Insulin resistance is associated with steatosis in nondiabetic patients with genotype 1 chronic hepatitis C

Insulin resistance derived from zinc deficiency in non-diabetic patients with chronic hepatitis C

Chronic hepatitis C virus (HCV) infection frequently evokes metabolic abnormalities including insulin resistance. A decrease in serum zinc (Zn) levels is often observed in association with hepatic fibrosis. Zn also plays important roles in insulin secretion. However, little is known about the relationship between Zn deficiency and insulin resistance in patients with HCV-related chronic liver disease. The main purpose of this study was to examine the contribution of Zn deficiency to insulin resistance in patients with chronic hepatitis C (CH-C). Forty-eight non-diabetic patients with CH-C were enrolled. Serum alanine aminotransferase (ALT), ferritin and Zn levels were examined in the enrolled patients with CH-C. Insulin resistance was determined by the Homeostasis model for assessment of insulin resistance (HOMA-IR). Zn deficiency was defined as serum Zn levels <65 μg/dl. Seven out of the 48 (15%) patients with CH-C fulfilled the criteria for Zn deficiency. Serum Zn levels were inversely correlated with serum ferritin levels (r=-0.364, p=0.0140). The values of HOMA-IR were positively linked to serum ferritin levels (r=0.299, p=0.0484). The mean value of HOMA-IR in the Zn deficiency group was significantly higher than that in the normal-range Zn group (3.76±0.66 vs. 2.08±1.35, p=0.0019). Serum ALT levels were also closely associated with serum ferritin levels (r=0.727, p<0.001). These findings were independent of HCV genotypes or loads of HCV-RNA. Our data suggest that iron overload in patients with CH-C derives from Zn deficiency and thereby causes insulin resistance.

Hepatitis C and hepatic steatosis

Hepatic steatosis is commonly seen in patients with chronic hepatitis C infection, and the two together have a greater association than by chance alone. Hepatitis C virus is closely associated with lipid metabolism throughout its lifecycle. Hepatic steatosis is more common in genotype 3 infection, due to direct viral effects including through microsomal triglyceride transfer protein, peroxisome proliferator activating receptor, and sterol regulatory element binding protein. In non-genotype 3 infection, hepatic steatosis is considered largely to be due to alterations in host metabolism, particularly through insulin resistance. The clinical relevance of this association has yet to be fully explored. Hepatic steatosis is associated with increased hepatic fibrosis and a reduced level of sustained virological response to pegylated interferon and ribavirin. Small studies trialing adjuvant anti-diabetic therapies or HMG-CoA reductase inhibitors with pegylated-interferon and ribavirin have shown an improved sustained virological response and reduced viral titer. Furthermore, simple lifestyle alterations showed positive effects on parameters of disease activity. These insights raise the possibility of novel treatment options.

Importance of hepatitis C virus-associated insulin resistance: Therapeutic strategies for insulin sensitization

Insulin resistance is one of the pathological features in patients with hepatitis C virus (HCV) infection. Generally, persistence of insulin resistance leads to an increase in the risk of life-threatening complications such as cardiovascular diseases. However, these complications are not major causes of death in patients with HCV-associated insulin resistance. Indeed, insulin resistance plays a crucial role in the development of various complications and events associated with HCV infection. Mounting evidence indicates that HCV-associated insulin resistance may cause (1) hepatic steatosis; (2) resistance to anti-viral treatment; (3) hepatic fibrosis and esophageal varices; (4) hepatocarcinogenesis and proliferation of hepatocellular carcinoma; and (5) extrahepatic manifestations. Thus, HCV-associated insulin resistance is a therapeutic target at any stage of HCV infection. Although the risk of insulin resistance in HCV-infected patients has been documented, therapeutic guidelines for preventing the distinctive complications of HCV-associated insulin resistance have not yet been established. In addition, mechanisms for the development of HCV-associated insulin resistance differ from lifestyle-associated insulin resistance. In order to ameliorate HCV-associated insulin resistance and its complications, the efficacy of the following interventions is discussed: a late evening snack, coffee consumption, dietary iron restriction, phlebotomy, and zinc supplements. Little is known regarding the effect of anti-diabetic agents on HCV infection, however, a possible association between use of exogenous insulin or a sulfonylurea agent and the development of HCC has recently been reported. On the other hand, insulin-sensitizing agents are reported to improve sustained virologic response rates. In this review, we summarize distinctive complications of, and therapeutic strategies for, HCV-associated insulin resistance. Furthermore, we discuss supplementation with branched-chain amino acids as a unique insulin-sensitizing strategy for patients with HCV-associated insulin resistance.

Low vitamin D serum level is related to severe fibrosis and low responsiveness to interferon-based therapy in genotype 1 chronic hepatitis C

25-Hydroxyvitamin D (25[OH]D) can potentially interfere with inflammatory response and fibrogenesis. Its role in disease progression in chronic hepatitis C (CHC) and its relation with histological and sustained virological response (SVR) to therapy are unknown. One hundred ninety-seven patients with biopsy-proven genotype 1 (G1) CHC and 49 healthy subjects matched by age and sex were consecutively evaluated. One hundred sixty-seven patients underwent antiviral therapy with pegylated interferon plus ribavirin. The 25(OH)D serum levels were measured by high-pressure liquid chromatography. Tissue expression of cytochrome (CY) P27A1 and CYP2R1, liver 25-hydroxylating enzymes, were assessed by immunochemistry in 34 patients with CHC, and in eight controls. The 25(OH)D serum levels were significantly lower in CHC than in controls (25.07 +/- 9.92 microg/L versus 43.06 +/- 10.19; P < 0.001). Lower levels of 25(OH)D were independently linked to female sex (P = 0.007) and necroinflammation (P = 0.04) by linear regression analysis. CYP27A1, but not CYP2R1, was directly related to 25(OH)D levels (P = 0.01), and inversely to necroinflammation (P = 0.01). Low 25(OH)D (odds ratio [OR], 0.942; 95% confidence interval [CI], 0.893-0.994) and cholesterol (OR, 0.981; 95%CI, 0.969-0.992) levels, older age (OR, 1.043; 95%CI, 1.002-1.085), high ferritin (OR, 1.003; 95%CI, 1.001-1.005), and necroinflammation (OR, 2.235; 95%CI, 1.014-4.929) were independently associated with severe fibrosis (F3-F4) by multivariate logistic analysis. Seventy patients (41%) achieved SVR. By multivariate analysis, hepatic steatosis (OR, 0.971; 95%CI, 0.944-0.999), lower cholesterol (OR, 1.009; 95% CI, 1.000-1.018), and 25(OH)D levels (OR, 1.039; 95%CI, 1.002-1.077) were independently associated with no SVR.

CONCLUSION

G1 CHC patients had low 25(OH)D serum levels, possibly because of reduced CYP27A1 expression. Low vitamin D is linked to severe fibrosis and low SVR on interferon (IFN)-based therapy.

Impact of amino acid substitutions in the hepatitis C virus genotype 1b core region on liver steatosis and hepatic oxidative stress in patients with chronic hepatitis C

BACKGROUND

Liver steatosis and hepatic oxidative stress are the histopathological features of chronic hepatitis C. Hepatitis C virus (HCV) genotype 1 core protein induces hepatic steatosis and reactive oxygen species production in transgenic mice. The amino acid substitutions in the HCV core region appear to be related to hepatocarcinogenesis.

AIMS

The aim of this study was to clarify the impact of mutations in the HCV core region on oxidative stress and lipid metabolism in patients with chronic hepatitis C.

METHODS

Sixty-seven patients (35 men, 32 women; mean age, 58.4 +/- 10.2 years) with chronic hepatitis C with high titres (>5 log IU/ml) were enrolled. Substitutions in amino acids 70, 75 and 91 of the HCV genotype 1b core region, the percentage of hepatic steatosis, and hepatic 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were investigated in all patients. Urinary 8-OHdG levels were measured in 35 patients.

RESULTS

Body mass index, alanine aminotransferase, gamma-glutamyl transferase, and triglyceride levels and substitutions of amino acid 70/Q (glutamine) were significantly associated with the presence of steatosis on univariate analysis. Multivariate analysis showed that substitution of amino acid 70 of glutamine and triglyceride levels were the independent factors related to liver steatosis. Hepatic and urinary 8-OHdG levels were significantly higher in patients with methionine at amino acid 91 of the HCV core region than in those with leucine.

CONCLUSION

Substitutions in the amino acids of the HCV genotype1b core region are associated with hepatic steatosis and oxidative stress in patients with chronic hepatitis C.

