Clearing hepatitis C virus with direct antiviral agents reduces cardiovascular events in patients with prediabetes. Commentary to Sasso and colleagues

Liver health is a key determinant of cardiovascular risk (CVR). Hepatic fibrosis is the shared common result of chronic hepatitis, irrespective of aetiology. Fibrosis profoundly distorts liver tissue architecture and perturbs hepatic physiology, dictates the course of chronic liver disease and is increasingly recognized as a CVR factor. The relative weights of pre-diabetes and hepatic fibrosis as risk factors for major adverse cardiac events (MACE) in patients with HCV remain an open issue. Sasso and Colleagues answered this research question by treating approximately half of 770 HCV positive pre-diabetic patients with direct antiviral agents (DAAs), while the rest served as historical controls. Data have shown that achieving HCV clearance with DAAs was associated with a 60% reduced risk of MACE, thereby implying that this antiviral strategy is recommended in HCV positive pre-diabetic patients, regardless of the severity of liver disease and concurrent CVR factors. This study paves the way for additional studies addressing the molecular patho-mechanisms and changes in the clinical spectrum involved in cardio-metabolic protection following HCV eradication in patients with pre-diabetes.

Perspectives on Precision Medicine Approaches to NAFLD Diagnosis and Management

Precision medicine defines the attempt to identify the most effective approaches for specific subsets of patients based on their genetic background, clinical features, and environmental factors. Nonalcoholic fatty liver disease (NAFLD) encompasses the alcohol-like spectrum of liver disorders (steatosis, steatohepatitis with/without fibrosis, and cirrhosis and hepatocellular carcinoma) in the nonalcoholic patient. Recently, disease renaming to MAFLD [metabolic (dysfunction)-associated fatty liver disease] and positive criteria for diagnosis have been proposed. This review article is specifically devoted to envisaging some clues that may be useful to implementing a precision medicine-oriented approach in research and clinical practice. To this end, we focus on how sex and reproductive status, genetics, intestinal microbiota diversity, endocrine and metabolic status, as well as physical activity may interact in determining NAFLD/MAFLD heterogeneity. All these factors should be considered in the individual patient with the aim of implementing an individualized therapeutic plan. The impact of considering NAFLD heterogeneity on the development of targeted therapies for NAFLD subgroups is also extensively discussed.

Epidemiology and pathophysiology of the association between NAFLD and metabolically healthy or metabolically unhealthy obesity

The prevalence of nonalcoholic fatty liver disease (NAFLD) is continuing to rise in many countries, paralleling the epidemic of obesity worldwide. In the last years, the concept of metabolically healthy obesity [MHO, generally defined as obesity without metabolic syndrome (MetS)] has raised considerable scientific interest. MHO is a complex phenotype with risks intermediate between metabolically healthy individuals with normal-weight (NWMH) and patients who are obese and metabolically unhealthy (MUO, i.e. obesity with MetS). In this review we aimed to examine the association and pathophysiological link of NAFLD with MHO and MUO. Compared to NWMH individuals, patients with obesity, regardless of the presence of MetS features, are at higher risk of all-cause mortality and cardiovascular events. Moreover, MHO patients have a greater risk of NAFLD development and progression compared to NWMH individuals. However, this risk is generally lower than that of MUO patients, suggesting a stronger adverse effect of coexisting MetS disorders than obesity per se on the severity of NAFLD. Nevertheless, since MHO is a dynamic state (with a significant proportion of MHO subjects progressing to MUO over time) and NAFLD itself may predict the transition from MHO to MUO, we believe that any effort should be made to identify NAFLD in all obese individuals, although they appear to be "metabolically healthy". Future research is needed to better understand the role of NAFLD and other pathogenic factors potentially involved in the transition from MHO to MUO and to elucidate how this transition may affect the presence and severity of NAFLD.

NAFLD in Some Common Endocrine Diseases: Prevalence, Pathophysiology, and Principles of Diagnosis and Management

Secondary nonalcoholic fatty liver disease (NAFLD) defines those complex pathophysiological and clinical consequences that ensue when the liver becomes an ectopic site of lipid storage owing to reasons other than its mutual association with the metabolic syndrome. Disorders affecting gonadal hormones, thyroid hormones, or growth hormones (GH) may cause secondary forms of NAFLD, which exhibit specific pathophysiologic features and, in theory, the possibility to receive an effective treatment. Here, we critically discuss epidemiological and pathophysiological features, as well as principles of diagnosis and management of some common endocrine diseases, such as polycystic ovary syndrome (PCOS), hypothyroidism, hypogonadism, and GH deficiency. Collectively, these forms of NAFLD secondary to specific endocrine derangements may be envisaged as a naturally occurring disease model of NAFLD in humans. Improved understanding of such endocrine secondary forms of NAFLD promises to disclose novel clinical associations and innovative therapeutic approaches, which may potentially be applied also to selected cases of primary NAFLD.

