HCV and diabetes. A two-question-based reappraisal

Effect of HCV eradication by DAAs on liver steatosis, carotid atherosclerosis, and associated metabolic comorbidities: A systematic review

BACKGROUND AND AIMS

The beneficial effect of Hepatitis C virus (HCV) eradication by direct antiviral agents (DAAs) on liver fibrosis is well defined. Despite this, the impact of viral eradication in both hepatic and extra-hepatic metabolic features is underreached. This systematic review aimed to synthesize the evidence on the impact of HCV eradication by DAAs on liver steatosis, carotid atherosclerosis, glucidic impairment, dyslipidaemia, and weight gain.

METHODS

A systematic search of the existing literature (up to December 2022) identified 97 original studies that fulfilled the inclusion criteria.

RESULTS

Whereas total cholesterol and low-density lipoprotein (LDL) seem to increase after viral eradication, the cardiovascular damage expressed as carotid plaques and intima-media thickness seems to improve. Otherwise, the effect on liver steatosis, glucidic homeostasis, and weight seems to be strictly dependent on the presence of baseline metabolic disorders.

CONCLUSION

Despite high heterogeneity and relatively short follow-up of included studies, we can conclude that the presence of metabolic risk factors should be strictly evaluated due to their impact on liver steatosis, glucidic and lipid homeostasis, and on weight gain to better identify patients at risk of liver disease progression despite the virus eradication.

Post-transplant diabetes mellitus in Canadian liver and renal transplant recipients

BACKGROUND: Post-transplant diabetes mellitus (PTDM) occurs in 10%-40% of liver and renal transplant recipients. Whether the risk factors for PTDM in liver and renal transplant recipients are similar and whether Indigenous Canadians, who have a high underlying prevalence of diabetes mellitus (DM), are at increased risk of developing PTDM have yet to be determined. OBJECTIVE: To describe and compare those variables associated with PTDM in adult Canadian liver and renal transplant recipients. METHODS: A retrospective chart review of adult liver and renal transplant recipients attending four transplant follow-up clinics in three Canadian provinces was undertaken. RESULTS: De novo PTDM was diagnosed in 184/905 (20.3%) liver and 179/390 (45.9%) renal transplant recipients. Older age, higher pre-transplant BMI, underlying immune-mediated liver disease, lower trough tacrolimus levels and longer duration of follow-up were independently associated with PTDM in liver transplant recipients and non-Caucasian race, higher pre-transplant BMI, and incidence of organ rejection in renal transplant recipients. Compared with Caucasians, Indigenous Canadians who had undergone renal transplantation had a significantly increased prevalence of PTDM (56.5% versus 40.0%, p = 0.035). The prevalence of PTDM in liver transplant recipients was similar in Indigenous Canadians and Caucasians (27.9% versus 20.1%, p = 0.215). CONCLUSIONS: The variables associated with PTDM differ in liver and renal transplant recipients. Compared with Caucasians, Indigenous Canadians undergoing renal transplantation are at increased risk of developing PTDM.

Molecular mechanisms underlying hepatitis C virus infection-related diabetes

Diabetes is a noncommunicable widespread disease that poses the risk of severe complications in patients, with certain complications being life-threatening. Hepatitis C is an infectious disease that mainly causes liver damage, which is also a profound threat to human health. Hepatitis C virus (HCV) infection has many extrahepatic manifestations, including diabetes. Multiple mechanisms facilitate the strong association between HCV and diabetes. HCV infection can affect the insulin signaling pathway in liver and pancreatic tissue and change the profiles of circulating microRNAs, which may further influence the occurrence and development of diabetes. This review describes how HCV infection causes diabetes and discusses the current research progress with respect to HCV infection-related diabetes.

Diabetes is associated with advanced fibrosis and fibrosis progression in non-genotype 3 chronic hepatitis C patients

BACKGROUND

Diabetes is a risk factor of fibrosis progression in chronic hepatitis C (CHC). However, only one longitudinal study exploring whether diabetes is associated with progression from non-cirrhotic liver to cirrhosis in CHC patients has been conducted.

AIMS

We investigated whether diabetes is associated with progression from non-cirrhotic liver to cirrhosis in non-genotype 3 CHC patients.

METHODS

A cohort consisting of 976 non-genotype 3 patients histologically proven to have CHC was studied. After excluding patients with biopsy-proven or ultrasound-identified cirrhosis, there were 684 patients without cirrhosis. All 684 patients underwent hepatocellular carcinoma surveillance using ultrasound every 6 months, with a median duration of follow-up evaluation of 102.4 months. During the follow-up period, 60 patients developed cirrhosis according to ultrasound findings.

