure and cardiac output and decreased systemic vascular resistance. This was associated with a significant increase in HVPG (from 16.7 +/- 1.5 to 19.2 +/- 1.6 mm Hg; P < 0.01) and a significant reduction in hepatic blood flow (from 1291 +/- 216 to 1034 +/- 152 mL-min-1; P < 0.05). All of these changes were intensified at 50% of target workload.
Conclusions: The present study shows that moderate exercise increases portal pressure and may therefore increase the risk of variceal bleeding in patients with esophageal varices. These findings suggest that cirrhotic patients with portal hypertension should be advised of potential risks during exercise.