Pathogenesis of hypothyroidism-induced NAFLD: Evidence for a distinct disease entity?

Nonalcoholic fatty liver disease (NAFLD), the most common liver disease worldwide, may be associated with primary hypothyroidism. However, the pathogenesis underlying such an association is complex and not completely understood. Here, we specifically discuss the pathogenic mechanisms potentially involved in hypothyroidism-induced NAFLD. To this end, we summarize the general pathophysiology of thyroid hormones (TH). Next, we analyze the published data from rodent studies by discussing whether hypothyroid rats may develop NAFLD via hyperphagia; whether mitochondria become energetically more efficient; what the overall energy balance is and if diversion of fatty substrates occurs; and the latest advancements in molecular pathogenesis brought about by metabolomics, cell imaging, lipophagy, autophagy and genetically engineered mouse models. Moreover, we discuss the data published regarding humans on the pathogenic role of TH, metabolic syndrome and other risk factors in hypothyroidism-related NAFLD as well as the putative mechanisms underlying the development of NAFLD-related hepatocellular carcinoma in hypothyroidism. In conclusion, although many research questions still remain unanswered, the pathophysiology of hypothyroidism-induced NAFLD makes this a potentially curable and distinct disease entity. However, further studies are needed to better elucidate the underlying mechanisms, and to ascertain whether treatment with either TH or thyromimetic agents improves NAFLD.

A round trip from nonalcoholic fatty liver disease to diabetes: molecular targets to the rescue?

Evidence suggests a close relationship between nonalcoholic fatty liver disease (NAFLD) and type two diabetes (T2D). On the grounds of prevalence of disease, both conditions account for a significant financial cost for health care systems and individuals. Aim of this review article is to explore the epidemiological basis and the putative molecular mechanisms underlying the association of NAFLD with T2D. Epidemiological studies have shown that NAFLD is associated to the development of incident T2D and either reversal or improvement of NAFLD will result into decreased risk of developing incident T2D. On the other side of the coin data have shown that T2D will worsen the course of NAFLD doubling the risk of disease progression (i.e. evolution from simple steatosis to advanced fibrosis, cirrhosis, hepatocellular carcinoma, liver transplant and death). Conversely, NAFLD will contribute to metabolic decompensation of T2D. The pathogenesis of T2D in NAFLD patients may be mediated by several hepatokines impairing metabolic control. Among these, Fetuin-B, which causes glucose intolerance and is increased in patients with T2D and NAFLD with fibrosis is one of the most promising. T2D may affect the progression of NAFLD by acting at different levels of the pathogenic cascade involving gut microbiota and expanded, inflamed, dysfunctional adipose tissue. In conclusion, T2D and NAFLD are mutually, closely and bi-directionally associated. An improved understanding of molecular pathogenesis underlying this bi-directional association may allow us to be able to prevent the development of T2D by halting the progression of NAFLD.

Do Nonalcoholic Fatty Liver Disease and Fetuin-A Play Different Roles in Symptomatic Coronary Artery Disease and Peripheral Arterial Disease?

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is strongly associated with both atherosclerotic cardiovascular disease (CVD) and Fetuin-A. However, the association of Fetuin-A with atherosclerosis is more controversial. We hypothesized that the pathogenic interplay of NAFLD, Fetuin-A and atherosclerosis varies based on arterial site. Accordingly, we aimed to assess NAFLD prevalence, Fetuin-A values and their relationship with symptomatic atherosclerosis occurring in different localizations: coronary artery disease (CAD) vs. peripheral arterial disease (PAD).

METHODS

One hundred and forty-nine consecutive patients with symptomatic atherosclerotic CVD were recruited: 45 with CAD diagnosed by coronary angiography and 104 with PAD detected by doppler-ultrasound and/or computed tomography angiography and/or angiography. NAFLD was diagnosed based on both ultrasonography and exclusion of competing etiologies. Serum Fetuin-A was measured with ELISA.

RESULTS

NAFLD was detected in 54% of the overall group, with higher rates in PAD (59%) than CAD (42%) patients. Median Fetuin-A values were 256 (111-662) μg/mL, higher in patients with CAD (378 (124-662) μg/mL) than those with PAD (236 (111-461) μg/mL). The main findings were: (1) CAD patients had higher Fetuin-A values and less frequently NAFLD than PAD patients; (2) NAFLD was positively associated with Fetuin-A values; however, this association was limited to CAD patients only; (3) Fetuin-A values were positively associated with both CAD and NAFLD.

CONCLUSION

The pathogenic interplay of NAFLD, Fetuin-A and atherosclerosis probably varies according to the arterial site.

NAFLD: Is There Anything New under the Sun?

