This 2 arm study will assess the efficacy and safety of PEGASYS plus COPEGUS, with or without concomitant pioglitazone, on hepatitis C virus titers in treatment-naive patients with genotype 1 chronic hepatitis C, and insulin resistance. Patients will be randomized to receive either a)PEGASYS 180 micrograms/week + Copegus 1000-1600 mg/day (according to body weight) for 48 weeks or b)16 weeks of pioglitazone (30 mg daily for 8 weeks, then 45 mg daily for 8 weeks), followed by PEGASYS 180 micrograms/week + Copegus 1000-1600 mg/day + pioglitazone 45 mg daily for 48 weeks. The anticipated time on study treatment is 1-2 years, and the target sample size is 100-500 individuals.