[Hepatitis C and metabolic syndrome]

Insulin resistance is a predictive factor of response to treatment with peginterferon and ribavirin in patients with hepatitis C. Insulin resistance impairs sensitivity to interferon and can block its intracellular signalling. Insulin resistance also induces the development of steatosis, progression of fibrosis and proinflammatory cytokine release and reduces the bioavailability of interferon. Suppressor of cytokine signalling 3 and protein tyrosine phosphatases are involved in blocking the intracellular signalling of interferon and insulin. Insulin resistance can be treated through diet, physical exercise and the use of insulin-sensitizing agents such as biguanides or glitazones. The TRIC-1 study demonstrated that adding metformin to routine treatment improves the possibilities of cure in women and in patients whose insulin sensitivity returns to normal during treatment.

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.

Hepatic steatosis in genotype 4 chronic hepatitis C patients: implication for therapy

BACKGROUND AND AIM

The association of hepatitis C virus genotype 4 (HCV-4) with hepatic steatosis has not been clarified. We aimed to determine the parameters associated with steatosis among HCV-4 patients and to assess the effect of steatosis on treatment with peginterferon and ribavirin.

METHODS

In a prospective study; 131 nondiabetic genotype 4 CHC patients were enrolled for analysis, treated with peginterferon-α-2b/ribavirin. Histopathologic, anthropometric, clinical, biochemical features, and insulin resistance (IR) estimated by the homeostasis model assessment index (HOMA-IR).

RESULTS

Hepatic steatosis was present in 58 patients (44.2%); 62% of them experienced mild steatosis. In univariable analysis, steatosis was associated with HOMA-IR, body mass index, waist circumference, serum triglycerides, cholesterol level, systolic hypertension, and histologic scores for inflammation and fibrosis. Multivariate analysis revealed that body mass index, waist circumference, and HOMA-IR were found to be significantly associated with steatosis. IR but not steatosis was associated with a lower rate of sustained virologic response when adjusted for known factors that predict response (odds ratio: 0.16, 95% CI 0.046-0.59, P=0.005).

CONCLUSIONS

In HCV-4 patients, the prevalence of steatosis was 44.2%; the majority (62%) has mild steatosis. Steatosis was significantly associated with metabolic factors. IR but not steatosis was independently associated with lower sustained virologic response.

Reversal of graft steatosis after liver transplantation: prospective study

OBJECTIVE

To determine the risk factors for reversal of liver graft steatosis.

PATIENTS AND METHODS

This prospective study included 70 patients (47 men and 23 women) who received steatotic liver grafts between July 2003 and February 2008. No grafts from prisoners were used in the study. Patients were divided into 3 groups according to degree of liver steatosis, as follows: mild (n = 29, group 1), moderate (n = 23, group 2), and severe (n = 18, group 3).

RESULTS

The median (SD) degree of steatosis in liver grafts at transplantation was 15.7% (7.3%) in group 1, 26.3% (10.5%) in group 2, and 45.1% (8.3%) in group 3. Postoperative histologic analysis demonstrated dramatically decreased steatosis in all graft recipients.

CONCLUSION

Graft steatosis can be decreased substantially after liver transplantation. Factors for reversibility of steatosis include donor age, degree of macrovesicular steatosis, and cold ischemia time.

Hepatic lipid profiling in chronic hepatitis C: an in vitro and in vivo proton magnetic resonance spectroscopy study

BACKGROUND & AIMS

Hepatic steatosis is an important factor in pathogenesis, progression and response to treatment in hepatitis C. We aimed to investigate differences in hepatic lipid composition in liver biopsies from patients with chronic hepatitis C using proton magnetic resonance spectroscopy ((1)H MRS) and to translate these findings to the in vivo clinical setting.

METHODS

Two cohorts of patients with histologically defined chronic hepatitis C were studied. High-resolution MR spectra were obtained from 47 liver biopsy samples. These data were used to derive biologically relevant prior knowledge for the assignment and interpretation of lower-resolution in vivo hepatic MRS data acquired at 1.5T from a second cohort of 59 patients. MRS data were obtained both in vitro and in vivo from a subset of 11 patients.

RESULTS

Multivariate factor analysis demonstrated characteristic MR spectral differences by fibrosis stage and genotype. Total lipid increased with fibrosis stage (r=0.43, p=0.003) and was higher in genotype 3 compared to genotype 1 (p=0.03), while lipid polyunsaturation decreased with increasing fibrosis stage (r=-0.55, p<0.0005) and, independently, with increasing steatosis. Non-invasive assessment using in vivo hepatic (1)H MRS corroborated in vitro findings, but the signal-to-noise ratio was insufficient for reliable assessment of lipid polyunsaturation in vivo.

CONCLUSIONS

Hepatic lipid composition was analysed using MRS in patients with chronic hepatitis C in vitro and in vivo, demonstrating significant differences in indices by disease severity. High-resolution data informed the analysis and interpretation of in vivo spectra, but further improvements in spectral quality in vivo are required.

Serum HCV RNA levels and HCV genotype do not affect insulin resistance in nondiabetic patients with chronic hepatitis C: a multicentre study

BACKGROUND

Chronic hepatitis C (CHC) induces insulin resistance (IR) and subsequently diabetes.

AIM

To examine viral, metabolic and histological predictors of IR in 275 CHC patients to test the hypothesis that IR differs among HCV genotypes and that viral replication directly affects IR.

METHODS

We studied 275 nondiabetic treatment-naïve CHC patients. Histological lesions were evaluated according to Ishak. IR was assessed using homeostasis model assessment for insulin resistance (HOMA-IR).

RESULTS

HOMA > 3.0 was found in 37% of patients, independently associated with higher BMI and GGT. In genotype non-3 patients, HOMA > 3.0 was associated with higher BMI and GGT values, while no significant association was noted in genotype 3 patients. In non-obese patients with minimal fibrosis, HOMA > 3.0 was found in 20% of cases without significant differences among genotypes. No association between HOMA > 3.0 and HCV-RNA levels was found. Severe fibrosis (stage 5-6) related to older age (OR:1.048), HOMA-IR (OR:1.177), necroinflammation (OR: 2.990) and higher ALT (OR: 1.009) and GGT (OR:1.006).

CONCLUSIONS

IR develops at early stages of CHC without significant differences among genotypes. It is more frequent in obese patients with steatosis and contributes to fibrosis progression. However, IR does not seem to be associated with viraemia and therefore its exact pathogenetic mechanism in CHC remains elusive.

Hepatitis C virus infection and metabolic syndrome---a community-based study in an endemic area of Taiwan

Metabolic syndrome (MS) is a complicated disorder associated with a high risk of future development of micro- and macrovascular complications. The extrahepatic manifestations of hepatitis C virus (HCV) infection can include multiple metabolic abnormalities. However, the extent, severity, and characteristics of MS in HCV-infected patients have rarely been investigated in community-based settings. This study aimed to determine the difference in prevalence and distribution of the components of MS between HCV-infected patients and healthy controls. Multipurpose mass screening of adults was conducted in an HCV-endemic area of Southern Taiwan. Clinical profiles in terms of anthropometric data and MS components, as well as viral hepatitis markers, were assessed. Two hundred and thirty-seven adults (94 males; mean age, 55.5 +/- 10.8 years) were recruited. The prevalence of anti-HCV seropositivity was 39.2% (93/237). The prevalence of MS was higher in the HCV-infected individuals (24.7%, 23/93) than in the control, uninfected subjects (13.2%, 19/144, p = 0.02). In terms of MS components, HCV-infected subjects had a higher prevalence of high waist circumference (51.6% vs. 25.7%, p < 0.001) and hypertension (58.1% vs. 36.8%, p = 0.001) than controls. Multivariate logistic regression analysis demonstrated that anti-HCV positivity was significantly associated with MS (odds ratio, 6.4; 95% confidence interval, 1.82-22.84; p = 0.004). HCV infection was associated with a higher prevalence of MS. Determination of MS in patients with HCV infection could therefore be indicated.

Reliability of the bright liver echo pattern in diagnosing steatosis in patients with cryptogenic and HCV-related hypertransaminasaemia

AIM

To evaluate the reliability of the bright liver (BL) echo pattern on ultrasound to detect histological steatosis in chronic cryptogenic hypertransaminasaemia (CCH) and hepatitis C virus (HCV)-related forms of hypertransaminasaemia.

MATERIALS AND METHODS

One hundred and fifty patients, 54 with CCH and 96 with HCV hypertransaminasaemia (76 genotype 1/2 and 20 genotype 3), were enrolled. Histological steatosis was measured as the percentage of hepatocytes involved. The reliability of the BL sign was estimated using the sensitivity, specificity, positive and negative predictive values.

