Insulin resistance predicts rapid virologic response to peginterferon/ribavirin combination therapy in hepatitis C genotype 4 patients

Impact of insulin resistance on HCV treatment response and impact of HCV treatment on insulin sensitivity using direct measurements of insulin action

OBJECTIVE

Insulin resistance, as measured by surrogate markers, is associated with lower response to hepatitis C virus (HCV) therapy and may improve with HCV eradication. We prospectively evaluated the impact of directly measured insulin resistance and abnormal glucose metabolism on achieving sustained virologic response (SVR) with HCV therapy and assessed whether SVR results in improved insulin sensitivity and fasting glucose.

RESEARCH DESIGN AND METHODS

A total of 50 noncirrhotic, nondiabetic, HCV-infected patients (27 untreated, 23 treated with pegylated interferon/ribavirin, nonrandomized) underwent clinical and histologic evaluation and 75-g oral glucose tolerance test. Insulin sensitivity was assessed directly with insulin suppression test by measuring steady-state plasma glucose (SSPG) concentration during a 240-min infusion of octreotide, glucose, and insulin. Of the subjects, 43 had at least one follow-up evaluation.

RESULTS

Patient characteristics were median age 48, 57% male, and 52% white. SVR was achieved in 61% (14 of 23) of treated subjects. SVR was independently associated with HCV genotypes 2 and 3 (odds ratio 8.8 [95% CI 1.2-61.7]) but was not strongly associated with insulin sensitivity. When controlling for elapsed time between measurements, being on interferon, and BMI, SSPG decreased by 36 mg/dL (-88 to 16) in those with SVR and decreased by 28 mg/dL (-93 to 38) in those without SVR, compared with the untreated group. BMI (coefficient 9.1 per 5 units; 95% CI 5.3-12.9) and interferon use (coefficient 56; 95% CI 6.8-105) were associated with SSPG.

CONCLUSIONS

Insulin resistance does not appear to be strongly associated with SVR. HCV therapy may improve insulin resistance regardless of virologic response; however, BMI and interferon use were clearly associated with insulin resistance.

Pioglitazone decreases hepatitis C viral load in overweight, treatment naïve, genotype 4 infected-patients: a pilot study

BACKGROUND

Insulin resistance (IR) is induced by chronic hepatitis C virus (HCV) genotypes 1 and 4 infections. It is not known whether drugs that affect IR such as Pioglitazone and Prednisone also affect serum HCV RNA titers independently of PEG-Interferon-α2/ribavirin treatment. The primary aim was to assess whether Pioglitazone by improving IR and/or inflammation decreases HCV viral load independently of standard of care HCV treatment. A secondary aim was to assess whether Prednisone, a drug that induces insulin resistance and stimulates HCV viral entry and replication in replicon culture systems, increases HCV viral load in this population.

METHODOLOGY/PRINCIPAL FINDINGS

We designed a two-arm, parallel Pilot Study of overweight, treatment naïve genotype 4 HCV-infected patients at a public referral Liver Clinic in Giza, Egypt. The subjects received Pioglitazone (30 mg/day for 14 days) or Prednisone (40 mg/day for 4 days) in a randomized fashion, but the two arms can be considered independent pilot studies. Only changes from baseline within each arm were assessed and no contrasts of the interventions were made, as this was not an aim of the study. Among 105 consecutive HCV genotype 4 patients, 39 were enrolled based on the optimal sample size and power analysis according to the CONSORT statement; 20 to the Pioglitazone group and 19 to the Prednisone group. Pioglitazone was effective in decreasing serum HCV RNA at day-14 (n = 10; difference of means = 205,618 IU/ml; 95% CI 26,600 to 384,600; P<0.001). Although Prednisone did increase serum HCV RNA at day-4 (n = 10; change from baseline = -42,786 IU/ml; 95% CI -85,500 to -15,700; P = 0.049), the log(10) HCV RNA titers were statistically not different from baseline day-0.

CONCLUSION/SIGNIFICANCE

This is the first documentation that Pioglitazone decreases the serum HCV RNA titers independently of PEG-Interferon-α2/ribavirin treatment. The novel findings of our Study provide the foundation for basic and clinical investigations on the molecular mechanisms responsible for the Pioglitazone-induced decrease in HCV genotype 4 RNA titers.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01157975.

