Insulin resistance in chronic hepatitis B virus infection

Hepatitis C Virus, Insulin Resistance, and Diabetes: A Review

Hepatitis C virus (HCV) infection and diabetes mellitus (DM) are two chronic diseases that are a cause of significant health and economic burdens worldwide. HCV is associated with the development of insulin resistance (IR) and diabetes mellitus (DM). The mechanisms through which HCV induces IR and DM include direct viral effects, pro-inflammatory cytokines and other immune-mediated processes. Type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) are both chronic diseases that involve impaired glucose homeostasis, albeit through different mechanisms. T1DM is an autoimmune disease that leads to the destruction of pancreatic beta cells resulting in insulin deficiency. In T2DM, a combination of peripheral insulin resistance and irregular production of insulin eventually lead to beta cell destruction and insulin insufficiency. Both type 1 and type 2 DM etiologies involve a combination of genetic and environmental factors. The data on HCV and T1DM association is limited, unlike T2DM, where a large body of evidence linking HCV to T2DM is available. Here, we intend to outline the current state of knowledge on HCV, IR, and DM. This article is protected by copyright. All rights reserved.

Serum leptin and homeostasis model assessment-IR as novel predictors of early liver fibrosis in chronic hepatitis B virus infection

BACKGROUND

The relationship between hepatitis B virus (HBV) infection, leptin and insulin resistance remains unclear. We hypothesised links between serum leptin and insulin resistance in non-diabetic patients with chronic viral hepatitis B infection and their relation to liver fibrosis.

METHODS

We recruited 190 untreated patients with chronic HBV infection and 72 healthy controls. Serum leptin, fasting glucose, insulin, liver function tests (LFTs), C-peptide and Homeostasis model assessment-IR (HOMA-IR) were measured/calculated by ELISA and standard techniques.

RESULTS

Serum leptin, C-peptide (both P < 0.001), HOMA-IR (P = 0.021) and several LFTs were increased in patients with chronic HBV-infection. In multivariate regression analysis, both HOMA-IR (P = 0.003) and leptin (P = 0.002) were significant independent predictors of HBV infection. There were significant positive correlations (P < 0.01) between leptin and HOMA-IR (r = 0.81), between serum leptin and METAVIR activity (r = 0.95), and between HOMA-IR and BMI (r = 0.75), fasting glucose (r = 0.005), and fasting insulin (r = 0.81). Several LFTs, glucose and insulin correlated modestly (r = 0.61-0.69, P < 0.05) with leptin.

CONCLUSION

Serum leptin may be related to the rate of fibrosis progression in nondiabetic patients with chronic HBV infection. Follow-up by serial measurement of serum leptin and HOMA-IR in non diabetic HBV-infected patients may be used as a non-invasive marker of early liver fibrosis.

Effect of hepatitis B virus on steatosis in hepatitis C virus co-infected subjects: A multi-centre study and systematic review

It remains unclear whether hepatitis B virus (HBV) infection may modify the severity of viral steatosis in patients coinfected with chronic hepatitis C virus (HCV). We examined the influence of coinfection with HBV on prevalence of steatosis in chronic hepatitis C in a multi-centre cohort of HBV-HCV subjects, and by performing a systematic review and meta-analysis of the literature. We centrally and blindly assessed steatosis prevalence and severity in a cohort of HBV-HCV coinfected subjects compared to HCV and HBV monoinfected controls and we performed a systematic review of studies addressing the prevalence of steatosis in HBV-HCV subjects compared to HCV controls. In the clinical cohort, we included 85 HBV-HCV, 69 HBV and 112 HCV subjects from 16 international centres. There was no significant difference in steatosis prevalence between the HBV-HCV and the HCV groups (33% vs 45%, P = .11). In subgroup analysis, lean HBV-HCV subjects with detectable HBV DNA had less steatosis than lean HCV subjects matched for HCV viremia (15% vs 45%, P = .02). Our literature search identified 5 additional studies included in a systematic review. Overall, prevalence of steatosis > 5% was similar in HBV-HCV infection compared to HCV (pooled odds ratio [OR] 0.91, 95% CI 0.53-1.6) although there was significant heterogeneity (I² 69%, P = .007). In conclusion, although the prevalence of steatosis is similar in HBV-HCV compared to HCV subjects, our analysis suggests that there may be an inhibitory effect of HCV-induced steatogenesis by HBV in certain subgroups of patients.