RESULTS

Histological steatosis was present in 102/150 patients (68%) divided into 59/96 (62%) in the HCV group and 43/54 (79.6%) in the CCH group (chi(2)=4.4; p=0.035). In a multivariate analysis, the variable associated with the BL echo pattern was steatosis percentage (p=0.0018). Steatosis percentage was higher in CCH group than in the HCV genotype 1/2 and 3 groups (p=0.02). The sensitivity of the BL echo pattern was 88% in the CCH group [confidence interval (CI) 95% 74-95] versus 61% (CI 95% 44-73) in the HCV genotype 1/2 group. The CI indicates that ultrasound can provide evidence for steatosis in a statistically significant way in the CCH versus HCV genotype 1/2 patients. In the genotype 3 group, the sensitivity was high (90%), but the limited number of cases limited the statistical significance due to the high CI.

CONCLUSION

In CCH the BL echo pattern has excellent reliability in diagnosing steatosis, better than in HCV hypertransaminasaemia because of the higher prevalence and extent of steatosis.

Molecular mechanisms of insulin resistance in chronic hepatitis C

It is now widely recognized that chronic hepatitis C (CHC) is associated with insulin resistance (IR) and type 2 diabetes, so can be considered a metabolic disease. IR is most strongly associated with hepatitis C virus (HCV) genotype 1, in contrast to hepatic steatosis, which is associated with genotype 3 infection. Apart from the well-described complications of diabetes, IR in CHC predicts faster progression to fibrosis and cirrhosis that may culminate in liver failure and hepatocellular carcinoma. More recently, it has been recognized that IR in CHC predicts a poor response to antiviral therapy. The molecular mechanisms for the association between IR and HCV infection are not well defined. This review will elaborate on the clinical associations between CHC and IR and summarize current knowledge regarding the molecular mechanisms that potentially mediate HCV-associated IR.

Insulin resistance is a major determinant of liver stiffness in nondiabetic patients with HCV genotype 1 chronic hepatitis

BACKGROUND

In patients with chronic hepatitis C (CHC), liver stiffness measurement (LSM) by transient elastography (TE), is closely related to the stage of fibrosis, but may be affected by necroinflammation. Other factors, such as insulin resistance (IR), might influence the performance of LSM.

AIMS

To evaluate in a cohort of nondiabetic patients with genotype 1 CHC, whether IR and other anthropometric, biochemical, metabolic and histological factors contribute to LSM and to identify the best cut-off values of LSM for predicting different stages of fibrosis.

METHODS

Nondiabetic patients with genotype 1 CHC (n = 156) were evaluated by liver biopsy (Metavir score), anthropometric, biochemical and metabolic features including IR. Furthermore, all subjects underwent LSM by TE.

RESULTS

Severe fibrosis (F3-F4) was associated with LSM (OR 1.291; 95%CI 1.106-1.508). LSM was also independently correlated with low platelets (P = 0.03), high gammaGT (P < 0.001) and high HOMA (P = 0.004) levels. A stiffness value > or =8 KPa was identified as the best cut-off for predicting severe fibrosis (AUC 0.870); yet this cut-off still failed to rule out F3-F4 fibrosis in 22.7% of patients (false-negative rate) or rule in F3-F4 in 19.6% (false-positive rate). Platelets <200 x 10(3)/mmc and a HOMA of >2.7 were the major determinants of these diagnostic errors in predicting severe fibrosis. Conclusions In nondiabetic patients with genotype 1 CHC, insulin resistance, gammaGT and platelet levels contribute to LSM independently of liver fibrosis. The identification of these three factors contributes to a more correct interpretation of LSM.

Elevation of serum gamma-glutamyltranspeptidase activity is frequent in chronic hepatitis C, and is associated with insulin resistance

BACKGROUND AND AIMS

Serum gamma-glutamyltranspeptidase level is often increased in patients with chronic hepatitis C, and we aimed to identify factors associated with this phenomenon in patients completely abstinent from alcohol (teetotaller).

PATIENTS AND METHODS

71 teetotaller patients have been identified by personal history, questioning of relatives, CAGE questionnaire administration and unscheduled alcoholemia measurements.

RESULTS

39 patients (55%) had elevated (>50IU/L) gamma-glutamyltranspeptidase level. Body mass index, insulin and C-peptide level, insulin resistance, piecemeal necrosis score > or =3, fibrosis score > or =2 and steatosis score > or =1 were significantly higher in these patients than in those (n=32) with normal gamma-glutamyltranspeptidase. At multiple linear regression analysis gamma-glutamyltranspeptidase level was associated with C-peptide level, insulin resistance and histopathologic grading. At multiple logistic regression analysis, C-peptide level (OR=2.13) and piecemeal necrosis score > or =3 (OR=4.59) were the only factors independently associated with elevated gamma-glutamyltranspeptidase. Sustained virological response during pegylated interferon plus ribavirine treatment was achieved by 97% and 49% patients with normal and elevated gamma-glutamyltranspeptidase, respectively (p=0.0001).

CONCLUSION

Serum gamma-glutamyltranspeptidase level is often elevated in chronic hepatitis C and is associated with metabolic and inflammatory factors; this phenomenon may contribute to explain and to predict resistance to treatment in this subgroup of patients.

Hyperferritinemia is a risk factor for steatosis in chronic liver disease

AIM

To investigate the relationship between ferritin and steatosis in patients with chronically abnormal liver function tests (LFTs) and high ferritin level.

METHODS

One hundred and twenty-four consecutive patients with hyperferritinemia (male > 300 ng/mL, female > 200 ng/mL) were evaluated; clinical, biochemical and serological data, iron status parameters, HFE gene mutations and homeostasis model assessment score were obtained. Steatosis was graded by ultrasound as absent or present. Histology was available in 53 patients only.

RESULTS

Mean level of ferritin was 881 +/- 77 ng/mL in men and 549 +/- 82 ng/mL in women. The diagnosis was chronic hepatitis C in 53 (42.7%), non-alcoholic fatty liver disease/non-alcoholic steatohepatitis in 57 (45.9%), and cryptogenic liver damage in 14 (11.3%). None was diagnosed as hereditary hemochromatosis (HH). Hepatic siderosis on liver biopsy was present in 17 of 54 (32%) patients; grade 1 in eight and grade 2 in nine. Overall, 92 patients (74.2%) had steatosis. By logistic regression, ferritin and gamma-glutamyltransferase were independent predictors of steatosis. Ferritin levels were significantly related to low platelet count, steatosis and hepatitis C virus infection.

CONCLUSION

In a non-obese cohort of non-alcoholic patients with chronically abnormal LFTs without HH, high serum ferritin level is a risk factor for steatosis.

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.

Time course of insulin resistance during antiviral therapy in non-diabetic, non-cirrhotic patients with genotype 1 HCV infection

Background

Genotype 1 (G1) hepatitis C virus (HCV) is associated with insulin resistance (IR) and its clearance seems to improve insulin sensitivity. We aimed to evaluate the time course of IR in response to antiviral therapy in non-diabetic, non-cirrhotic G1 HCV patients and to assess the effect of metabolic factors on sustained virological response (SVR).

Methods

A total of 83 consecutive treatment-naive G1 chronic hepatitis C (CHC) patients were evaluated by anthropometric and metabolic measurements, including IR using the homeostasis model assessment (HOMA). Patients were considered to have IR if HOMA was >2.7. All cases had a liver biopsy scored for staging, grading and steatosis. Anthropometric parameters and HOMA were re-evaluated at the end of antiviral therapy and at follow-up.

Results

SVR was achieved in 46 (55.4%) patients. By logistic regression, female gender (odds ratio [OR] 0.132, 95% confidence interval [CI] 0.33–0.529), γ-glutamyltransferase >50 IU (OR 0.217, 95% CI 0.066–0.720) and presence of steatosis (OR 0.134, 95% CI 0.028–0.654) were independent negative predictors of SVR, whereas low-density lipoprotein cholesterol >107 IU (OR 6.671, 95% CI 1.164–11.577) was a positive predictor of SVR. The proportion of patients with IR significantly decreased ( P=0.02) during antiviral therapy and at follow-up in patients achieving SVR. A similar trend, even if not significant, was observed in relapsers and non-responders.

Conclusions

In non-diabetic G1 HCV patients undergoing antiviral therapy, IR improved in all patients, independently of virological outcome. HCV viral clearance was an additional factor in IR improvement. Female gender, hepatic steatosis and other metabolic parameters, but not IR, were identified as negative predictors of SVR in this study.