Insulin resistance impairs viral dynamics independently of ethnicity or genotypes

BACKGROUND AND AIM

Data concerning the influence of insulin resistance (IR) and ethnicity on early phases of viral kinetics after initiation of peginterferon plus ribavirin in treatment-naive, chronic hepatitis C (CHC) patients are limited.

METHODS

A total of 263 nondiabetic CHC patients treated with peginterferon plus ribavirin were enrolled for analysis from an Egyptian and Spanish center. IR was evaluated by homeostasis model assessment (HOMA)-IR. Hepatitis C virus (HCV) RNA levels were measured at baseline, 48 hours, 2, 4, and 12 weeks after treatment initiation. Sustained virological response (SVR) was examined 24 weeks after therapy discontinuation.

RESULTS

Baseline HOMA-IR strongly influenced 48 hours viral dynamics. HCV-RNA decay observed at 48 hours after the first injection of peginterferon was significantly lower (0.91±0.51 log) in patients with HOMA ≥2 compared with those with HOMA <2 (1.8±0.95 log, P=0.005) this effect was independent of stage of liver fibrosis, HCV genotype, and ethnicity. These differences remained with several cutoffs such as HOMA >3 or HOMA >4. Multivariate analysis identified baseline insulin levels as the main independent variable affecting the 48-hour response in addition to baseline HCV-RNA. The difference in early viral kinetics between patients with HOMA ≥2 or <2 is associated with a significant difference in the percentage of patients achieving both rapid virological response and SVR.

CONCLUSIONS

IR is a major determinant of the early viral kinetic response to peginterferon plus ribavirin, which has a great impact on subsequent rapid virological response and SVR in CHC patients. This suggests that strategies to improve IR may have a positive effect on SVR and may be early monitored.

Chronic hepatitis C treatment outcomes in low- and middle-income countries: a systematic review and meta-analysis

OBJECTIVE

To assess the effectiveness of treatment for hepatitis C virus (HCV) infection in low- and middle-income countries and identify factors associated with successful outcomes.

METHODS

We performed a systematic review and meta-analysis of studies of HCV treatment programmes in low- and middle-income countries. The primary outcome was a sustained virological response (SVR). Factors associated with treatment outcomes were identified by random-effects meta-regression analysis.

FINDINGS

The analysis involved data on 12 213 patients included in 93 studies from 17 countries. The overall SVR rate was 52% (95% confidence interval, CI: 48-56). For studies in which patients were predominantly infected with genotype 1 or 4 HCV, the pooled SVR rate was 49% (95% CI: 43-55). This was significantly lower than the rate of 59% (95% CI: 54-64) found in studies in which patients were predominantly infected with other genotypes (P = 0.012). Factors associated with successful outcomes included treatment with pegylated interferon and ribavirin, infection with an HCV genotype other than genotype 1 or 4 and the absence of liver damage or human immunodeficiency virus infection at baseline. No significant difference in the SVR rate was observed between weight-adjusted and fixed-dose ribavirin treatment. Overall, 17% (95% CI: 13-23) of adverse events resulted in treatment interruption or dose modification, but only 4% (95% CI: 3-5) resulted in treatment discontinuation.

CONCLUSION

The outcomes of treatment for HCV infection in low- and middle-income countries were similar to those reported in high-income countries.

Steatosis and insulin resistance in response to treatment of chronic hepatitis C

This review will focus on the impact of steatosis and insulin resistance on the response to antiviral therapy for chronic hepatitis C. Hepatitis C virus (HCV) infection is known to have direct and/or indirect effects on lipid and glucose metabolism, leading to, among other disturbances, steatosis and insulin resistance, respectively. Some of these disturbances have a marked HCV genotype distribution. For example, on average, patients with HCV genotype 3 have the highest prevalence and severity of viral fatty liver. On the other hand, the current global spread of the metabolic syndrome represents a formidable cofactor of morbidity in HCV-related chronic liver disease. Thus, the pathogenesis of steatosis and insulin resistance in patients with chronic hepatitis C may often be dual, i.e. viral and metabolic. This distinction is relevant because the effect (if any) of steatosis or insulin resistance on the response to antiviral agents seems to depend on their pathogenesis. Accumulating data suggest that viral fatty liver may not impact on response to therapy, while metabolic steatosis does. Similarly, viral insulin resistance may not reduce the rate of response to therapy to the same extent that metabolic insulin resistance does. Some implications for patient management are discussed.

