Long term prognosis of fatty liver: risk of chronic liver disease and death

Nonalcoholic fatty liver disease, metabolic risk factors, and hepatocellular carcinoma: an open question

Non-alcoholic liver disease (NAFLD) defines liver abnormalities ranging from simple steatosis to nonalcoholic steatohepatitis with or without cirrhosis development, occurring in the absence of significant alcohol consumption, use of teratogenic medication, or hereditary disorders. The association between NAFLD and metabolic syndrome is well documented and widely recognized. Obesity, type 2 diabetes mellitus (T2DM), and dyslipidemia are the most common metabolic risk factors associated with NAFLD. Among the components of metabolic syndrome, current evidence strongly indicates obesity and diabetes as hepatocellular carcinoma (HCC) risk factors. There is also growing evidence that suggests an increased risk of HCC in NAFLD patients, even surpassing other etiologies in some high-income countries. Epidemiologic data demonstrate a parallel rise in prevalence of obesity, diabetes, NAFLD, and HCC. As obesity and its related diseases have steadily afflicted larger populations, HCC incidence is expected to increase in the future. Pathophysiologic mechanisms that underlie NAFLD development and subsequent progression to nonalcoholic steatohepatitis and cirrhosis (insulin resistance and hyperinsulinemia, oxidative stress, hepatic stellate cell activation, cytokine/adipocytokine signaling pathways, and genetic and environmental factors) appear to play a significant role in the development of NAFLD-related HCC. However, a comprehensive view of molecular mechanisms linking obesity, T2DM, and NAFLD-related HCC, as well as the exact sequence of molecular events, is still not understood in its entirety. Good-quality data are still necessary, and efforts should continue towards better understanding the underlying carcinogenic mechanisms of NAFLD-related HCC. In this paper, we aimed to centralize the most important links supporting these relationships, focusing on obesity, T2DM, and NAFLD-related HCC, as well as point out the major gaps in knowledge regarding the underlying molecular mechanisms behind them.

Non-invasive methods for the diagnosis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease and includes simple steatosis and nonalcoholic steatohepatitis (NASH). Since NASH progresses to cirrhosis more frequently and increases liver-related and cardiovascular disease risk substantially more than simple steatosis, there is a great need to differentiate the two entities. Liver biopsy is the gold standard for the diagnosis of NAFLD but its disadvantages, including the risk of complications and sampling bias, stress the need for developing alternative diagnostic methods. Accordingly, several non-invasive markers have been evaluated for the diagnosis of simple steatosis and NASH, including both serological indices and imaging methods. The present review summarizes the current knowledge on the role of these markers in the diagnosis of NAFLD. Current data suggest that ultrasound and the fibrosis-4 score are probably the most appealing methods for detecting steatosis and for distinguishing NASH from simple steatosis, respectively, because of their low cost and relatively high accuracy. However, currently available methods, both serologic and imaging, cannot obviate the need for liver biopsy for diagnosing NASH due to their substantial false positive and false negative rates. Therefore, the current role of these methods is probably limited in patients who are unwilling or have contraindications for undergoing biopsy.

Trends in the management and burden of alcoholic liver disease

Alcoholic liver disease (ALD) is the most prevalent cause of advanced liver disease in Europe and is the leading cause of death among adults with excessive alcohol consumption. There is a dose-response relationship between the amount of alcohol consumed and the risk of ALD. The relative risk of cirrhosis increases in subjects who consume more than 25 g/day. The burden of alcohol-attributable liver cirrhosis and liver cancer is high and is entirely preventable. Health agencies should develop population-based policies to reduce the prevalence of harmful and/or hazardous alcohol consumption and foster research in this field to provide new diagnostic and therapeutic tools. Disease progression of patients with ALD is heavily influenced by both genetic and environmental factors. Non-invasive methods for the diagnosis of fibrosis have opened new perspectives in the early detection of advanced ALD in asymptomatic patients. Alcoholic hepatitis, the most severe form of ALD, carries a high short-term mortality (around 30-50% at 3 months). Corticosteroids improve short-term survival in patients with severe alcoholic hepatitis but duration of therapy should be adapted to early response. Liver transplantation is the best option for patients with severe liver dysfunction. However, alcohol relapse after transplantation remains a critical issue and drinking habits of transplanted patients need to be routinely screened.

NAFLD: a multisystem disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries that is predicted to become also the most frequent indication for liver transplantation by 2030. Over the last decade, it has been shown that the clinical burden of NAFLD is not only confined to liver-related morbidity and mortality, but there is now growing evidence that NAFLD is a multisystem disease, affecting extra-hepatic organs and regulatory pathways. For example, NAFLD increases risk of type 2 diabetes mellitus (T2DM), cardiovascular (CVD) and cardiac diseases, and chronic kidney disease (CKD). Although the primary liver pathology in NAFLD affects hepatic structure and function to cause morbidity and mortality from cirrhosis, liver failure and hepatocellular carcinoma, the majority of deaths among NAFLD patients are attributable to CVD. This narrative review focuses on the rapidly expanding body of clinical evidence that supports the concept of NAFLD as a multisystem disease. The review discusses the factors involved in the progression of liver disease in NAFLD and the factors linking NAFLD with other extra-hepatic chronic diseases, such as T2DM, CVD, cardiac diseases and CKD. The review will not discuss NAFLD treatments as these are discussed elsewhere in this issue of the Journal. For this review, PubMed was searched for articles using the keywords "non-alcoholic fatty liver disease" or "fatty liver" combined with "diabetes", "cardiovascular (or cardiac) disease", "cardiovascular mortality" or "chronic kidney disease" between 1990 and 2014. Articles published in languages other than English were excluded.

Nonalcoholic Fatty liver disease and risk of diabetes and cardiovascular disease: what is important for primary care physicians?

Nonalcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver condition in Western World and across the globe. NAFLD prevalence is estimated to be around one-third of the total population. There are no published data that project the future prevalence of NAFLD, but with an increase in epidemic of diabetes and obesity, it is possible to suggest an increase in a number of individuals with NAFLD. NAFLD is associated with insulin resistance and occurs with an increase in cluster of features of metabolic syndrome and type 2 diabetes. Therefore, it is important to exclude the possibility of diabetes in those individuals with evidence of fatty liver. The global diabetes epidemic continues to grow, and it is estimated that the number of people with diabetes will double by year 2030. NAFLD is also a risk factor for an increase in cardiovascular incidence independent of age, sex, low-density lipoprotein-cholesterol, smoking, and cluster of metabolic syndromes. It is expected that NAFLD will be an important challenge for health providers in the near future. Taking all these factors into consideration, we believe that increasing awareness of metabolic and cardiovascular impact of NAFLD among general practitioners and health authorities may decrease the serious consequences of late diagnosis of NAFLD. Importantly, the collaboration between medical specialties is vital in decreasing the impact of the epidemic of NAFLD. The focus of this review is in the role of primary care physician in diagnosis, treatment and prevention of NAFLD and patients education.