Insulin Resistance Predicts Virological Response to Interferon-α in Chronic Hepatitis B Patients

GOALS

To elucidate impact of insulin resistance (IR) on the response to interferon-α (IFN-α) therapy in chronic hepatitis B (CHB) patients.

BACKGROUND

Metabolic factors influencing the virological response of CHB patients on IFN-α treatment are still unexplored.

STUDY

Eighty CHB patients were treated with IFN-α for 48 weeks. The IR was evaluated by homeostasis model assessment of IR (HOMA-IR) before treatment. Viral load and biochemical parameters were measured at 12, 24, and 48 weeks after starting treatment, and then 24 weeks after the end of treatment. IFN-γ and tumor necrosis factor-α were tested at baseline and 12 weeks of treatment.

RESULTS

Pretreatment HOMA-IR proved to be the only independent predictor of primary nonresponse, as well as the pretreatment HOMA-IR, viral load and primary nonresponse were independently associated with virological response at 24, 48 weeks of treatment and at the follow-up endpoint. The significant higher virological relapse rate in patients with IR was observed in patients with virological response at 48 weeks of treatment. The mean HOMA-IR was significantly lower in virological responders than in virological nonresponders. The secretion of IFN-γ and tumor necrosis factor-α was not induced in patients with IR at 12 weeks after IFN-α treatment.

CONCLUSIONS

Our data suggest that IR is strongly associated with virological response, thus reflecting the important role played by metabolic factors in the viral kinetics during IFN-α treatment. These findings suggested clinical application of pretreatment HOMA-IR could enable treatment outcome to be predicted and treatment regimens to be determined.

A "systems medicine" approach to the study of non-alcoholic fatty liver disease

The prevalence of fatty liver (steatosis) in the general population is rapidly increasing worldwide. The progress of knowledge in the physiopathology of fatty liver is based on the systems biology approach to studying the complex interactions among different physiological systems. Similarly, translational and clinical research should address the complex interplay between these systems impacting on fatty liver. The clinical needs drive the applications of systems medicine to re-define clinical phenotypes, assessing the multiple nature of disease susceptibility and progression (e.g. the definition of risk, prognosis, diagnosis criteria, and new endpoints of clinical trials). Based on this premise and in light of recent findings, the complex mechanisms involved in the pathology of fatty liver and their impact on the short- and long-term clinical outcomes of cardiovascular, metabolic liver diseases associated with steatosis are presented in this review using a new "systems medicine" approach. A new data set is proposed for studying the impairments of different physiological systems that have an impact on fatty liver in different subsets of subjects and patients.

Patatin-Like Phospholipase Domain-Containing 3 I148M Variant Is Associated with Liver Steatosis and Fat Distribution in Chronic Hepatitis B

BACKGROUND

The patatin-like phospholipase domain-containing 3 gene (PNPLA3) has been associated with liver steatosis and disease progression in nonalcoholic steatohepatitis and chronic hepatitis C.

AIMS

The aim of the present study was to evaluate the influence of the PNPLA3 I148M polymorphisms on the clinical, histological, viral, and host parameters in Italian patients with chronic hepatitis B (CHB).

METHODS

Ninety-nine patients with CHB entered the study and underwent a clinical, histological, virological, and biochemical evaluation. PNPLA3 (p.I148M) variants were genotyped.

RESULTS

PNPLA3 rare variant (148M) was significantly associated with liver steatosis (p = 0.0019) and cholesterol (p = 0.04) levels, but not with fibrosis or histological activity index. The 13 patients with severe liver steatosis (score > 3) (38%) were more frequently homozygous for PNPLA3 148M variant than the 86 without (6%, p = 0.003). At logistic regression analysis, severe steatosis was independently associated with the rare allele (p = 0.001) and waist circumference, but not with body mass index (BMI).

