Effect of branched-chain amino acid-enriched nutritional supplementation on interferon therapy in Japanese patients with chronic hepatitis C virus infection: a retrospective study

BACKGROUND: The aims of this study were to evaluate the effects of nutritional supplementation with branched-chain amino acids (BCAA) with zinc component (Aminofeel®) on adherence to and outcome of therapy in patients treated with interferon (IFN) for chronic hepatitis C and cirrhosis and to determine whether to recommend the supplement. METHODS: In this retrospective study, 51 patients who received IFN therapy were investigated among 203 consecutive patients who visited our hospital and were advised regarding the potential benefit of taking Aminofeel®. Each patient was free to choose whether to purchase and take Aminofeel®. RESULTS: Twenty four patients (group 1-A) took Aminofeel® during standard IFN therapy and 13 (group 1-B) did not. Low-dose, long-term IFN (maintenance) therapy, mainly peglated (Peg)-IFN alpha 2a, was administered to 14 patients who were difficult to treat, because of no effect or harmful side effects with standard IFN therapy, and who had advanced liver fibrosis. Among the 14, 11 patients (group 2-A) took Aminofeel® and 3 (group 2-B) did not. The prevalence of obesity was significantly higher (P=0.04) in group 1-A than in group 1-B. The rate of adherence to IFN therapy was higher in group 1-A (83.3%) than in group 1-B (53.8%, P=0.05). There were no significant differences between the two groups in the rates of sustained virological response (SVR) to IFN therapy. According to multivariate analysis, two factors, SVR and intake of Aminofeel®, were associated with successful adherence to IFN therapy. The adjusted odds ratios for these two factors were 13.25 and 12.59, respectively, and each was statistically significant. The SVR rate of maintenance IFN therapy was in 18.2% group 2-A and 0% in group 2-B. CONCLUSION: Our data show that BCAA intake is useful for adherence to and effect of IFN therapy for patients with chronic hepatitis C. Nutritional supplementation with BCAA seems to be useful for HCV-infected patients receiving IFN therapy because it is impossible to introduce standard treatment for all patients among Japan's aging population.