Branched chain amino acid metabolism profiles in progressive human nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a globally widespread disease of increasing clinical significance. The pathological progression of the disease from simple steatosis to nonalcoholic steatohepatitis (NASH) has been well defined, however, the contribution of altered branched chain amino acid metabolomic profiles to the progression of NAFLD is not known. The three BCAAs: leucine, isoleucine and valine are known to mediate activation of several important hepatic metabolic signaling pathways ranging from insulin signaling to glucose regulation. The purpose of this study is to profile changes in hepatic BCAA metabolite levels with transcriptomic changes in the progression of human NAFLD to discover novel mechanisms of disease progression. Metabolomic and transcriptomic data sets representing the spectrum of human NAFLD (normal, steatosis, NASH fatty, and NASH not fatty livers) were utilized for this study. During the transition from steatosis to NASH, increases in the levels of leucine (127% of normal), isoleucine (139%), and valine (147%) were observed. Carnitine metabolites also exhibited significantly elevated profiles in NASH fatty and NASH not fatty samples and included propionyl, hexanoyl, lauryl, acetyl and butyryl carnitine. Amino acid and BCAA metabolism gene sets were significantly enriched among downregulated genes during NASH. These cumulative alterations in BCAA metabolite and amino acid metabolism gene profiles represent adaptive physiological responses to disease-induced hepatic stress in NASH patients.

Nonalcoholic fatty liver disease as a potential risk factor of cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic component of the metabolic syndrome. The aim of this review is to summarize the available data linking NAFLD with cardiovascular disease (CVD). The following topics are reviewed: (a) the clinical evidence linking NAFLD to increased prevalence of CVD; (b) the relationship between NAFLD (which is diagnosed by liver biopsy, serum liver enzymes, or ultrasonography) and incidence of CVD; (c) the mechanism linking NAFLD to CVD and clinical implication; and (d) the potential impact of NAFLD treatment on cardiac complications. CVD dictates the outcome (or outcomes) in patients with NAFLD more frequently and to a greater extent than does the progression of liver disease. NAFLD patients have a higher risk of all-cause death than the general population, mainly because of CVD or liver-related causes. The biologic mechanism linking NAFLD and CVD might be associated with various factors, involving a complex interaction among insulin resistance, oxidative stress, abnormal adipocytokine profile, endothelial dysfunction, lipid abnormalities, and activation of inflammatory cascade. Lifestyle modifications and pharmacotherapy are helpful to treat patients with NAFLD. NAFLD is likely to be associated with an increased risk of CVD, and raises the possibility that NAFLD may not only be a marker but also an early mediator of CVD.

Role of receptor for advanced glycation end products (RAGE) in liver disease

Receptor for advanced glycation end products (RAGE) belongs to a immunoglobulin superfamily of cell surface molecules that could bind to a number of ligands such as advanced glycation end products, high-mobility group protein box-1, S-100 calcium-binding protein, and amyloid-β-protein, inducing a series of signal transduction cascades, and being involved in a variety of cellular function, including inflammation, proliferation, apoptosis, angiogenesis, migration, and fibrosis. RAGE is expressed in hepatic stellate cells and hepatocytes and hepatoma cells. There is accumulating evidence that engagement of RAGE with various ligands elicits oxidative stress generation and subsequently activates the RAGE downstream pathway in the liver, thereby contributing to the development and progression of numerous types of hepatic disorders. These observations suggest that inhibition of the RAGE signaling pathway could be a novel therapeutic target for liver diseases. This article summarizes the pathological role of RAGE in hepatic insulin resistance, steatosis and fibrosis, ischemic and non-ischemic liver injury, and hepatocellular carcinoma growth and metastasis and its therapeutic interventions for these devastating disorders.

Serum levels of toxic AGEs (TAGE) may be a promising novel biomarker in development and progression of NASH

Nonalcoholic fatty liver disease (NAFLD) ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), leads to fibrosis and potentially cirrhosis, liver failure, and hepatocellular carcinoma, and is one of the most common causes of liver disease worldwide. NAFLD has also been implicated in other medical conditions such as insulin resistance, obesity, metabolic syndrome, hyperlipemia, hypertension, cardiovascular disease, and diabetes. Continuous hyperglycemia has been implicated in the pathogenesis of diabetic micro- and macro-vascular complications via various metabolic pathways, and numerous hyperglycemia-induced metabolic and hemodynamic conditions exist, including the increased generation of various types of advanced glycation end-products (AGEs). We recently demonstrated that glyceraldehyde-derived AGEs (Glycer-AGEs), the predominant components of toxic AGEs (TAGE), played an important role in the pathogenesis of angiopathy in diabetic patients. Moreover, a growing body of evidence suggests that the interaction between TAGE and the receptor for AGEs may alter intracellular signaling, gene expression, and the release of pro-inflammatory molecules and also elicits the generation of oxidative stress in numerous types of cells including hepatocytes and hepatic stellate cells. Serum levels of TAGE were significantly higher in NASH patients than in those with simple steatosis and healthy controls. Moreover, serum levels of TAGE inversely correlated with adiponectin (adiponectin is produced by adipose tissue and is an anti-inflammatory adipokine that can increase insulin sensitivity). Furthermore, immunohistochemical staining of TAGE showed intense staining in the livers of patients with NASH. Serum levels of TAGE may be a useful biomarker for discriminating NASH from simple steatosis. The administration of atorvastatin (10 mg daily) for 12 months significantly improved NASH-related metabolic parameters and significantly decreased serum levels of TAGE. The steatosis grade and NAFLD activity score were also significantly improved. These results demonstrated that atorvastatin decreased the serum levels of TAGE in NASH patients with dyslipidemia and suggest the usefulness of TAGE as a biomarker for the attenuation of NASH. Serum levels of TAGE were significantly higher in non-B or non-C hepatocellular carcinoma (NBNC-HCC) patients than in NASH subjects without HCC or control subjects. TAGE may be involved in the pathogenesis of NBNC-HCC, and could, therefore, be a biomarker that could discriminate NBNC-HCC from NASH. We propose that serum levels of TAGE are promising novel targets for the diagnosis of and therapeutic interventions against NASH.

Factors associated with significant liver fibrosis assessed using transient elastography in general population

AIM

To investigate the prevalence of significant liver fibrosis assessed using transient elastography (TE) and its predictors in asymptomatic general population.

METHODS

A total of 159 subjects without chronic viral hepatitis who underwent comprehensive medical health check-up between January 2012 and July 2012 were prospectively recruited. Significant liver fibrosis was defined as liver stiffness value>7.0 kPa.

RESULTS

The mean age and body mass index (BMI) of the study population (men 54.7%) was 56.0 years and 24.3 kg/m2. Among the study subjects, 11 (6.9%) showed significant liver fibrosis. On univariate analysis, BMI, alanine aminotransferase (ALT), homeostasis model assessment of insulin resistance, carotid intimal media thickness (IMT), number of calcified plaques on carotid ultrasound, and visceral fat area on computed tomography were significantly higher in subjects with significant liver fibrosis than in those without (all P<0.05). However, on multivariate analysis, BMI [odds ratio (OR)=.487; P=0.045], ALT (OR=1.078; P=0.014), carotid IMT (OR=3.244; P=0.027), and the number of calcified carotid plaques (OR=1.787; P=0.031) were independent predictors of significant liver fibrosis.

CONCLUSION

The prevalence of significant liver fibrosis assessed using TE was 6.9% in apparently healthy subjects. High BMI, high ALT, thicker carotid IMT, and higher numbers of calcified carotid plaques were independently associated with the presence of significant liver fibrosis.