CONCLUSIONS

In our CHB patients, the PNPLA3 polymorphisms influenced the development of liver steatosis, but not fibrosis status. The association of PNPLA3 p.I148M with liver steatosis increased with the greater amount of abdominal fat, irrespective of BMI.

Influence of gastrointestinal factors on glucose metabolism in patients with cirrhosis

BACKGROUND AND AIM

The impaired glucose tolerance in cirrhosis is poorly understood. We evaluated the influence of gastrointestinal-mediated glucose disposal and incretin effect in patients with cirrhosis.

METHODS

Non-diabetic patients with Child-Pugh A or B cirrhosis (n = 10) and matched healthy controls (n = 10) underwent a 50-g oral glucose tolerance test (OGTT) and an isoglycemic intravenous glucose infusion. We presented data as median ± interquartile range and compared groups using non-parametric analysis of variance.

RESULTS

Patients with cirrhosis were glucose intolerant compared with healthy controls (4-h OGTTAUC : 609 ± 458 vs 180 ± 155 min × mmol/L; P = 0.005), insulin resistant (homeostatic model assessment for insulin resistance: 3.7 ± 4.9 vs 2.6 ± 1.4; P = 0.014) and had fasting hyperglucagonemia (8 ± 3 vs 3 ± 4 pmol/L; P = 0.027). Isoglycemia was achieved using 35 ± 12 g of intravenous glucose in patients with cirrhosis compared with 24 ± 10 g in healthy controls (P = 0.003). The gastrointestinal-mediated glucose disposal was markedly lower in patients with cirrhosis (30 ± 23 vs 52 ± 20%; P = 0.003). Despite higher levels of the incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic peptide patients with cirrhosis had reduced incretin effect (35 ± 44 vs 55 ± 30%; P = 0.008).

CONCLUSION

Impaired gastrointestinal-mediated glucose disposal and reduced incretin effect may contribute to the glucose intolerance seen in patients with cirrhosis.

Systematic review: Preventive and therapeutic applications of metformin in liver disease

Metformin, a biguanide derivative, is the most commonly prescribed medication in the treatment of type 2 diabetes mellitus. More recently, the use of metformin has shown potential as a preventive and therapeutic agent for a broad spectrum of conditions, including liver disease and hepatic malignancies. In this systematic review, we critically analyze the literature behind the potential use of metformin across the spectrum of liver disease and malignancies. The PubMed and Ovid MEDLINE databases were searched from 2000 to March 2015, using a combination of relevant text words and MeSH terms: metformin and mammalian target of rapamycin, hepatitis B virus (HBV), hepatitis B virus (HCV), non-alcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC) or cholangiocarcinoma. The search results were evaluated for pertinence to the issue of metformin in liver disease as well as for quality of study design. Metformin has a number of biochemical effects that would suggest a benefit in treating chronic liver diseases, particularly in the context of insulin resistance and inflammation. However, the literature thus far does not support any independent therapeutic role in NAFLD or HCV. Nonetheless, there is Level III evidence for a chemopreventive role in patients with diabetes and chronic liver disease, with decreased incidence of HCC and cholangiocarcinoma. The use of metformin seems to be safe in patients with cirrhosis, and provides a survival benefit. Once hepatic malignancies are already established, metformin does not offer any therapeutic potential. In conclusion, there is insufficient evidence to recommend use of metformin in the adjunctive treatment of chronic liver diseases, including NAFLD and HCV. However, there is good evidence for a chemopreventive role against HCC among patients with diabetes and chronic liver disease, and metformin should be continued in patients even with cirrhosis to provide this benefit.

Serum HBV surface antigen positivity is associated with low prevalence of metabolic syndrome in Korean adult men

Background

Metabolic syndrome has clinical implications for chronic liver disease, but the relationship between chronic hepatitis B and metabolic syndrome remains unclear. The aim of this study was to determine whether hepatitis B surface antigen (HBsAg) positivity is associated with metabolic syndrome.

Methods

Data were obtained from the Third Korean National Health and Nutrition Examination Survey (KNHANES). Participant sera were tested for HBsAg. Metabolic syndrome was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III guidelines for Koreans.