Impact of insulin resistance on sustained response in HCV patients treated with pegylated interferon and ribavirin: a meta-analysis

BACKGROUND & AIMS

Recent studies suggested that SVR rates might be lower in HCV patients with insulin resistance (IR) than in patients without IR, but the extent of the impact of IR on treatment response has not been established. We aimed to confirm the role of IR assessed by the homoeostasis model assessment (HOMA-IR) on SVR and to determine its magnitude.

METHODS

We performed meta-analysis of studies evaluating the impact of IR in HCV patients treated with pegylated interferon and ribavirin.

RESULTS

Fourteen studies involving 2732 patients were included. SVR was less frequent in patients with IR than in patients without IR (mean difference: -19.6%, 95% CI: -29.9% to -9.4%, p<0.001). In sensitivity analyses according to HCV-1 patients, patients with IR also less frequently attained a SVR than patients without IR (mean difference: -13.0%, 95% CI: -22.6% to -3.4%, p=0.008). In addition, the baseline HOMA-IR index was lower in responders than in non-responders (mean difference: -0.92, 95% CI: -1.53 to -0.32, p<0.001). In sensitivity analyses restricted to HCV-1 patients, the baseline HOMA-IR index remained lower in responders than in non-responders (mean difference: -0.63, 95% CI: -1.13 to -0.14, p<0.001).

CONCLUSIONS

HCV patients with IR have a 20% lower SVR than patients without IR. The baseline HOMA-IR index is a major determinant of SVR.

Peroxisome proliferator-activated receptors and hepatitis C virus

The prevalence of type 2 diabetes mellitus and insulin resistance are higher among people chronically infected with hepatitis C (CHC) when compared with the general population and people with other causes of chronic liver disease. Both insulin resistance and diabetes are associated with adverse outcomes across all stages of CHC, including the liver transplant population. CHC is also associated with the development of hepatic steatosis, a common histological feature present in approximately 55% (32-81%) of cases. There is a complex interrelationship between insulin resistance and hepatic steatosis and both are postulated to aggravate each other. The peroxisome proliferator-activated receptors (PPARs) are nuclear factors involved in the regulation of glucose, lipid homeostasis, inflammatory response, cell differentiation, and cell cycle. The relationship between hepatitis C virus replication and PPARs has been the focus of recent study. Given the availability of potent agonists, PPARs may represent a novel pharmacological target in the treatment of CHC.

Use of HOMA-IR in hepatitis C

Chronic infection with hepatitis C virus (HCV) can induce insulin resistance (IR) in a genotype-dependent manner and contributes to steatosis, progression of fibrosis and resistance to interferon plus ribavirin therapy. Our understanding of HCV-induced IR has improved considerably over the years, but certain aspects concerning its evaluation still remain elusive to clinical researchers. One of the most important issues is elucidating the ideal method for assessment of IR in the setting of hepatitis C. The hyperinsulinaemic euglycaemic clamp is the gold standard method for determining insulin sensitivity, but is impractical as it is labour intensive and time-consuming. To date, all human studies except for four where IR was evaluated in the HCV setting, an estimation of IR has been used rather than direct measurements of insulin-mediated glucose uptake. The most commonly used estimation in the HCV population is the homeostasis model assessment of insulin resistance (HOMA-IR) which is calculated from a single measurement of fasting insulin and glucose. In this article, we review the use and reporting of HOMA in the literature and provide guidance on its appropriate as well as inappropriate use in the hepatitis setting.

Metabolic alterations and chronic hepatitis C: treatment strategies

INTRODUCTION

Chronic hepatitis C (HCV) infection is considered a metabolic disease. It is associated with a specific metabolic syndrome, HCV-associated dysmetabolic syndrome (HCADS), consisting of steatosis, hypocholesterolemia and insulin resistance/diabetes. These metabolic derangements contribute to a decrease in sustained virological response (SVR) to pegylated-interferon-α-ribavirin as standard of care (SOC), and are associated with progression of liver fibrosis.