Pediatric Non-Alcoholic Fatty Liver Disease

The rapidly increasing prevalence of childhood obesity and its associated co-morbidities such as hypertriglyceridemia, hyper-insulinemia, hypertension, early atherosclerosis, metabolic syndrome, and non-alcoholic fatty liver disease are major public health concerns in many countries. Therefore the trends in child and adolescent obesity should be closely monitored over time, as in the near future, we may anticipate a major increase of young adults with the stigmata of the metabolic syndrome, and of the related non-alcoholic fatty liver disease (NAFLD), that may lead to non-alcoholic steatohepatitis.

Involvement of the TAGE-RAGE system in non-alcoholic steatohepatitis: Novel treatment strategies

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease around the world. It includes a spectrum of conditions from simple steatosis to non-alcoholic steatohepatitis (NASH) and can lead to fibrosis, cirrhosis, liver failure, and/or hepatocellular carcinoma. NAFLD is also associated with other medical conditions such as obesity, diabetes mellitus (DM), metabolic syndrome, hypertension, insulin resistance, hyperlipidemia, and cardiovascular disease (CVD). In diabetes, chronic hyperglycemia contributes to the development of both macro- and microvascular conditions through a variety of metabolic pathways. Thus, it can cause a variety of metabolic and hemodynamic conditions, including upregulated advanced glycation end-products (AGEs) synthesis. In our previous study, the most abundant type of toxic AGEs (TAGE); i.e., glyceraldehyde-derived AGEs, were found to make a significant contribution to the pathogenesis of DM-induced angiopathy. Furthermore, accumulating evidence suggests that the binding of TAGE with their receptor (RAGE) induces oxidative damage, promotes inflammation, and causes changes in intracellular signaling and the expression levels of certain genes in various cell populations including hepatocytes and hepatic stellate cells. All of these effects could facilitate the pathogenesis of hypertension, cancer, diabetic vascular complications, CVD, dementia, and NASH. Thus, inhibiting TAGE synthesis, preventing TAGE from binding to RAGE, and downregulating RAGE expression and/or the expression of associated effector molecules all have potential as therapeutic strategies against NASH. Here, we examine the contributions of RAGE and TAGE to various conditions and novel treatments that target them in order to prevent the development and/or progression of NASH.

Involvement of the TAGE-RAGE system in non-alcoholic steatohepatitis: Novel treatment strategies

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease around the world. It includes a spectrum of conditions from simple steatosis to non-alcoholic steatohepatitis (NASH) and can lead to fibrosis, cirrhosis, liver failure, and/or hepatocellular carcinoma. NAFLD is also associated with other medical conditions such as obesity, diabetes mellitus (DM), metabolic syndrome, hypertension, insulin resistance, hyperlipidemia, and cardiovascular disease (CVD). In diabetes, chronic hyperglycemia contributes to the development of both macro- and microvascular conditions through a variety of metabolic pathways. Thus, it can cause a variety of metabolic and hemodynamic conditions, including upregulated advanced glycation end-products (AGEs) synthesis. In our previous study, the most abundant type of toxic AGEs (TAGE); i.e., glyceraldehyde-derived AGEs, were found to make a significant contribution to the pathogenesis of DM-induced angiopathy. Furthermore, accumulating evidence suggests that the binding of TAGE with their receptor (RAGE) induces oxidative damage, promotes inflammation, and causes changes in intracellular signaling and the expression levels of certain genes in various cell populations including hepatocytes and hepatic stellate cells. All of these effects could facilitate the pathogenesis of hypertension, cancer, diabetic vascular complications, CVD, dementia, and NASH. Thus, inhibiting TAGE synthesis, preventing TAGE from binding to RAGE, and downregulating RAGE expression and/or the expression of associated effector molecules all have potential as therapeutic strategies against NASH. Here, we examine the contributions of RAGE and TAGE to various conditions and novel treatments that target them in order to prevent the development and/or progression of NASH.

Non-invasive assessment of liver steatosis in non-alcoholic fatty liver disease

AIM

The diagnosis of non-alcoholic fatty liver disease (NAFLD) is based on the histological findings. Further, there may be interobserver differences. Liver to spleen (L/S) ratio on computed tomography (CT) is employed to detect or even quantify the fat content of the liver. The objective of this study was to accurately diagnose fatty liver by evaluating the relationship between L/S ratio and histological findings.

METHODS

Sixty-seven biopsy-proven NAFLD patients were enrolled. L/S ratio on CT was calculated. The area of steatosis in liver specimens was measured by BIOREVO BZ-9000 microscope, and the percentage of steatosis was calculated using Dynamic cell count BZ-H1C software.

RESULTS

Steatotic grade assessed by pathologist was significantly correlated with the percentage of steatosis and L/S ratio. Factors associated with steatosis were L/S ratio, aspartate aminotransferase and Homeostasis Model of Assessment - Insulin Resistance as determined by multivariate analysis. L/S ratios were: S0, 1.16 ± 0.20 (mean ± standard deviation); S1, 0.88 ± 0.28; S2, 0.76 ± 0.20; and S3, 0.40 ± 0.18, respectively. The optimal cut-off value of L/S ratio to exclude steatosis was 1.1, and the area under the receiver-operator curve for the diagnosis of steatosis was 0.886.

CONCLUSION

Our study suggests that while 0% of steatosis showed 1.296 L/S ratio, the cut-off value of L/S ratio would be 1.1 at least to exclude clinically important liver steatosis.

Apolipoprotein c3 gene polymorphisms are not a risk factor for developing non-alcoholic Fatty liver disease: a meta-analysis

CONTEXT

Our objective was to evaluate the effect of gene polymorphisms of apolipoprotein C3 (APOC3) on the development of non-alcoholic fatty liver disease (NAFLD) in different populations.

EVIDENCE ACQUISITION

We performed a meta-analysis of all relevant studies published in the literature. A total of 115 clinical trials or reports were identified, but only seven trials met our inclusion criteria. A meta-analysis was performed according to the Cochrane Reviewers' Handbook recommendations.

RESULTS

Five hospital-based and two population-based case-control studies were included in the final analysis. The overall frequency of APOC3 gene polymorphisms was 67.5% (1177/1745) in NAFLD and 68.8% (988/1437) in controls. The summary odds ratio for the association of gene polymorphisms of APOC3 and the risk of NAFLD was 1.03 (95% CI: 0.89-1.22),which was not statistically significant (P > 0.05).

CONCLUSIONS

Our meta-analysis, while not ruling out possible publication bias, showed no association between gene polymorphisms of APOC3 and the risk of NAFLD development in different populations in the world.

Long-term follow-up and liver-related death rate in patients with non-alcoholic and alcoholic related fatty liver disease

BACKGROUND

Few studies have compared the prognosis and liver-related mortality in patients with NAFLD (nonalcoholic fatty liver disease) and AFLD (alcoholic fatty liver disease). We aimed to investigate the etiology and liver-related mortality of patients with liver biopsy verified fatty liver disease in a population based setting.

METHODS

In this retrospective study, all patients who underwent a liver biopsy 1984-2009 at the National University Hospital of Iceland were identified through a computerized pathological database with the code for fatty liver. Only patients with NAFLD and AFLD were included and medical records reviewed. The patients were linked to the Hospital Discharge Register, the Causes of Death Registry and Centre for Addiction Medicine.