RESULTS

For the subgroup of 684 patients without cirrhosis, Kaplan-Meier survival analyses showed no significantly different cumulative incidences of cirrhosis (log-rank test; P = 0.71) among the patients with diabetes as compared to those without. However, after making adjustments for age, gender, fibrosis, steatosis, sustained virological response status, and obesity using Cox's proportional hazard model, diabetes was found to be an independent predictor for cirrhosis (HR = 1.9; 95% CI = 1.05-3.43, P = 0.03).

CONCLUSIONS

Diabetes is associated with progression from non-cirrhotic liver to cirrhosis in non-genotype 3 CHC patients.

The association between steatosis and diabetes with hepatocellular carcinoma in non-genotype 3 chronic hepatitis C patients

BACKGROUND & AIMS

Diabetes mellitus (DM) has been found to be strongly associated with an increased risk of hepatocellular carcinoma (HCC) among chronic hepatitis C (CHC) patients. Several studies have also found an association between metabolic steatosis and the risk of HCC in CHC patients, whether this latter association has been accounted for by the known relationship between DM and HCC is still unknown.

METHODS

A cohort consisting of 976 non-genotype 3 patients histologically proven to have CHC and treated with interferon and ribavirin was studied. Cumulative incidence and HCC risk were analysed using the Kaplan-Meier method and Cox proportional hazard analysis.

RESULTS

Hepatocellular carcinoma developed in 140 subjects over a median follow-up period of 97.3 months, while 699 patients achieved sustained virological response (SVR). According to multivariate analyses, age ≥ 60 years, advanced fibrosis and genotype 1 were identified as independent factors significantly associated with HCC development in SVR patients. Furthermore, using the absence of steatosis and absence of DM as references, the presence of steatosis without DM (HR = 2.09, 95% CI = 1.12-3.9, P = .021), the presence of DM without steatosis (HR = 2.78, 95% CI = 1.3-5.92, P = .008) and the combined presence of steatosis and DM (HR = 3.25, 95% CI = 1.44-7.33, P = .004) were identified as independent factors significantly associated with HCC development in the SVR patients. In contrast, steatosis alone, DM alone and the combined presence of steatosis and DM were not associated with HCC development in non-SVR patients.

CONCLUSIONS

Steatosis and DM may be associated with HCC development in non-genotype 3 CHC patients with SVR.

Type 2 Diabetes in Non-Alcoholic Fatty Liver Disease and Hepatitis C Virus Infection--Liver: The "Musketeer" in the Spotlight

The pathogenesis of type 2 diabetes (T2D) involves chronic hyperinsulinemia due to systemic and hepatic insulin resistance (IR), which if uncorrected, will lead to progressive pancreatic beta cell failure in predisposed individuals. Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of fatty (simple steatosis and steatohepatitis) and non-fatty liver changes (NASH-cirrhosis with or without hepatocellular carcinoma (HCC)) that are commonly observed among individuals with multiple metabolic derangements, notably including visceral obesity, IR and T2D. Hepatitis C virus (HCV) infection is also often associated with both hepatic steatosis and features of a specific HCV-associated dysmetabolic syndrome. In recent years, the key role of the steatotic liver in the development of IR and T2D has been increasingly recognized. Thus, in this comprehensive review we summarize the rapidly expanding body of evidence that links T2D with NAFLD and HCV infection. For each of these two liver diseases with systemic manifestations, we discuss the epidemiological burden, the pathophysiologic mechanisms and the clinical implications. To date, substantial evidence suggests that NAFLD and HCV play a key role in T2D development and that the interaction of T2D with liver disease may result in a "vicious circle", eventually leading to an increased risk of all-cause mortality and liver-related and cardiovascular complications. Preliminary evidence also suggests that improvement of NAFLD is associated with a decreased incidence of T2D. Similarly, the prevention of T2D following HCV eradication in the era of direct-acting antiviral agents is a biologically plausible result. However, additional studies are required for further clarification of mechanisms involved.

Treatment of type 2 diabetes mellitus by viral eradication in chronic hepatitis C: Myth or reality?

