Study the Relationship Between Obesity and Hepatitis C Replication

Inclusion Criteria: * Infection with HCV genotype 1 or 4 (subjects infected with multiple genotypes are not eligible) * BMI greater than 25 Kg/m2 * HCV-infected subjects naïve to treatment: subjects who either have never been treated for HCV infection or who previously received HCV treatment ending more than 3 months prior to enrollment for not longer than 2 weeks * Plasma HCV RNA concentration of \>10,000 IU/mL at the screening evaluation Exclusion Criteria: * Previous intolerance to Pioglitazone, Rosiglitazone, Troglitazone or corticosteroids * Women who are pregnant or breastfeeding * History of diabetes mellitus requiring treatment other than diet * Decompensated liver disease or other known causes of liver disease including, but not limited to autoimmune hepatitis, Wilson's disease, hemochromatosis, primary biliary cirrhosis, schistosomiasis, sclerosing cholangitis, alcohol- or drug-induced liver disease, or alpha-one antitrypsin deficiency * Concurrent hepatitis B virus (HBV) infection * Known immunodeficiency disease, autoimmune disorders or active gastrointestinal disease * Abuse of alcohol or illicit drugs within 6 months before enrollment * Use of an investigational drug within 4 weeks before the screening visit or during the screening period. * Use of systemic immunosuppressants * History of poorly controlled psychiatric disease or poorly controlled pulmonary disease