Nonalcoholic fatty liver disease (NAFLD) is an "umbrella" definition that encompasses a spectrum of histological liver changes ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) with/without fibrosis, "cryptogenic" cirrhosis, and hepatocellular carcinoma (HCC), occurring in a dysmetabolic milieu, though in the absence of excessive alcohol consumption and other competing etiologies of chronic liver disease [1].[...].

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.

The Role of Nuclear Receptors in the Pathophysiology, Natural Course, and Drug Treatment of NAFLD in Humans

Nonalcoholic fatty liver disease (NAFLD) describes steatosis, nonalcoholic steatohepatitis with or without fibrosis, and hepatocellular carcinoma, namely the entire alcohol-like spectrum of liver disease though observed in the nonalcoholic, dysmetabolic, individual free of competing causes of liver disease. NAFLD, which is a major public health issue, exhibits intrahepatic triglyceride storage giving rise to lipotoxicity. Nuclear receptors (NRs) are transcriptional factors which, activated by ligands, are master regulators of metabolism and also have intricate connections with circadian control accounting for cyclical patterns in the metabolic fate of nutrients. Several transcription factors, such as peroxisome proliferator-activated receptors, liver X receptors, farnesoid X receptors, and their molecular cascades, finely regulate energetic fluxes and metabolic pathways. Dysregulation of such pathways is heavily implicated in those metabolic derangements characterizing insulin resistance and metabolic syndrome and in the histogenesis of progressive NAFLD forms. We review the role of selected NRs in NAFLD pathogenesis. Secondly, we analyze the role of NRs in the natural history of human NAFLD. Next, we discuss the results observed in humans following administration of drug agonists or antagonists of the NRs pathogenically involved in NAFLD. Finally, general principles of treatment and lines of research in human NAFLD are briefly examined.

Relationship between Non-Alcoholic Fatty Liver Disease and Psoriasis: A Novel Hepato-Dermal Axis?

Over the past 10 years, it has become increasingly evident that nonalcoholic fatty liver disease (NAFLD) is a multisystem disease that affects multiple extra-hepatic organ systems and interacts with the regulation of several metabolic and immunological pathways. In this review we discuss the rapidly expanding body of clinical and epidemiological evidence supporting a strong association between NAFLD and chronic plaque psoriasis. We also briefly discuss the possible biological mechanisms underlying this association, and discuss treatment options for psoriasis that may influence NAFLD development and progression. Recent observational studies have shown that the prevalence of NAFLD (as diagnosed either by imaging or by histology) is remarkably higher in psoriatic patients (occurring in up to 50% of these patients) than in matched control subjects. Notably, psoriasis is associated with NAFLD even after adjusting for metabolic syndrome traits and other potential confounding factors. Some studies have also suggested that psoriatic patients are more likely to have the more advanced forms of NAFLD than non-psoriatic controls, and that psoriatic patients with NAFLD have more severe psoriasis than those without NAFLD. In conclusion, the published evidence argues for more careful evaluation and surveillance of NAFLD among patients with psoriasis.

Epidemiological modifiers of non-alcoholic fatty liver disease: Focus on high-risk groups

An improved understanding of non-alcoholic fatty liver disease epidemiology would lead to identification of individuals at high risk of developing chronic liver disease and extra-hepatic complications, thus contributing to more effective case finding of non-alcoholic fatty liver disease among selected groups. We aimed to illustrate the epidemiology of non-alcoholic fatty liver disease in high-risk groups, which were identified based on existing literature. To this end, PubMed was searched to retrieve original articles published until May 2015 using relevant and pertinent keywords "nonalcoholic fatty liver disease" and "diabetes", "obesity", "hyperlipidaemia", "familial heterozygous hypobetalipoproteinaemia", "hypertension", "metabolic syndrome", "ethnicity", "family history" or "genetic polymorphisms". We found that age, sex and ethnicity are major physiological modifiers of the risk of non-alcoholic fatty liver disease, along with belonging to "non-alcoholic fatty liver disease families" and carrying risk alleles for selected genetic polymorphisms. Metabolic syndrome, diabetes, obesity, mixed hyperlipidaemia and hypocholesterolaemia due to familial hypobetalipoproteinaemia are the major metabolic modifiers of non-alcoholic fatty liver disease risk. Compared with these metabolic conditions, however, arterial hypertension appears to carry a relatively more modest risk of non-alcoholic fatty liver disease. A better understanding of the epidemiology of non-alcoholic fatty liver disease may result in a more liberal policy of case finding among high-risk groups.

