Clinical expression of insulin resistance in hepatitis C and B virus-related chronic hepatitis: Differences and similarities

Expert opinion on managing chronic HCV infection in patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) has been identified as an extrahepatic manifestation of chronic HCV infection. Conversely, in the context of chronic HCV infection, T2DM can accelerate the course of HCV-induced liver disease leading to increased risk of fibrosis, cirrhosis and hepatocellular carcinoma. The presence of T2DM negatively impacts the efficacy of interferon-based antiviral therapy, but real-world data with high-efficacy direct-acting antiviral therapies suggest high viral clearance rates in T2DM patients. In HCV-infected individuals, viral eradication is associated with a reduced risk of de novo T2DM in non-diabetic patients and beneficial metabolic changes in patients with T2DM, highlighting the importance of antiviral treatment and physician awareness of this association.

[Insulin resistance and chronic hepatitis C]

AIM

To estimate the spread of insulin resistance (IR) in patients with chronic hepatitis C (CHC) and to define the role of IR in the development of hepatic steatosis (HS) and in the progression of liver fibrosis (LF), as well as the impact of IR on the results of antiviral therapy (AVT).

SUBJECTS AND METHODS

A total of 211 patients with CHC were examined. A comparison group consisted of 75 patients with chronic hepatitis B (CHB). The patients were divided according to the presence and absence of IR and type 2 diabetes mellitus (DM). IR was analyzed in patients with CHC with a body mass index (BMI) of <25 kg/m2 and with the initial manifestations of LF.

RESULTS

In the patients with CHC, IR without DM was 1.7-fold more common and type 2 DM was 2.6 times more frequently seen than in those with CHB. The highest biochemical activity, subclinical inflammation (as evaluated from ferritin and C-reactive protein levels), and an advanced LF stage were noted in the presence of IR and type DM. IR and type 2 DM were associated with metabolic syndrome and its individual components and with no response to AVT. When the BMI was <25 kg/m2, HS, inadequate 25(OH)D provision, an advanced LF stage, and slowly progressive inflammation were related to IR. In the presence of the initial manifestations of fibrosis, IR was associated with obesity, HS, 25(OH)D deficiency, a rise in C-reactive protein greater than 3 mg/l, and no response to AVT.

CONCLUSION

The presence of IR in CHC patients with a BMI of <25 kg/m2 and with the initial manifestations of LF and the association of IR with HS and an advanced LF stage necessitate an examination of all patients with CHC in an effort to identify IR and to perform active therapy of detected abnormalities.

Intrahepatic vascular changes in non-alcoholic fatty liver disease: Potential role of insulin-resistance and endothelial dysfunction

Metabolic syndrome is a cluster of several clinical conditions characterized by insulin-resistance and high cardiovascular risk. Non-alcoholic fatty liver disease is the liver expression of the metabolic syndrome, and insulin resistance can be a frequent comorbidity in several chronic liver diseases, in particular hepatitis C virus infection and/or cirrhosis. Several studies have demonstrated that insulin action is not only relevant for glucose control, but also for vascular homeostasis. Insulin regulates nitric oxide production, which mediates to a large degree the vasodilating, anti-inflammatory and antithrombotic properties of a healthy endothelium, guaranteeing organ perfusion. The effects of insulin on the liver microvasculature and the effects of IR on sinusoidal endothelial cells have been studied in animal models of non-alcoholic fatty liver disease. The hypotheses derived from these studies and the potential translation of these results into humans are critically discussed in this review.

Association between diabetes mellitus and cirrhosis mortality: the Singapore Chinese Health Study

BACKGROUND & AIM

Diabetes mellitus has been linked to cirrhosis-related mortality in Western populations, but less is known about this relationship in Asian populations. We studied the impact of diabetes on the risk of cirrhosis mortality in a population-based cohort among Chinese in Singapore.

METHODS

We used data collected and analysed from the Singapore Chinese Health Study, a prospective community-based cohort of 63 275 subjects aged 45-74 years during enrolment between 1993 and 1998. Information on diet, lifestyle and medical history was collected via structured questionnaire. Mortality cases from cirrhosis in the cohort were identified via linkage with nationwide death registry up to 31 December 2014. Cox proportional regression models were used to estimate the associations with adjustment for risk factors of cirrhosis.

