Insulin resistance and steatosis in hepatitis C virus infection

Alcohol and hepatocellular carcinoma

BACKGROUND

Alcohol is classified as a Group 1 carcinogen by the International Agency for Research on Cancer because it induces hepatocellular carcinoma (among other cancers) in humans. An excessive alcohol intake may result in fatty liver, acute/chronic hepatitis, and cirrhosis and eventually lead to hepatocellular carcinoma. It has been reported that alcohol abuse increases the relative risk of hepatocellular carcinoma by 3- to 10-fold.

AIM AND METHODS

To clarify the known mechanisms of alcohol-related carcinogenesis, we searched Pubmed using the terms alcohol and immune mechanism, alcohol and cancer, and immune mechanism and cancer and summarized the articles as a qualitative review.

RESULTS

From a clinical perspective, it is well known that alcohol interacts with other factors, such as smoking, viral hepatitis, and diabetes, leading to an increased risk of hepatocellular carcinoma. There are several possible mechanisms through which alcohol may induce liver carcinogenicity, including the mutagenic effects of acetaldehyde and the production of ROS due to the excessive hepatic deposition of iron. Furthermore, it has been reported that alcohol accelerates hepatitis C virus-induced liver tumorigenesis through TLR4 signaling. Despite intense investigations to elucidate the mechanisms, they remain poorly understood.

CONCLUSION

This review summarizes the recent findings of clinical and pathological studies that have investigated the carcinogenic effects of alcohol in the liver.

Lipids, glucose and iron metabolic alterations in chronic hepatitis C after viral eradication - comparison of the new direct-acting antiviral agents with the old regimens

BACKGROUND

Hepatitis C virus (HCV) is a unique virus which interacts with cholesterol, iron and insulin metabolism. There is limited data on the effects of direct-acting antiviral agents (DAAs) on metabolic profiles. We aimed at evaluating the behavior of metabolic risk factors of chronically HCV-infected patients after sustained virologic response (SVR), comparing the outcomes with the new DAAs versus the old treatment regimen Peg-interferon ± ribavirin.

METHODS

A total of 178 patients who achieved SVR and completed one year of follow-up were prospectively included in this study: group 1 with 105 patients treated with DAAs and group 2 with 73 patients treated with old regimens. Outcomes included lipid, glucose and iron metabolism variation after SVR.

RESULTS

There was a significant increase in total cholesterol in both groups (group 1: p < .001, 95% CI: 0.41-0.78; group 2: p < .001, 95% CI: 0.24-0.69). Triglyceride levels significantly decreased (p = .015, 95% CI: -0.33-0.04) in group 1 and increased (p = .014, 95% CI: 0.07-0.59) in group 2. LDL levels increased in group 1 (p = .029, 95% CI: 0.05-0.88), but no significant variation was found in group 2. No significant variation in HDL, fast glucose and iron was seen in both groups. There was a significant increase of HOMA (p = .002, 95% CI: 0.17592-0.72317) only in group 2. Ferritin serum levels significantly decreased (p < .001, 95% CI:-138.3-74.4) in group 1 but no significant variation was found in group 2.

CONCLUSION

Patients who have achieved SVR may have increased risk of cardiovascular outcomes due to development of hyperlipidemia and insulin resistance.

Alcoholic liver disease and hepatitis C virus infection

Alcohol consumption and hepatitis C virus (HCV) infection have a synergic hepatotoxic effect, and the coexistence of these factors increases the risk of advanced liver disease. The main mechanisms of this effect are increased viral replication and altered immune response, although genetic predisposition may also play an important role. Traditionally, HCV prevalence has been considered to be higher (up to 50%) in alcoholic patients than in the general population. However, the presence of advanced alcoholic liver disease (ALD) or intravenous drug use (IDU) may have confounded the results of previous studies, and the real prevalence of HCV infection in alcoholic patients without ALD or prior IDU has been shown to be lower. Due to the toxic combined effect of HCV and alcohol, patients with HCV infection should be screened for excessive ethanol intake. Patients starting treatment for HCV infection should be specifically advised to stop or reduce alcohol consumption because of its potential impact on treatment efficacy and adherence and may benefit from additional support during antiviral therapy. This recommendation might be extended to all currently recommended drugs for HCV treatment. Patients with alcohol dependence and HCV infection, can be treated with acamprosate, nalmefene, topiramate, and disulfiram, although baclofen is the only drug specifically tested for this purpose in patients with ALD and/or HCV infection.

Alcoholic liver disease and hepatitis C virus infection

Alcohol consumption and hepatitis C virus (HCV) infection have a synergic hepatotoxic effect, and the coexistence of these factors increases the risk of advanced liver disease. The main mechanisms of this effect are increased viral replication and altered immune response, although genetic predisposition may also play an important role. Traditionally, HCV prevalence has been considered to be higher (up to 50%) in alcoholic patients than in the general population. However, the presence of advanced alcoholic liver disease (ALD) or intravenous drug use (IDU) may have confounded the results of previous studies, and the real prevalence of HCV infection in alcoholic patients without ALD or prior IDU has been shown to be lower. Due to the toxic combined effect of HCV and alcohol, patients with HCV infection should be screened for excessive ethanol intake. Patients starting treatment for HCV infection should be specifically advised to stop or reduce alcohol consumption because of its potential impact on treatment efficacy and adherence and may benefit from additional support during antiviral therapy. This recommendation might be extended to all currently recommended drugs for HCV treatment. Patients with alcohol dependence and HCV infection, can be treated with acamprosate, nalmefene, topiramate, and disulfiram, although baclofen is the only drug specifically tested for this purpose in patients with ALD and/or HCV infection.

n-3 polyunsaturated fatty acid supplementation reduces insulin resistance in hepatitis C virus infected patients: a randomised controlled trial

BACKGROUND

Insulin resistance promotes liver disease progression and may be associated with a lower response rate in treated hepatitis C virus (HCV) infected patients. n-3 polyunsaturated fatty acid (PUFA) supplementation may reduce insulin resistance. The present study aimed to evaluate the effect of n-3 PUFA supplementation on insulin resistance in these patients.

METHODS

In a randomised, double-blind clinical trial, 154 patients were screened. After applying inclusion criteria, 52 patients [homeostasis model assessment index of insulin resistance (HOMA-IR ≥2.5)] were randomly divided into two groups: n-3 PUFA (n = 25/6000 mg day(-1) of fish oil) or control (n = 27/6000 mg day(-1) of soybean oil). Both groups were supplemented for 12 weeks and underwent monthly nutritional consultation. Biochemical tests were performed at baseline and after intervention. Statistical analysis was performed using the Wilcoxon Mann-Whitney test for comparisons and the Wilcoxon test for paired data. Statistical package r, version 3.02 (The R Project for Statistical Computing) was used and P < 0.05 (two-tailed) was considered statistically significant.