Chronic hepatitis C is a systemic disease inducing metabolic alterations leading to extrahepatic consequences. In particular, hepatitis C virus (HCV) infection seems to increase the risk of incident type 2 diabetes mellitus in predisposed individuals, independently of liver disease stage. The mechanisms through which hepatitis C induces T2DM involve direct viral effects, insulin resistance, pro-inflammatory cytokines and other immune-mediated processes. Many studies have reported the clinical consequences of type 2 diabetes mellitus on hepatitis C outcome, but very few studies have addressed the issue of microangiopathic complications among patients with hepatitis C only, who develop type 2 diabetes mellitus. Moreover, clinical trials in HCV-positive patients have reported improvement in glucose metabolism after antiviral treatment; recent studies have suggested that this metabolic amelioration might have a clinical impact on type 2 diabetes mellitus-related complications. These observations raise the question as to whether the HCV eradication may also have an impact on the future morbidity and mortality due to type 2 diabetes mellitus. The scope of this review is to summarise the current evidence linking successful antiviral treatment and the prevention of type 2 diabetes mellitus and its complications in hepatitis C-infected patients.

Pathogenesis and significance of hepatitis C virus steatosis: An update on survival strategy of a successful pathogen

Hepatitis C virus (HCV) is a successful pathogen on the grounds that it exploits its host’s metabolism to build up viral particles; moreover it favours its own survival by inducing chronic disease and the development of specific anatomic changes in the infected organ. Steatosis, therefore, is associated with HCV infection by necessity rather than by chance alone. Approximately 6% of HCV patients have steatohepatitis. Interestingly, HCV steatosis occurs in the setting of multiple metabolic abnormalities (hyperuricemia, reversible hypocholesterolemia, insulin resistance, arterial hypertension and expansion of visceral adipose tissue) collectively referred to as “hepatitis C-associated dysmetabolic syndrome” (HCADS). General, nonalcoholic fatty liver disease (NAFLD)-like, mechanisms of steatogenesis (including increased availability of lipogenic substrates and de novo lipogenesis; decreased oxidation of fatty substrates and export of fatty substrates) are shared by all HCV genotypes. However, genotype 3 seemingly amplifies such steatogenic molecular mechanisms reported to occur in NAFLD via more profound changes in microsomal triglyceride transfer protein; peroxisome proliferator-activated receptor alpha; sterol regulatory element-binding proteins and phosphatase and tensin homologue. HCV steatosis has a remarkable clinical impact in as much as it is an acknowledged risk factor for accelerated fibrogenesis; for impaired treatment response to interferon and ribavirin; and development of hepatocellular carcinoma. Recent data, moreover, suggest that HCV-steatosis contributes to premature atherogenesis via both direct and indirect mechanisms. In conclusion, HCV steatosis fulfills all expected requirements necessary to perpetuate the HCV life cycle. A better understanding of the physiology of HCADS will likely result in a more successful handling of disease with improved antiviral success rates.

Type 2 diabetes mellitus and the risk of hepatitis C virus infection: a systematic review

The aim of this study was to evaluate the relationship between type 2 diabetes mellitus (T2DM) and hepatitis C virus (HCV) infection and to examine whether T2DM enhances the risk of HCV infection compared with the risk in the general population. We followed standard guidelines to perform a meta-analysis. The associated literature was selected based on the established inclusion criteria. The summary odds ratio (OR) and 95% confidence interval (95% CI) were used to investigate the strength of the association. Through electronic database and manual searching, 22 studies were identified for the final analysis, which included a total of 78,051 individuals. Based on the random effects model, the meta-analysis results showed that patients with T2DM were at a higher risk of acquiring HCV infection than non-T2DM patients (summary OR = 3.50, 95% CI = 2.54–4.82, I² = 82.3%). Based on the current limited evidence, this study suggests that T2DM is associated with increased susceptibility to HCV infection.

From NAFLD in clinical practice to answers from guidelines

This review of the literature consists of three sections. First, papers concerning non-alcoholic fatty liver disease (NAFLD) awareness among the general population, general practitioners, and liver and non-liver specialists were retrieved and analyzed to highlight the perception of disease, verify knowledge of current recommendations, and identify the main difficulties experienced in clinical practice. Next, position papers and clinical practice guidelines issued by International and National Hepatological Scientific Societies were identified and critically assessed in order to pinpoint the areas of convergence/difference. Finally, practical suggestions on NAFLD diagnosis and management in daily practice are provided and the open questions highlighted.

Hepatitis C virus genotype distribution in Egyptian diabetic patients: a preliminary study

BACKGROUND AND STUDY AIMS

There is controversy regarding whether a specific hepatitis C virus (HCV) genotype is associated with diabetes mellitus. This study aimed to investigate HCV genotype distribution in diabetics and its relation to some clinical and laboratory variables in HCV-positive diabetic versus non-diabetic Egyptians in East Delta.

