Objective: Hepatitis C virus (HCV) infection is associated with higher insulin levels and insulin resistance. We evaluated factors associated with insulin resistance in a cohort of HIV/HCV-coinfected patients and determined the effect of insulin resistance on the development of hepatic fibrosis.
Methods: Data were analysed from 158 nondiabetic participants in a prospective Canadian cohort of HIV/HCV-coinfected patients. Patients were defined as having insulin resistance using the homeostasis model for assessment of insulin resistance (HOMA-IR) index. Factors associated with a high index (HOMA-IR ≥ 2) were identified using multivariate logistic regression. Incidence rates of liver fibrosis [aspartate aminotransferase- to-platelet ratio index (APRI) ≥ 1.5] were calculated, and multivariate time-dependent Cox regression models used to assess the effect of baseline insulin resistance on the risk of developing an APRI score of at least 1.5 during follow-up.
Results: Overall, 56% had baseline HOMA-IR of at least 2. In the adjusted multivariate logistic analysis, only baseline BMI of more than 25 kg/m2 remained associated with insulin resistance [adjusted odds ratio 3.66, 95% confidence interval (CI) 1.70-7.92]. Rates of progression to significant hepatic fibrosis (APRI ≥ 1.5) were higher in those with HOMA-IR of at least 2 (16.32 per 100 person-years, 95% CI 6.68-25.97) compared with those with HOMA-IR less than 2 (7.95 per 100 person-years, 95% CI 0.16-15.75). Baseline HOMA-IR of at least 2 was associated with the development of significant fibrosis (adjusted hazard ratio 7.71, 95% CI 2.55-23.36).