Results

Of the 5108 participants, 209 (4.1%) tested positive for HBsAg, and 1364 (26.7%) were diagnosed with metabolic syndrome. The prevalence of metabolic syndrome was 23.4% in HBsAg-positive men, 31.5% in HBsAg-negative men, 18.6% in HBsAg-positive women, and 23.7% in HBsAg-negative women. After adjusting for multiple factors, male participants who tested positive for serum HBsAg had an odds ratio of 0.612 (95% confidence interval [CI] 0.375–0.998) for metabolic syndrome and an odds ratio of 0.631 (95% CI 0.404–0.986) for elevated triglycerides. Women who tested positive for serum HBsAg had an odds ratio of 0.343 (95% CI 0.170–0.693) for elevated triglycerides.

Conclusions

Positive results for serum HBsAg are inversely associated with metabolic syndrome in men and with elevated triglycerides in men and women. This suggests that elevated triglycerides may contribute to the inverse association between HBsAg and metabolic syndrome.

Prevalence of and factors influencing impaired glucose tolerance among hepatitis B carriers: a nationwide cross-sectional study in the Republic of Korea

Diabetes is associated with a poor prognosis for liver disease, particularly in chronic hepatitis carriers. We investigated the prevalence of factors associated with impaired glucose tolerance (IGT) including diabetes and impaired fasting glucose (IFG) among individuals with hepatitis B virus (HBV) infection.We used data from the Korean National Health and Nutrition Examination Survey, a nationwide cross-sectional survey conducted between 2007 and 2011. Sociodemographic information was collected using a structured questionnaire. The HBV surface antigen, liver enzymes, and lipid profile were measured from blood samples.IFG was found in 18.1% of HBV carriers and 19.3% of noncarriers (P = 0.25). Diabetes was observed in 10.0% of HBV carriers and 12.2% of noncarriers (P = 0.08). Lower level of educational attainment was associated with a higher prevalence of IGT: high school education (odds ratio [OR] = 1.94 [95% confidence interval (CI) 1.14-3.29] and less than a high school education (OR = 3.20 [95% CI, 1.66-6.15] vs more than or equal to a college education. Elevated alanine transaminase and triglyceride by 10 were associated with increased risk of IGT (OR = 1.10 [95% CI, 1.01-1.20] and OR = 1.04 [95% CI, 1.01-1.07], respectively). Being a man and older in age were associated with a higher prevalence of IGT, and individuals with a low body mass index were at lower risk for IGT.Given the synergistic effect of diabetes and HBV infection on liver disease prognosis, we recommend targeted IGT screening and follow-up for HBV carriers. These efforts should include health policies and intervention programs aimed at reducing educational disparities and encouraging early control of elevated liver enzymes or lipid profiles.

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.

Metabolic syndrome association with fibrosis development in chronic hepatitis B virus inactive carriers

BACKGROUND AND AIM

There are few data of fibrosis development in chronic hepatitis B (CHB) patients classified as inactive carriers. The aim of this study is to determinate the prevalence of significant fibrosis and probable cirrhosis measured by FibroScan in real inactive CHB carriers and investigate the relationship with virological, epidemiological, and metabolic factors.

METHODS

Cross-sectional cohort study including CHB inactive carriers. Liver stiffness measurement was performed with transient elastography (FibroScan). Significant fibrosis (≥ F2) was defined as stiffness > 7.5 kPa, and probable cirrhosis as > 11.8 kPa. Factors associated with significant fibrosis were explored with univariate and multivariate adjusted logistic regression analyses.

RESULTS

Ninety-six CHB inactive carriers were analyzed. Of them, 24 (25%) had significant fibrosis and 7 (7%) probable cirrhosis; mean stiffness was 6.2 ± 2.3 kPa. Of them, 24% had metabolic syndrome, with higher FibroScan value than those without (8.4 kPa vs 5.5 kPa, P < 0.001). Factors associated with significant fibrosis were (odds ratio, 95% confidence interval, P value): central obesity (7.1, 1.8-27.9, 0.005), elevated fasting glucose (4.3, 1.3-27.9, 0.036), reduced high-density lipoprotein cholesterol (5.2, 1.2-23.6, 0.032) and elevated triglycerides (6.2, 1.4-28.3, 0.019). Factors as age, sex, transaminases, hepatitis B virus DNA or genotype were not related with liver fibrosis. The presence of metabolic syndrome has a 69% of positive predictive value and 89% of negative predictive value for significant fibrosis.