RESULTS

Comparisons between groups showed that n-3 PUFA supplementation was more effective than the control for reducing HOMA-IR (P = 0.015) and serum insulin (P = 0.016). The n-3 PUFA group not only showed a significant reduction in HOMA-IR 3.8 (3.2-5.0) versus 2.4 (1.8-3.3) (P = 0.002); serum insulin 17.1 (13.8-20.6) μIU mL(-1) versus 10.9 (8.6-14.6) μIU mL(-1) (P = 0.001); and glycated haemoglobin 5.4% (5.0-5.7%) versus 5.1% (4.8-5.6%) (P = 0.011), but also presented an increase in interleukin-1 97.5 (0.0-199.8) pg mL(-1) versus 192.4 (102.2-266.8) pg mL(-1) (P = 0.003) and tumour necrosis factor 121.2 (0.0-171.3) pg mL(-1) versus 185.7 (98.0-246.9) pg mL(-1) (P = 0.003).

CONCLUSIONS

n-3 PUFA supplementation reduces insulin resistance in genotype 1 HCV infected patients.

Correlates of adiponectin in hepatitis C-infected children: the importance of body mass index

OBJECTIVES

Adiponectin is a regulator of cytokines that, in turn, play a vital role in inflammatory and immune responses. Adiponectin is therefore likely to have a contributory role in hepatitis C virus (HCV) infection. We sought to characterize adiponectin levels and examine correlates in a pediatric HCV-infected cohort.

METHODS

We performed a cross-sectional study in children (5-17 years of age, n = 86) in the Pediatric Study of Hepatitis C (PEDS-C) trial. Adiponectin levels were univariately correlated with patient demographics, anthropometrics, and viral and histological measures. Multivariate regression models were used to identify the unique (ie, nonconfounded) associations with adiponectin concentrations.

RESULTS

Body mass index (BMI) had the highest univariate inverse correlation with log(e) adiponectin (r = -0.5, P < 0.0001). In multivariate analysis, BMI remained inversely correlated with log(e) adiponectin after accounting for age and route of HCV transmission (r = -0.38, P = 0.0003). Steatosis and fibrosis were inversely related to log(e) adiponectin in univariate analysis, but these associations were not statistically significant after multivariate adjustments (P ≥ 0.1827).

CONCLUSIONS

High BMI among HCV-infected children is associated with lower adiponectin levels. Practitioners should be cognizant of the possible risks of low adiponectin when managing HCV-infected children who are overweight. Further studies are indicated to determine the impact of having low adiponectin on HCV infection in youth.

Reduced heme oxygenase-1 expression in steatotic livers infected with hepatitis C virus

Hepatic nonalcoholic fatty liver disease (NAFLD) is known to exacerbate liver injury due to chronic hepatitis C infection. Heme oxygenase-1 (HO-1) is an important protective antioxidative defense enzyme that is known to be induced in response to NAFLD and other liver injuries. The aim of this study was to evaluate HO-1 expression in HCV infected human livers with concomitant NAFLD.

METHODS

We compared levels of HO-1 in NAFLD liver biopsies from patients with or without chronic HCV infection using immunohistochemistry, immunoblots and real time RT-PCR. We also evaluated frozen sections of liver with dihydroethidium (DHE) or dichlorofluorescein (DCF) fluorescence staining to evaluate O(2)(-) and peroxide production respectively.

RESULTS

HO-1 expression was only increased in NAFLD livers without HCV infection, while HCV infected livers showed reduced HO-1 levels, regardless whether NAFLD was present. In uninfected livers with NAFLD, HO-1 expression was primarily localized in hepatocytes containing fat and areas of injury around the central vein. However, both NAFLD with and without concomitant HCV infection showed high levels of O(2)(-) or peroxide production compared to normal human liver control samples.

CONCLUSIONS

These findings support the hypothesis that NAFLD is an important process for hepatocyte oxidative stress and injury in liver diseases. They also suggest that HCV can repress HO-1 induction in vivo even when other inducers of HO-1 are present.

Effect of soy protein supplementation in patients with chronic hepatitis C: a randomized clinical trial

AIM

To evaluate the effects of soy supplementation on insulin resistance, fatty liver and alanine aminotransferase (ALT) levels in non-diabetic patients with chronic hepatitis C (CHC).

METHODS

In a prospective, randomized and single-blinded clinical trial, we compared patients with CHC who had casein as a supplement (n = 80) (control group), with patients who consumed a soy supplement diet (n = 80) [intervention group (IG)]. Both groups received 32 g/d of protein for 12 wk.

RESULTS

Patients' baseline features showed that 48.1% were overweight, 43.7% had abdominal fat accumulation, 34.7% had hepatic steatosis and 36.3% had an homeostasis model assessment index of insulin resistance (HOMA-IR) ≥ 3.0. Descriptive analysis showed that protein supplementation diet reduced hepatic steatosis in both groups; however, significant reductions in ALT levels occurred in the soy group. Multiple regression modeling indicated that in the presence of severe fibrosis (F3/F4), γ glutamyl transferase elevation and high density lipoprotein (HDL) reduction, the intervention group had 75% less chance of developing hepatic steatosis (OR= 0.25; 95% CI: 0.06-0.82) and 55% less chance of presenting with an ALT level ≥ 1.5 × the upper limit of normal (ULN) (OR = 0.45, 95% CI: 0.22-0.89). Soy treatment did not have any effect on insulin resistance (OR = 1.92; 95% CI: 0.80-4.83), which might be attributed to the fact that the HOMA-IR values at baseline in most of our patients were in the normal range. Advanced hepatic fibrosis, an ALT level > 1.5 × ULN and visceral fat were predictors of an HOMA-IR ≥ 3. The IG group had a reduced risk of an ALT level > 1.5 × ULN. An HOMA-IR ≥ 3.0 and HDL < 35 mg/dL were also risk factors for increased ALT.

CONCLUSION

Soy supplementation decreased ALT levels and thus may improve liver inflammation in hepatitis C virus (HCV) patients; it also reduced hepatic steatosis in a subgroup of patients but did not change insulin resistance. It should be considered in the nutritional care of HCV patients.