RESULTS

After a mean follow-up of 16.9 years, there were 133 deaths from cirrhosis. Diabetes was associated with an increased risk of cirrhosis mortality (hazard ratio [HR]: 2.80; 95% confidence interval [CI]: 2.04-3.83), and for both viral (HR: 2.20; 95% CI: 1.18-4.11) and non-viral hepatitis-related cirrhosis mortality (HR: 3.06; 95% CI: 2.13-4.41). The association between diabetes and non-viral hepatitis-related cirrhosis mortality was stronger among participants of body mass index (BMI) less than 23 kg/m² (HR: 7.11; 95% CI: 3.42-14.79) compared to heavier individuals (HR: 2.28; 95% CI: 1.20-4.35) (P_interaction =0.02).

CONCLUSION

Diabetes is a risk factor for cirrhosis mortality, especially for non-viral hepatitis-related cirrhosis in population with BMI considered low or normal in Asia.

Application of network construction to estimate functional changes to insulin receptor substrates 1 and 2 in Huh7 cells following infection with the hepatitis C virus

Hepatitis C virus (HCV) is closely associated with insulin resistance (IS), acting primarily by interfering with insulin signaling pathways, increasing cytokine-mediated (tumor necrosis factor α, interleukin 6) inflammatory responses and enhancing oxidative stress. In the insulin signaling pathways, the insulin receptor substrate (IRS) is one of the key regulatory factors. The present study constructed gene regulatory sub-networks specific for IRS1 and IRS2 in Huh7 cells and HCV-infected Huh7 (HCV-Huh7) cells using linear programming and a decomposition algorithm, and investigated the possible mechanisms underlying the function of IRS1/2 in HCV-induced IS in Huh7 cells. All data were obtained from GSE20948 of the Gene Expression Omnibus database from the National Center for Biotechnology Information. Genes which were significantly differentially expressed between Huh7 and HCV-Huh7 cells were analyzed using the significance analysis of microarray algorithm. The top 50 genes, including IRS1/2, were used as target genes to determine the gene regulatory networks and next the sub-networks of IRS1 and IRS2 in HCV-Huh7 and Huh7 cells using Gene Regulatory Network Inference Tool, an algorithm based on linear programming and the decomposition process. The IRS1/2 sub-networks were divided into upstream/downstream groups and activation/suppression clusters, and were further analyzed using Molecule Annotation System 3.0 and Database for Annotation, Visualization, and Integrated Discovery software, two online platforms for enrichment and clustering analysis and visualization. The results indicated that in Huh7 cells, the downstream network of IRS2 is more complex than that of IRS1, indicating that the insulin metabolism in Huh7 cells may be primarily mediated by IRS2. In HCV-Huh7 cells, the downstream pathway of IRS2 is blocked, suggesting that this may be the underlying mechanism in HCV infection that leads to insulin resistance. The present findings add a further dimension to the understanding of the pathological mechanisms of HCV infection-associated insulin resistance, and provide novel concepts for insulin resistance and glucose metabolism research.

Effect of coexisting diabetes mellitus and chronic kidney disease on mortality of cirrhotic patients with esophageal variceal bleeding

BACKGROUND

Esophageal variceal bleeding (EVB) is a serious and common complication of cirrhosis. Diabetes mellitus (DM) and chronic kidney disease (CKD) increase mortality in patients with cirrhosis. However, whether coexisting DM and CKD increase mortality in cirrhotic patients with EVB remains unclear.

METHODS

We enrolled cirrhotic patients hospitalized with the first presentation of EVB from 2005 through 2010 using Longitudinal Health Insurance Database 2005. The hazard ratios (HRs) of 42-day and one-year EVB mortality were calculated using Cox regression model.

RESULTS

We identified 888 patients hospitalized with the first presentation of EVB. Among the cirrhotic patients with EVB, all-cause mortality at 42-day and one-year were 21.3 and 45.0 %, respectively. The respective HRs for the 42-day and one-year mortality were 1.80 (95 % confidence interval [CI], 1.10-2.97) and 1.52 (95 % CI, 1.06-2.17) for patients with CKD and 0.79 (95 % CI, 0.57-1.10) and 0.88 (95 % CI, 0.71-1.09) for patients with DM. Specifically, coexisting CKD and DM increased the 42-day and one-year mortality with respective HRs of 1.99 (95%CI, 1.03-3.84) and 1.84 (95%CI, 1.14-2.98) compared with those without CKD and DM. The HRs for 42-day and 1-year mortality in female patients with DM and CKD were 4.03 (95%CI, 1.40-11.59) and 2.84 (95%CI, 1.31-6.14) respectively, and were 2.93 (95%CI, 1.14-7.57) and 2.42 (95%CI, 1.28-4.57) in male patients with DM and CKD.

