We investigated the gender difference in responsiveness to 48-week interferon (IFN) and ribavirin combination treatment in patients infected with hepatitis C virus (HCV) genotype 1b and high baseline viral loads. In patients under 50 years old, the sustained viral response (SVR) rate showed no difference by gender. However, in patients over 50 years old, the SVR rate in male was significantly higher than that in female. Multiple regression analysis revealed several factors that are independently associated with better response to the combination therapy: male, no IFN-dose reduction, ICG R15 less than 15% and ribavirin dose/body weight ratio at no less than 11.0. Further investigation would be needed to explain why the effect of the combination therapy varies by gender in those older than 50 years old.