The impact of host metabolic factors on treatment outcome in chronic hepatitis C

Background. Recent data suggest that chronic hepatitis C has to be considered a metabolic disease further to a viral infection. The aim of this study was to elaborate on the complex interactions between hepatitis C virus, host metabolic factors, and treatment response. Methods. Demographic, virological, and histological data from 356 consecutive patients were analyzed retrospectively. Hepatic steatosis, obesity, and insulin resistance were examined in relation to their impact on treatment outcome. Comparison between genotype 1 and 3 patients was performed to identify differences in the determinants of hepatic steatosis. Results. Histological evidence of hepatic steatosis was found in 113 patients, distributed in 20.3%, 9.0%, and 2.5% for grades I, II, and III, respectively. Hepatic steatosis was associated with past alcohol abuse (P = 0.003) and histological evidence of advanced fibrosis (P < 0.001). Older age (OR 2.51, P = 0.002), genotype (OR 3.28, P < 0.001), cirrhosis (OR 4.23, P = 0.005), and hepatic steatosis (OR 2.48, P = 0.001) were independent predictors for nonresponse. Correlations of hepatic steatosis with alcohol, insulin resistance, and fibrosis stage were found similar for both genotypes 1 and 3. Conclusions. Host metabolic factors may predict treatment outcome, and this impact remains significant even in genotype 3, where steatosis has been believed to be exclusively virus related.

Hepatitis C core protein impairs insulin downstream signalling and regulatory role of IGFBP-1 expression

Chronic infection with hepatitis C virus (HCV), mainly genotype 1, has been shown to be associated with insulin resistance and type 2 diabetes. The mechanisms underlying this association are partly understood. Increased levels of tumor necrosis factor (TNF)-α occurring in HCV infection have an important role in HCV-mediated insulin resistance; however, other direct effects of HCV core protein on disrupting insulin signalling have been suggested. The insulin receptor substrate (IRS) proteins are key players in insulin signal transduction and are the major substrates of the insulin receptor. To further elucidate the direct effect of HCV core protein on insulin signalling. We studied the direct effects of HCV core protein in two cell lines transfected with HCV core protein. We found several impairments in the insulin signalling cascade which could be attributed to a significant proteasomal degradation of IRS-1 protein, in a dose-dependent way. In addition, our data show that liver cells transfected by HCV core protein show a marked attenuation of the regulatory inhibitory role of insulin on insulin growth factor binding protein-1 (IGFBP-1) expression. Since IGFBP-1 may have a role in glucose regulation and hepatic insulin sensitivity, this effect of HCV core protein can contribute to insulin resistance in chronic HCV infection. Our data suggest that the degradation of IRS-1 by HCV core protein translates to impaired ability of insulin to inhibit the expression of the target gene IGFBP-1 in the liver and may serve as a novel mechanism for insulin resistance and hyperglycaemia.

Metabolic syndrome in patients with chronic hepatitis C virus genotype 1 infection who do not have obesity or type 2 diabetes

OBJECTIVE

The individual components of metabolic syndrome may be independent predictors of mortality in patients with liver disease. We aimed to evaluate the prevalence of metabolic syndrome and its related components in hepatitis C virus-infected patients who are not obese and do not have type 2 diabetes.

METHODS

This cross-sectional study included 125 patients infected with hepatitis C virus genotype 1. Metabolic syndrome was defined according to the International Diabetes Federation. Anthropometric data were measured according to standardized procedures. Bioimpedance analysis was performed on all patients.

RESULTS

Metabolic syndrome was diagnosed in 21.6% of patients. Of the subjects with metabolic syndrome, 59.3% had hypertension, 77.8% had insulin resistance, 85.2% were overweight, 48.1% had a high waist circumference, 85.2% had an increased body fat percentage, and 92.3% had an elevated waist:hip ratio. In the bivariate analysis, female sex (OR 2.58; 95% CI: 1.09-6.25), elevated gamma-glutamyl transferase (γGT) (OR 2.63; 95% CI: 1.04-7.29), elevated fasting glucose (OR 8.05; 95% CI: 3.17-21.32), low HDL cholesterol (OR 2.80; 95% CI: 1.07-7.16), hypertriglyceridemia (OR 7.91; 95% CI: 2.88-22.71), elevated waist circumference (OR 10.33; 95% CI: 3.72-30.67), overweight (OR 11.33; 95% CI: 3.97-41.07), and increased body fat percentage (OR 8.34; 95% CI: 2.94-30.08) were independent determinants of metabolic syndrome. Using the final multivariate regression model, similar results were observed for abdominal fat (OR 9.98; 95% CI: 2.63-44.41) and total body fat percentage (OR 8.73; 95% CI: 2.33-42.34). However, metabolic syndrome risk was also high for those with blood glucose >5.55 mmol/L or HDL cholesterol <0.9 mmol/L (OR 16.69; 95% CI: 4.64-76.35; OR 7.23; 95% CI: 1.86-32.63, respectively).

CONCLUSION

Metabolic syndrome is highly prevalent among hepatitis C virus-infected patients without type 2 diabetes or obesity. Metabolic syndrome was significantly associated with hypertension, insulin resistance, increased abdominal fat, and overweight.

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.

Chemokine antagonism in chronic hepatitis C virus infection

Immune responses to hepatitis C virus (HCV) fail to clear the virus in most individuals. Why patients who are less likely to clear HCV infection have high plasma levels of CXCL10 (also known as IP-10), a chemokine that directs T cells to sites of infection, has long been unclear. In this issue of the JCI, Casrouge and colleagues shed light on this paradox by showing that CXCL10 in the plasma of many HCV patients is enzymatically processed to produce a CXCL10 receptor antagonist. These findings introduce a role for chemokine antagonism during HCV infection and unveil new avenues for improved HCV diagnosis and therapy.

Hepatitis C and metabolic syndrome

Hepatitis C virus (HCV) and the hepatic manifestation of metabolic syndrome, nonalcoholic fatty liver disease, are the two major causes of chronic liver disease worldwide. Liver histology of both diseases can be associated with steatosis, oxidative stress and fibrogenesis. Although better defined for HCV, approximately 20% of patients with these diseases can also develop cirrhosis or hepatocellular carcinoma. In recent years, it has become clear that the presence of metabolic syndrome and nonalcoholic fatty liver disease negatively impacts HCV-related outcomes, while simultaneously, the progression of HCV may have metabolic consequences in that it encourages or exacerbates insulin resistance. A growing body of evidence suggests that successful treatment of HCV may rely on understanding and addressing the complex and often mutually confounding relationship between HCV and the individual elements that comprise metabolic syndrome.