CONCLUSION

We identified that coexisting DM and CKD increased risk of mortality at 42 days and 1 year following EVB.

Epidemiology of hepatitis C virus in Iran

In Iran, the prevalence of hepatitis C virus (HCV) infection is relatively low according to the population-based epidemiological studies. However, the epidemiology of HCV is changing and the rate of HCV infection is increasing due to the growth in the number of injecting drug users in the society. In addition, a shift has occurred in the distribution pattern of HCV genotypes among HCV-infected patients in Iran. Genotype 1a is the most prevalent genotype in Iran, but in recent years, an increase in the frequency of 3a and a decrease in 1a and 1b have been reported. These variations in the epidemiology of HCV reflect differences in the routes of transmission, status of public health, lifestyles, and risk factors in different groups and geographic regions of Iran. Health policy makers should consider these differences to establish better strategies for control and prevention of HCV infection. Therefore, this review was conducted to present a clear view regarding the current epidemiology of HCV infection in Iran.

The impact of obesity and metabolic syndrome on chronic hepatitis B and drug-induced liver disease

Steatosis and insulin resistance (IR) are no more frequent in chronic hepatitis B (CHB) than in the general population. Although experimental studies suggest that the HBx protein induces liver fat, human studies have shown that steatosis and IR are related to coexistent metabolic risk factors, thus epidemiologically linked rather than virally induced. Diabetes and obesity are associated with advanced fibrosis and increased risk of hepatocellular carcinoma in CHB. Despite abundant experimental data showing that fatty liver is more susceptible to liver injury, drug-induced liver disease seems no more frequent in NAFLD patients, except, possibly, a higher incidence but not severity of acetaminophen hepatotoxicity.

Insulin resistance in non-diabetic patients of chronic Hepatitis C

Objective: To determine insulin resistance in non-diabetic chronic hepatitis C patients using Homeostatic Model Assessment of Insulin Resistance (HOMA-IR).

Methodology: Patients having anti-HCV positive were included in this study. Patients with diabetes mellitus, thyroid disease, hyperlipidemias, hypercortisolism and infective diseases other than hepatitis C were excluded. Age, weight, height and absence of diabetes were documented. Fasting blood glucose and fasting insulin levels were done. Body mass index and insulin resistance was calculated using the formulas. Patients having insulin resistance using formula HOMA-IR>2.5 were labeled as insulin resistant. Data was analyzed using SPSS-18.

Results: One hundred and fifty five patients according to sample size estimation were enrolled, in whom HOMA-IR was calculated, the mean value was found to be 2.47 ±1.30. A total of 79 (51%) of patients had HOMA-IR more than 2.5 showing insulin resistance.

Conclusion: In a third world country like Pakistan, where there is a high prevalence of hepatitis C infection, the consequences of the disease are also very common. Insulin resistance was found in 51% of patients with chronic hepatitis C.

Patatin-like phospholipase domain-containing 3 I148M affects liver steatosis in patients with chronic hepatitis B

Steatosis is a common histopathological feature of chronic hepatitis B (CHB) and has been associated with severity of liver disease. Recently, the rs738409 I148M patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphism has been demonstrated to influence steatosis susceptibility and fibrosis progression in patients with different liver diseases, but no data are yet available for CHB. The aim of this study was to evaluate whether PNPLA3 I148M influences steatosis susceptibility in a large series of patients with CHB. We enrolled 235 treatment-naïve CHB patients consecutively examined by percutaneous liver biopsy. In ≥2-cm-long liver tissue cores, steatosis and fibrosis were staged by Kleiner and METAVIR scores, respectively. The I148M polymorphism was determined by Taqman assays. Steatosis was present in 146 (62%) patients, of whom 24 (10%) had severe (>33% of hepatocytes) steatosis. Steatosis was independently associated with age (odds ratio [OR]: 2.67; confidence interval [CI]: 1.50-4.92; for age ≥50 years), body mass index (BMI; OR, 2.84; CI, 1.30-6.76; for BMI ≥27.5 kg/m(2) ), diabetes or impaired fasting glucose (OR, 4.45; CI, 1.10-30.0), and PNPLA3 148M allele (OR, 1.62; CI, 1.00-7.00; for each 148M allele). Independent predictors of severe steatosis were BMI (OR, 3.60; CI, 1.39-9.22; for BMI ≥27.5 kg/m(2) ) and PNPLA3 148M allele (OR, 6.03; CI, 1.23-5.0; for each 148M allele). PNPLA3 148M alleles were associated with a progressive increase in severe steatosis in patients with acquired cofactors, such severe overweight and a history of alcohol intake (P = 0.005).