Influence of insulin resistance on hepatic fibrosis and steatosis in hepatitis C virus (HCV) mono-infected compared with HIV-HCV co-infected patients

BACKGROUND

Insulin resistance (IR), the major feature of the metabolic syndrome, is also common in patients with chronic HCV infection. Liver fibrosis and steatosis are known potential outcome of chronic hepatitis B or C infection. Studies have shown that HIV positive individuals co-infected with HCV have more rapid live disease progression than those with HIV alone. Few data have reported the influence of IR on steatosis and fibrosis in the context of HIV-HCV coinfection.

AIM

To test the association among insulin resistance (IR), liver fibrosis and liver steatosis in HIV-HCV and HCV-infected patients.

PATIENTS AND METHODS

A total of 170 HIV-HCV-infected patients matched by age, gender and genotype with 170 HCV mono-infected patients were included. Patients were considered to be IR when the homeostasis model assessment of IR >2. Significant fibrosis was considered if METAVIR >or=F2 and significant steatosis if >or=10%.

RESULTS

Insulin resistance was independently associated in HCV patients with fibrosis [odds ratio (OR) = 2.04 (95% CI 1.02-4)], a body mass index (BMI) >25 kg/m(2) [OR = 3.33 (1.47-7.69)] and steatosis [OR = 3.33 (1.67-6.67)]. Fibrosis >or=F2 was associated in HCV patients with high liver activity grade (>or=A2) [OR = 8.33 (3.85-16.67)], male gender [OR = 3.03 (1.33-7.14)] and IR [OR = 2.44 (1.15-5)]. In HIV-HCV patients, >or=A2 [OR = 5.56 (1.64-20)] was associated with fibrosis. Steatosis >or=10% was associated in HCV patients with IR [OR = 3.13 (1.59-6.25) and >or=F2 (OR = 2.22 (1.15-4.17)]. In HIV-HCV, a BMI >25 kg/m(2) [OR = 3.85 (1.64-9.10)], >or=A2 [OR = 2.16 (1.02-4.55); P = 0.044] and nucleoside reverse transcriptase inhibitor [OR = 3.61 (1.19-10.96); P = 0.023] were independently associated with significant liver steatosis.

CONCLUSIONS

Insulin resistance is associated with liver fibrosis and steatosis in HCV mono-infected, but not in HIV-HCV co-infected patients. Significant liver fibrosis is associated with IR independent of liver steatosis only in HCV mono-infected patients.

Amino acid substitutions in the hepatitis C virus core region of genotype 1b are the important predictor of severe insulin resistance in patients without cirrhosis and diabetes mellitus

Previous studies provided a direct experimental evidence for the contribution of HCV core protein in the development of insulin resistance (IR), but the clinical impact of HCV core region on IR is still not clear. The present study evaluated the impact of Amino acid (aa) substitutions of HCV-1b core region on IR in 123 Japanese patients infected with HCV-1b without cirrhosis and diabetes mellitus, and investigated the treatment efficacy of 48-week pegylated interferon (PEG-IFN) plus ribavirin (RBV) according to HOMA-IR values. Patients with IR (HOMA-IR > or = 2.5) and severe IR (HOMA-IR > or = 3.5) were present in 51.2% and 27.6%, respectively. Multivariate analysis identified body mass index (> or = 25 kg/m(2)) and hepatocyte steatosis (> or = 5%) as significant determinants of IR. Furthermore, multivariate analysis identified hepatocyte steatosis (> or = 5%), aa substitutions of the core region (Gln70 (His70) and/or Met91), and age (> or = 55 years) as significant determinants of severe IR. Especially, significantly lower proportions of patients with Gln70 (His70) and/or Met91 were noted among those without severe IR (59.6%) than those with severe IR (82.4%). The rates of sustained virological response in patients with IR (50.0%) were not significantly different from those without IR (52.9%). Furthermore, the rates of non-virological response in patients with IR (28.9%) were not significantly also different from those without IR (20.6%). In conclusion, the present study indicated that substitutions of HCV-1b core region were the important predictor of severe IR in patients without cirrhosis and diabetes mellitus, but HOMA-IR values might be not useful as predictors of 48-week PEG-IFN plus RBV therapy.

Hyperferritinemia is a risk factor for steatosis in chronic liver disease

AIM: To investigate the relationship between ferritin and steatosis in patients with chronically abnormal liver function tests (LFTs) and high ferritin level.

METHODS: One hundred and twenty-four consecutive patients with hyperferritinemia (male > 300 ng/mL, female > 200 ng/mL) were evaluated; clinical, biochemical and serological data, iron status parameters, HFE gene mutations and homeostasis model assessment score were obtained. Steatosis was graded by ultrasound as absent or present. Histology was available in 53 patients only.

RESULTS: Mean level of ferritin was 881 ± 77 ng/mL in men and 549 ± 82 ng/mL in women. The diagnosis was chronic hepatitis C in 53 (42.7%), non-alcoholic fatty liver disease/non-alcoholic steatohepatitis in 57 (45.9%), and cryptogenic liver damage in 14 (11.3%). None was diagnosed as hereditary hemochromatosis (HH). Hepatic siderosis on liver biopsy was present in 17 of 54 (32%) patients; grade 1 in eight and grade 2 in nine. Overall, 92 patients (74.2%) had steatosis. By logistic regression, ferritin and γ-glutamyltransferase were independent predictors of steatosis. Ferritin levels were significantly related to low platelet count, steatosis and hepatitis C virus infection.

CONCLUSION: In a non-obese cohort of non-alcoholic patients with chronically abnormal LFTs without HH, high serum ferritin level is a risk factor for steatosis.

Endocrine manifestations of hepatitis C virus infection

Chronic infection with hepatitis C virus (HCV) can result in both hepatic and extrahepatic disease and endocrine dysfunction represents an important class of HCV-related extrahepatic disease. The most frequently occurring--and clinically important--of these endocrine disorders are thyroid disease and type 2 diabetes mellitus. In this Review, we evaluate the evidence in support of a link between HCV infection and endocrine-system dysfunction, and discuss potential pathophysiological mechanisms. A meta-analysis of the literature has revealed significant associations between chronic HCV infection, thyroid autoimmunity and hypothyroidism. Furthermore, a high prevalence of thyroid cancer has been reported in HCV-positive patients. Several clinicoepidemiological studies have demonstrated that chronic HCV infection could lead to the development of type 2 diabetes mellitus, possibly as a result of HCV-induced metabolic disturbances. Some researchers have postulated that a type 1 T-helper -cell mediated immune response underpins the association of chronic HCV infection with endocrine disease. Indeed, the available data suggest that a common immunological, type 1 T-helper cell pattern of cytokine expression and activation (via interferon-gamma) could provide the pathophysiological basis for this association. Nonetheless, additional studies will be necessary to elucidate fully all the mechanisms involved in HCV-related endocrine dysfunction.

Hepatitis C virus-infected patients are 'spared' from the metabolic syndrome but not from insulin resistance. A comparative study of nonalcoholic fatty liver disease and hepatitis C virus-related steatosis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C feature steatosis and insulin resistance (IR), conditions associated with the metabolic syndrome (MS).

OBJECTIVES

To assess the prevalence of MS and determinants of IR in patients with NAFLD and chronic hepatitis C.

METHODS

Ninety-three consecutive patients with NAFLD, 97 with chronic hepatitis C virus (HCV) genotypes 1 and 2, and 182 'healthy' controls without steatosis were enrolled in the present study. The prevalence of MS was assessed by modified Adult Treatment Panel III criteria and IR by the homeostasis model assessment of insulin resistance (HOMA-IR). IR was defined as the 75th percentile of the HOMA-IR of control subjects.

RESULTS

While the prevalence of IR was similar in NAFLD and HCV-infected subjects (70.0% and 78.7%, respectively), the prevalence of MS was significantly higher in NAFLD patients than in HCV-infected patients (27.9% versus 4.1%) and in controls (5.6%). With multivariate analysis, IR was predicted by body mass index (OR 1.263; 95% CI 1.078 to 1.480) and triglyceridemia (OR 1.011; 95% CI 1.002 to 1.020) in NAFLD and by sex (OR for female sex 0.297; 95% CI 0.094 to 0.940) and fibrosis stage (OR 2.751; 95% CI 1.417 to 5.340) in chronic hepatitis C.

CONCLUSIONS

IR is independently associated with body mass index and triglyceridemia in NAFLD, sex and fibrosis in chronic HCV infection, and has a higher prevalence in NAFLD and chronic hepatitis C than in controls. However, the frequency of MS in HCVinfected patients, similar to that of controls, is significantly lower than that seen in NAFLD patients. The current diagnostic criteria of MS are more likely to 'capture' patients with NAFLD than with chronic hepatitis C, although both groups are insulin resistant.

