Background: Peripheral and splanchnic arteriolar tone is often decreased in patients with cirrhosis. The responsible circulating vasodilator(s) would be expected to also lower renal vascular resistance. To examine this possibility we have undertaken a hemodynamic study of the renal circulation in patients with stable, well characterized, compensated cirrhosis and in healthy controls of similar age and sex.
Methods: Clearance techniques were used to assess splanchnic and renal hemodynamics and hepatocellular function.
Results: Renal vascular resistance was significantly reduced in the cirrhotic patients (P = 0.048) and was accompanied by a significant (P = 0.014) and proportional (r = -0.45; P = 0.016) increase in glomerular filtration rate. The hepatic extraction of indocyanine green, a measure of functional intrahepatic portasystemic shunts, was the only independent predictor of glomerular filtration rate (r = -0.65; P = 0.002).
Conclusions: The results support the hypothesis that, in patients with cirrhosis, the presence of portasystemic shunts results in an increased delivery of endogenous vasodilator(s) into the systemic circulation where their principal action on the renal circulation is to preferentially decrease afferent arteriolar tone. The resultant glomerular hyperfiltration may contribute to the pathogenesis of cirrhotic glomerulosclerosis.