Chronic hepatitis C virus infection associated with autonomic dysfunction

BACKGROUND

Impaired autonomic function has been described in patients with chronic liver diseases from different aetiologies, and has proven to be a poor prognostic indicator. To date, it is not known how chronic hepatitis C virus (HCV) infection affects the autonomic nervous system.

AIMS

In the present study, we compared cardiovagal autonomic function in patients with chronic HCV infection and healthy controls and examined the relation between autonomic function and serum levels of aminotransferases, HCV RNA, cryoglobulins, albumin and glucose.

METHODS

Autonomic function was assessed in 45 treatment-naïve patients with chronic HCV infection and in 40 healthy controls by determining spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV) indices. The R-R interval was determined by electrocardiogram recording; continuous radial artery pressure was monitored simultaneously by applanation tonometry. Laboratory analyses and quantitative polymerase chain reaction for serum HCV RNA level were performed by standard procedures.

RESULTS

BRS and HRV time and frequency domain indices were lower in patients with HCV infection compared with healthy controls [7.1+/-3.4 vs. 11.5+/-6.5 ms/mmHg for BRS, 168.5+/-160.9 vs. 370.7+/-349.4 ms(2) for low-frequency HRV (mean+/-SD); P<0.01]. Multivariate analysis showed that autonomic dysfunction in HCV-infected patients correlated with elevated alanine aminotransferase levels, but was not associated with serum HCV RNA levels and cryoglobulins.

CONCLUSION

Our results suggest that impaired autonomic function is caused by chronic HCV infection. Further studies are needed, however, to identify the underlying mechanisms.

Mechanisms of glucose intolerance in patients with chronic hepatitis C: Implications for treatment

Both diabetes and chronic hepatitis C virus (HCV) infection are common conditions that often coexist in the same subject. Studies seem to confirm the presence of an association between them. Mechanisms leading to HCV-induced insulin resistance and glucose intolerance are beginning to be elucidated. Insulin resistance in the setting of chronic HCV infection could be related etiologically to viral factors but is also often seen with concomitant nonalcoholic fatty liver disease, the hepatic manifestation of the metabolic syndrome. Insulin resistance decreases the likelihood of response to interferon-based therapies and may be an independent risk factor for the progression of HCV-related liver disease.

Insulin resistance predicts response to peginterferon-alpha/ribavirin combination therapy in chronic hepatitis C patients

BACKGROUND/AIMS

Insulin resistance (IR) might be associated with hepatitis C virus (HCV) infection. This study aimed to elucidate impact of IR and beta-cell function on the response to peginterferon-alpha (PEG-IFN)/ribavirin combination therapy in chronic hepatitis C (CHC) patients.

METHODS

Three hundred and thirty patients without overt diabetes were treated with combination therapy with (PEG-IFN)/ribavirin for 24 weeks. The IR and beta-cell function were evaluated by homeostasis model assessment of IR (HOMA-IR) and homeostasis model assessment of beta-cell function (HOMA-beta) before treatment.

RESULTS

HCV genotype, pretreatment HCV RNA level and pretreatment HOMA-IR, but not HOMA-beta, were independent factors associated with sustained virologic response (SVR). In 150 patients with genotype 1b infection, pretreatment HCV RNA level, HOMA-IR and age were independent predictors for SVR. The significantly lower SVR rate in high HOMA-IR patients was observed in 76 patients with high HCV RNA levels (>or=400,000IU/mL) who were defined as 'difficult-to-treat' patients. The mean HOMA-IR of 'difficult-to-treat' patients was significantly lower in 42 sustained responders than in 34 non-responders.

CONCLUSIONS

IR was associated with SVR to (PEG-IFN)/ribavirin therapy for CHC, especially among 'difficult-to-treat' patients. These findings suggested clinical application of pretreatment HOMA-IR could enable treatment outcome to be predicted and treatment regimens to be determined.

A novel role for adiponectin in regulating the immune responses in chronic hepatitis C virus infection

Adipose tissue releases pro-inflammatory and anti-inflammatory mediators, including adiponectin, which elicit a broad range of metabolic and immunological effects. The study aim was to determine in subjects infected with chronic hepatitis C virus (HCV) the effects of total adiponectin and its high-molecular-weight (HMW) and low-molecular-weight isoforms on HCV-specific immune responses. Serum levels of total adiponectin and its isoforms were determined by immunoassay. The ex vivo effect of adiponectin on the HCV-specific T-cell response was examined by interferon gamma (IFN-gamma) enzyme-linked immunosorbent spot and enzyme-linked immunosorbent assay cytokine assays. The role of the mitogen-activated protein kinase (MAPK) signaling pathway in mediating the adiponectin effect on T cells was also evaluated. We found that serum levels of total and HMW adiponectin were significantly decreased in subjects with chronic HCV and increased body mass index (BMI) compared with HCV-infected lean subjects. The presence of an anti-HCV specific immune response was strongly associated with lower BMI (P = 0.004) and higher serum total (P = 0.01) and HMW (P = 0.02) adiponectin. In ex vivo assays, total adiponectin and the HMW adiponectin isoform enhanced HCV-specific IFN-gamma production (P = 0.02 and 0.03, respectively). Adiponectin-R1 receptors were expressed on T cells and monocytes. In depletion experiments, the IFN-gamma response to adiponectin was entirely dependent on the simultaneous presence of both CD4 and CD8 T cells, and to a lesser extent, natural killer cells. Selective inhibition of p38MAPK activity by SB203580 abrogated the IFN-gamma response to adiponectin, whereas extracellular signal-regulated kinase 1/2 inhibition by PD98059 did not affect the response.

CONCLUSION

In chronic HCV, a reciprocal association exists between BMI, adiponectin, and the anti-HCV immune responses, emphasizing the important role played by adiposity in regulating the immune response in HCV infection.

Treatment responses in Asians and Caucasians with chronic hepatitis C infection

AIM: To conduct a multicentre retrospective review of virological response rates in Asians infected with genotype 1 chronic hepatitis C (CHC) treated with combination interferon and ribavirin and then to compare their responses to that among Caucasians.

METHODS: Asian patients infected with genotype 1 CHC treated at 4 Australian centres between 2001 to 2005 were identified through hospital databases. Baseline demographic characteristics, biochemical, virological and histological data and details of treatment were collected. Sustained virological responses (SVR) in this cohort were then compared to that in Caucasian subjects, matched by genotype, age, gender and the stage of hepatic fibrosis.