CONCLUSION

Different components of metabolic syndrome are associated with fibrosis development in CHB inactive carriers. In the absence of metabolic syndrome, significant fibrosis is uncommon in this population.

The risky body mass index ranges for significant hepatitis B viral load: A campus-based study

SUMMARY

Significant hepatitis B viral load (≥10,000 copies/mL) was established to increase risk of advanced liver diseases. The aim of this study was to explore the metabolic risk factors for significant hepatitis B viral load. A campus-based cohort consisting of 146 participants of chronic hepatitis B virus (HBV) infection in Northern Taiwan was investigated in 2009. Clinical profiles including serum levels of deoxyribonucleic acid of hepatitis B virus (HBV DNA) were collected. Hepatitis B e antigen (HBeAg) serostatus, high alanine aminotransferase level, body mass index (BMI) ranges, and insulin resistance were related to significant HBV DNA levels in univariate analysis. Compared to individuals with BMI 23-24.9 kg/m(2) in multivariate analysis, those with BMI ≥25 kg/m(2) (OR = 3.86, 95% CI = 1.38-10.8, P = 0.010) and those with BMI <23 kg/m(2) (OR = 4.47, 95% CI = 1.32-15.2, P = 0.016) were at higher risk for significant HBV DNA levels. This phenomenon was also manifest in HBeAg seronegatives, who contributed to a majority of significant viral load in our study. Furthermore, insulin resistance and BMI ≥25 kg/m(2) had positive additive effects on significant HBV DNA levels (adjusted OR = 9.34, 95% CI = 1.74-50.3, P = 0.009). In conclusion, having certain BMI ranges (BMI ≥25 kg/m(2) or BMI <23 kg/m(2)) could be a risk factor of significant HBV DNA levels.:

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.

Serum adiponectin levels are associated with hepatitis B viral load in overweight to obese hepatitis B virus carriers

OBJECTIVE

This study aimed to investigate the association between serum adiponectin and chronic hepatitis B virus (HBV) infection.

DESIGN AND METHODS

We conducted a campus-based cross-sectional study in Northern Taiwan, an HBV-endemic country. A total of 506 participants, including 147 chronic HBV-infected individuals and 359 healthy controls, were assessed for anthropometric indices, serum adiponectin levels, serum HBV viral load and markers, serum alanine aminotransferase levels and metabolic factors.

RESULTS

Older age, male gender, higher alanine aminotransferase, higher body mass index, greater waist circumference, lower fasting glucose, higher triglycerides, and higher adiponectin were associated with chronic HBV infection in univariate analyses. In multivariate analysis, the presence of chronic HBV infection was positively associated with serum adiponectin levels (P < 0.0001) and high adiponectin levels over the 75th percentile (odds ratio, 4.25; 95% confidence interval, 2.36-7.66; P < 0.0001) after adjusting for age, gender, body mass index, and insulin resistance index. Furthermore, serum adiponectin levels were positively associated with HBV viral load in overweight to obese HBV-infected subjects (P = 0.018).

CONCLUSION

Although chronic HBV-infected individuals were heavier than healthy controls, they had significantly higher serum adiponectin levels than healthy counterparts. Additionally, adiponectin levels were positively associated with HBV viral load in overweight to obese HBV-infected subjects. Future research should focus on elucidating adiponectin pathways, which may contribute to the development of adjuvant treatments for chronic HBV infection.

Prevalence and predictors of impaired fasting glucose among Nigerian patients with hepatitis B virus infection

AIM

Previous studies on the relationship between hepatitis B virus (HBV) infection and type 2 diabetes mellitus (DM) are conflicting. We aimed to elucidate the relationship by investigating the prevalence and predictors of impaired fasting glucose (IFG) in HBV-infected patients.