Insulin resistance and metabolic syndrome in chronic liver diseases: old entities with new implications

Insulin resistance (IR) and metabolic syndrome have recently been implicated in the pathogenesis and progression of chronic liver diseases, especially chronic hepatitis C (CHC) and non-alcoholic fatty liver disease (NAFLD). In this review, we provide current information on their deleterious effect on the liver, with particular interest in those two entities. In NAFLD, IR causes both the accumulation of fat in hepatocytes and the progression to non-alcoholic steatohepatitis (NASH). Moreover, the presence of metabolic syndrome seems to be associated with severe fibrosis in NASH patients. In CHC, IR develops early in the course of the disease and precedes steatosis. It is also independently associated with histological severity and negatively affects treatment response, irrespective of genotype. Consequently, therapies targeting IR and metabolic syndrome could indirectly ameliorate the prognosis of both NAFLD and CHC. As specific therapies do not exist, patients with metabolic syndrome and CHC and NAFLD should be counseled to lose weight and ameliorate their glycemic control and lipid profile.

Metabolic syndrome, non-alcoholic fatty liver disease and hepatitis C virus: impact on disease progression and treatment response

Non-alcoholic fatty liver disease (NAFLD), a spectrum of liver disease ranging from simple steatosis to non-alcoholic steatohepatitis, is increasingly recognized as the hepatic manifestation of metabolic syndrome and is an important cause of liver-related morbidity and mortality. It is among the most common forms of liver disease. NAFLD reflects abnormal partitioning of fat, such that fat deposition is increased in the liver, and provides a link between NAFLD and the metabolic syndrome, a constellation of metabolic disorders that can also be associated with visceral fat or central adiposity. Together, the features of the metabolic syndrome presage overt diabetes and increase cardiovascular risk. Hepatitis C virus (HCV) appears to exacerbate the metabolic syndrome by eliciting increased insulin resistance (IR) and promoting truncal obesity. Moreover, the concomitant presence of HCV and NAFLD is associated with an increased likelihood of diabetes, hypertension and/or hypertriglyceridaemia. Metabolic abnormalities have been shown to influence response to treatment such that the presence of IR or obesity reduces the likelihood of a sustained virological response (SVR); conversely, SVR has been demonstrated to ameliorate IR and improve beta-cell function. Clinically, these data suggest that attention must be paid not only to optimizing antiviral response but also to screening for and treatment of the various components of the metabolic syndrome.

Association of a genetic polymorphism in ectonucleotide pyrophosphatase/phosphodiesterase 1 with hepatitis C virus infection and hepatitis C virus core antigen levels in subjects in a hyperendemic area of Japan

BACKGROUND

The clinical course of chronic hepatitis C virus (HCV) infection is strongly associated with insulin resistance and obesity. The K121Q polymorphism in the ectonucleotide pyrophosphatase/phosphodiesterase (ENPP)-1 gene and the rs7566605 genotype located near insulin-induced gene 2 have been shown to be associated with insulin resistance and obesity. This study examined whether the K121Q polymorphism in ENPP1 or the rs7566605 genotype is associated with the clinical course of HCV infection.

METHODS

The relationships between the clinical characteristics of 469 anti-HCV antibody-seropositive subjects (353 were positive for HCV core antigen or RNA, whereas 116 were negative for HCV RNA) and the polymorphisms were analyzed.

RESULTS

No significant differences in body mass index, plasma glucose level, serum insulin level, and other biochemical markers were observed between subgroups of subjects with different genotypes at the K121Q polymorphism or rs7566605. The frequency of the homozygous wild-type genotype at K121Q in HCV carriers, however, was significantly higher than that in subjects who were negative for HCV RNA (84.5% vs. 75.9%; P < 0.05). Moreover, in HCV carriers, HCV core antigen levels in subjects homozygous for the wild-type genotype at K121Q were significantly higher than in heterozygous carriers of K121Q (5358 fmol/l vs. 4002 fmol/l; P = 0.04). In contrast, the rs7566605 genotype was not associated with hepatitis C viremia or with the HCV core antigen level.

CONCLUSIONS

The K121Q variant of ENPP1 may be associated with hepatitis C viremia and core antigen levels in HCV carriers.

Hepatic steatosis in patients with chronic hepatitis C virus genotype 2 or 3 does not affect viral response in patients treated with peginterferon alpha-2a (40KD) (PEGASYS) plus ribavirin (COPEGUS) for 16 or 24 weeks

BACKGROUND

Hepatic steatosis is common in patients infected with hepatitis C virus (HCV). The effect of steatosis on anti-HCV therapy efficacy is unclear.

METHODS

We studied host and viral factors associated with steatosis and the effect of steatosis on treatment efficacy using the database of a large prospective trial in patients with HCV genotypes 2 and 3.

RESULTS

Out of 885 patients assessed for steatosis, a total of 614 patients or 69% had steatosis. Patients with genotype 3 were more likely to have steatosis than those with genotype 2 (79 vs. 59%, P<0.001). Using the logistic regression model, steatosis was associated with genotype 3 (P<0.0001), older age (P=0.0025), heavier weight (P<0.0001), higher HCV RNA (P<0.0001), and higher ALT levels (P=0.015). By univariate analysis, steatosis was associated with lower sustained virological response (SVR) in patients with genotype 3, but not in patients with genotype 2. When all factors associated with steatosis and SVR were evaluated by logistic regression analysis; genotype, age, bodyweight, histological diagnosis, ALT quotient, baseline HCV RNA and treatment duration were associated with the probability of SVR, but gender, race and steatosis were not. Further analysis showed that steatosis remained a non-significant factor while baseline viral load was significantly associated with the probability of an SVR.

CONCLUSIONS

Steatosis did not influence the efficacy of treatment in our study population. Baseline viral load is a confounding factor, particularly in patients infected with genotype 3 and once baseline viral load was accounted for, the association between steatosis and SVR was not relevant.

Insulin resistance is a major determinant of sustained virological response in genotype 1 chronic hepatitis C patients receiving peginterferon alpha-2b plus ribavirin

BACKGROUND

Cross-sectional studies suggest insulin resistance is strongly associated with hepatic steatosis and fibrosis in patients with chronic hepatitis C (CHC), which might affect the efficacy of antiviral therapy. Aim To investigate retrospectively the impact of insulin resistance on treatment response in Chinese genotype 1 CHC patients receiving a 24-week course therapy with peginterferon alpha-2b/ribavirin.

METHODS

A total of 133 biopsy-proven CHC patients were enrolled for analyses. Insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR). Hepatic fibrosis was graded by the METAVIR scoring system.

RESULTS

Mean HOMA-IR progressively elevated along with the severity of hepatic fibrosis (F1-F2 fibrosis: 2.55 +/- 0.16 vs. F3-F4 fibrosis: 3.61 +/- 0.20, P < 0.001). Compared with patients with sustained virological response (SVR), patients without SVR had significantly higher percentages of F3-F4 fibrosis (62.2% vs. 21.6%, P < 0.001) and baseline high viral load (>or=600,000 IU/mL; 64.4% vs. 35.6%, P = 0.038). In addition, patients without SVR had significantly higher plasma levels of insulin (15.03 +/- 0.89 vs. 10.19 +/- 0.55 microU/mL, P < 0.001) and HOMA-IR values (3.76 +/- 0.23 vs. 2.50 +/- 0.15, P < 0.001). Multivariate analyses showed that F1-F2 fibrosis (odds ratio: 4.49, P = 0.001), HOMA-IR < 2 (odds ratio: 7.15, P = 0.005) and pre-treatment hepatitis C virus RNA < 600,000 IU/mL (odds ratio: 3.26, P = 0.012) were the independent factors associated with SVR.

CONCLUSIONS

Insulin resistance is a major determinant of SVR in genotype 1 CHC patients receiving peginterferon alpha-2b/ribavirin. Strategies to modify insulin resistance may be effective in enhancing SVR before or during anti-viral therapy.

Insulin resistance is a risk factor for esophageal varices in hepatitis C virus cirrhosis

Indirect methods to predict the presence of esophageal varices (EV) in patients with cirrhosis are not sensitive enough to be used as a surrogate for endoscopy. We tested the effectiveness of liver stiffness measurement (LSM) by transient elastography and the presence of insulin resistance (IR), a marker associated with fibrosis progression, in the noninvasive prediction of portal hypertension. One hundred four consecutive patients with newly diagnosed Child A hepatitis C virus (HCV) cirrhosis underwent upper gastrointestinal endoscopy to search for EV. Clinical, anthropometric, biochemical, ultrasonographic, and metabolic features, including IR by the homeostasis model assessment (HOMA), and LSM by transient elastography, were recorded at the time of endoscopy. EVs were detected in 63 of 104 patients (60%). In 10 patients (16%), the EVs were medium-large (>or=F2). By multivariate analysis, the presence of EVs was independently associated with a low platelet count/spleen diameter ratio (OR, 0.998; 95% CI, 0.996-0.999) and a high HOMA-IR score (OR, 1.296; 95%CI, 1.018-1.649), not with LSM (OR, 1.009; 95%CI, 0.951-1.070). It is noteworthy that nine of ten patients with medium-large EVs had a platelet/spleen ratio of less than 792 or an HOMA-IR of greater than 3.5. The independent association between low platelet count/spleen diameter ratio (OR, 0.998; 95%CI, 0.996-1.000), high HOMA-IR score (OR, 1.373; 95%CI, 1.014-1.859) and presence of EV was confirmed in the subgroup of 77 nondiabetic subjects.

