An effective therapeutic strategy for suppressing liver fibrosis should improve the overall prognosis of patients with chronic liver diseases. Although enormous efforts are ongoing to develop anti-fibrotic agents, no drugs have yet been approved as anti-fibrotic agents for humans. Insulin resistance (IR) is reportedly involved in the progression of liver fibrosis. The aim of the present study was to evaluate the effect of combination treatment with a clinically used branched-chain amino acid (BCAA) and an angiotensin-converting enzyme inhibitor (ACE-I) on several fibrotic indices in patients with liver cirrhosis under the condition of IR. BCAA granules (Livact; 12 g/day) and/or ACE-I (perindopril; 4 mg/day) were administered, and several indices were analyzed. A 48-month follow-up revealed that the combination treatment with BCAA and ACE-I markedly improved the progression of serum fibrosis markers, whereas single treatment with either BCAA or ACE-I did not exert these inhibitory effects. The plasma level of transforming growth factor-β was significantly attenuated almost in parallel with the suppression of serum fibrosis markers. Furthermore, the combined treatment with BCAA and ACE-I improved the serum albumin level and IR, which was evaluated using the homeostasis model assessment method for IR. Taken together, since both BCAA and ACE-I are widely used with safety in clinical practice, these results indicate that this combination therapy may represent a potential new future strategy against liver fibrosis development in patients with liver cirrhosis under the condition of IR.
Keywords: branched-chain amino acid; angiotensin-II; liver fibrosis; insulin resistance.