AREAS COVERED

The review, highlighting the impact of HCADS and metabolic syndrome components of HCV disease progression and SOC, discusses current knowledge and perspectives on metabolic therapeutic strategies aimed at improving SVR rate of SOC for chronic hepatitis C.

EXPERT OPINION

HCV, features of HCADS and of metabolic syndrome may coexist in the same patient, thus all components of the metabolic syndrome must be assessed to individualize treatment. The results of therapeutic trials evaluating metabolic strategies combined with current SOC indicate that weight loss is a critical part of treatment which will improve both disease outcome and therapeutic response to SOC. Similarly, statins seem to improve response rate to SOC representing, once confirmed to be safe, an important therapeutic tool for HCV-infected patients. Findings from studies using insulin sensitizers combined with SOC are not conclusive and do not justify the use of this class of drugs in clinical practice.

Current understanding of insulin resistance in hepatitis C

Important breakthroughs have been made in recent years into understanding the close interaction between hepatitis C virus (HCV) infection and glucose homeostasis. Both cross-sectional and longitudinal studies have demonstrated that infection with HCV is associated with an increased risk of developing insulin resistance and Type 2 diabetes. A direct effect of HCV on hepatocyte insulin signaling has been shown in experimental models. Some preliminary observations seem to suggest that indirect mechanisms involving extrahepatic organs might also play a role. The interaction between HCV and glucose metabolism has significant clinical consequences. Insulin resistance and Type 2 diabetes not only accelerate the histological and clinical progression of chronic hepatitis C, but also reduce the virological response to IFN-α-based therapy. Thus, understanding the mechanisms underlying HCV-associated glucose metabolism derangements is of paramount interest in order to improve the clinical management of chronic hepatitis C. This article will focus on the studies that consistently argue in favor of an interrelation between HCV and insulin resistance and will highlight the latest discoveries in this field.

Meta-analysis: insulin resistance and sustained virological response in hepatitis C

BACKGROUND

A higher baseline homeostasis model assessment of insulin resistance (HOMA-IR) score has sometimes predicted a poorer sustained virological response (SVR) rate to peginterferon/ribavirin therapy in treatment-naïve chronic hepatitis C patients.

AIM

To perform a meta-analysis to evaluate the impact of HOMA-IR on SVR in hepatitis C.

METHODS

Relevant studies were identified by searching Medline and EMBASE. We identified 17 publications that addressed the influence of insulin resistance on SVR. The random effect model of Der Simonian and Laird method were used for heterogeneous studies using the Meta-Disc software 1.4, Madrid, Spain.

RESULTS

Normal insulin sensitivity was associated with a higher rate of SVR [odds ratio (OR) 2.86 (95%CI: 1.97-4.16)] in comparison with insulin resistance. Moreover, in separate analysis by genotype selecting studies that used HOMA-IR > 2 as cut-off defining insulin resistance, SVR was higher in patients with HOMA-IR < 2 in all genotypes: HCV-1 [OR: 2.16 (95%CI: 1.51-3.08)], HCV-2&3 [OR: 3.06 (95%CI: 1.06-8.82)] and HCV-4 [OR: 6.65(95%CI: 2.51-17.61)]. Studies reporting no association between HOMA and SVR included easy-to-cure cohorts, analysed variables strongly related with insulin resistance like body mass index, steatosis, hyper γGT, age and fibrosis and reported differences in handling and interpretation of HOMA-IR.

CONCLUSION

Elevated HOMA-IR was associated with a lower cure rate of patients with hepatitis C treated with Peg-IFN-α/ribavirin irrespective of genotype, and the more difficult-to-treat cohort, the better the HOMA-IR prediction. HOMA-IR is, as a surrogate marker of insulin resistance, susceptible to some biases derived from both handling and interpretation.