Nonalcoholic fatty liver disease: a precursor of the metabolic syndrome

The conventional paradigm of nonalcoholic fatty liver disease representing the "hepatic manifestation of the metabolic syndrome" is outdated. We identified and summarized longitudinal studies that, supporting the association of nonalcoholic fatty liver disease with either type 2 diabetes mellitus or metabolic syndrome, suggest that nonalcoholic fatty liver disease precedes the development of both conditions. Online Medical databases were searched, relevant articles were identified, their references were further assessed and tabulated data were checked. Although several cross-sectional studies linked nonalcoholic fatty liver disease to either diabetes and other components of the metabolic syndrome, we focused on 28 longitudinal studies which provided evidence for nonalcoholic fatty liver disease as a risk factor for the future development of diabetes. Moreover, additional 19 longitudinal reported that nonalcoholic fatty liver disease precedes and is a risk factor for the future development of the metabolic syndrome. Finally, molecular and genetic studies are discussed supporting the view that aetiology of steatosis and lipid intra-hepatocytic compartmentation are a major determinant of whether fatty liver is/is not associated with insulin resistance and metabolic syndrome. Data support the novel paradigm of nonalcoholic fatty liver disease as a strong determinant for the development of the metabolic syndrome, which has potentially relevant clinical implications for diagnosing, preventing and treating metabolic syndrome.

Potential for statins in the chemoprevention and management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common, treatment-resistant malignancy with a complex molecular pathogenesis. Statins are a widely used class of cholesterol-lowering drugs with potential anticancer activity. We reviewed the evidence for a role of statins in primary and secondary chemoprevention of HCC and slowing the course of otherwise incurable primary or recurrent disease. A literature search (key words: Statins, hepatocellular carcinoma) conducted to this end, retrieved 119 references. Here we summarize the history, mechanism of action and cardiovascular use of statins and highlight that statins can affect several pathways implicated in the development of HCC. In vitro and animal studies provide strong evidence for a favorable effect of statins on HCC. However, evidence in humans is conflicting. We discuss in full detail the methodological strengths and pitfalls of published data including three cohort studies suggesting that the use of statins may protect from the development of HCC and of a single trial reporting increased survival in those with advanced HCC randomized to receive statins. A remarkably hepato-safe class of drugs acting on both hepatocyte and endothelial cells, statins also have potentially beneficial effects in lowering portal hypertension. In conclusion, there is strong experimental evidence that statins are beneficial in chemopreventing and slowing the growth of HCC. However, randomized controlled trials are necessary in order to investigate the role of statins in the chemoprevention of HCC and in slowing the course of otherwise incurable disease in humans.

Insulin resistance in nonalcoholic steatohepatitis: necessary but not sufficient - death of a dogma from analysis of therapeutic studies?

Studies on pathogenesis tend to blame insulin resistance as the chief pathogenic agent in the development and progression of nonalcoholic steatohepatitis (NASH). In this article, studies reporting histological changes induced by pharmacological therapy and nonpharmacological interventions in NASH are critically reviewed, assuming that analysis of morphological findings can provide further insight into the pathogenesis of NASH. PubMed database analysis provided 16 studies describing light microscopy in adults and three in children; ultrastructural analysis was conducted through electron microscopy in two human and four animal studies. Analysis of the data disclosed methodological issues, such as variable histological criteria, limited series, failure to stratify enrolled patients for their risk of progression and very few electron microscopy studies. Moreover, no particularly convincing 'proof-of-concept' study that might assist in understanding the pathogenesis of NASH was found. It is noteworthy that insulin sensitizers fail to treat NASH in all cases, do not reverse or even worsen mitochondrial abnormalities in NASH and, conversely, histological improvement of disease, at least in some patients, is observed with agents acting through mechanisms other than insulin sensitization, such as vitamin E. The finding that correction of insulin resistance may not be sufficient to successfully treat NASH in the majority of patients seems to conflict with studies on pathogenesis. This might imply that NASH is the shared end result of varying pathogenic mechanisms concurring to determine liver damage to a variable extent in the individual patients. If this hypothesis is true, we should try to tailor treatment to each subject.

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.

HCV and diabetes. A two-question-based reappraisal

We used available studies to answer two clinically relevant questions, i.e. whether those with type 2 diabetes should undergo hepatitis C virus screening and whether hepatitis C virus positive individuals should be screened for diabetes. Four reasons argue against the hypothesis of screening diabetics for hepatitis C virus. First, although it induces insulin resistance, hepatitis C virus is not directly diabetogenic. Second, the clinical phenotype of hepatitis C virus-associated type 2 diabetes might be a clue to target the specific diabetic population to be screened. Third, diabetic patients are expected to be poor responders to antivirals and evidence that this might result in recovery from type 2 diabetes is insufficient. Fourth, no econometric data are available in the specific subset of those with type 2 diabetes. Case finding of type 2 diabetes in those with hepatitis C virus infection, in contrast, might be considered in those patients with type 2 diabetes who have cirrhosis, in whom--due to increased prevalence and severity of hepatic encephalopathy--diabetes is associated with increased mortality. Preliminary evidence suggests that the prognosis of cirrhosis might benefit from improved glycemic control and thus from earlier diagnosis of type 2 diabetes. Finally, studies are needed to ascertain the most cost-effective strategy of case-finding type 2 diabetes among those who are hepatitis C virus-infected. In conclusion, available data enabled us to answer the two questions. Hepatitis C virus screening should best be restricted to those (lean) diabetic patients with (advanced) liver disease. Glucose tolerance testing should best be performed in those with hepatitis C virus-related cirrhosis. However, additional studies are needed to support the cost-effectiveness of our conclusions.