METHODS

A total of 204 consecutive patients with hepatitis B surface antigen (HBsAg) seropositivity for ≥ 6 months were recruited in a cross-sectional study. Patients with DM were excluded. Information regarding age, gender, ethnicity, residence, family history of DM, alcohol use, and cigarette smoking were obtained using a structured questionnaire. Fasting plasma glucose, lipid profile, liver enzymes and hepatitis Be antigen (HBeAg) were tested.

RESULTS

The participants had a mean age of 33.6 ± 8.4 years and included 123 (60.3%) females, 40 (19.6%) with HBeAg seropositivity, and 29 (14.2%) with family history of DM. The prevalence of IFG was 52 (25.5%). On multivariate analysis, the independent predictors of IFG were family history of DM (OR = 8.23, 95% CI = 2.78-24.31), male gender (OR = 2.83, 95% CI = 1.17-6.64), HBeAg seropositivity (OR = 4.97, 95% CI = 1.87-13.18) and elevated GGT (OR = 7.27, 95% C.I = 2.88-18.35).

CONCLUSION

The prevalence of IFG among HBV-infected patients is high. Targeted screening and follow-up of HBV-infected patients for abnormalities of glucose metabolism is recommended.

Association between obesity, hypertriglyceridemia and low hepatitis B viral load

OBJECTIVE

This study aimed to investigate the metabolic risk factors of high hepatitis B viral load.

DESIGN

Large-scale, community-based cross-sectional study.

SUBJECTS

A total of 3587 hepatitis B virus (HBV)-infected participants without liver cirrhosis at study entry were investigated. High HBV viral load was defined as a serum level 10(4) copies per ml for hepatitis B e antigen (HBeAg) seronegatives or 10(8) copies per ml for HBeAg seropositives.

RESULTS

Among HBeAg seropositives (n=545), high HBV viral load was reversely associated with extreme obesity (odds ratio (OR), 0.30; 95% confidence interval (CI), 0.13-0.68; P=0.004) or central obesity (OR, 0.53; 95% CI, 0.34-0.82; P=0.004) after adjustment for gender, hypertriglyceridemia, hyperuricemia and history of hypertension. High HBV viral load remained significantly inversely associated with extreme obesity (OR, 0.17; 95% CI, 0.05-0.63; P=0.008) and central obesity (OR, 0.44; 95% CI, 0.25-0.78; P=0.005) in male HBeAg-seropositive participants in stratification analyses by gender. Among HBeAg seronegatives (n=3042), however, high HBV viral load was inversely associated with hypertriglyceridemia (OR, 0.74; 95% CI, 0.61-0.89, P=0.002) after adjustment for age, gender, high serum alanine aminotransferase level, and extreme obesity or central obesity. High HBV viral load was still inversely associated with hypertriglyceridemia in both female (OR, 0.70; 95% CI, 0.50-0.97; P=0.041) and male (OR, 0.75; 95% CI, 0.60-0.94; P=0.011) HBeAg-seronegative participants.

CONCLUSION

Extreme obesity and central obesity were associated with a low prevalence of high HBV viral load in HBeAg seropositives, especially in men; while hypertriglyceridemia was associated with a low prevalence of high viral load in HBeAg seronegatives in both women and men.

Ultrasonographically detected non-alcoholic fatty liver disease is an independent predictor for identifying patients with insulin resistance in non-obese, non-diabetic middle-aged Asian adults

OBJECTIVES

We assessed the association among ultrasonographically detected non-alcoholic fatty liver disease (US-NAFLD), metabolic syndrome (MetS), and insulin resistance (IR) in non-obese, non-diabetic middle-aged adults, to find out whether US-NAFLD is independently associated with IR in this population.

METHODS

A total of 5,878 non-obese (body mass index, ≥ 18.5 and < 25), non-diabetic individuals were analyzed. IR was estimated with the homeostasis model assessment index (HOMA2-IR) and defined when HOMA2-IR ≥ 1.5. MetS was defined by the Adult Treatment Panel III (ATP III) criteria.

