Insulin resistance as a non-invasive method for the assessment of fibrosis in patients with hepatitis C: a comparative study of biochemical methods.

INTRODUCTION: Insulin resistance (IR) promotes the progression of fibrosis and diminishes response to treatment in patients with hepatitis C. Recently, Sydney's index (includes IR) has been proposed as a non-invasive method for the prediction of fibrosis. OBJECTIVE: To assess the usefulness of Sydney's index for the prediction of advanced fibrosis (F3-F4) or absence of significant fibrosis (F0-F1) in patients with chronic hepatitis C. PATIENTS AND METHODS: We included 131 patients suffering from chronic hepatitis C. Mean age was 40 +/- 11, 78 men and 53 women. Fibrosis stage was (F0-F1) 69 patients, F2: 40, and advanced (F3-F4) in 22 patients. We measured baseline AST, ALT, GGT, platelet, cholesterol, alcohol, and IR (HOMA - IR) levels. Sydney, Forns' and APRI indexes were calculated. RESULTS: The area under the curve for the diagnosis of absence of significant fibrosis in each method was: Sydney: 0.80, Forns: 0.71, APRI: 0.70; p = ns. Moreover, the diagnostic capacity of advanced fibrosis was: Sydney: 0.88, Forns: 0.83, APRI: 0.82; p = ns. The predictive negative value of significant fibrosis was 74, 72, and 67%, respectively. Due to the presence of intermediate values, the indexes were not applicable to 36, 44 and 43% of patients respectively. CONCLUSIONS: The incorporation of insulin resistance among biochemical non-invasive methods slightly improves the yield of other indexes. Nevertheless, results are suboptimal, and more than one third of patients might not be correctly classified.