Management of hepatitis C virus genotype 4: recommendations of an international expert panel

HCV has been classified into no fewer than six major genotypes and a series of subtypes. Each HCV genotype is unique with respect to its nucleotide sequence, geographic distribution, and response to therapy. Genotypes 1, 2, and 3 are common throughout North America and Europe. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa, where it is responsible for more than 80% of HCV infections. It has recently spread to several European countries. HCV-4 is considered a major cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation in these regions. Although HCV-4 is the cause of approximately 20% of the 170 million cases of chronic hepatitis C in the world, it has not been the subject of widespread research. Therefore, this document, drafted by a panel of international experts, aimed to review current knowledge on the epidemiology, natural history, clinical, histological features, and treatment of HCV-4 infections.

Insulin resistance and chronic liver disease

Increased insulin resistance is frequently associated with chronic liver disease and is a pathophysiological feature of hepatogenous diabetes. Distinctive factors including hepatic parenchymal cell damage, portal-systemic shunting and hepatitis C virus are responsible for the development of hepatogenous insulin resistance/diabetes. Although it remains unclear whether insulin secretion from pancreatic beta cells is impaired as it is in type 2 diabetes, retinopathic and cardiovascular risk is low and major causes of death in cirrhotic patients with diabetes are liver failure, hepatocellular carcinoma and gastrointestinal hemorrhage. Hemoglobin A1c is an inaccurate marker for the assessment and management of hepatogenous diabetes. Moreover, exogenous insulin or sulfonylureas may be harmful because these agents may promote hepatocarcinogenesis. Thus, pathogenesis, cause of death, assessment and therapeutic strategy for hepatogenous insulin resistance/diabetes differ from those for lifestyle-related type 2 diabetes. In this article, we review features of insulin resistance in relationship to chronic liver disease. We also discuss the impact of anti-diabetic agents on interferon treatment and hepatocarcinogenesis.

IL28B polymorphisms, IP-10 and viral load predict virological response to therapy in chronic hepatitis C

BACKGROUND

Hepatitis C virus (HCV) is a major cause of chronic liver disease, cirrhosis and hepatocellular carcinoma and the identification of the predictors of response to antiviral therapy is an important clinical issue.

AIM

To determine the independent contribution of factors including IL28B polymorphisms, IFN-gamma inducible protein-10 (IP-10) levels and the homeostasis model assessment of insulin resistance (HOMA-IR) score in predicting response to therapy in chronic hepatitis C (CHC).

METHODS

Multivariate analysis of factors predicting rapid (RVR) and sustained (SVR) virological response in 280 consecutive, treatment-naive CHC patients treated with peginterferon alpha and ribavirin in a prospective multicentre study.

RESULTS

Independent predictors of RVR were HCV RNA <400 000 IU/mL (OR 11.37; 95% CI 3.03-42.6), rs12980275 AA (OR 7.09; 1.97-25.56) and IP-10 (OR 0.04; 0.003-0.56) in HCV genotype 1 patients and lower baseline γ-glutamyl-transferase levels (OR=0.02; 0.0009-0.31) in HCV genotype 3 patients. Independent predictors of SVR were rs12980275 AA (OR 9.68; 3.44-27.18), age <40 years (OR=4.79; 1.50-15.34) and HCV RNA <400 000 IU/mL (OR 2.74; 1.03-7.27) in HCV genotype 1 patients and rs12980275 AA (OR=6.26; 1.98-19.74) and age <40 years (OR 5.37; 1.54-18.75) in the 88 HCV genotype 1 patients without a RVR. RVR was by itself predictive of SVR in HCV genotype 1 patients (OR 33.0; 4.06-268.32) and the only independent predictor of SVR in HCV genotype 2 (OR 9.0, 1.72-46.99) or genotype 3 patients (OR 7.8, 1.43-42.67).

CONCLUSIONS

In HCV genotype 1 patients, IL28B polymorphisms, HCV RNA load and IP-10 independently predict RVR. The combination of IL28B polymorphisms, HCV RNA level and age may yield more accurate pre-treatment prediction of SVR. HOMA-IR score is not associated with viral response.

Prevalence and impact of hepatic steatosis on the response to antiviral therapy in Saudi patients with genotypes 1 and 4 chronic hepatitis C

BACKGROUND

Hepatic steatosis in hepatitis C virus (HCV)-infected patients has been shown to enhance the progression of liver fibrosis and decrease the response to antiviral therapy.