RESULTS

MetS was present in 381 (6.5%) participants, IR was present in 801 (13.6%) participants, and US-NAFLD was present in 1,611 (27.4%) participants. The increase in the prevalence of US-NAFLD closely followed the increase in the number of metabolic components diagnosed according to the ATP III criteria (15.2%, 28.5%, 48.0%, 65.7%, 71.4%, and 100% for 0, 1, 2, 3, 4, and 5 metabolic components, respectively, P < 0.001). US-NAFLD showed a significantly higher odds ratio (OR) for IR, regardless of the number of metabolic components (OR (95% confidence interval) of 3.48 (2.45-4.94), 3.63 (2.74-4.82), 3.19 (2.29-4.44), and 2.43 (1.43-3.81) for 0, 1, 2, and ≥ 3 metabolic components, respectively, P < 0.001 for all values). MetS showed a low sensitivity (0.22) for the identification of individuals with IR, and either US-NAFLD alone (0.60) or US-NAFLD with MetS (0.66) improved sensitivity with acceptable trade-off in specificity.

CONCLUSIONS

US-NAFLD was an independent predictor for IR, irrespective of the number of metabolic components of MetS in the non-obese, non-diabetic middle-aged Asian adults. US-NAFLD could identify individuals with IR that cannot be identified by MetS in this population.

Hepatic steatosis and insulin resistance are associated with severe fibrosis in patients with chronic hepatitis caused by HBV or HCV infection

BACKGROUND AND AIMS

Steatosis and insulin resistance (IR) are the major disease modifying in patients with chronic hepatitis C (CHC). Only few studies evaluated these features in patients with chronic hepatitis B (CHB). We aimed to assess the prevalence and the factors related to steatosis and IR in CHB patients, compared with CHC subjects, and to evaluate the potential association between these features and fibrosis severity.

MATERIAL AND METHODS

One hundred and seventy consecutive patients with CHB (28 HBeAg positive, 142 HBeAg negative), were evaluated using liver biopsy and metabolic measurements and matched for sex, age and body mass index with 170 genotype 1 CHC patients. IR was defined if HOMA-IR>2.7. All biopsies were scored for grading and staging by Scheuer's score, and the steatosis was considered significant if ≥ 10%.

RESULTS

The prevalence of significant steatosis was similar in both CHB and CHC patients (31 vs. 38%; P=0.14). IR rate was significantly higher in CHC than in CHB patients (42 vs. 26%; P=0.002). Severe fibrosis (F3-F4), at multivariate analysis, was independently associated with older age (OR 1.050, 95% CI 1.009-1.093), steatosis >10% (OR 4.375, 95% CI 1.749-10.943), and moderate-severe necroinflammatory activity (OR 8.187, 95% CI 2.103-31.875), regardless of HBeAg status, in CHB patients, and with older age (OR 1.080, 95% CI 1.028-1.136), IR (OR 2.640, 95% CI 1.110-6.281), steatosis >10% (OR 3.375, 95% CI 1.394-8.171), and moderate-severe necroinflammatory activity (OR 8.988, 95% CI 1.853-43.593) in CHC patients.

CONCLUSIONS

CHB patients had high steatosis prevalence, similar to CHC controls, but lower IR rate. Both steatosis and IR in CHC, and only steatosis in CHB, are independently associated with fibrosis severity.

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.

Asymptomatic chronic hepatitis B virus infection does not increase the risk of diabetes mellitus: a ten-year observation

BACKGROUND AND AIM

Chronic hepatitis C virus infection has been known to increase the risk of diabetes. Whether this association holds true for chronic hepatitis B virus (HBV) infection remains unclear. We thus conducted this study to investigate the influence of asymptomatic chronic HBV infection on the incidence of diabetes in a longitudinal cohort.

METHODS

A total of 1233 adults who received health examinations in 1997-1998 and in 2000-2001 were enrolled. Among them, 483 subjects who received a third health examination in 2006-2008 were further sampled. The prevalence and incidence of diabetes between asymptomatic HBV carriers and non-HBV controls were compared using the chi(2)-test and logistic regression.