RESULTS

A total of 151 had NAFLD and 94 AFLD with median survival of 24 years and 20 years, respectively (p = NS). A total of 10/151 (7%) patients developed cirrhosis in the NAFLD group and 19/94 (20%) in AFLD group (p = 0.03). The most common cause of death in the NAFLD group was cardiovascular disease (48%). Liver disease was the most common cause of death in the AFLD group (36%), whereas liver-related death occurred in 7% of the NAFLD group. The mean liver-related death rate among the general population during the study period was 0.1% of all deaths. There was a significantly worse survival for patients in the AFLD group compared to the NAFLD group after adjusting for gender, calendar year of diagnosis and age at diagnosis (HR 2.16, p = 0.009). The survival for patients with moderate to severe fibrosis was significantly worse than for patients with mild fibrosis after adjusting for gender, calendar year of diagnosis and age at diagnosis (HR 2.09, p = 0.01).

CONCLUSIONS

Patients with fatty liver disease showed a markedly higher risk of developing liver-related death compared to the general population. The AFLD group had higher liver-related mortality and had a worse survival than the NAFLD group. Patients with more severe fibrosis at baseline showed a worse survival than patients with none or mild fibrosis at baseline.

Elevation of Serum Levels of Advanced Glycation End Products in Patients With Non-B or Non-C Hepatocellular Carcinoma

BACKGROUND

The prevalence of non-B or non-C hepatocellular carcinoma (NBNC-HCC) has been increasing all over the world. Advanced glycation end products (AGE) play a role in the pathogenesis of alcoholic liver injury or nonalcoholic steatohepatitis (NASH).

METHODS

We examined here whether serum levels of AGE were elevated in NBNC-HCC patients compared with NASH subjects without HCC and investigated which anthropometric and clinical variables were independent determinants of AGE.

RESULTS

Ninety NBNC-HCC, 56 NASH, and 27 control subjects underwent a complete history and physical examination, determination of blood chemistries, including AGE levels. Serum levels of AGE were significantly higher in NBNC-HCC patients compared with NASH and control subjects [9.1 ± 2.7, 5.2 ± 1.7, 3.5 ± 1.2 (U/ml), respectively, P < 0.05]. Univariate analysis showed that AGE levels were associated with male (P < 0.05), age (P < 0.01), aspartate aminotransferase (P < 0.05), γ-glutamyl transpeptidase (GGT) (P < 0.01), HDL-cholesterol (inversely, P < 0.01), fasting plasma glucose (P < 0.01), and HbA1c (P < 0.05). By the use of multiple stepwise regression analysis, age, GGT, and HDL-cholesterol (inversely) remained significant and were independently related to AGE levels (R(2) = 0.406).

CONCLUSION

The present results suggest that AGE might be involved in the pathogenesis of NBNC-HCC, thereby being a biomarker that could discriminate NBNC-HCC from NASH.

Increased risk of cirrhosis and hepatocellular cancer during long-term follow-up of patients with biopsy-proven NAFLD

OBJECTIVE

Our aims were to investigate the natural history of biopsy-proven non-alcoholic fatty liver disease (NAFLD) in Sweden, its associated complications, the clinical and biochemical factors associated with more advanced liver disease and the survival rate with a mean follow-up time of 27 years.

MATERIAL AND METHODS

All subjects participating in the population-based prospective cohort study Malmö Preventive Project (MPP) from 1974 to 1992 who had undergone liver biopsy with the diagnosis of NAFLD were included. The remaining MPP cohort was used as a control group. Subjects with other liver diseases and alcohol overconsumption were excluded. A panel of blood tests was analyzed in the MPP cohort. Follow-up of the NAFLD patients included studies of medical records, pathology records and mortality rates from the Swedish National Board of Health and Welfare's register until the end of 2011.

RESULTS

A total of 36 patients were diagnosed with biopsy-proven NAFLD. Median follow-up time was 27.0 years (6.32-35.3). Nine patients (25%) were diagnosed with cirrhosis and five (14%) with hepatocellular cancer, all with a previous diagnosis of cirrhosis. There were significant differences in liver function tests, insulin resistance (as homeostasis model assessment of insulin resistance) and body mass index (BMI) in patients with NAFLD compared with the control group. Mortality in the NAFLD group was significantly higher, 58.3% compared to 33.8% (p = 0.004). Hepatocellular cancer accounted for 23.8% of all deaths in the NAFLD group, compared to 0.7% (p = 0.000).

CONCLUSIONS

NAFLD can progress to advanced liver disease, including cirrhosis, with a higher than expected mortality and incidence of hepatocellular cancer.

Combination of alcohol and fructose exacerbates metabolic imbalance in terms of hepatic damage, dyslipidemia, and insulin resistance in rats

Although both alcohol and fructose are particularly steatogenic, their long-term effect in the development of a metabolic syndrome has not been studied in vivo. Consumption of fructose generally leads to obesity, whereas ethanol can induce liver damage in the absence of overweight. Here, Sprague-Dawley rats were fed ad libitum for 28 days on five diets: chow (control), liquid Lieber-DeCarli (LDC) diet, LDC +30%J of ethanol (L-Et) or fructose (L-Fr), and LDC combined with 30%J ethanol and 30%J fructose (L-EF). Body weight (BW) and liver weight (LW) were measured. Blood and liver samples were harvested and subjected to biochemical tests, histopathological examinations, and RT-PCR. Alcohol-containing diets substantially reduced the food intake and BW (≤3^rd week), whereas fructose-fed animals had higher LW than controls (P<0.05). Additionally, leukocytes, plasma AST and leptin levels were the highest in the fructose-administered rats. Compared to the chow and LDC diets, the L-EF diet significantly elevated blood glucose, insulin, and total-cholesterol levels (also vs. the L-Et group). The albumin and Quick-test levels were the lowest, whereas ALT activity was the highest in the L-EF group. Moreover, the L-EF diet aggravated plasma triglyceride and reduced HDL-cholesterol levels more than 2.7-fold compared to the sum of the effects of the L-Et and L-Fr diets. The decreased hepatic insulin clearance in the L-EF group vs. control and LDC groups was reflected by a significantly decreased C-peptide:insulin ratio. All diets except the control caused hepatosteatosis, as evidenced by Nile red and H&E staining. Hepatic transcription of insulin receptor substrate-1/2 was mainly suppressed by the L-Fr and L-EF diets. The L-EF diet did not enhance the mitochondrial β-oxidation of fatty acids (Cpt1α and Ppar-α expressions) compared to the L-Et or L-Fr diet. Together, our data provide evidence for the coaction of ethanol and fructose with a high-fat-diet on dyslipidemia and insulin resistance-accompanied liver damage.

