Objective Patient-reported outcomes (PROs) are important measures of the quality of life (QOL) and symptoms in patients with hepatitis C virus (HCV). We evaluated the PROs at the beginning of direct-acting antiviral (DAA) treatment and three years later. A low QOL in patients with chronic liver disease suggested a low muscle mass. We compared the relationship between the QOL and muscle mass. Methods DAAs were administered to 100 patients with HCV infection. The PROs included the cirrhosis-related symptom score (CSS), presence of restless legs syndrome, Pittsburg sleep quality index (PSQI) to evaluate sleep disturbance, SF-36 to measure the QOL, and calculated body muscle mass (CBMM) measured at the beginning of treatment and three years later. Computed tomography (CT) was used to screen 82 patients for hepatocellular carcinoma at the beginning of treatment and three years later. Cross-sectional CT images of the third lumbar vertebrae were analyzed to evaluate the body composition. Results The general health perception (GHN) of SF-36 was better at three years after DAA administration than at the beginning. Changes in the GHN (dGHN) were related to an improved sleep quality on the PSQI and CSS and increased CBMM. The dGHN was positively related to changes in the skeletal muscle. The sleep quality, sleep latency, fatigue, and abdominal fullness were related to dGHN. Conclusion The QOL is related to sleep disturbance and several other symptoms. Furthermore, in patients with an increased muscle volume after DAA treatment, increased muscle mass is associated with an improvement in the QOL.