PATIENTS AND METHODS

The study included 100 HCV-positive patients of which 66 were diabetic in addition to 35 healthy adults as a control group. Clinical assessment, laboratory measurements of plasma glucose, insulin, C-peptide, C-reactive protein (CRP), tumour necrosis factor-α (TNF-α) and liver functions (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT)) as well as HCV genotype determination were done, and AST/platelet ratio index (APRI) and Homoeostasis Model of Assessment-Insulin Resistance (HOMA-IR) were calculated.

RESULTS

The main results were the presence of HCV genotype 3, in 31.8% of the diabetic group and in 26.5% of the non-diabetic group, while the remainder of cases had genotype 4, the predominant genotype in Egypt. This is the first report of the presence of HCV genotype 3 in about 30% of an Egyptian cohort. However, there was no significant difference in genotype distribution between both groups. Further, there were significantly higher values of HOMA-IR, insulin and C-peptide in HCV-positive groups in comparison to the control group, while TNF-α was significantly higher in the HCV-positive diabetic group. However, there were no significant differences between both genotypes regarding these parameters.

CONCLUSION

Although this study reveals for the first time the presence of HCV genotype 3 in a significant percentage of a group of Egyptian patients, where the majority were diabetic, the association between diabetes and certain HCV genotypes could not be confirmed on the basis of our findings. Hence, taking into consideration the impact of such a finding on the treatment decisions of those patients, further studies are warranted to explore these findings to a greater extent.

Liver and diabetes. A vicious circle

The complex and bi-directional relationship linking the liver and diabetes has recently gained intense new interest. This critical review of the published work aims to highlight the most recent basic and clinical data underlying the development of type 2 diabetes, in those with non-alcoholic fatty liver disease. Moreover, the potentially detrimental effects of type 2 diabetes in liver injury are also discussed in each of the two sections of the present paper. Fatty liver and diabetes share insulin resistance as their chief pathogenic determinant. The roles of the hypothalamus, the intestinal microbiome, white adipose tissue and inflammation are discussed in detail. Molecular insights into hepatocyte insulin resistance as the initiator of systemic insulin resistance are also presented with full coverage of the danger of fatty acids. Lipotoxicity, apoptosis, lipoautophagy, endoplasmic reticular stress response and recent developments in genetics are discussed. Closing the circle, special emphasis is given to biochemical pathways and clinical evidence supporting the role of type 2 diabetes as a risk factor for the development of progressive liver disease, including non-alcoholic steatohepatitis, cirrhosis and primary liver cancer. In conclusion, data support non-alcoholic fatty liver disease as a risk factor for the development of type 2 diabetes which is, in turn, a major contributor to progressive liver disease. This pathway leading from fatty liver to type 2 diabetes and back from the latter to the progressive liver disease is a vicious circle.

IRS1 Expression in Hepatic Tissue and Leukocytes in Chronic Hepatitis C Virus Infected Patients: A Comparative Study

Aims. To determine lymphocyte IRS (IRS1 cells) in HCV patients, correlating it to liver IRS (IRS 1liver) and HOMA-IR. This study tested the hypothesis that IRS1 cells expression can be used as insulin resistance (IR) marker in HCV-infected patients. IRS1 cells were not studied before in HCV infection. Materials and Methods. HCV chronically infected patients, naïve, nonobese, noncirrhotic, and nondiabetic were prospectively included and compared to controls (blood donors). Blood was taken, and leukocytes were separated. IRS1 was determined by real-time PCR. Liver tissue was obtained from transplant donors as controls. Results. 41 HCV-positive patients were included, 26 males (60.5%); mean age of 45 (±7.9); 33 (80.5%) from genotype 1. 6 out of 12 controls were males (50%); mean age was 26.7 (±3.2). There was expression of IRS1 in leukocytes. The median IRS1 cells (HCV) were 0.061 (0.004 to 0.469); the median IRS 1liver (HCV) was 0.0003 (0.00002 to 0.0186)-lower than in controls (resp., P = 0.005 and P = 0.018). HOMA-IR had an inverse correlation with IRS 1liver (P = 0.04). There was no correlation between IRS1 liver and IRS1 cells (P = 0.930). Conclusions. There was expression of IRS1 in leukocytes. IRS1 cells and IRS1 liver were lower in HCV patients than in controls.