Chronic ethanol consumption inhibits glucokinase transcriptional activity by Atf3 and triggers metabolic syndrome in vivo

Chronic ethanol consumption induces pancreatic β-cell dysfunction through glucokinase (Gck) nitration and down-regulation, leading to impaired glucose tolerance and insulin resistance, but the underlying mechanism remains largely unknown. Here, we demonstrate that Gck gene expression and promoter activity in pancreatic β-cells were suppressed by chronic ethanol exposure in vivo and in vitro, whereas expression of activating transcription factor 3 (Atf3) and its binding to the putative Atf/Creb site (from −287 to −158 bp) on the Gck promoter were up-regulated. Furthermore, in vitro ethanol-induced Atf3 inhibited the positive effect of Pdx-1 on Gck transcriptional regulation, enhanced recruitment of Hdac1/2 and histone H3 deacetylation, and subsequently augmented the interaction of Hdac1/Pdx-1 on the Gck promoter, which were diminished by Atf3 siRNA. In vivo Atf3-silencing reversed ethanol-mediated Gck down-regulation and β-cell dysfunction, followed by the amelioration of impaired glucose tolerance and insulin resistance. Together, we identified that ethanol-induced Atf3 fosters β-cell dysfunction via Gck down-regulation and that its loss ameliorates metabolic syndrome and could be a potential therapeutic target in treating type 2 diabetes. The Atf3 gene is associated with the induction of type 2 diabetes and alcohol consumption-induced metabolic impairment and thus may be the major negative regulator for glucose homeostasis.

Treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is now the commonest cause of chronic liver disease in developed countries. Treatment depends on the stage of disease, and non-invasive methods for risk stratification are urgently needed. Lifestyle modification (aimed at weight loss and increasing physical activity) and management of the features of metabolic syndrome are vital for all patients with NAFLD. Metformin is the first-line therapy for diabetic patients with NAFLD and also reduces the risk of hepatocellular carcinoma. Clinicians should have a low threshold for introducing a statin for the management of dyslipidaemia. Antihypertensive agents that target the renin-angiotensin system should be first-line in NAFLD for the management of hypertension. For patients with progressive disease, liver-directed pharmacotherapy with vitamin E should be considered. Non-alcoholic steatohepatitis cirrhosis is an increasingly common indication for liver transplantation.

Non-alcoholic fatty liver disease: a practical approach to diagnosis and staging

Non-alcoholic fatty liver disease (NAFLD) is now the commonest cause of abnormal liver function tests (LFTs) in the UK with approximately a third of the population being affected. The exact prevalence is not known, but population studies from the USA and China using magnetic resonance spectroscopy estimate that approximately 30% of the general population have steatosis. It is a spectrum of disease ranging from simple steatosis, to non-alcoholic steatohepatitis (NASH), through to advanced fibrosis and cirrhosis. The majority have simple steatosis, but approximately 10-30% develop NASH and the development of NASH cirrhosis is associated with a poor long-term prognosis. Patients with NASH have increased liver-related and cardiovascular mortality. Many patients with NAFLD remain undiagnosed, and recognising those at risk is the first step. Clinicians overly rely on abnormal liver enzymes to identify patients with NAFLD, so patients with significant liver disease can be overlooked, potentially missing opportunities for intervention. Although liver biopsy is the gold standard method for diagnosing and staging NAFLD, the majority of patients can be effectively diagnosed non-invasively with tests that are routinely available in the clinic today. This review discusses a pragmatic approach to diagnosis and staging of NAFLD so that patients at the highest risk of liver-related complications can be identified.

A 4-polymorphism risk score predicts steatohepatitis in children with nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in industrialized countries in adults and children, following the trail of the epidemic diffusion of obesity. Nonalcoholic steatohepatitis (NASH) is a potentially serious form of NAFLD linked with a significant increase in overall and liver-related morbidity and mortality. Because diagnosis still requires liver biopsy, there is urgent need of developing noninvasive early markers. The aim of the present study was to assess whether the simultaneous detection of genetic risk factors could predict NASH.

METHOD

We enrolled 152 untreated, consecutive obese children and adolescents with biopsy-proven NAFLD and increased liver enzymes. The PNPLA3 rs738409 C>G (I148 M), SOD2 rs4880 C>T, KLF6 rs3750861 G>A, and LPIN1 rs13412852 C>T polymorphisms were detected by Taqman assays.

RESULTS

A multivariate logistic model based on the genetic risk factors significantly predicted NASH (area under the receiver-operating characteristic curve [AUC] 0.75, 95% confidence interval [CI] 0.67-0.82, P < 0.0001), performing better than a clinical risk score identified at stepwise regression based on age, aspartate aminotransferase levels, and diastolic blood pressure (AUC 0.66, 95% CI 0.57-0.75). A single cutoff value of the genetic risk score had 90% sensitivity and 36% specificity for NASH. A risk score combining the clinical and genetic risk factors resulted in an AUC of 0.80 (95% CI 0.73-0.87).

CONCLUSIONS

A score based on genetic risk factors significantly predicts NASH in obese children with increased liver enzymes, representing a proof-of-principle that genetic scores may be useful to predict long-term outcomes of the disease and guide clinical management.

Ectopic fat, insulin resistance, and nonalcoholic fatty liver disease: implications for cardiovascular disease

Ectopic fat accumulation in the liver causes nonalcoholic fatty liver disease (NAFLD), which is the most common cause of chronic liver disease in Western countries. Ectopic liver lipid, particularly diacylglycerol, exacerbates hepatic insulin resistance, promotes systemic inflammation, and increases risk of developing both type 2 diabetes mellitus and cardiovascular disease. Increasing evidence suggests that NAFLD is an emerging risk factor for cardiovascular disease, and although there are currently no licensed treatments for NAFLD per se, current evidence suggests that statin treatment is safe in NAFLD. Presently, there is insufficient evidence to indicate that statins or other cardioprotective agents, such as angiotensin receptor blockers, are effective in treating NAFLD. In this brief narrative review, we discuss the diagnosis of NAFLD and the role of ectopic liver fat to cause insulin resistance and to increase risk of both type 2 diabetes mellitus and cardiovascular disease. For this review, PubMed was searched for articles using the key words non-alcoholic fatty liver disease or fatty liver combined with diabetes risk, cardiovascular risk, and cardiovascular mortality between 1990 and 2014. Articles published in languages other than English were excluded.

Efficacy of probucol for the treatment of non-alcoholic steatohepatitis with dyslipidemia: An open-label pilot study

AIM

Oxidative stress plays a pivotal role in the transition from simple steatosis to non-alcoholic steatohepatitis (NASH). Probucol is a lipid-lowering agent with strong antioxidant properties, and is reported to be effective for the treatment of NASH in several studies. The aim of the present study was to evaluate the efficacy of probucol for the treatment of NASH with dyslipidemia.

METHODS

Twenty-six patients with biopsy-proven NASH accompanied by dyslipidemia were treated with 500 mg of probucol daily for 48 weeks. Body mass index, visceral fat area, liver function tests, serum lipids, fibrosis markers, ferritin, adiponectin, leptin, urinary 8-hydroxy-2'-deoxyguanosine (U-8OHdG) and elasticity were measured periodically during the study. Follow-up liver biopsy was performed in 18 patients.

RESULTS

Serum levels of aminotransferases, total cholesterol and U-8OHdG significantly decreased (P < 0.01). Levels of hemoglobin A1c (HbA1c), the Homeostasis Model of Assessment - Insulin Resistance index and serum levels of ferritin, type IV collagen 7S and hyaluronic acid significantly decreased (P < 0.05). The serum levels of adiponectin tended to be increased. Liver stiffness significantly decreased from 8.8 ± 6.8 to 6.6 ± 4.0 kPa (P < 0.01). Non-alcoholic fatty liver disease activity scores were significantly improved from 4.2 ± 1.4 to 3.4 ± 1.6 (P < 0.05) and fibrotic stages tended to be improved from 1.6 ± 0.8 to 1.3 ± 1.1, respectively. No adverse effects of this treatment were noted.