RESULTS: A total of 108 Asians with genotype 1 CHC were identified. The end of treatment response (ETR) for the cohort was 79% while the SVR was 67%. Due to the relatively advanced age of the Asian cohort, only sixty-four subjects could be matched with Caucasians. The ETR among matched Asians and Caucasians was 81% and 56% respectively (P = 0.003), while the SVR rates were 73% and 36% (P < 0.001) respectively. This difference remained significant after adjusting for other predictive variables.

CONCLUSION: Genotype 1 CHC in Asian subjects is associated with higher rates of virological response compared to that in Caucasians.

Evidence of oxidative stress as a cofactor in the development of insulin resistance in patients with chronic hepatitis C

AIM

The mechanisms by which metabolic disorders develop in patients with chronic hepatitis C are unknown. Our study aimed to test whether oxidative stress contributes to these mechanisms.

METHODS

The index of homeostasis model assessment-insulin resistance (HOMA-IR) and serum and hepatic levels of thioredoxin (Trx), which are markers of oxidative stress, were evaluated in 203 biopsy-proven chronic hepatitis C patients with hepatitis C virus (HCV) genotype 1 or 2 infection. HOMA-IR and Trx levels were compared with baseline values after phlebotomy in 23 patients.

RESULTS

HOMA-IR and serum Trx levels were significantly correlated with disease stage (HOMA-IR, P < 0.00001; Trx, P < 0.0001) and independently predicted fibrosis scores (HOMA-IR, P < 0.05; Trx, P < 0.005). Steatosis (%) was significantly correlated with HOMA-IR (P < 0.00005) and Trx (P < 0.001) stage (P < 0.00001). Serum Trx levels were significantly correlated with HOMA-IR (P < 0.05), even after adjustment for body mass index (P < 0.05). Furthermore, the mRNA levels of hepatic Trx were significantly correlated with HOMA-IR (P < 0.05) and independently-predicted HOMA-IR (P < 0.05). The alanine aminotransferase (P < 0.00001), Trx (P < 0.05), and HOMA-IR (P < 0.05) serum levels decreased significantly after phlebotomy; these effects were similar even in non-responders to interferon.

CONCLUSION

Oxidative stress contributed to the development of IR irrespective of obesity in patients with HCV genotype 1 or 2 infection. This study could contribute to our understanding of how metabolic disorders develop and how they should be treated in chronic hepatitis C patients.

Effect of Breathwalk on body composition, metabolic and mood state in chronic hepatitis C patients with insulin resistance syndrome

AIM

To identify the anthropometric, metabolic and mood state in hepatitis C virus (HCV)-infected patients from the west of Mexico and to evaluate the effect of Breathwalk (BW), a combination of walking, synchronized breathing and focussed attention, on those patients.

METHODS

In an experimental study, 17 patients with serological and molecular diagnosis of HCV, not receiving pharmacological treatment, were studied. One hour sessions of BW were practiced 3 times at week for six months. Body composition was assessed by electric impedance. Biochemical profiles and insulin resistance (IR) risk was assessed by conventional methods. Mood state was evaluated with specific and open questions at the beginning and at the end of the program.

RESULTS

Seventy percent of patients were overweight or obese, and 77% of the patients presented with IR at the beginning of the study. Improvements were observed at the 3rd mo, and statistically significant differences were recorded at the 6th mo using the fitness score (76 vs 83, P < 0.01), in alanine aminotransferase (ALT) (106 +/- 93 U/L vs 59 +/- 32 U/L, P < 0.01), total bilirubin (0.09 +/- 1 mg/dL vs 0.62 +/- 0.2 mg/dL, P < 0.01), ALT/AST ratio (1.04 vs 0.70, P < 0.01), triglycerides (165 +/- 86 mg/dL vs 124 +/- 49 mg/dL, P < 0.01) and the IR risk (4.0 vs 2.7). Most patients (88%) indicated to feel better at the end of BW (P < 0.01).

CONCLUSION

Breathwalk has an important effect on body composition, lipid profile and liver enzymes. It is also easy, inexpensive and has a beneficial effect on metabolic and mood state in HCV patients.

Altered expression of glucagon-like peptide-1 and dipeptidyl peptidase IV in patients with HCV-related glucose intolerance

BACKGROUND AND AIM

The pathogenesis of hepatitis C virus (HCV)-associated glucose intolerance remains unclear. Glucagon-like peptide-1 (GLP-1), a gut hormone, synthesizes hepatic glycogen and is inactivated by dipeptidyl peptidase IV (DPPIV). The aims of this study were to investigate the alterations in the expression of GLP-1 and DPPIV in HCV-associated glucose intolerance.

METHODS

We enrolled patients with HCV- or hepatitis B virus (HBV)-related liver disease (n = 94 and 37, respectively), patients with inflammatory bowel disease (IBD; n = 14) as disease controls, and healthy controls (n = 48). The serum or tissue GLP-1 and DPPIV expression levels were determined by enzyme immunoassay, immunoblotting, or immunostaining. The hepatic glycogen content was assayed by periodic acid-Schiff staining.

RESULTS

The serum GLP-1 levels were significantly decreased in the HCV group (4.9 +/- 0.3 ng/mL) than those in the controls (7.5 +/- 0.6 ng/mL), the HBV group (7.0 +/- 0.5 ng/mL), or the IBD group (10.8 +/- 1.0 ng/mL, P < 0.01). Although the ileum GLP-1 expression was not significantly different between the controls and the HCV group, the DPPIV expression was significantly increased in the ileum, liver, and serum in the HCV group. Hepatic glycogen content was decreased to a greater extent in the HCV group than that in the HBV group (127.5 +/- 5.3 vs 187.7 +/- 6.6 arbitrary units; n = 19, P < 0.01).

CONCLUSION

We demonstrated the altered expressions of GLP-1 and DPPIV in patients with HCV-associated glucose intolerance. Since hepatic glycogen synthesis, a GLP-1 action, was impaired, the altered expressions of GLP-1 and DPPIV may be involved in the development of HCV-associated glucose intolerance.

Effect of Breathwalk on body composition, metabolic and mood state in chronic hepatitis C patients with insulin resistance syndrome

AIM: To identify the anthropometric, metabolic and mood state in hepatitis C virus (HCV)-infected patients from the west of Mexico and to evaluate the effect of Breathwalk (BW), a combination of walking, synchronized breathing and focussed attention, on those patients.

METHODS: In an experimental study, 17 patients with serological and molecular diagnosis of HCV, not receiving pharmacological treatment, were studied. One hour sessions of BW were practiced 3 times at week for six months. Body composition was assessed by electric impedance. Biochemical profiles and insulin resistance (IR) risk was assessed by conventional methods. Mood state was evaluated with specific and open questions at the beginning and at the end of the program.