CONCLUSIONS

In patients with Child A HCV cirrhosis, two simple, easy-to-get tests, namely the platelet/spleen ratio and insulin resistance measured by HOMA-IR, regardless of the presence of diabetes, significantly predict the presence of EV, outweighing the contribution given by transient elastography.

Natural history: the importance of viral load, liver damage and HCC

Chronic hepatitis B and hepatitis C virus infections are the major causes of liver disease, hepatocellular carcinoma (HCC) and liver-related mortality worldwide. Among factors known to influence the natural history of viral hepatitis are age at the time of infection, duration of infection, serum alanine aminotransferase (ALT) levels, male sex, alcohol consumption, and coinfections. In hepatitis B, serum HBV DNA concentration emerges as the key factor for predicting the development of liver disease. Even patients with low viraemia seem at increased risk for liver cirrhosis and HCC. Coinfections with hepatitis C, hepatitis D and/or HIV are common and are associated with a more severe liver disease. The course of chronic hepatitis C is variable, but usually fibrosis advances slowly. In addition to the better-known factors- including coinfections with HBV and HIV- progression of liver disease is adversely affected by smoking, hepatic steatosis and insulin resistance.

Liver diseases and metabolic syndrome

Emerging attention has been paid to metabolic syndrome, which comprises several metabolic disorders including visceral obesity, diabetes mellitus, dyslipidemia, and hypertension. Whether the severity of each disease is mild to moderate, the comorbidity of these metabolic disorders has a serious impact on the development of atherosclerosis. Nonalcoholic fatty liver disease (NAFLD) is the major hepatic disorder in patients with metabolic syndrome, and indeed it is the most common cause of abnormal liver function tests in the working population in industrialized countries. In recent years, it has become recognized that NAFLD is no longer just a trivial disease, and a rather considerable proportion of the patients develop liver cirrhosis. Furthermore, chronic infection of hepatitis C virus also develops a pathological feature of steatohepatitis, and extended hepatic steatosis has a serious impact not only on the progression of hepatic fibrosis but also on the antiviral efficacy of interferon therapy. Emerging lines of studies indicated that insulin resistance, abnormal lipid metabolism, and dysregulation of cytokines/adipokines (e.g., tumor necrosis factor-alpha, adiponectin, and leptin) are profoundly involved in the pathogenesis of NAFLD. This review aims to integrate the reported evidence and to provide the current point of view for comprehensive understanding of the pathophysiology of steatohepatitis.

Body-mass index and progression of hepatitis B: a population-based cohort study in men

PURPOSE

To determine prospectively whether body-mass index (BMI) is associated with liver-related morbidity and mortality among male hepatitis B virus (HBV) carriers.

PATIENTS AND METHODS

We performed a prospective study of 2,903 male HBV surface antigen-positive government employees who were free of cancer at enrollment between 1989 and 1992. Main outcome measures included ultrasonography, biochemical tests, incident hepatocellular carcinoma (HCC), and liver-related death.

RESULTS

During mean follow-up of 14.7 years, 134 developed HCC and 92 died as a result of liver-related causes. In Cox proportional hazards models adjusting for age, number of visits, diabetes, and use of alcohol and tobacco, the hazard ratios for incident HCC were 1.48 (95% CI, 1.04 to 2.12) in overweight men (BMI between 25.0 and 29.9 kg/m(2)) and 1.96 (95% CI, 0.72 to 5.38) in obese men (BMI >or= 30.0 kg/m(2)), compared with normal-weight men (BMI between 18.5 and 24.9 kg/m(2)). Liver-related mortality had adjusted hazard ratios of 1.74 (95% CI, 1.15 to 2.65) in overweight men and 1.50 (95% CI, 0.36 to 6.19) in obese men. Excess BMI was also associated with the occurrence of fatty liver and cirrhosis detected by ultrasonography, as well as elevated ALT and gamma-glutamyltransferase (GGT) activity during follow-up. The association of BMI with GGT was stronger than with ALT, and elevated GGT activity and cirrhosis were the strongest predictors for incident HCC and liver-related death.

CONCLUSION

This longitudinal cohort study indicates that excess body weight is involved in the transition from healthy HBV carrier state to HCC and liver-related death among men.

Genotype-specific interactions of insulin resistance, steatosis, and fibrosis in chronic hepatitis C

The interaction between insulin resistance (IR), steatosis and genotype to fibrosis in chronic hepatitis C virus (HCV) infection has not been comprehensively assessed. We hypothesized that IR is a key mediator for the development of both steatosis and fibrosis in 346 untreated, nondiabetic patients solely infected with either genotype 1 or 3. We examined for genotype-specific interactions between IR, steatosis and fibrosis by performing subgroup analyses. Because cirrhosis is known to cause IR, we repeated the analysis in a cohort of 313 noncirrhotic HCV-infected patients. We confirmed the impact of IR on fibrosis by analysis of 153 lean subjects in whom any effect of steatosis would be minimized. In HCV genotype 3 patients, increased steatosis was linked to high viral load (P = 0.001), and was not associated with fibrosis (P = 0.1). In contrast, body mass index (P = 0.04) and homeostasis model assessment of insulin resistance (HOMA-IR) (P = 0.01) contributed directly to steatosis in HCV genotype 1. HOMA-IR rather than steatosis was independently associated with fibrosis for both HCV genotype 1 (OR, 3.22; P = 0.02) and genotype 3 (OR, 3.17; P = 0.04). Exclusion of cirrhotic subjects did not alter the findings with respect to the greater contribution of IR compared to hepatic steatosis, as a predictor of fibrosis (P = 0.02). Genotype-specific subgroup analyses did not alter this finding. The extent of HOMA-IR remained significantly associated with fibrosis in lean patients, independent of the confounding effect of body mass index on IR (OR, 8.02; P = 0.003).

CONCLUSION

IR is a major independent determinant of fibrosis in chronic HCV infection, regardless of the genotype and the severity of liver damage.

Retinol-binding protein 4: a new marker of virus-induced steatosis in patients infected with hepatitis c virus genotype 1

Retinol-binding protein 4 (RBP4) is an adipocytokine associated with insulin resistance (IR). We tested serum levels of RBP4 to assess its link with steatosis in patients with genotype 1 chronic hepatitis C (CHC) or nonalcoholic fatty liver disease (NAFLD). Nondiabetic patients with CHC (n = 143) or NAFLD (n = 37) were evaluated by liver biopsy and anthropometric and metabolic measurements, including IR by the homeostasis model assessment. Biopsies were scored by Scheuer classification for CHC, and Kleiner for NAFLD. Steatosis was tested as a continuous variable and graded as absent-mild <30%, or moderate-severe > or =30%. Thirty nondiabetic, nonobese blood donors served as controls. RBP4 levels were measured by a human competitive enzyme-linked immunosorbent assay kit (AdipoGen). Mean values of RBP4 were similar in NAFLD and CHC (35.3 +/- 9.3 microg/L versus 36.8 +/- 17.6; P = 0.47, respectively), and both were significantly higher than in controls (28.9 +/- 12.1; P = 0.02 and P = 0.01, respectively). RBP4 was higher in CHC patients with steatosis than in NAFLD (42.1 +/- 19.7 versus 35.2 +/- 9.3; P = 0.04). By linear regression, RBP4 was independently linked to steatosis only (P = 0.008) in CHC, and to elevated body mass index (P = 0.01) and low grading (P = 0.04) in NAFLD. By linear regression, steatosis was independently linked to homeostasis model assessment score (P = 0.03) and high RBP4 (P = 0.003) in CHC. By logistic regression, RBP4 was the only variable independently associated with moderate-severe steatosis in CHC (odds ratio, 1.045; 95% confidence interval, 1.020 to 1.070; P = 0.0004), whereas waist circumference was associated with moderate-severe steatosis in NAFLD (odds ratio, 1.095; 95% confidence interval, 1.007 to 1.192; P = 0.03).

