Changes in insulin sensitivity and body weight during and after peginterferon and ribavirin therapy for hepatitis C.

BACKGROUND & AIMS: Chronic hepatitis C is associated with an increased prevalence of insulin resistance, which might result from liver disease, metabolic factors, or the hepatitis C virus (HCV) itself. The effect of antiviral treatment on insulin sensitivity is not well-known. We evaluated changes in insulin resistance and weight in patients with hepatitis C during and after peginterferon and ribavirin therapy. METHODS: Virahep-C was a prospective, multicenter study of a 48-week course of combination antiviral therapy in patients infected with HCV genotype 1. Insulin resistance (IR) was estimated by the homeostasis model assessment index (HOMA2-IR) based on fasting glucose and insulin levels. RESULTS: Among 341 patients, 40% had insulin resistance (HOMA2-IR > 2.0). The presence of insulin resistance was associated with increasing age, body mass index (BMI), and fibrosis stage. Among patients with insulin resistance at the start of the trial, median decreases in HOMA2-IR values during treatment were 0.74 at 24 weeks and 0.89 at 48 weeks, whereas BMI decreased by 1.2 and 2.2 at the same time points (P < .001 for all). At follow-up, HOMA2-IR and BMI levels returned toward baseline values in patients who did not respond or relapsed, but HOMA2-IR values remained significantly lower in patients with sustained virologic response (SVR) (P < .001), despite increases in BMI. CONCLUSIONS: In patients with HCV genotype 1 infections, therapy with peginterferon and ribavirin is associated with decreases in body weight and insulin resistance. Among patients with insulin resistance before treatment, resolution of HCV infection results in sustained improvements in the HOMA-IR index, suggesting that HCV could have a direct role in the pathogenesis of insulin resistance.

Associations between serum lipids and hepatitis C antiviral treatment efficacy.

UNLABELLED: Approximately one half of patients who undergo antiviral therapy for chronic hepatitis C virus (HCV) genotype 1 infection do not respond to treatment. African Americans (AAs) are less responsive to treatment than Caucasian Americans (CAs), but the reasons for this disparity are largely unknown. Recent studies suggest that serum lipids may be associated with treatment response. The aims of this study were to evaluate baseline and changes in serum lipids during therapy, determine whether serum lipids are associated with virological response, and assess whether these measures explain the racial difference in efficacy. The study participants were from Virahep-C, a prospective study of treatment-naïve patients with genotype 1 HCV infection who received peginterferon (PEG-IN) alfa-2a plus ribavirin therapy for up to 48 weeks. Fasting serum lipids were analyzed at baseline and during and after therapy in 160 AAs and 170 CAs. A relative risk (RR) model was employed to evaluate characteristics associated with sustained virological response (SVR). Antiviral therapy was associated with changes in serum lipids during and after antiviral therapy, with the changes differing by race and the amount of PEG-IFN taken. Baseline lipid measures independently associated with higher rates of SVR were lower triglyceride and higher low-density lipoprotein cholesterol, with an interaction between high-density lipoprotein cholesterol (HDLc) and gender. Lipid measures did not contribute significantly to an explanation of the racial difference in SVR. CONCLUSION: Serum lipids are associated with SVR, although these paramaters did not explain the racial difference in treatment response. The results of this study are compatible with proposed biological mechanisms of HCV entry, replication, and secretion, and may underscore new potential therapeutic targets for HCV eradication.

Race, insulin resistance and hepatic steatosis in chronic hepatitis C.

UNLABELLED: Hepatic steatosis is common in chronic hepatitis C and has been linked to concurrent obesity, insulin resistance, diabetes, disease severity, and poor response to therapy. Racial differences in rates of obesity and diabetes may contribute to racial differences in hepatic steatosis and treatment response. The aim of the present study was to compare hepatic steatosis and its associations between African American (AA) and Caucasian American (CA) patients with chronic hepatitis C, genotype 1, participating in a prospective study of peginterferon and ribavirin therapy. Liver biopsy results were available from 194 AA patients and 205 CA patients. The 2 groups were compared for anthropometric, clinical, and biochemical features and insulin resistance estimated by the homeostasis model assessment index (HOMA-IR). Sixty-one percent of the AA patients and 65% of the CA patients had hepatic steatosis (P = 0.38). In univariable analysis, steatosis was associated with HOMA-IR, body mass index, waist circumference, serum triglycerides, aminotransferase level, and histological scores for inflammation and fibrosis. After adjusting for these features, AA patients had a lower risk of steatosis than did CA patients (OR 0.54, 95% CI 0.32-0.91, P = 0.02). Insulin resistance but not steatosis was associated with a lower rate of sustained virological response when adjusted for known factors that predict response (relative risk 0.87, 95% CI 0.77-0.99, P = 0.028). CONCLUSION: After adjusting for the higher prevalence of features associated with hepatic steatosis, AA patients had a lower prevalence of hepatic steatosis than did CA patients with chronic hepatitis C, genotype 1. Insulin resistance but not steatosis was independently associated with lower sustained virological response.

Peginterferon and ribavirin treatment in African American and Caucasian American patients with hepatitis C genotype 1.

BACKGROUND & AIMS: Compared with Caucasian Americans (CA), African Americans (AA) with chronic hepatitis C are less likely to respond to interferon-based antiviral therapy. METHODS: In a multicenter treatment trial, 196 AA and 205 CA treatment-naive patients with hepatitis C virus (HCV) genotype 1 infection were treated with peginterferon alfa-2a (180 microg/wk) and ribavirin (1000-1200 mg/day) for up to 48 weeks. The primary end point was sustained virologic response (SVR). RESULTS: Baseline features were similar among AA and CA, including HCV-RNA levels and histologic severity, but AA had higher body weights, a higher prevalence of diabetes and hypertension, and lower alanine transaminase levels (P < .001 for all). The SVR rate was 28% in AA and 52% in CA (P < .0001). Racial differences in viral responses were evident as early as treatment week 4. Breakthrough viremia was more frequent among AA than CA (13% vs 6%, P = .05); relapse rates were comparable (32% vs 25%, P = .30). Proportions of patients with serious adverse events and dose modifications and discontinuations were similar among AA and CA. In multiple regression analyses, CA had a higher SVR rate than AA (relative risk, 1.96; 95% confidence interval, 1.48-2.60; P < .0001). Other factors independently associated with higher SVR included female sex, lower baseline HCV-RNA level, less hepatic fibrosis, and more peginterferon taken. CONCLUSIONS: AA with chronic hepatitis C genotype 1 have lower rates of virologic response to peginterferon and ribavirin than CA. These differences are not explained by disease characteristics, baseline viral levels, or amount of medication taken.