RESULTS: Seventy percent of patients were overweight or obese, and 77% of the patients presented with IR at the beginning of the study. Improvements were observed at the 3^rd mo, and statistically significant differences were recorded at the 6^th mo using the fitness score (76 vs 83, P < 0.01), in alanine aminotransferase (ALT) (106 ± 93 U/L vs 59 ± 32 U/L, P < 0.01), total bilirubin (0.09 ± 1 mg/dL vs 0.62 ± 0.2 mg/dL, P < 0.01), ALT/AST ratio (1.04 vs 0.70, P < 0.01), triglycerides (165 ±86 mg/dL vs 124 ± 49 mg/dL, P < 0.01) and the IR risk (4.0 vs 2.7). Most patients (88%) indicated to feel better at the end of BW (P < 0.01).

CONCLUSION: Breathwalk has an important effect on body composition, lipid profile and liver enzymes. It is also easy, inexpensive and has a beneficial effect on metabolic and mood state in HCV patients.

Branched-chain amino acids improve insulin resistance in patients with hepatitis C virus-related liver disease: report of two cases

Hepatitis C virus (HCV) infection causes insulin resistance. Because increased insulin resistance is a risk factor for development of hepatocellular carcinoma and reduced long-term survival, insulin resistance is a therapeutic target in patients with HCV infection. Branched-chain amino acids (BCAAs) are not only structural constituents of proteins but they are also considered as regulators of insulin signalling. We first describe two cases suggesting that administration of BCAAs improves insulin resistance associated with HCV-related liver disease. Although there were no changes in body weight, plasma glucose concentration and haemoglobin A1c (HbA1c) value were decreased. Moreover, BCAAs caused a decrease in both fasting insulin concentration and the value of homeostasis model assessment for insulin resistance. Thus, BCAAs are a potential therapeutic agent for improving insulin resistance in patients with HCV-related liver disease.

Increased serum gamma-glutamyl-transpeptidase concentration is associated with nonalcoholic steatosis and not with cholestasis in patients with chronic hepatitis C

BACKGROUND AND AIM

Increased pretreatment gamma-glutamyl-transpeptidase (gammaGT) is common in patients with chronic hepatitis C and with little or no alcohol consumption. The mechanism involved in this phenomenon is unclear, and the aim of this study was to investigate factors associated with increased gammaGT levels, specifically looking at the role of cholestasis that frequently accompanies hepatitis C.

METHODS

Fifty patients with chronic hepatitis C enrolled in two trials of antiviral treatment, 25 with normal and 25 with elevated pretreatment gammaGT levels, were retrospectively selected. In addition to the common liver function and virological tests, other values measured were serum bile acid concentration and composition by gas-chromatography as a sensitive index of cholestasis, and liver biopsy scores for cholestasis and steatosis in addition to siderosis, fibrosis and inflammation.

RESULTS

Total mean serum bile acid concentration was 11.6 +/- 1.4 micromol/L and 8.5 +/- 1.2 micromol/L (not significant) in patients with elevated and with normal gammaGT, respectively, and individual bile acid composition was similar in the two groups. By univariate analysis, serum gammaGT level was linearly related to total serum bile acid (P < 0.05) and to cholestasis score (P < 0.001) among other variables, but steatosis score (P < 0.001) and Knodell score (P < 0.04) were the only variables independently associated with elevated serum gammaGT level by multivariate analysis.

CONCLUSIONS

Increased serum gammaGT level in patients with chronic hepatitis C is associated with liver steatosis and fibrosis, and indicates more advanced liver disease rather than reflecting the cholestasis that often accompanies this condition.

Post-load insulin resistance is an independent predictor of hepatic fibrosis in virus C chronic hepatitis and in non-alcoholic fatty liver disease

BACKGROUND

Insulin resistance is a significant risk factor for hepatic fibrosis in patients with both non-alcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC), either directly or by favouring hepatic steatosis. Several methods are available to assess insulin resistance, but their impact on this issue has never been evaluated.

AIMS

To determine the relative contribution of steatosis, metabolic abnormalities and insulin resistance, measured by different basal and post-load parameters, to hepatic fibrosis in CHC and in NAFLD patients.

METHODS

In 90 patients with CHC and 90 pair-matched patients with NAFLD, the degree of basal insulin resistance (by the homeostasis model assessment, (HOMA)) and post-load insulin sensitivity (by the oral glucose insulin sensitivity (OGIS) index) was assessed, together with the features of the metabolic syndrome according to Adult Treatment Panel III definition. Data were correlated with hepatic histopathology.

RESULTS

The prevalence of basal insulin resistance (HOMA values >75th percentile of normal) was 23.3% in CHC patients and 57.8% in NAFLD, but it increased to 28.8 and 67.8% when measured by post-load insulin resistance (OGIS <25th percentile). In a multivariate model, after adjustment for age, gender and body mass index, OGIS was a predictor of severe fibrosis in CHC and in NAFLD patients, independently of steatosis. An OGIS value below the cut-off of the 25th percentile increased the likelihood ratio of severe fibrosis by a factor of 1.5-2 and proved to be a more sensitive and generally more specific test than HOMA-R for the identification of subjects with severe fibrosis both in NAFLD and in CHC.

CONCLUSIONS

Post-load insulin resistance (OGIS <9.8 mg/kg/min) is associated with severe hepatic fibrosis in both NAFLD and CHC patients, and may help identify subjects at risk of progressive disease.

Topological and evolutional relationships between HCV core protein and hepatic lipid vesicles: Studies in vitro and in conditionally transgenic mice

AIM: To investigate a specific association between hepatic steatosis and hepatitis C virus (HCV) core.

METHODS: HeLa cells and primary mouse hepatocytes were transfected with HCV core plasmid, and conditional transgenics in which hepatic over-expression of HCV core is regulated by the tetracycline-off system, were developed. The expression of the HCV core was assessed over one to six months after withdrawal of doxycycline (dox) by immunohistochemistry (IHC) and Western blotting and by sequential liver biopsy. Hepatic steatosis was evaluated using oil red stain. 8-hydroxydeoxyguanosine (8-OHdG) stains and caspase levels were conducted to clarify hepatic oxidative stress and apoptosis rate. Serum aminotransferase was checked.

RESULTS: The transfected hepatocytes had globular cores under the lipid vesicles. In transgenic mice on control diet, core expression was robust, localized to the cytoplasmic vesicle membrane and strongly associated with microvesicular steatosis, which was gradually replaced by macrovesicular steatosis. However, both steatosis and core positive hepatocytes diminished with time. Increases in aminotransferase, caspase and 8-OHdG were associated with peak core expression.

