Viral eradication by direct-acting antivirals does not decrease the serum myostatin level in hepatitis C virus-infected patients

• The effect of viral eradication on serum myostatin in patients with HCV was evaluated. • We compared the serum myostatin level before and after DAA treatment. • Serum myostatin correlated with the skeletal muscle index and liver fibrosis markers. • Viral eradication did not change the serum myostatin level in patients with HCV : Myostatin has been assumed to be involved in the development of sarcopenia in patients with chronic liver disease, but the effect of hepatitis C virus elimination on myostatin is unclear. This study assessed the effect of a sustained virologic response at 24 weeks (SVR24) following direct-acting antiviral (DAA) therapy on serum myostatin levels in hepatitis C virus-infected patients. : In this single-center retrospective study based on data collected from a university hospital, we analyzed hepatitis C virus-infected patients treated with DAA between 2014 and 2017. We compared the serum myostatin level before and after DAA treatment and evaluated the correlation between myostatin and laboratory data. : In the 91 participants, the median myostatin level at the start of DAA and after achieving an SVR24 were 3042 (924-10177) pg/mL and 3349 (498-7963) pg/mL, respectively. There was no significant difference in the myostatin level between the start of DAA treatment and after achieving an SVR24 (P=0.79). The serum myostatin levels were significantly higher in men than in women and in cirrhosis patients than in chronic hepatitis patients both at the start of DAA and after achieving an SVR24. The serum myostatin level showed a significant positive correlation with the skeletal muscle index and liver fibrosis markers (e.g. type Ⅳ collagen 7S, APRI score and FIB-4 index). : Viral eradication by DAA treatment did not decrease the serum myostatin level in hepatitis C virus-infected patients.