CONCLUSION

In CHB patients, the PNPLA3 I148M polymorphism influences susceptibility to steatosis and, in particular, when associated with severe overweight and alcohol intake, severe steatosis.

Association between the hepatitis B and C viruses and metabolic diseases in patients stratified by age

BACKGROUND

Hepatitis B/C viruses cause liver disease and metabolic disturbances.

AIMS

The purpose of this study was to evaluate the association between hepatitis B/C infection and metabolic syndrome (MS).

METHODS

In total, 26,305 subjects were included in this multicentre, cross-sectional study. Systolic and diastolic blood pressures, body mass index and waist circumference were measured. Total cholesterol, high- and low-density lipoprotein cholesterol, triglyceride, fasting blood glucose and uric acid were determined, and hepatitis B serum antigen (HBsAg) and anti-HCV antibodies were assayed using commercial kits.

RESULTS

MS was diagnosed in 2712 (23.0%) females, including 131 and 166 positive for HBsAg and anti-HCV respectively. In the men, 4594 (31.6%) were diagnosed with MS, including 326 positive for HBsAg and 131 positive for anti-HCV. No significant difference in the prevalence of MS was identified in any group, except men and women >45 years who were anti-HCV positive. Various metabolic alterations in both men and women >45 years were noted, including waist circumference, body mass index, fasting blood glucose and systolic and diastolic blood pressure. Notably, high- and low-density lipoproteins were significantly lower in positive subjects compared to those weakly positive and/or negative for anti-HCV.

CONCLUSIONS

There were obvious metabolic derangements in patients coinflicted with MS and hepatitis C infections, particularly those >45 years of age. There is a pressing need to identify strategies to improve/resolve metabolic derangements to maximize sustained virological response rates in patients infected with HCV (and potentially HBV).

Post-challenge hyperglycemia is a significant risk factor for the development of hepatocellular carcinoma in patients with chronic hepatitis C

BACKGROUND

Several epidemiological studies have reported that diabetes mellitus is a risk factor for hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-positive patients. However, it is unclear whether or not post-challenge hyperglycemia is a risk factor. The purpose of this study was to determine the association between post-challenge hyperglycemia and hepatocarcinogenesis in HCV-positive patients.

METHODS

A total of 203 HCV-RNA-positive subjects (108 males, mean age 54.3 ± 10.8 years; 95 females, mean age 56.6 ± 10.3 years; genotype 1b/2a/2b/3a: 152/38/12/1) who underwent liver biopsy and a 75-g oral glucose tolerance test, and who were treated with interferon (IFN) were enrolled in this study. None of the subjects had been treated with antidiabetic drugs. The subjects underwent ultrasonography and/or computed tomography every 6 months after the end of the IFN therapy.

RESULTS

Thirteen patients, including one patient who achieved a sustained viral response (SVR) with IFN, developed HCC. On multivariate analysis, male sex, age >65 years, excessive alcohol consumption, non-SVR, liver steatosis area >5% in liver specimens, and 120-min post-challenge hyperglycemia were risk factors for the development of HCC. After matching subjects for sex, age, alcohol intake, and response to the IFN therapy, advanced fibrosis stages [hazard ratio (HR) 2.8], liver steatosis (HR 5.4), and 120-min post-challenge hyperglycemia (HR 4.9) were significant risk factors for the development of HCC. Furthermore, after matching for the fibrosis stage, liver steatosis (HR 5.7) and 120-min post-challenge hyperglycemia (HR 6.9) remained as significant factors for HCC development.

CONCLUSION

Post-challenge hyperglycemia is an independent risk factor for HCC in HCV-positive patients.

The association between Helicobacter pylori infection and insulin resistance: a systematic review

BACKGROUND

Helicobacter pylori infection has been associated with diverse extradigestive morbidity, including insulin resistance (IR) syndrome. The aim of this systematic review was to summarize the epidemiologic evidence concerning the association between H. pylori infection and IR quantitative indexes.

MATERIALS AND METHODS

A computerized literature search in PubMed electronic databases and Cochrane Central Register of Controlled Trials was performed.