Fatty liver, carotid disease and gallstones: A study of age-related associations

AIM: To evaluate carotid intima-media thickening (IMT) and plaques, gallstone disease (GD) and fatty liver (FL) as a function of age.

METHODS: In 449 subjects, FL and carotid disease were assessed ultrasonographically. In a subgroup of 65/449 patients with non-alcoholic fatty liver disease (NAFLD), carotid disease, GD and associated factors were determined.

RESULTS: FL of unspecified etiology was more common in younger and GD in older individuals. FL subjects had an increased prevalence of IMT and a decreased prevalence of plaques and manifested carotid disease earlier. Plaques were more common in subjects with GD. Age was an independent predictor of carotid disease outcome and FL was a protective factor for plaques. In NAFLD, there was an inverse correlation between body weight and age and the latter independently predicted carotid findings.

CONCLUSION: Cardiovascular risk in patients with FL and NAFLD needs to be assessed as a function of age and body weight.

Hepatitis C and steatosis: a reappraisal

The overall prevalence of steatosis in patients with Hepatitis C virus (HCV) chronic infection is 55.5% (range 34.8-81.2%). This is a two to threefold increase compared with the prevalence of steatosis in chronic hepatitides because of other aetiologies and of the figures expected on the grounds of a steatosis-HCV chance association. HCV genotype 3 (HCV-3) has specific epidemiological features; furthermore, as compared with HCV-non-3 genotypes, it is associated with a higher prevalence (74.1%vs 47.9%, P < 0.01) and with more severe grades of steatosis (prevalence of grade 3 steatosis 29.6 vs 5.5 P < 0.01). Host and viral factors play a role, although to a variable extent, in the pathogenesis of HCV-3 and non-3 steatosis. HCV load and body mass index are associated with steatosis in HCV-3 and in HCV-non-3 patients respectively. Serum cholesterol levels and liver steatosis at baseline follow an inverse relationship in HCV infection. As hypocholesterolaemia corrects only in those sustained responders to antiviral treatment both in genotype 3 and in non-3 genotypes, the occurrence of a virally induced, acquired and reversible hypobetalipoproteinaemia seems plausible. Steatosis affects the natural course of HCV infection: it is associated with fibrosis, a possible mediator of increased risk to develop type 2 diabetes, it impairs the response to antiviral treatment in HCV-3 patients and might constitute a risk factor for the development of hepatocellular carcinoma. These observations indicate the need to evaluate the efficacy of combined antiviral and 'metabolic' approaches vs standard antiviral regimes in patients with steatosis and HCV chronic infection.

Hepatic steatosis and insulin resistance: does etiology make a difference?

BACKGROUND/AIMS

To ascertain whether the etiology of hepatic steatosis modulates insulin resistance (IR) and to determine the predictors of IR.

METHODS

We studied IR through HOMA IR in 146 subjects, 99 of whom had ultrasonographic and/or histologic steatosis. Twenty-two had familial heterozygous hypobetalipoproteinemia (FHBL), 48 had non-alcoholic fatty liver disease (NAFLD), 34 HCV infection (17 with HCV1b, 17 with HCV3a) and 42 were healthy controls without steatosis.

RESULTS

Steatosis was present in 77.3% of FHBL and, by enrolment criteria, in all NAFLD and HCV cases. Overall HOMA-IR correlated with BMI and GGT (P<0.01). FHBL and healthy groups had similar HOMA-IR and GGT values, whereas higher levels were observed in HCV and NAFLD. HCV3a and FHBL patients were hypolipidemic. HOMA-IR was similar in FHBL patients and controls and lower than in HCV and NAFLD. FHBL patients had a high extent of steatosis, similar to that observed in HCV3a, but lower grading and staging than NAFLD and HCV. At multivariate analysis, steatosis and GGT predicted HOMA-IR.

CONCLUSIONS

Data suggest that not all hepatic fat associates with IR. FHBL patients, for some aspects, resemble HCV3a infection, possibly suggesting a shared steatogenic mechanism. Among steatotic patients serum GGT levels is the independent predictor of IR.