CONCLUSION

In nondiabetic, nonobese patients with genotype 1 CHC, serum RBP4 levels might be the expression of a virus-linked pathway to steatosis, largely unrelated to IR.

Liver eosinophilic infiltrate is a significant finding in patients with chronic hepatitis C

Eosinophilic infiltrate of liver tissue is described in primary cholestatic diseases, hepatic allograft rejection and drug-induced liver injury, but its significance and its implications in chronic hepatitis C are unknown. The aim of this study was to investigate the clinical significance of eosinophilic liver infiltrate in patients with chronic hepatitis C. We retrospectively evaluated 147 patients with chronic hepatitis C. The presence of eosinophilic infiltrate was investigated in liver biopsies, and a numeric count of eosinophilic leucocytes in every portal tract was assessed. An eosinophilic infiltrate of liver tissue (> or =3 cells evaluated in the portal / periportal spaces) was observed in 46 patients (31%), and patients who consumed drugs had an odds ratio (OR) of 4.02 (95% CI: 1.62-9.96) to have an eosinophilic infiltrate in liver biopsy. By logistic regression analysis, the presence of steatosis was independently associated with eosinophilic infiltrate (OR 5.86; 95% CI: 2.46-13.96) and homeostasis model assessment-score (OR 1.18; 95% CI: 1.00-1.39). Logistic regression analysis also showed that fibrosis staging > or = 2 by Scheuer score was associated with grading >1 by Scheuer score (OR 6.82; 95% CI 2.46-18.80) and eosinophilic infiltrate (OR 4.00; 95% CI 1.23-12.91). In conclusion, we observed that the eosinophilic infiltrate of liver tissue was significantly more frequent in patients who assumed drugs, and found a significant association between eosinophilic infiltrate, liver steatosis and liver fibrosis. These preliminary data could lead to a constant assumption of drugs as a co-factor of eosinophils-mediated liver injury in chronic hepatitis C.

Morphological changes in intracellular lipid droplets induced by different hepatitis C virus genotype core sequences and relationship with steatosis

Hepatocellular steatosis is common in patients with chronic hepatitis C. Steatosis can be considered as a true cytopathic lesion induced by hepatitis C virus (HCV) genotype 3, suggesting that one or more viral proteins produced during genotype 3 infection are involved in the steatogenic process, while the same proteins produced during infection by other genotypes are not. We examined in vitro interactions between lipid droplets and full-length core protein isolated from patients with HCV genotype 3a infection, with and without steatosis, and from steatosis-free patients infected by HCV genotype 1b. We also examined morphological changes in the lipid droplets according to the HCV genotype and the presence of steatosis in vivo. Core protein processing by signal peptide peptidase was not affected by sequence differences between the variants. We showed that the core protein of both HCV genotypes 1b and 3a binds tightly to the surface of intracellular lipid droplets. However, cells transfected with genotype 3a contain more neutral lipids in lipid droplets, and more large lipid droplets, than cells transfected with genotype 1b sequences. This suggests that HCV core protein-lipid droplet interaction could play a role in virus-induced steatosis. Importantly, we found no genetic or functional differences between genotype 3a core proteins from patients with and without HCV-induced steatosis.

CONCLUSION

This suggests that other viral proteins and/or host factors are involved in the development of hepatocellular steatosis in patients infected by HCV genotype 3a.

Hepatitis C virus infection: molecular pathways to metabolic syndrome

Chronic infection with hepatitis C virus (HCV) can induce insulin resistance (IR) in a genotype-dependent fashion, thus contributing to steatosis, progression of fibrosis and resistance to interferon therapy. The molecular mechanisms in genotype 1 patients that lead to metabolic syndrome are still ambiguous. Based on our current understanding, HCV proteins associate with mitochondria and endoplasmic reticulum and promote oxidative stress. The latter mediates signals involving the p38 mitogen-activated protein kinase and activates nuclear factor kappa B. This transcription factor plays a key role in the expression of cytokines, tumor necrosis factor alpha (TNF-alpha), interleukin 6, interleukin 8, tumor growth factor beta, and Fas ligand. TNF-alpha inhibits the function of insulin receptor substrates and decreases the expression of the glucose transporter and lipoprotein lipase in peripheral tissues, which is responsible for the promotion of insulin resistance. Furthermore, reduced adiponectin levels, loss of adiponectin receptors, and decreased anti-inflammatory peroxisome proliferator-activated receptor alpha in the liver of HCV patients may contribute to reduced fatty acid oxidation, inflammation, and eventually lipotoxicity. This chain of events may be initiated by HCV-associated IR and provides a direction for future research in the areas of therapeutic intervention.

Insulin resistance and diabetes increase fibrosis in the liver of patients with genotype 1 HCV infection

OBJECTIVES

Metabolic factors may affect the course of chronic hepatitis C (CHC). Insulin resistance (IR) determines steatosis, but its direct role in affecting progression of hepatic fibrosis is less clear. We aimed to assess whether increasing degrees of IR, up to overt diabetes, are linked to steatosis and higher stages of fibrosis in patients with CHC resulting from genotype 1 HCV (G1-HCV).

METHODS

Two hundred one consecutive patients with G1-HCV infection were evaluated by liver biopsy and anthropometric and metabolic measurements, including IR, by the homeostasis model assessment (HOMA). Nondiabetic patients were defined as insulin resistant if HOMA-IR was >2.7. All biopsies were scored by one pathologist for staging and grading (Scheuer), and graded for steatosis.

RESULTS

Ninety-six patients were noninsulin resistant (group 1), 76 were insulin resistant without diabetes (group 2), and 29 were diabetic (group 3). At multivariate analysis, fibrosis of >/=3 was independently associated with high necroinflammatory activity (odds ratio [OR] 2.994, 95% confidence interval [CI] 1.422-6.098), low platelets (OR 0.994, 95% CI 0.981-0.999), low cholesterol (OR 0.987, 95% CI 0.976-0.998), high ferritin (OR 1.002, 95% CI 1.001-1.004), and a high prevalence of IR (OR 2.692, 95% CI 1.463-4.954). Diabetic patients were twice as likely to have severe fibrosis (60%) than those with IR but no diabetes (30%) (P= 0.006). The degree of steatosis and that of fibrosis were weakly associated with each other (P= 0.42).

CONCLUSIONS

In subjects with CHC resulting from G1-HCV, IR and overt diabetes are major determinants of advanced fibrosis, regardless of the degree of steatosis, mainly in the presence of severe necroinflammation.

Clinical significance of metabolic syndrome in the setting of chronic hepatitis C virus infection

BACKGROUND & AIMS

The metabolic syndrome (MS) is a unique condition in which the underlying mechanism is related to insulin resistance. In hepatitis C virus (HCV) patients, insulin resistance has been linked to treatment failure. The aim of this study was to estimate the prevalence of MS in HCV patients undergoing antiviral therapy and to assess its predictive value in treatment outcome.

METHODS

All HCV treatment-naive patients who met the inclusion/exclusion criteria were studied (n = 228). MS was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria. A logistic regression analysis was performed to study multivariable associations. The final model contained sex, ethnicity, body mass index, viral load, genotype, steatosis, fibrosis stage, and MS.

RESULTS

MS was present in 59 of 228 (26%) patients. Genotype 1 (P = .002) and presence of steatosis (P < .001) were found to be associated significantly with MS. Overall, sustained virologic response (SVR) was achieved in 108 of 228 (47%) patients. Male sex, non-Caucasian ethnicity, higher body mass index, high viral load, genotype 1, higher fibrosis stage, and MS were associated significantly with a lack of SVR. After adjusting for confounding variables, MS remained independently associated with a lack of SVR (P < .01). Specifically, subjects with MS were 3.8 (95% confidence interval, 1.4-10.5) times more likely to fail treatment than those without MS.

CONCLUSIONS

MS is seen frequently in patients with chronic HCV and is associated independently to lack of SVR. These findings support the concept that an aggressive intervention approach comprising lifestyle modification alone or in combination with drug treatment of the MS components may play an important role in improving antiviral responses in these patients.