CONCLUSION: The core protein was readily detected and morphologically associated with steatosis in individual hepatocytes both in vitro and in vivo. In vivo, oxidative stress caused by the core potentially reduced the number of core positive hepatocytes and in parallel the level of steatosis. To our knowledge, this is the first animal model that directly shows topological relationship between HCV core and hepatic lipid vesicles.

The impact of insulin resistance, serum adipocytokines and visceral obesity on steatosis and fibrosis in patients with chronic hepatitis C

AIMS

To assess whether host metabolic factors influence the degree of hepatic steatosis and fibrosis in patients infected with hepatitis C virus, and to evaluate the impact of anti-viral therapy on insulin resistance and serum levels of adipocytokines.

METHODS

Clinical and biochemical features, anthropometrical characteristics, and levels of fasting insulin, leptin, adiponectin and resistin were measured in 'naïve' patients with chronic hepatitis C, before, during and after therapy with Peg-Interferon-alpha 2a plus Ribavirin.

RESULTS

Forty-eight patients were included (M/F 28/20; mean age 50.0 +/- 12.6 years; 62.5% genotype-1). Body mass index was 26.4 +/- 4.0 kg/m(2), and visceral obesity was present in 24 patients. At multivariate analysis (RR; 95% CI), steatosis was associated to older age (1.08; 1-1.18), necroinflammatory activity (17.67; 1.6-194.46), and raised insulin levels (1.39; 1.1-1.77). Fibrosis was related to necroinflammatory activity (25.73; 2.54-261.11), and steatosis (6.47; 1.09-38.29). Sustained viral response was achieved by 62.5% of patients and was associated with younger age (0.92; 0.85-0.99), genotype non-1 (10.61; 1.52-73.76) and absence of visceral obesity (13.78; 2.36-80.29). At the end of follow-up, insulin and the homeostasis model assessment for insulin resistance were reduced and adiponectin increased when compared with baseline, all unrelated to the outcome of treatment.

CONCLUSIONS

Visceral obesity correlates with the degree of steatosis and fibrosis, and it negatively affects treatment response. Significant changes of insulin resistance and adipocytokines occur under treatment, irrespective of virological outcome.

A growing burden: the pathogenesis, investigation and management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic disorder in western countries, and its incidence is increasing. This review outlines the significant health burden posed by NAFLD and discusses what is presently known about its pathogenesis, including the roles of the metabolic syndrome, obesity, insulin resistance, hepatic steatosis, reactive oxygen species, inflammatory cytokines and adipocytokines. The way in which NAFLD is clinically diagnosed is described, and areas of uncertainty surrounding its investigation are identified, before discussing the relative merits of the limited treatment options available and looking ahead to potential therapeutic strategies for the future.

[Steatosis and non-alcoholic steatohepatitis in patients with chronic hepatitis due to hepatitis C virus infection]

BACKGROUND

[corrected] Hepatic steatosis is a common finding in patients with hepatitis C, mainly virus C genotype 3. Steatosis in these cases might be associated with antiviral treatment response and with prognosis of chronic hepatitis.

AIMS

To determine the presence of steatosis and non-alcoholic steatohepatitis in chronic hepatitis C and its correlation with genotype and hepatic fibrosis.

PATIENTS AND METHODS

One hundred and twenty patients with chronic hepatitis C were retrospectively evaluated; genotype was done in 102 patients. All specimens were stained with hematoxylin-eosin, picrosirius and perls. Staging of hepatitis C was scored by Brazilian Classification and the diagnosis of non-alcoholic steatohepatitis by the American Association for the Study of Liver Diseases criteria

RESULTS

Steatosis was found in 65 of 120 cases (54.2%); it was mild in 37/65 (56.9%), moderate in 12/65 (18.5%) and severe in 10/65 (15.4%). In relation to fibrosis, 80 of 120 patients had mild fibrosis F0-F2 (66.6%) and 40 (33.3%) had more advanced fibrosis (F3 or F4). Steatosis was associated with genotype 3 (76.7%) in comparison with other genotypes (49,0%). There were no relationship between steatosis and advanced fibrosis F3/F4 (52,5%) or mild fibrosis (54,4%). Non-alcoholic steatohepatitis was diagnosed in 8/120 cases (6.7%) and was significantly associated with hepatitis C virus genotype 3 and with advanced fibrosis (F3 and F4)

CONCLUSIONS

The presence of steatosis and non-alcoholic steatohepatitis in chronic hepatitis C are associated to genotype 3; moreover non-alcoholic steatohepatitis was correlated with more advanced fibrosis.

Clearance of HCV improves insulin resistance, beta-cell function, and hepatic expression of insulin receptor substrate 1 and 2

OBJECTIVES

Hepatitis C virus (HCV) infection is linked to greater insulin resistance. Although HCV itself is a candidate for the development of insulin resistance, the effects of antiviral treatment on impaired glucose metabolism remain unclear. The aim of this study is to examine the effects of clearance of HCV on insulin resistance, beta-cell function, and hepatic expression of insulin receptor substrate (IRS)1/2, central molecules for insulin signaling.

METHODS

We analyzed 89 biopsy-proven patients with chronic HCV infection. Patients received interferon-alpha or interferon-alpha plus ribavirin for 6 months and were classified into three groups at 6 months after the conclusion of antiviral therapy according to their response to antiviral therapy: sustained responders (N = 29), relapsers (N = 12), and nonresponders (N = 48). Insulin resistance and beta-cell function were assessed by the homeostasis model assessment method (HOMA-IR and HOMA-%B, respectively). Hepatic expression of IRS1/2 was evaluated by immunoblotting and immunostaining in 14 sustained responders.

RESULTS

In nonresponders and relapsers, there were no significant changes in HOMA-IR and HOMA-%B values after antiviral therapy. On the other hand, in sustained responders, HOMA-IR values significantly decreased to 1.7 +/- 0.8 from 3.1 +/- 1.1 (P < 0.05) after antiviral therapy. Similarly, HOMA-%B values significantly decreased to 90.6 +/- 10.0 from 113.7 +/- 15.3 (P < 0.05). Immunoblotting showed a threefold increase in IRS1/2 expression after clearance of HCV. Immunostaining revealed that greater IRS1/2 expression was seen in hepatocytes.

CONCLUSIONS

We showed that clearance of HCV improves insulin resistance, beta-cell function, and hepatic IRS1/2 expression.