RESULTS

Nine studies reporting data on 2120 participants were finally eligible for this systematic review. Seven of them were cross-sectional studies and two were nonrandomized, open-label, controlled trials investigating the effect of H. pylori eradication on IR. Homeostatic model of assessment insulin resistance (HOMA-IR) was used in all studies to quantify IR. There seems to be a trend toward a positive association between H. pylori infection and HOMA-IR, strengthened by regression analysis in one study. However, there was significant heterogeneity between studies regarding the method(s) of H. pylori infection diagnosis based on and the study populations. The studies for the effect of H. pylori eradication on HOMA-IR revealed conflicting results.

CONCLUSIONS

Although data seem to indicate a potential association between H. pylori infection and IR, further studies are needed to strengthen this association and to clarify whether there is a causative link between them. If a causal link is confirmed in the future, this may have a major impact on the pathophysiology and management of IR syndrome, including type 2 diabetes mellitus and nonalcoholic fatty liver disease.

Insulin resistance, steatosis, and fibrosis in Egyptian patients with chronic Hepatitis C virus infection

BACKGROUND/AIM

Both nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C virus (HCV) infection are common in Egypt, and their coexistence is expected. There is controversy regarding the influence of NAFLD on chronic HCV disease progression. This study evaluates the effect of NAFLD on the severity of chronic hepatitis C (CHC) (necroinflammation and fibrosis) and assesses the relative contribution of insulin resistance syndrome to the occurrence of NAFLD in patients with chronic HCV infection.

PATIENTS AND METHODS

Untreated consecutive adults with chronic HCV infection admitted for liver biopsy were included in this study. Before liver biopsy, a questionnaire for risk factors was completed prospectively, and a blood sample was obtained for laboratory analysis.

RESULTS

Our study included 92 male patients. Their mean ± SD age and aspartate aminotransferase (AST) level were 42 ± 7.7 years (range 20-56) and 68 ± 41.7 U/L (range 16-214), respectively. The mean insulin level and insulin resistance index were 15.6 ± 18.3 mIU/mL (range 5.1-137.4) and 5.9 ± 15.2 (range 0.9-136.2), respectively. Fifty four percent of patients had steatosis and 65% had fibrosis. In multivariate analyses, steatosis was associated with insulin resistance and fibrosis was associated with high AST level, age ≥40 years, and steatosis.

CONCLUSIONS

Steatosis is a histopathologic feature in >50% of patients with chronic HCV infection. Insulin resistance has an important role in the pathogenesis of steatosis, which represents a significant determinant of fibrosis together with high serum AST level and older age.

Steatosis as a co-factor in chronic liver diseases

The finding of lipid accumulation in the liver, so-called hepatic steatosis or non-alcoholic fatty liver disease, is a common condition frequently found in healthy subjects. Its prevalence, in fact, has been estimated by magnetic resonance studies to be about 35% in the general population and 75% in obese persons. Nevertheless, its presence generates liver damage only in a small percentage of subjects not affected by other liver diseases. It should be defined as a “co-factor” capable of affecting severity and progression, and also therapeutic perspectives, of liver diseases to which it is associated. Herein we will evaluate the impact of hepatic steatosis and obesity on the most common liver diseases: chronic viral hepatitis C and B, and alcoholic liver disease.

Metabolic syndrome and alanine aminotransferase: a global perspective from the NAVIGATOR screening population

AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with features of the metabolic syndrome (MetS) and may be an expression of the syndrome within the liver. Using screening data from the Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) study (n = 42 149), we examined whether alanine aminotransferase (ALT), a biomarker for NAFLD, clustered with features of MetS and whether the clusters differed across global geographic regions.

METHODS

Exploratory factor analysis using principle components analysis was applied to data drawn from the NAVIGATOR screening population (n = 41 111). Demographic data, anthropomorphic measurements and blood pressure (BP) collected during the screening visit, as well as blood samples analysed for ALT, total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, and fasting and 2-h glucose measures after an oral glucose tolerance test were used for our analysis.

RESULTS

Two factors, interpreted as lipid (Factor 1), and BP/obesity (Factor 2) were identified, explaining approximately 50% of the variance in the overall population. Similar patterns of aggregation were reproducible across all geographic regions except Asia, where fasting glucose loaded more consistently on Factor 1. ALT loaded with mean arterial pressure, fasting glucose and waist circumference except in Asia, where it loaded only with mean arterial pressure and waist circumference.

CONCLUSIONS

ALT aggregated with components of MetS, and the pattern of aggregation of ALT with other features of MetS was similar across regions except Asia, possibly indicating a different pathophysiology for NAFLD in Asia. Predictive models of NAFLD may need to be adjusted for regional and ethnic differences.