Review article: hepatic steatosis and insulin resistance

Hepatic steatosis may be both an adaptive phenomenon and an example of lipotoxicity. Its prevalence ranks in the same order of magnitude of insulin resistance in the general population. Studies support the finding that hepatic steatosis is secondary to insulin resistance and not vice versa. A steatotic liver will further contribute to the development of insulin resistance through impaired clearance of insulin from the portal blood, creating a vicious cycle. Insulin resistance is the leading force in the pathogenesis and natural history of non-alcoholic fatty liver disease. Dysfunction of energetic homeostasis and the interaction of adiponectin, leptin and tumour necrosis factor-alpha are key events in the pathogenesis of steatosis and insulin resistance. Insulin resistance represents the frame within which hepatic and extrahepatic non-alcoholic fatty liver disease-related clinical manifestations are to be anticipated and interpreted.

[Hepatitis C virus-associated and metabolic steatosis. Different or overlapping diseases?]

Hepatic steatosis is the hallmark of nonalcoholic fatty liver disease (NAFLD), which is the consequence of multiple metabolic derangements among which insulin resistance plays a pivotal role. Steatosis is, also, a feature of hepatitis C virus (HCV) infection. However, in chronic hepatitis C, the prevalence of steatosis is 2.5-fold more elevated than that expected by a chance concurrence with NAFLD, suggesting that HCV may be implied in the development of steatosis. As observed in NAFLD, in patients infected with HCV genotype 1 steatosis is associated with an increased body mass index. On the other hand, in patients infected with genotype 3 the extent of steatosis strictly correlates with the viral load indicating that steatosis is mainly "virus-related". Regardless of the "metabolic" or "viral" etiology, hepatic steatosis in HCV contributes to the progression of liver fibrosis, to the development of hepatocellular carcinoma and to an impaired response to interferon treatment. Features such as obesity, insulin resistance and type 2 diabetes mellitus are shared by NAFLD and HCV-associated steatosis. In addition, HCV infection, directly or through steatosis, favors the development of type 2 diabetes mellitus. Hyperlipidemia is an independent predictor of the development of NAFLD, but not of HCV-associated steatosis. Arterial hypertension is common in nonalcoholic steatohepatitis patients, and HCV infection has recently been acknowledged as an independent risk factor for atherosclerosis. The role of iron in the progression of both NAFLD and HCV-associated steatosis remains controversial while lipoperoxidation and oxidative stress are pathogenic mechanisms shared by both. Some metabolic risk factors may be shared by both HCV-associated steatosis and NAFLD although the disease progression and pathophysiological background may be different. Preliminary data suggest that the therapeutic options for NAFLD may also be useful to improve HCV-associated steatosis.

The wide spectrum of steatohepatitis: a report of four cases and a review of the literature

We report on four cases displaying the wide range of aetiological risk factors (presence or absence of family history of dyslipidaemia and cryptogenic cirrhosis, from subnormal body mass index through morbid obesity, from absent through hepatotoxic alcohol consumption), laboratory test results (from subnormal through elevated uric acid and ferritin values), ultrasonographic changes (from normal findings through 'bright liver' with or without attenuation of ultrasound beam and absence/presence of focal lesions), and histological severity of steatohepatitis (fibrosis appearing to be inversely related to the amount of liver fat but zone 3 accentuation of lesions and ballooning being observed in all cases). Cases illustrate the concepts of overlapping aetiologies of steatohepatitis (hepatitis C, diabetes and lipodystrophy); the relationships between cryptogenic cirrhosis, familial cirrhosis, non-alcoholic fatty liver disease and hepatocellular carcinoma; familial hypobetalipoproteinaemia as an aetiology of steatohepatitis; and alcoholic liver disease in the obese. These issues, which are worthy of future investigation, are reviewed.

[Bleeding gastrointestinal angiodysplasias: our experience and a review of the literature]

The aim of the present study was to draw an outline of the clinical epidemiology of bleeding gastrointestinal angiodysplasias. The study includes a report of a case and of our series of patients with bleeding gastrointestinal angiodysplasias admitted, between 1993 and 2003, to a ward of Internal Medicine where digestive endoscopy is also performed. A review of the literature is also provided. An 80-year-old cirrhotic woman with aortic stenosis, was referred to our Department because of anemia due to melena. In spite of 13 hospitalizations during which numerous diagnostic procedures including endoscopy, X-ray studies, arteriography, labeled red blood cells scanning and laparotomy with intraoperative ileoscopy, the site and nature of the bleeding lesion remained unidentified. Her red blood cell requirement progressively increased from 6 U in 1993 to 24 U in 1994 to 40 U as of September 1995. Enteroscopy disclosed duodeno-jejunal angiodysplasia. The patient subsequently received 35 additional red blood cell units during 7 new admissions. Between 1993 and 2003, 24 patients were identified. They were mainly women and their average age was 77 years. Angiodysplasias were localized in the large bowel in 92% of cases. Comorbidities included: heart disease (79%), chronic liver disease (29%) and chronic renal failure (21%). One fourth of patients were under anticoagulant drugs or had a hemostatic blood disorder. All patients received blood transfusions and endoscopic treatment was performed in approximately half of the cases. The most relevant updates are related to the pathogenic relationship between aortic stenosis, von Willebrand's disease and bleeding gastrointestinal angiodysplasias, the hemostatic alterations associated with liver cirrhosis or with chronic renal failure and the diagnosis and treatment of bleeding gastrointestinal angiodysplasias. A better understanding of the clinical epidemiology of bleeding gastrointestinal angiodysplasias may facilitate their diagnosis and contribute to an effective clinical management.