CONCLUSION

Probucol improved clinical and histological findings probably through its ability to reduce insulin resistance and oxidative stress. Probucol therapy was safe and effective for Japanese NASH patients with dyslipidemia.

Fatty liver predicts the risk for cardiovascular events in middle-aged population: a population-based cohort study

OBJECTIVE

We investigated if the differences in liver fat content would predict the development of non-fatal and fatal atherosclerotic endpoints (coronary heart disease and stroke).

DESIGN, SETTING AND PARTICIPANTS

Our study group is a population-based, randomly recruited cohort (Oulu Project Elucidating Risk of Atherosclerosis, OPERA), initiated in 1991. The cohort consisted of 988 middle-aged Finnish participants.

INTERVENTION

Total mortality and hospital events were followed up to 2009 based on the registry of the National Institute for Health and Welfare and the National death registry.

MAIN OUTCOME MEASURE

The severity of hepatic steatosis was measured by ultrasound and divided into three groups (0-2). Cox regression analysis was used in the statistical analysis.

RESULTS

In the follow-up of years 1991-2009, 13.5% of the participants with non-fatty liver, 24.2% of participants having moderate liver fat content and 29.2% of the participants having severe fatty liver experienced a cardiovascular event during the follow-up time (p<0.001). Severe liver fat content predicted the risk for future risk of cardiovascular event even when adjusted for age, gender and study group (HR 1.92, CI 1.32 to 2.80, p<0.01). When further adjustments for smoking, alcohol consumption, low-density lipoprotein-cholesterol, body mass index and systolic blood pressure were conducted, the risk still remained statistically significant (HR 1.74, CI 1.16 to 2.63, p<0.01). Statistical significance disappeared with further adjustment for QUICKI.

CONCLUSIONS

Liver fat content increases the risk of future cardiovascular disease event in long-term follow-up but it is seems to be dependent on insulin sensitivity.

Extrahepatic complications of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease, and is strongly associated with the metabolic syndrome. In the last decade, it has become apparent that the clinical burden of NAFLD is not restricted to liver-related morbidity or mortality, and the majority of deaths in NAFLD patients are related to cardiovascular disease (CVD) and cancer. These findings have fuelled concerns that NAFLD may be a new, and added risk factor for extrahepatic diseases such as CVD, chronic kidney disease (CKD), colorectal cancer, endocrinopathies (including type 2 diabetes mellitus [T2DM] and thyroid dysfunction), and osteoporosis. In this review we critically appraise key studies on NAFLD-associated extrahepatic disease. There was marked heterogeneity between studies in study design (cross-sectional versus prospective; sample size; presence/absence of well-defined controls), population (ethnic diversity; community-based versus hospital-based cohorts), and method of NAFLD diagnosis (liver enzymes versus imaging versus biopsy). Taking this into account, the cumulative evidence to date suggests that individuals with NAFLD (specifically, nonalcoholic steatohepatitis) harbor an increased and independent risk of developing CVD, T2DM, CKD, and colorectal neoplasms. We propose future studies are necessary to better understand these risks, and suggest an example of a screening strategy.

Risk of cardiovascular, cardiac and arrhythmic complications in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a public health problem of epidemic proportions worldwide. Accumulating clinical and epidemiological evidence indicates that NAFLD is not only associated with liver-related morbidity and mortality but also with an increased risk of coronary heart disease (CHD), abnormalities of cardiac function and structure (e.g., left ventricular dysfunction and hypertrophy, and heart failure), valvular heart disease (e.g., aortic valve sclerosis) and arrhythmias (e.g., atrial fibrillation). Experimental evidence suggests that NAFLD itself, especially in its more severe forms, exacerbates systemic/hepatic insulin resistance, causes atherogenic dyslipidemia, and releases a variety of pro-inflammatory, pro-coagulant and pro-fibrogenic mediators that may play important roles in the pathophysiology of cardiac and arrhythmic complications. Collectively, these findings suggest that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions to decrease the risk for CHD and other cardiac/arrhythmic complications. The purpose of this clinical review is to summarize the rapidly expanding body of evidence that supports a strong association between NAFLD and cardiovascular, cardiac and arrhythmic complications, to briefly examine the putative biological mechanisms underlying this association, and to discuss some of the current treatment options that may influence both NAFLD and its related cardiac and arrhythmic complications.

Hepatic steatosis and steatohepatitis: Are they really two distinct entities?

Non-alcoholic fatty liver disease affects nearly 30% of Americans. A histopathological spectrum exists from simple steatosis to NASH which may progress to cirrhosis and HCC. NASH is currently the third most common indication for liver transplant with increasing incidence. Steatosis can be considered the hepatic manifestation of the metabolic syndrome as insulin resistance is a major risk factor for its development. While liver biopsy is the gold standard for diagnosis, non-invasive methods are currently being developed to appropriately determine who needs histologic evaluation. Management focuses on mitigation of risk factors, since targeted therapies to halt progression of fibrosis have not been validated. Simple steatosis does not affect overall survival, but NASH conveys increased mortality. Because of this, non-invasive strategies to diagnose patients and management algorithms are needed. This review supports the definitions of simple steatosis and NASH as two distinct entities based on pathophysiology, diagnosis, management, and prognosis.

The Role of Non-alcoholic Fatty Liver Disease in Cardiovascular Disease

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease in western countries and is closely related to the metabolic syndrome. When NAFLD is associated with hepatocellular damage and inflammation (non-alcoholic steatohepatitis [NASH]) it can lead to severe liver disease. However, it has become clear that NAFLD is also associated with an increased risk of cardiovascular disease (CVD), independently of classical known risk factors for the latter. In the current review we briefly summarise the current clinical evidence on the role of NAFLD in CVD and discuss the potential mechanisms by which NAFLD can be linked to the pathophysiology of CVD.

Hard clinical outcomes in patients with NAFLD

Non-alcoholic fatty liver disease (NAFLD), once regarded as an innocuous condition, is now considered to be the most common cause of chronic liver disease worldwide. Evidence suggests a strong association between NAFLD and other potentially life-threatening diseases. A significant proportion of these patients develops progressive liver injury leading to cirrhosis and hepatocellular carcinoma. Unrecognized NAFLD constitutes a substantial proportion of patients with cryptogenic cirrhosis. Several large community-based studies have found increased mortality in NAFLD patients compared to the expected mortality of the general population of the same age and sex. Cardiovascular disease is an important cause of morbidity and mortality in patients with NAFLD and accounts for up to 30 % of overall death. Cardiovascular mortality does not seem to differ between simple steatosis and non-alcoholic steatohepatitis. NAFLD is associated with increased risk of both hepatic and extra-hepatic malignancy. Malignancy is among the most important causes of death in NAFLD patients. NAFLD is a risk factor for liver cancer even without cirrhosis. The steatotic liver has poor ability to regenerate after volume loss, which may lead to the development of liver failure and increased mortality after extended liver resection. Also, transplantation of steatotic liver results in an increased rate of poor graft function, primary graft non-function, and poorer outcome. There is a high recurrence rate of fatty liver disease in patients transplanted for NASH.

