Background: The renin-angiotensin system plays an important role in hepatic fibrosis and portal hypertension. We evaluated the long-term effects of olmesartan, an angiotensin type 1 (AT1) receptor blocker, on hemodynamics and liver fibrosis.
Methods: Forty-eight selected patients with cirrhosis were randomly divided into two groups of 24 patients each, those who received and those who did not receive olmesartan treatment for 1 year. Hepatic hemodynamic studies, and measurements of transforming growth factor-beta1 (TGF-beta1) and blood markers of hepatic fibrosis, including serum hyaluronic acid (HA), type IV collagen, and procollagen III N-terminal propeptide levels, were also performed at the beginning and end of the study.
Results: The median dose of the final drug administration was 20 mg (range 10-40 mg). Olmesartan reduced the hepatic venous pressure gradient (HVPG) by -12.9 ± 9.1% (p = 0.035) after 1 year. No significant changes were seen in controls. Six of the 24 patients (25%) in the olmesartan group showed a >20% reduction of HVPG from baseline values. TGF-beta1 was significantly decreased in patients who received olmesartan (7.0 ± 8.2 vs. 3.1 ± 1.6 ng/mL, p = 0.046) but there was no decrease in the controls. A significant trend was shown by correlating HA and TGF-beta1 variations in cirrhosis patients (p = 0.018, r = 0.377). Fibrosis markers were unchanged at the end of the study in both groups.
Conclusions: Olmesartan induced a mild reduction of portal pressure and TGF-beta1 for 1 year, but did not suppress hepatic fibrosis markers.