Steatosis and hepatitis C virus: mechanisms and significance for hepatic and extrahepatic disease

Nonalcoholic fatty liver disease (NAFLD) and hepatitis C virus (HCV)-related liver disease are common in the general population, but their concurrence is 2- to 3-fold higher than would be expected by chance alone. In patients with chronic HCV infection, steatosis is attributable to a variable combination of the mechanisms considered to play a role in the pathogenesis of NAFLD--insulin resistance in the obese and in the lean subject--along with a direct effect of HCV on hepatic lipid metabolism that leads to triglyceride accumulation through inhibition of export proteins that are required for very low density lipoprotein (VLDL) assembly and secretion. Accumulating evidence suggests that steatosis contributes to the progression of fibrosis in HCV-related disease in a pattern similar to that observed in NAFLD. Potential mechanisms of this effect include the increased sensitivity of steatotic livers to oxidative stress and cytokine-mediated injury. Steatosis-related hepatic insulin resistance may also play a role through the profibrogenic effects of the compensatory hyperinsulinemia and provides a potential explanation for the association between HCV and type 2 diabetes mellitus. Indeed, an appreciation of the importance of fat in HCV has recently led to trials of adjuvant therapy for HCV directed at steatosis-associated disease mechanisms, with encouraging results reported for various modalities, including weight loss and antioxidants. Future therapy should be aimed at exploiting the interactions of HCV with host insulin and lipid metabolism, particularly in nonresponders to standard antiviral schedules.

Intestinal Wegener's granulomatosis in a patient with severe alpha-1-antitrypsin deficiency resulting from a unique combination of two deficiency alleles (PiZ and PiMProcida)

Alpha-1-antitripsyn neutralizes the tissue damaging effects of proteases. Alpha-1-antitripsyn deficiency manifests with necrotizing vasculitis. Wegener's granulomatosis is a systemic necrotizing vasculitis that uncommonly affects the gut. The molecular genetics of patients with Wegener's granulomatosis of the gastrointestinal tract have never been characterized. A 63-year-old man with emphysema was admitted with a fever of unknown origin. Initially, this fever was linked to ileocolic Crohn's disease and later attributed to antineutrophil cytoplasm antibody-positive systemic vasculitis. Genetic analysis revealed that the alpha-1-antitripsyn deficiency was due to a previously unreported compound heterozygosity for two mutations (PiZ and PiMProcida). Our findings appear to support the concept that severe alpha-1-antitripsyn deficiency is implicated in the pathogenesis of the Crohn's disease-like milder intestinal manifestations belonging to the spectrum of Wegener's granulomatosis.

Of liver, whisky and plants: a requiem for colchicine in alcoholic cirrhosis?

Colchicine decreases liver fibrosis in experimental and human disease, but a meta-analysis recently concluded that colchicine should not be used for liver fibrosis or cirrhosis irrespective of the aetiology. In this issue, Cortez-Pinto et al. confirm such negative conclusions in their series of 55 outpatients with biopsy-proven alcoholic cirrhosis followed for a median of 3.5 years. Although well tolerated, colchicine did not affect either the annual incidence rate of complications or liver function tests. Current treatment of alcoholic cirrhosis includes correction of nutritional deficiencies, exogenous administration of antioxidants (notably S-adenosylmethionine and polyenylphosphatidylcholine), and liver transplantation. In the future, preventive/therapeutic strategies will include campaigns to decrease alcohol abuse aimed at subjects genetically prone to develop alcoholic liver injury, prevention of liver fibrosis via inhibition of the Na+/H+ exchange, stimulation of apoptosis of stellate cells, antagonism of cytokines involved in liver injury, degradation of extracellular matrix, and reversal of ethanol-induced inflammatory and fibrotic changes via increased nitric oxide levels. On the grounds that it renders the hepatocyte more vulnerable to necrosis, steatosis has a key role in the pathogenesis of alcoholic and non-alcoholic liver disease. Conditions associated with insulin resistance have been recognized as risk factors for chronic liver disease and hepatocellular carcinoma in the alcoholic. This suggests that, through steatosis, insulin resistance could be a co-factor of alcoholic liver disease. Were such a hypothesis confirmed, it would unify our view of the pathogenesis of alcoholic and non-alcoholic liver disease, with all its inherent therapeutic implications.

