['Hepatitis C virus (HCV) infection is associated with insulin resistance (IR), which is a condition known to influence the progression of liver fibrosis and the response to pegylated interferon (PEG-IFN)/ribavirin (RBV) therapy. We aimed to assess whether a sustained virological response (SVR) after antiviral therapy prevents the development of IR in the long term. Members of the Milan Safety Tolerability study cohort, who received PEG-IFNα2a/RBV or PEG-IFNα2b/RBV, underwent a homeostasis model assessment (HOMA) at the baseline and 24 months after treatment completion. For all patients (n = 431), a liver biopsy sample was scored for grading, staging (Ishak), and steatosis. At the baseline, IR (HOMA value > 2) was detected in 48 patients (12%), and it was associated with body weight (P = 0.03), an HCV load < 0.6 × 10(6) IU/L (P = 0.006), fibrosis staging ≥ 4 (P = 0.01), and moderate to severe steatosis (P = 0.03). IR did not influence the rates of end-of-treatment response (75% versus 69%, P = 0.4), SVR (63% versus 60%, P = 0.8), or relapse (19% versus 24%, P = 0.5). After treatment, IR developed in 49 of the 384 nondiabetic patients (14%). Although the mean baseline and posttreatment HOMA values were similar in SVR patients (1.11 ± 0.8 versus 1.18 ± 1.1, P = 0.25), patients experiencing treatment failure showed a significant increase in the mean HOMA value at the follow-up visit (1.20 ± 0.85 versus 1.49 ± 1.3, P = 0.007), and there was an increased rate of de novo IR in non-SVR patients versus SVR patients (17% versus 7%, P = 0.007). According to a logistic regression analysis, treatment failure (odds ratio = 2.81, 95% confidence interval = 1.39-5.67, P = 0.004) and a 10% body mass index increase (odds ratio = 6.42, 95% confidence interval = 1.69-24.3, P = 0.006) were significantly associated with the development of de novo IR.'] Does sustained virological response prevent the development of insulin resistance in patients with chronic hepatitis C?