Steatohepatitis is associated with diabetes and fibrosis in genotype 1b HCV-related chronic liver disease

Prevalence of Type 2 Diabetes Mellitus among Hepatitis C Virus-Infected Patients: A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> The ever-increasing global prevalence of hepatitis C infection is fueling the burden of diabetes mellitus, which exacerbates various complications and may be a cause of death of millions of people. Several studies have reported that hepatitis C virus infection is an important risk factor for the development of diabetes mellitus. However, fragmented studies have reported variable and inconsistent findings regarding the prevalence of type 2 diabetes mellitus among hepatitis C virus-infected patients. Therefore, this meta-analysis aimed to estimate the overall prevalence of type 2 diabetes mellitus among patients infected with hepatitis C virus. <b><i>Methods:</i></b> This systematic review and meta-analysis includes original articles reporting on cohort and cross-sectional studies. A systematic search was performed in PubMed, ScienceDirect, and Google Scholar. A random-effects meta-analysis model was used to estimate the global pooled prevalence of type 2 diabetes mellitus among hepatitis C-infected patients. A sensitivity analysis was conducted to check the stability of the summary estimate. Heterogeneity was assessed using the <i>I</i>² statistic. A subgroup analysis was also conducted based on geographical region. Funnel plots were used to spot publication bias. <b><i>Results:</i></b> A total of 40 eligible articles reporting data on 14,765 study participants were included in this meta-analysis. The pooled prevalence of type 2 diabetes mellitus among hepatitis C virus-infected patients was 19.67% (95% CI: 17.25, 22.09). The subgroup analysis showed a pooled prevalence of 27.72% (95% CI: 20.79, 34.65) in Africa, 20.73% (95% CI: 17.57, 23.90) in Asia, 16.64% (95% CI: 6.79, 26.49) in North America, and 15.02% (95% CI: 10.66, 19.38) in Europe. <b><i>Conclusions:</i></b> The overall prevalence of type 2 diabetes mellitus among hepatitis C virus-infected patients was considerably higher than in the general population in a global perspective. The highest prevalence was noted in Africa and Asia, followed by North America and Europe. Therefore, early intervention is needed (prevention and early treatment of hepatitis C virus infection) to prevent the development of type 2 diabetes mellitus.

Adiponectin serum level in chronic hepatitis C infection and therapeutic profile

Hepatic steatosis is commonly seen in the patients with chronic hepatitis C virus (HCV) infection. HCV is closely associated with lipid metabolism, and viral steatosis is more common in genotype 3 infection owing to a direct cytopathic effect of HCV core protein. In non-genotype 3 infection, hepatic steatosis is considered largely to be the result of the alterations in host metabolism; metabolic steatosis is primarily linked with HCV genotype 1. Adipose tissue secretes different hormones involved in glucose and lipid metabolisms. It has been demonstrated that adipocytokines are involved in the pathogenesis of non-alcoholic fatty liver disease, as the decreased plasma adiponectin levels, a soluble matrix protein expressed by adipoctyes and hepatocyte, are associated with liver steatosis. Various studies have shown that steatosis is strongly correlated negatively with adiponectin in the patients with HCV infection. The role of adiponectin in hepatitis C virus induced steatosis is still not completely understood, but the relationship between adiponectin low levels and liver steatosis is probably due to the ability of adiponectin to protect hepatocytes from triglyceride accumulation by increasing β-oxidation of free fatty acid and thus decreasing de novo free fatty acid production.

Insulin resistance and liver steatosis in chronic hepatitis C infection genotype 3

Hepatitis C virus (HCV) infection is a common chronic liver disease worldwide. Non-alcoholic fatty liver disease and insulin resistance (IR) are the major determinants of fibrosis progression and response to antiviral therapy. The pathogenetic link between IR and chronic HCV infection is complex, and is associated with HCV genotype. Liver steatosis is the most common in the patients infected with genotype 3 virus, possibly due to direct effects of genotype 3 viral proteins. To the contrary, hepatic steatosis in the patients infected with other genotypes is thought to be mostly due to the changes in host metabolism, involving IR. In HCV genotype 3, liver steatosis correlates with viral load, reverts after reaching the sustained virologic response and reoccurs in the relapsers. A therapeutic strategy to improve IR and liver steatosis and subsequently the response to antiviral treatment in these patients is warranted.

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.

Gene expression profile associated with superimposed non-alcoholic fatty liver disease and hepatic fibrosis in patients with chronic hepatitis C

BACKGROUND

Hepatic steatosis occurs in 40-70% of patients chronically infected with hepatitis C virus [chronic hepatitis C (CH-C)]. Hepatic steatosis in CH-C is associated with progressive liver disease and a low response rate to antiviral therapy.

AIM

Gene expression profiles were examined in CH-C patients with and without hepatic steatosis, non-alcoholic steatohepatitis (NASH) and fibrosis.

METHODS

This study included 65 CH-C patients who were not receiving antiviral treatment. Total RNA was extracted from peripheral blood mononuclear cells, quantified and used for one-step reverse transcriptase-polymerase chain reaction to profile 153 mRNAs that were normalized with six 'housekeeping' genes and a reference RNA. Multiple regression and stepwise selection assessed differences in gene expression and the models' performances were evaluated.

RESULTS

Models predicting the grade of hepatic steatosis in patients with CH-C genotype 3 involved two genes: SOCS1 and IFITM1, which progressively changed their expression level with the increasing grade of steatosis. On the other hand, models predicting hepatic steatosis in non-genotype 3 patients highlighted MIP-1 cytokine encoding genes: CCL3 and CCL4 as well as IFNAR and PRKRIR. Expression levels of PRKRIR and SMAD3 differentiated patients with and without superimposed NASH only in the non-genotype 3 cohort (area under the receiver operating characteristic curve=0.822, P-value 0.006]. Gene expression signatures related to hepatic fibrosis were not genotype specific.

CONCLUSIONS

Gene expression might predict moderate to severe hepatic steatosis, NASH and fibrosis in patients with CH-C, providing potential insights into the pathogenesis of hepatic steatosis and fibrosis in these patients.