Nonalcoholic fatty liver disease: An overview of current insights in pathogenesis, diagnosis and treatment

Estimates of people suffering from overweight (one billion) and obesity (300 million) are increasing. The accumulation of triglycerides in the liver, in the absence of excess alcohol intake, has been described in the early sixties. It was not until 1980, however, that Ludwig et al named this condition nonalcoholic steatohepatitis (NASH). Subsequently, nonalcoholic fatty liver disease (NAFLD) has been used as a general name for conditions ranging from simple steatosis through steatohepatitis to end-stage liver disease (cirrhosis). Many studies have demonstrated the significant correlation with obesity and insulin resistance. Other studies have revealed a significant correlation between hepatic steatosis, cardiovascular disease and increased intima-media thickness. WHO estimated that at least two million patients will develop cirrhosis due to hepatic steatosis in the years to come. Longitudinal cohort studies have demonstrated that those patients with cirrhosis have a similar risk to develop hepatocellular carcinoma as those with other causes of cirrhosis. Taken all together, NAFLD has become the third most important indication for liver transplantation. Therefore, training programmes in internal medicine, gastroenterology and hepatology should stress the importance of diagnosing this entity and treat properly those at risk for developing complications of portal hypertension and concomittant cardiovascular disease. This review will focus on the clinical characteristics, pathophysiology, imaging techniques and the readily available therapeutic options.

Connective tissue growth factor, steatosis and fibrosis in patients with chronic hepatitis C

BACKGROUND/AIM

Both steatosis and insulin resistance have been linked to accelerated fibrosis in chronic hepatitis C. Connective tissue growth factor (CTGF) plays a major role in extracellular matrix production in fibrotic disorders including cirrhosis, and its expression is stimulated in vitro by insulin and glucose. We hypothesized that CTGF may link steatosis, insulin resistance and fibrosis.

METHODS

We included 153 chronic hepatitis C patients enrolled in the Swiss Hepatitis C Cohort Study and for whom a liver biopsy and plasma samples were available. CTGF expression was assessed quantitatively by immunohistochemistry. In 94 patients (57 with genotypes non-3), plasma levels of glucose, insulin and leptin were also measured. CTGF synthesis was investigated by immunoblotting on LX-2 stellate cells.

RESULTS

Connective tissue growth factor expression was higher in patients with steatosis (P=0.039) and in patients with fibrosis (P=0.008) than those without these features. CTGF levels were neither associated with insulinaemia or with glycaemia, nor with inflammation. By multiple regression analysis, CTGF levels were independently associated with steatosis, a past history of alcohol abuse, plasma leptin and HCV RNA levels; when only patients with genotypes non-3 were considered, CTGF levels were independently associated with a past history of alcohol abuse, plasma leptin levels and steatosis. Leptin stimulated CTGF synthesis in LX-2 cells.

CONCLUSIONS

In patients with chronic hepatitis C and steatosis, CTGF may promote fibrosis independently of inflammation. CTGF may link steatosis and fibrosis via increased leptin levels.

Interplay between oxidative stress and hepatic steatosis in the progression of chronic hepatitis C

BACKGROUND/AIMS

The contribution of oxidative stress to the pathogenesis of chronic hepatitis C (CHC) is still poorly elucidated. This study investigated the relationship between oxidative stress, insulin resistance, steatosis and fibrosis in CHC.

METHODS

IgG against malondialdehyde-albumin adducts and HOMA-IR were measured as markers of oxidative stress and insulin resistance, respectively, in 107 consecutive CHC patients.

RESULTS

Oxidative stress was present in 61% of the patients, irrespective of age, gender, viral load, BMI, aminotransferase level, histology activity index (HAI) and HCV genotype. Insulin resistance and steatosis were evident in 80% and 70% of the patients, respectively. In the patients infected by HCV genotype non-3, but not in those with genotype 3 infection HOMA-IR (p<0.03), steatosis (p=0.02) and fibrosis (p<0.05) were higher in the subjects with oxidative stress than in those without. Multiple regression analysis revealed that, HOMA-IR (p<0.01), fibrosis (p<0.01) and oxidative stress (p<0.05) were independently associated with steatosis, whereas steatosis was independently associated with oxidative stress (p<0.03) and HOMA-IR (p<0.02). Steatosis (p<0.02) and HAI (p=0.007) were also independent predictors of fibrosis.

CONCLUSIONS

In patients infected by HCV genotype non-3, oxidative stress and insulin resistance contribute to steatosis, which in turn exacerbates both insulin resistance and oxidative stress and accelerates the progression of fibrosis.

Insulin resistance in chronic hepatitis C: association with genotypes 1 and 4, serum HCV RNA level, and liver fibrosis

BACKGROUND & AIMS

Our study was designed to test the association between insulin resistance (IR) and hepatitis C virus (HCV) genotypes, serum HCV RNA level and liver fibrosis stage in a large prospective cohort of chronic hepatitis C (CHC) patients.

METHODS

Six hundred consecutive patients (CHC, n = 500; chronic hepatitis B (CHB), n = 100) were evaluated on the day of liver biopsy. IR (Homeostasis Model for Assessment of Insulin Resistance) and all components of the metabolic syndrome were assessed. By logistic regression, independent factors associated with IR and those associated with significant fibrosis were assessed in nondiabetic and noncirrhotic CHC, respectively. Parameters of IR were compared between hepatitis B and 240 CHC matched by epidemiologic, metabolic, and histologic features.

RESULTS

IR was present in 32.4% of the 462 nondiabetic CHC and associated with the metabolic syndrome, genotypes 1 and 4, significant fibrosis, and severe steatosis. IR was diagnosed in 15% of 145 CHC without metabolic syndrome or significant fibrosis, and associated with genotypes 1 and 4, high serum HCV RNA level, and moderate-severe necroinflammation. Significant fibrosis was present in 51.1% of the 454 noncirrhotic CHC patients and associated with male sex, age >40 years, IR, moderate-severe necroinflammation, and severe steatosis. IR was less frequent in CHB than in matched CHC (5% vs 35%, respectively, P < .001).

CONCLUSIONS

IR is a specific feature of CHC, associated with genotypes 1 and 4 and high serum HCV RNA level. Significant fibrosis is associated with IR independent from steatosis.

High hepatitis C viral load is associated with insulin resistance in patients with chronic hepatitis C

BACKGROUND AND AIMS

Although insulin resistance affects liver fibrosis progression and treatment response in chronic hepatitis C (CHC), the relationship between chronic hepatitis C virus (HCV) infection and insulin resistance (IR) remains to be firmly established. We thus studied the impact of host, metabolic and viral factors on IR in CHC patients.

METHODS

A total of 162 CHC patients with complete clinical data were enrolled. Among them, 94 received histological examinations. Quantitative HCV RNA was assayed by a real-time polymerase chain reaction (PCR) assay. Genotyping was performed by reverse transcription PCR with type-specific primers. The pretreatment IR index was determined using homeostasis model assessment (HOMA), and an index value of more than 2.4 was designated IR. Unadjusted and adjusted association of the HCV RNA level and IR was further analysed.

RESULTS

In multivariate linear regression analysis, a dose-response relationship was observed between the log(10) HCV RNA level and the presence of IR. IR was positively correlated with body mass index, triglyceride, HCV RNA and alanine aminotransferase levels, but negatively correlated with adiponectin level. Subgroup analysis stratified by HCV genotype showed that there was a trend towards a higher HOMR-IR index value and lower adiponectin levels in genotype 1 patients. Histological analysis showed that IR was positively associated with the severity of hepatic steatosis.

CONCLUSIONS

Our data indicate that higher HCV RNA levels are associated with the presence of IR in CHC patients. Further studies are needed to clarify the interplays between HCV infection, IR and adiponectin in an attempt to develop new adjuvant therapy for CHC.

Assessment of hepatitis C virus-RNA clearance under combination therapy for hepatitis C virus genotype 1: performance of the transcription-mediated amplification assay

Monitoring of HCV-RNA in blood during antiviral therapy is performed mostly by commercially available reverse transcription polymerase chain reaction-based (RT-PCR) assays, with a lower detection limit of 30-50 IU/mL of HCV-RNA. Use of different tests in the pivotal trials of combination therapy has generated some discordance, in terms of predictive value of the early virological response (EVR). To evaluate whether the use of a more sensitive test, as a qualitative assay based on transcription mediated amplification (TMA) with a lower detection limit of 5-10 IU/mL of HCV-RNA, may obtain a better prediction of EVR and of the ultimate virological outcome, we retrospectively evaluated serial samples from 108 naïve patients with HCV genotype 1 chronic hepatitis, treated with pegylated alpha2b interferon plus ribavirin for 48 weeks and with a 24 weeks stopping rule. Serum samples of patients, obtained during treatment at weeks 4, 12, 24 and 48 and after treatment at week 24, were evaluated by TMA. Comparison of the RT-PCR and TMA assays for the qualitative detection of HCV-RNA showed no significant differences in performance when these tests were used at the end of the treatment period for assessing patients without an on-treatment virological response and those who eventually obtain a sustained virological response. Our results show instead that the use of TMA assay to detect HCV-RNA at 12 and 24 weeks of the combination therapy is more effective than RT-PCR in identifying patients with the highest probability of sustained HCV-RNA clearance.