Fasting insulin and uric acid levels but not indices of iron metabolism are independent predictors of non-alcoholic fatty liver disease. A case-control study

BACKGROUND

Non-alcoholic fatty liver disease is a common reason for hepatological consultation and may herald severe hepatic and extra-hepatic disease. The aetiopathogenesis of this condition is an area of increasing interest.

AIM

To evaluate anthropometric and biochemical factors associated to non-alcoholic fatty liver disease in a case-control study. Methods. Demographic and biochemical data of 60 consecutive patients with bright liver absent-to-low alcohol consumption, no evidence of viral, genetic and autoimmune diseases, were compared to those of 60 age- and gender-matched historical controls without fatty liver by univariate and multiple logistic regression analysis.

RESULTS

Patients were more often hypertriglyceridaemic, obese and diabetic than controls (p<.01). Mean values of alanine transaminase, gammaglutamyltranspeptidase, triglycerides, uric acid, fasting and log insulin, transferrin percent saturation and ferritin were significantly higher in the patients, while transferrin and quantitative insulin sensitivity check index, a quantitative insulin sensitivity index, were lower. No iron storage was found in those who underwent liver biopsy At univariate analysis the relative risk for non-alcoholic fatty liver disease significantly increased (p<0. 05) with increasing body mass index, fasting insulin, alanine transaminase, uric acid, triglycerides and gammaglutamyltranspeptidase; it decreased with increasing transferrin and quantitative insulin sensitivity check index. Multiple logistic regression analysis disclosed only fasting insulin and uric acid to be independent predictors of non-alcoholic fatty liver disease (p<0.05).

CONCLUSIONS

Fasting insulin and serum uric acid levels indicating insulin resistance, but not indices of iron overload, are independent predictors of non-alcoholic fatty liver disease.

Hereditary hemochromatosis masquerading as rheumatoid arthritis

Early erroneous diagnosis of rheumatic disease is common in subjects with arthropathy due to hereditary hemochromatosis. A 71-year-old male with chronic obstructive pulmonary disease and monoclonal gammopathy underwent hip replacement and was referred to our Department because of altered liver function tests. Test results were negative for hepatitis B surface antigen and hepatitis C virus, and positive for rheumatoid factor. A diagnosis of rheumatoid arthritis had been made on the basis of compatible joint involvement and laboratory data and steroid treatment prescribed. Since his serum ferritin was 3249 ng/mL, genetic testing for hereditary hemochromatosis was carried out and revealed homozygosity for Cys282Tyr mutation in the HFE gene. Liver biopsy disclosed cirrhosis compatible with hemochromatosis. Following a review of the patients' radiographs, the diagnosis of hemochromatosis arthropathy was made. Phlebotomies and family screening for hereditary hemochromatosis were done. The most logical explanation for the positive rheumatoid factor result in this subject are his age and the presence of two chronic diseases involving long-standing antigenic stimulation and monoclonal gammopathy of uncertain significance. It is important to distinguish rheumatoid arthritis from hemochromatosis arthropathy for several reasons: patients with hereditary hemochromatosis do not require corticosteroid treatment; in case of erroneous diagnosis of rheumatoid arthritis, phlebotomy is not started early, and familial genetic counseling is not considered. In male subjects with positive rheumatoid factor and joint and liver disease, hereditary hemochromatosis should be considered. More liberal use of genetic testing is justified in such cases.

Are there any sex differences in fatty liver? A study of glucose metabolism and body fat distribution

BACKGROUND AND AIMS

Fatty liver is a common condition found more often in males. Whether sex differences affect its development is presently unknown. The hypothesis that glucose metabolism alterations or central body fat distribution are gender-related in fatty liver was investigated.

METHODS

Overall 199 consecutive subjects seen in the Division of Internal Medicine and Gastroenterology, Modena City Hospital, were enrolled. In the main arm of the present study, 44 men with sonographic fatty liver and 47 controls without, and 18 women with and 19 without fatty liver had their body mass index (an index of overall adiposity), hepatobiliary serum enzymes, serum cholesterol and triglycerides determined. All underwent oral glucose tolerance tests (estimated through the glucose area under the curve with the trapezoidal method). In the ancillary arm study, 17 other men with and 14 without, and 11 other women with and 29 without fatty liver had anthropometric measurements of body fat distribution (waist/hip, waist/height and skinfold thickness).

RESULTS

Following statistical evaluation including univariate and multivariate analyses (main study), elevated body mass index was found to be an independent predictor of fatty liver in either sex. Glucose area under the curve and a central-type body fat distribution (ancillary study) predicted FL only in women.

CONCLUSIONS

Fatty liver could be gender-related in the present series.