RESULTS

In 1997-1998, the prevalence rates of diabetes (9.49 and 12.0%) and glucose intolerance (28.5 and 25.4%) in HBV carriers and non-HBV controls were comparable (P > 0.05). There was no significant correlation between asymptomatic HBV infection and the presence of diabetes in subjects examined in 1997-1998, 2000-2001, or 2006-2008 when adjusted for age, gender, and body mass index (P > 0.05). In 296 non-diabetic subjects during 1997-1998, the ten-year incidence of diabetes/glucose intolerance was similar between HBV carriers and non-HBV controls (40.0 and 38.7%, P > 0.05). Moreover, no significant correlation was found between asymptomatic HBV infection and the incidence of diabetes/glucose intolerance in 2006-2008 (P = 0.775).

CONCLUSIONS

Compared to non-HBV controls, subjects with asymptomatic chronic HBV infection do not have an increased risk of diabetes, and thus HBV itself is not pro-diabetic.

Adenovirus infection results in alterations of insulin signaling and glucose homeostasis

Recombinant adenovirus (Ad) vectors can initiate an inflammatory response, limiting its use in gene therapy and basic research. Despite increased efforts to better understand Ad infection, little is known about how it affects cellular metabolic responses. In the current studies, we explored the effects of Ad vectors on insulin signaling molecules and glucose homeostasis. Nonreplicative Ad vectors were injected into rats through the tail vein, and at 4-13 days postinjection insulin signaling and glucose tolerance were examined. Ad vector infection significantly reduced total levels of the insulin receptor (IR), and insulin receptor substrates 1 and 2 (IRS-1, IRS-2) in the liver of rats, resulting in decreased insulin-induced tyrosine phosphorylation of IR, IRS-1, and IRS-2, and decreased interaction of IRS-1 and IRS-2 with phosphoinositide 3-kinase (PI3K). In addition, Ad infection resulted in impaired systemic glucose homeostasis, which recovered by 13 days, after the protein levels of IR, IRS-1, and IRS-2 had started to normalize. Expression of a TNF inhibitor or Kupffer cell depletion attenuated the Ad vector-induced decreases of insulin signaling molecules, indicating a potential role of Kupffer cell activation in this process. These studies provide evidence that systemic administration of Ad vectors can impair insulin signaling in liver, resulting in altered systemic glucose metabolism. Thus, effects of Ad vector infection on insulin action and glucose metabolism need to be considered when Ad vectors are used in research or gene therapy and may be more broadly applicable to other viral agents.

Interaction of adipokines and hepatitis B virus on histological liver injury in the Chinese

OBJECTIVES

Chronic hepatitis B patients with diabetes and metabolic syndrome are at increased risk of cirrhosis and hepatocellular carcinoma, but the underlying mechanism is unclear. Our objective was to test whether dysregulation of adipokines contributes to liver injury. We also studied whether viral factors affected adipokines, insulin resistance, and hepatic steatosis.

METHODS

A prospective cohort of 266 chronic hepatitis B patients undergoing liver biopsy was studied. Fasting blood was taken for the analysis of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), adiponectin, leptin, and resistin. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA-IR). Factors associated with significant necroinflammation and cirrhosis were identified.

RESULTS

Histological activity index was correlated with serum TNF-alpha (R=0.40, P<0.0001) and IL-6 (R=0.32, P<0.0001) but not with adiponectin, leptin, or resistin. By multivariate analysis, TNF-alpha was associated with significant necroinflammation after adjusting for age and viral factors (odds ratio (OR) 1.041, 95% confidence interval (CI) 1.002-1.082, P=0.04). Serum adiponectin had positive correlation with hepatitis B virus DNA (R=0.17, P=0.007) and was decreased in patients with insulin resistance and hepatic steatosis. On the other hand, viral load, hepatitis B e-antigen status, and genotypes had no association with insulin resistance, hepatic steatosis, and the levels of TNF-alpha and IL-6. A total of 68 (25.6%) patients had cirrhosis. HOMA-IR, but not adipokine dysregulation, was independently associated with cirrhosis (OR 1.09, 95% CI 1.02-1.15, P=0.006).

CONCLUSIONS

TNF-alpha and/or IL-6 contribute to hepatic necroinflammation in chronic hepatitis B patients. Adiponectin protects against insulin resistance and hepatic steatosis but does not affect liver injury. Adipokines and viral factors contribute to liver injury independently.

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.