Drug-induced steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease in the United States. The term NALFD was first used by Ludwig in 1980 to describe the presence of hepatic steatosis and steatohepatitis in a series of patients with no identifiable cause. Since then, our insight into the pathogenesis of NAFLD has expanded significantly. We now know that NAFLD is closely related to metabolic syndrome and chronic low-grade inflammation. In the following review, the authors summarize the current evidence about drugs that lead to hepatic steatosis and steatohepatitis and pathogenic mechanisms thereof.

Diet-induced mouse model of fatty liver disease and nonalcoholic steatohepatitis reflecting clinical disease progression and methods of assessment

Shortcomings of previously reported preclinical models of nonalcoholic steatohepatitis (NASH) include inadequate methods used to induce disease and assess liver pathology. We have developed a dietary model of NASH displaying features observed clinically and methods for objectively assessing disease progression. Mice fed a diet containing 40% fat (of which ∼18% was trans fat), 22% fructose, and 2% cholesterol developed three stages of nonalcoholic fatty liver disease (steatosis, steatohepatitis with fibrosis, and cirrhosis) as assessed by histological and biochemical methods. Using digital pathology to reconstruct the left lateral and right medial lobes of the liver, we made comparisons between and within lobes to determine the uniformity of collagen deposition, which in turn informed experimental sampling methods for histological, biochemical, and gene expression analyses. Gene expression analyses conducted with animals stratified by disease severity led to the identification of several genes for which expression highly correlated with the histological assessment of fibrosis. Importantly, we have established a biopsy method allowing assessment of disease progression. Mice subjected to liver biopsy recovered well from the procedure compared with sham-operated controls with no apparent effect on liver function. Tissue obtained by biopsy was sufficient for gene and protein expression analyses, providing the opportunity to establish an objective method of assessing liver pathology before subjecting animals to treatment. The improved assessment techniques and the observation that mice fed the high-fat diet exhibit many clinically relevant characteristics of NASH establish a preclinical model for identifying pharmacological interventions with greater likelihood of translating to the clinic.

A systematic review of follow-up biopsies reveals disease progression in patients with non-alcoholic fatty liver

BACKGROUND & AIMS

Disease progression in non-alcoholic fatty liver disease (NAFLD) is not well understood and there is controversy about whether non-alcoholic fatty liver (NAFL, i.e., steatosis alone or with mild inflammation not qualifying for steatohepatitis) can evolve towards steatohepatitis (NASH) with fibrosis.

METHODS

We reviewed 70 patients with untreated NAFLD and with two biopsies performed more than one year apart. Clinical and biological data were recorded at the time of both biopsies. Alcohol consumption did not change during follow-up.

RESULTS

Initially 25 patients had NAFL and 45 had NASH and/or advanced fibrosis. After a mean follow-up of 3.7 years (s.d. 2.1), 16 NAFL patients developed NASH, eight with severe ballooning and six with bridging fibrosis on the follow-up biopsy. Patients with mild lobular inflammation or any degree of fibrosis were at higher risk of progression than those with steatosis alone. Those with unambiguous disease progression were older and had worsening of their metabolic risk factors (higher weight and more diabetes at baseline and during follow-up). In the whole cohort, ballooning progression and bridging fibrosis often occurred together and co-existed with a reduction in ALT, higher weight gain, and a higher incidence of diabetes during follow-up.

CONCLUSIONS

A substantial proportion of patients with NAFL can progress towards well-defined NASH with bridging fibrosis, especially if metabolic risk factors deteriorate. Even mild inflammation or fibrosis could substantially increase the risk of progression when compared to steatosis alone. Current monitoring practices of these patients should be revised.

Differences in innate immune signaling between alcoholic and non-alcoholic steatohepatitis

The similar histopathological characteristics of alcoholic steatohepatitis (ASH) and non-alcoholic steatohepatitis (NASH), and the crucial role of the innate immune response in both conditions may lead to the assumption that ASH and NASH represent the same pathophysiological entities caused by different risk factors. In this review paper, we elaborate on the pathophysiological differences between these two entities and highlight the disease-specific involvement of signaling molecules downstream of the Toll-like receptor 4, and the differential mechanism by which the inflammasome contributes to ASH versus NASH. Our findings emphasize that ASH and NASH have disease-specific mechanisms and therefore represent distinct biological entities. Further studies are needed to dissect the emerging differences in pathogenesis of these two conditions.

Improved hepatic lipid composition following short-term exercise in nonalcoholic fatty liver disease

CONTEXT

Hepatic steatosis, insulin resistance, inflammation, low levels of polyunsaturated lipids, and adiponectin are implicated in the development and progression of nonalcoholic fatty liver disease (NAFLD).

OBJECTIVE

We examined the effects of short-term aerobic exercise on these metabolic risk factors.

DESIGN AND PARTICIPANTS

Obese individuals (N = 17, 34.3 ± 1.0 kg/m²) with clinically confirmed NAFLD were enrolled in a short-term aerobic exercise program that consisted of 7 consecutive days of treadmill walking at ~85% of maximal heart rate for 60 minutes per day. Preintervention and postintervention measures included hepatic triglyceride content, and a lipid saturation index and polyunsaturated lipid index (PUI) of the liver, obtained by (1)H magnetic resonance spectroscopy (N = 14). Insulin sensitivity was estimated from an oral glucose tolerance test (OGTT), and mononuclear cells were isolated to assess reactive oxygen species production during the OGTT. Circulating glucose, insulin, and high molecular weight (HMW) adiponectin were determined from plasma.

MAIN OUTCOME

Short-term aerobic exercise training improved hepatic lipid composition in patients with NAFLD.

RESULTS

Exercise training resulted in an increase in liver PUI (P < .05), increased insulin sensitivity (Matsuda Index: P < .05), HMW adiponectin (P < .05), and maximal oxygen consumption (P < .05). Reactive oxygen species production during the OGTT was reduced following exercise training (P < .05). HMW adiponectin was increased after the exercise program and the increase was positively correlated with the increase in liver PUI (r = 0.52, P = .05). Body weight remained stable during the program (P > .05).

CONCLUSION

Short-term exercise can target hepatic lipid composition, which may reduce the risk of NAFLD progression. The improvement in hepatic lipid composition may be driven by adiponectin.

Progression of NAFLD to diabetes mellitus, cardiovascular disease or cirrhosis

NAFLD is a spectrum of progressive liver disease that encompasses simple steatosis, NASH, fibrosis and, ultimately, cirrhosis. NAFLD is recognized as the hepatic component of the metabolic syndrome, as these conditions have insulin resistance as a common pathophysiological mechanism. Therefore, NAFLD is strongly associated with type 2 diabetes mellitus and abdominal obesity. As lifestyles have become increasingly sedentary and dietary patterns have changed, the worldwide prevalence of NAFLD has increased dramatically and is projected to be the principal aetiology for liver transplantation within the next decade. Importantly, a growing body of clinical and epidemiological evidence suggests that NAFLD is associated not only with liver-related morbidity and mortality, but also with an increased risk of developing both cardiovascular disease and type 2 diabetes mellitus. This article reviews the evidence that suggests NAFLD is a multisystem disease and the factors that might determine interindividual variation in the development and progression of its major hepatic and extrahepatic manifestations (principally type 2 diabetes mellitus and cardiovascular disease).