An assessment of adverse effects of vildagliptin versus comparators on the liver, the pancreas, the immune system, the skin and in patients with impaired renal function from a large pooled database of Phase II and III clinical trials

AIM

To assess the safety of vildagliptin versus all comparators (ACs) with regard to organs, systems or tissues of particular interest in type 2 diabetes (T2DM) and areas of potential concern with dipeptidyl peptidase-IV (DPP-4) inhibitors.

METHODS

Data were pooled from 38 studies where vildagliptin was given for > or =12 to > 104 weeks in patients with T2DM. Absolute and exposure-adjusted incidence rates and Peto odds ratios (ORs) versus ACs with corresponding 95% confidence intervals (CI) were calculated.

RESULTS

There were > 7000 subject-years of exposure (SYE) to vildagliptin 50 mg bid and > 6500 SYE to ACs. For mild hepatic enzyme elevations with and without elevated bilirubin levels, the ORs for vildagliptin 50 mg bid were 1.24 (95% CI: [0.80, 1.93]) and 1.19 (95% CI: [0.29, 4.90]), respectively. The exposure-adjusted incidences of markedly elevated hepatic enzymes and for enzyme elevations with bilirubin > or = 2x ULN with vildagliptin 50 mg bid were < or = those in the ACs group. For hepatic and pancreatitis-related AEs, the ORs for vildagliptin 50 mg bid were 0.87 (95% CI: [0.64, 1.19]) and 0.70 (95% CI: [0.26, 1.88]), respectively, and for any AE in the infections and infestations SOC, this was 1.04 (95% CI: [0.96, 1.13]). The incidences of skin-related AEs were low and the risk with vildagliptin 50 mg bid was not significantly different from ACs [(OR = 1.10 (95% CI: [0.80, 1.51])].

CONCLUSIONS

The present meta-analyses indicate that vildagliptin was not associated with increased risk of hepatic events or hepatic enzyme elevations indicative of drug-induced liver injury, pancreatitis, infections or skin-related toxicity.

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.

Hepatitis C and diabetes: the inevitable coincidence?

Type 2 diabetes (T2D) and HCV infection are common conditions involving, respectively, at least 170 and 130 million people worldwide. However, the distribution of such cases does not overlap in the same age groups in different geographic areas. Following pioneering reports of increased prevalence of T2D in HCV-positive cirrhosis, interest concerning the relationship between HCV and T2D has escalated. HCV is able to induce insulin resistance (IR) directly and the role of specific viral genotypes responsible for such effect is disputed. IR has consistently been found to be closely linked to fibrosis in HCV infection, although also typically associated with T2D in prefibrotic stages. HCV infection could be associated with a reduced prevalence of metabolic syndrome owing to virus-associated reduction in BMI (reported in population but not clinical studies) and hypobetaliproteinemia. A three- to ten-fold increased risk of HCV infection was reported among diabetic patients in comparison with different control groups and a meta-analysis showed a 1.8-fold excess risk of T2D among HCV-positive compared with HBV-positive patients. Moreover, HCV positivity is associated with an increased risk of T2D in patients receiving liver or kidney transplantations. T2D and IR are independent predictors of a more rapid progression of liver fibrosis and impaired response to antiviral treatment in chronic hepatitis C. Patients with cirrhosis and T2D have an increased susceptibility to hepatic encephalopathy and hepatocellular carcinoma (HCC). However, the beneficial effects of antiviral treatment on IR and T2D are controversial. Theoretically, glycemic control in chronic hepatitis C, and particularly in cirrhotic patients, could improve the prognosis and the response to antivirals, although the evidence for this is limited. Future studies should elucidate the relationship between insulin signaling, HCV and interferon signaling, entity of cardiovascular risk in patients with HCV infection, the potential role of 'metabolic' strategies added to antiviral treatment schedules, the impact of IR on liver failure, portal hypertension and HCC, particularly in patients managed in a transplant setting.

Dysmetabolic changes associated with HCV: a distinct syndrome?

Although not associated with the metabolic syndrome, HCV is linked with impaired insulin signalling, insulin resistance, hypocholesterolemia and steatosis which represent a distinct HCV-associated dysmetabolic syndrome. Insulin resistance affects the development of diabetes, fibrosis, impaired response to antivirals and perhaps hepatocellular carcinoma risk. HCV infection is associated with hypocholesterolemia and steatosis reversible after sustained virologic response. A "viral", and a "metabolic" steatosis exist as function of viral genotypes. Little is known about the possible role of HCV in further components of the metabolic syndrome such as atherosclerosis, obesity, arterial hypertension, hyperuricemia and thrombotic risk factors.