Steatosis as a cofactor in other liver diseases: hepatitis C virus, alcohol, hemochromatosis, and others

As obesity prevalence rises, there is evidence that fatty liver disease can act synergistically with other chronic liver diseases to aggravate parenchymal injury. This is characterized best in chronic hepatitis C, where steatosis is caused by viral and metabolic effects. There is evidence that steatosis and its metabolic abnormalities also exacerbate other diseases, such as alcoholic liver disease, hemochromatosis, and, possibly, drug-induced liver disease. The pathogenesis seems related to increased susceptibility of steatotic hepatocytes to apoptosis, enhanced oxidative injury, and altered hepatocytic regeneration. Data suggest that active management of obesity may improve liver injury and decrease the progression of fibrosis in patients who have other chronic liver diseases.

Liver biopsy assessment in chronic viral hepatitis: a personal, practical approach

The terminology for assessment of chronic viral hepatitis in liver biopsy specimens has become confusing with the proliferation of grading and staging schemes that have paralleled the rise of the hepatitis C epidemic and the importance of mixed viral infections. This review represents a personal approach to the interpretation of these biopsy specimens, aiming at clarifying and simplifying the important points for the general pathologist confronted by these diagnostic dilemmas. The most commonly used schemes-Ishak modification of the Knodell 'hepatic activity index', Scheuer, Metavir, Batts-Ludwig classifications-are presented with evaluation of their pros and cons. Which scheme is selected is less important than the consistent use of a single scheme and the clear naming of that scheme in pathology reports. The importance and clinical implications of identifying severe necroinflammatory activity in the form of 'confluent necrosis' is discussed. Pathologists must also be clear about assessing concomitant diseases, in particular, alcoholic or non-alcoholic fatty liver disease, and be aware that grading/staging schemes for chronic hepatitis do not apply to mixed disease conditions. Other important features to be evaluated in all chronic hepatitis biopsy specimens include iron (which may represent hereditary hemochromatosis or secondary uptake) and neoplasia-associated changes, namely large cell change and small cell change; these findings and their clinical import are updated and reviewed. Sample approaches to composing useful diagnostic reports are also presented.

Histological assessment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an important complication of the metabolic syndrome, which is becoming an increasingly common cause of chronic liver disease. Histological changes typically mainly affect perivenular regions of the liver parenchyma and include an overlapping spectrum of steatosis, steatohepatitis and persinusoidal or pericellular fibrosis, in some cases leading to cirrhosis. Once cirrhosis has developed, typical hepatocellular changes are often no longer conspicuous, leading to such cases being mistakenly diagnosed as 'cryptogenic'. Portal inflammation, ductular reaction and periportal fibrosis can also be seen as part of the morphological spectrum of NAFLD, particularly in the paediatric population. Hepatocellular carcinoma has also been described as a complication of NAFLD-associated cirrhosis. NAFLD is also an important cofactor in other chronic liver diseases, especially hepatitis C. Histological assessments have an important role to play in the diagnosis and management of NAFLD. These include making the potentially important distinction between simple steatosis and steatohepatitis and providing pointers to the aetiology, including cases where a dual pathology exists. A number of systems have been devised for grading and staging the severity of fatty liver disease. These require further evaluation, but have a potentially important role to play in determining prognosis and monitoring therapeutic responses.

Sustained virological response correlates with reduction in the incidence of glucose abnormalities in patients with chronic hepatitis C virus infection

OBJECTIVE

There is evidence to suggest that hepatitis C virus (HCV) infection is a high-risk condition for developing type 2 diabetes. However, there are no interventional studies that confirm that HCV infection causes diabetes. The main aim of this study was to compare the incidence of glucose abnormalities (diabetes plus impaired fasting glucose) between HCV-infected patients with or without sustained virological response (SVR) after antiviral therapy.

RESEARCH DESIGN AND METHODS

Patients with normal fasting glucose (<100 mg/dl) with biopsy-proven chronic hepatitis C without cirrhosis and with at least 3 years of follow-up after finishing antiviral therapy were included in the study (n = 234). Patients received interferon alpha-2b (alone or with ribavirin) for 6 or 12 months according to genotype. Cumulative incidence of glucose abnormalities was evaluated by using the Kaplan-Meier method comparing subjects with and without a SVR to antiviral treatment. A multivariate Cox proportional hazards analysis was performed to explore the variables independently associated with the development of glucose abnormalities.

RESULTS

During follow-up, 14 of 96 (14.6%) patients with SVR and 47 of 138 (34.1%) nonsustained responders developed glucose abnormalities (P = 0.001). Patients with SVR did not develop diabetes during follow-up, whereas nine cases of diabetes were detected in nonsustained responders (P = 0.007). After adjustment for the recognized predictors of type 2 diabetes, the hazard ratio for glucose abnormalities in patients with SVR was 0.48 (95% CI [0.24-0.98], P = 0.04).

CONCLUSIONS

Our results provide evidence that eradication of HCV infection significantly reduces the incidence of glucose abnormalities in chronic hepatitis C patients. In addition, this study supports the concept that HCV infection causes type 2 diabetes.

Chronic hepatitis C virus infection: genotyping and its clinical role

Chronic hepatitis C virus (HCV) infection is a worldwide public health problem with a global prevalence of 2%. A high proportion of those infected are at risk of developing cirrhosis and hepatocellular carcinoma and modeling data predicts that the burden of disease could soon increase substantially. The liver disease associated with chronic infection has led investigators to look for correlates between viral properties and disease progression, severity of disease and the response to antiviral therapy. HCV has been classified into six genotypes but genotype does not appear to influence disease presentation or severity of disease. However, genotype has been identified as a major predictor of response to interferon-based antiviral therapy. Antiviral regimens have been optimized for infections with HCV genotypes 1-4, although treatment strategies for genotypes 5 and 6 have yet to be developed. The molecular basis for the differences in response of HCV genotypes has yet to be determined.

Impact of obesity on treatment of chronic hepatitis C

Obesity and the metabolic syndrome have hepatic manifestations, including steatosis and progression of fibrosis. In individuals with chronic hepatitis C, obesity is associated with inflammation, insulin resistance, steatosis, progression of fibrosis, and nonresponse to treatment with interferon or peginterferon alpha and ribavirin. Patients with both hepatitis C and obesity-related nonalcoholic fatty liver disease are at greater risk for more advanced liver disease. We review the mechanisms by which obesity may be associated with decreased efficacy of interferon-based therapies in individuals with chronic hepatitis C and the therapeutic strategies that may increase the effectiveness of these therapies in obese individuals.