AIMS

We aimed to determine the role of HCV genotype 4 (HCV-G4) in the prevalence of hepatic steatosis, its impact on antiviral therapy, and its associations and predictive factors in comparison to HCV-G1-infected patients.

METHODS

Treatment-naïve HCV patients who were started on pegylated interferon a-2b plus ribavirin therapy in two centers in Saudi Arabia were included. The severity of steatosis was assessed using the METAVIR and NAS (non-alcoholic fatty liver disease [NAFLD] activity score) scoring systems. Sustained virological response (SVR) was studied in relation to the degree of steatosis. Associations between steatosis and multiple demographic, laboratory, and virological factors were examined. HCV-G1 and HCV-G4 patients were compared.

RESULTS

A total of 116 patients (HCV-G4 85 [73.3%]; HCV-G1 31 [26.7%]) were included. The mean age was 50.4±10.7 years and 56.9% were males. In terms of steatosis grading using the NAS scoring system, 50% had steatosis grade 0, 26.7% grade 1, 14.7% grade 2, and 8.6% grade 3, while the overall staging of steatosis revealed that 43.1% had mild steatosis, 42.2% moderate, and 14.7% severe. Gamma-glutamyl transpeptidase (GGT), platelet count, body mass index (BMI), cholesterol level, presence of hyperlipidemia, liver histology stage, and grade were significantly correlated with hepatic steatosis in one or more of the statistical analyses. Twenty-two out of 55 patients (40.0%) had an SVR in the mild steatosis group, compared to 52.7% in the moderate group and 7.3% in the severe group (P=0.03). The HCV genotype did not correlate with steatosis or SVR.

CONCLUSION

Our study confirms the high prevalence of steatosis in HCV-G4 and HCV-G1 patients, but with no difference in the grade or score of steatosis between the two genotypes. The grade of steatosis correlates with GGT, platelet count, and BMI, while the NAS score of steatosis correlates with response to antiviral therapy.

Role of interleukin-28B polymorphisms in the treatment of hepatitis C virus genotype 2 infection in Asian patients

Genome-wide association studies have linked single nucleotide polymorphisms (SNPs) near the interleukin-28B gene to the hepatitis C virus genotype 1 (HCV-1) response to peginterferon/ribavirin treatment. We aimed to explore the impact on the treatment outcomes of Asian HCV-2 patients. We determined rs8105790, rs8099917, rs4803219, and rs10853728 to be candidate SNPs in 482 Asian HCV-2 patients treated with the standard of care. Because the first three SNPs were in very strong linkage disequilibrium with one another (r2 = 0.94-0.96), rs8099917 and rs10853728 were selected for an analysis of their influence on the achievement of rapid virological response [RVR; seronegativity for hepatitis C virus (HCV) RNA in treatment week 4] and sustained virological response (SVR; seronegativity for HCV RNA throughout 24 weeks of posttreatment follow-up). The rs10853728 genotype did not predict RVR or SVR in HCV-2 patients. However, patients with the rs8099917 TT genotype, in comparison with patients with GT/GG genotypes, had a significantly higher rate of achieving RVR (85.2% versus 72.0%, P = 0.017) but did have not a significantly higher rate of achieving SVR (89.4% versus 86.0%). Multivariate analysis revealed that a baseline HCV viral load <400,000 IU/mL was the strongest predictor of RVR [odds ratio (OR) = 4.27, 95% confidence interval (CI) = 2.31-7.87, P < 0.001], and this was followed by advanced liver fibrosis (OR = 0.28, 95% CI = 0.15-0.53, P < 0.001), the carriage of the rs8099917 TT genotype (OR = 3.10, 95% CI = 1.34-7.21, P = 0.008), and the pretreatment level of aspartate aminotransferase (OR = 0.996, 95% CI = 0.99-1.00, P = 0.04). Nevertheless, the achievement of RVR was the single predictor of SVR with an OR of 19.37 (95% CI = 8.89-42.23, P < 0.001), whereas the rs8099917 genotypes played no role in achieving SVR with or without RVR.

CONCLUSION

The rs8099917 TT genotype is significantly independently predictive of RVR, which is the single best predictor of SVR, in Asian HCV-2 patients.