Nonalcoholic Steatohepatitis: Diagnostic Challenges

This article reviews diagnostic criteria for nonalcoholic steatohepatitis (NASH), current grading and staging methodology, and diagnostic challenges and pitfalls in routine practice. Current practice guidelines and prognostic and treatment considerations are discussed. The clinical diagnosis of nonalcoholic fatty liver disease may represent stable disease without progressive liver damage, in the form of nonalcoholic fatty liver (NAFL), or aggressive disease that will progress to advanced fibrosis, in the form of NASH. NASH is diagnosed from a liver biopsy after assessment by a pathologist to distinguish NASH from NAFL (and other histologic mimics of NASH); this distinction is critical for patient management.

Estimation of diagnosis and treatment costs of non-alcoholic Fatty liver disease: a two-year observation

BACKGROUND

There are insufficient data available on utilization and health care costs of non-alcoholic fatty liver disease. The cost data for different health conditions and services is a major gap in Iranian health system. So this study is the primary or first step towards filling this gap.

OBJECTIVES

This study aims to estimate the diagnosis and treatment costs of Non-alcoholic Fatty Liver.

PATIENTS AND METHODS

This cross-sectional study was conducted on 528 subjects. The subjects had been diagnosed with non-alcoholic fatty liver. All the subjects had been referred to the Tehran Fatty Liver Clinic, a clinic of the Baqiyatallah Research Center for Gastroenterology and Liver Diseases, in 2009 and they had been observed for 2 years to determine the frequency of health care utilization (physician visit, laboratory tests, medication and cost of sonography). The costs of diagnosis and treatment for each person were estimated in Purchasing Power Parity dollars (PPP$).

RESULTS

The average total cost was 5,043 PPP$ per person in the 2 years of observation. Majority of these 528 patients (87.9%) had a BMI ≥ 25 (kg/m2). Also, 33.9% were diagnosed with comorbid diseases such as Diabetes Mellitus (DM), Coronary Artery Disease (CAD), hypertension (HTN) and hypothyroidism (HYPO).

CONCLUSIONS

The results confirmed that the total costs for non-alcoholic fatty liver among the Iranian adult urban population alone exceeded 1 billion PPP$ per year. These costs can be saved or reduced by effective disease management and early prevention.

The communication of a secondary care diagnosis of autoimmune hepatitis to primary care practitioners: a population-based study

Background

Autoimmune Hepatitis is a chronic liver disease which affects young people and can result in liver failure leading to death or transplantation yet there is a lack of information on the incidence and prevalence of this disease and its natural history in the UK. A means of obtaining this information is via the use of clinical databases formed of electronic primary care records. How reliably the diagnosis is coded in such records is however unknown. The aim of this study therefore was to assess the proportion of consultant hepatologist diagnoses of Autoimmune Hepatitis which were accurately recorded in General Practice computerised records.

Methods

Our study population were patients with Autoimmune Hepatitis diagnosed by consultant hepatologists in the Queens Medical Centre, Nottingham University Hospitals (UK) between 2004 and 2009. We wrote to the general practitioners of these patients to obtain the percentage of patients who had a valid READ code specific for Autoimmune Hepatitis.

Results

We examined the electronic records of 51 patients who had biopsy evidence and a possible diagnosis of Autoimmune Hepatitis. Forty two of these patients had a confirmed clinical diagnosis of Autoimmune Hepatitis by a consultant hepatologist: we contacted the General Practitioners of these patients obtaining a response rate of 90.5% (39/42 GPs). 37/39 of these GPs responded with coding information and 89% of these patients (33/37) used Read code J638.00 (Autoimmune Hepatitis) to record a diagnosis.

Conclusions

The diagnosis of Autoimmune Hepatitis made by a Consultant Hepatologist is accurately communicated to and electronically recorded by primary care in the UK. As a large proportion of cases of Autoimmune Hepatitis are recorded in primary care, this minimises the risk of introducing selection bias and therefore selecting cases using these data will be a valid method of conducting population based studies on Autoimmune Hepatitis.

Association between noninvasive fibrosis markers and mortality among adults with nonalcoholic fatty liver disease in the United States

The clinical and public health significance of nonalcoholic fatty liver disease (NAFLD) is not well established. We investigated the long-term effect of NAFLD on mortality. This analysis utilized the National Health and Nutrition Examination Survey conducted in 1988-1994 and subsequent follow-up data for mortality through December 31, 2006. NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other known liver diseases. The presence and severity of hepatic fibrosis in subjects with NAFLD was determined by the NAFLD fibrosis score (NFS), the aspartate aminotransferase to platelet ratio index (APRI), and FIB-4 score. Of 11,154 participants, 34.0% had NAFLD--the majority (71.7%) had NFS consistent with lack of significant fibrosis (NFS <-1.455), whereas 3.2% had a score indicative of advanced fibrosis (NFS >0.676). After a median follow-up of 14.5 years, NAFLD was not associated with higher mortality (age- and sex-adjusted hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 0.93-1.19). In contrast, there was a progressive increase in mortality with advancing fibrosis scores. Compared to subjects without fibrosis, those with a high probability of advanced fibrosis had a 69% increase in mortality (for NFS: HR, 1.69, 95% CI: 1.09-2.63; for APRI: HR, 1.85, 95% CI: 1.02-3.37; for FIB-4: HR, 1.66, 95% CI: 0.98-2.82) after adjustment for other known predictors of mortality. These increases in mortality were almost entirely from cardiovascular causes (for NFS: HR, 3.46, 95% CI: 1.91-6.25; for APRI: HR, 2.53, 95% CI: 1.33-4.83; for FIB-4: HR, 2.68, 95% CI: 1.44-4.99).

CONCLUSIONS

Ultrasonography-diagnosed NAFLD is not associated with increased mortality. However, advanced fibrosis, as determined by noninvasive fibrosis marker panels, is a significant predictor of mortality, mainly from cardiovascular causes, independent of other known factors.

Heterogeneity of fibrosis patterns in non-alcoholic fatty liver disease supports the presence of multiple fibrogenic pathways

BACKGROUND

Adult non-alcoholic fatty liver disease (NAFLD) involves lobular necroinflammatory activity and fibrosis is typically centrilobular, whereas paediatric NAFLD has predominantly portal fibrosis. The reasons for these differences are unclear. We aimed to determine (a) how centrilobular and portal fibrosis in children relate to histological parameters; and (b) whether atypical fibrosis patterns exist in adults that are unexplained by current fibrogenesis models.

METHODS

Histological features of paediatric (n = 38) and adult (n = 56) NAFLD were assessed using conventional scoring systems. Keratin-7 immunostaining was used to assess hepatic progenitor cell numbers and the ductular reaction. Centrilobular and portal components of fibrosis were independently scored and fibrosis patterns were classified according to accepted types. Post-treatment (rosiglitazone/gastric banding) biopsies were also examined in adults.

RESULTS

Twenty-six children (68.4%) had portal-predominant fibrosis, although the typical "adult" pattern was seen in 11 (28.9%). Portal fibrosis was associated with a ductular reaction (P = 0.021) and hepatic progenitor cell expansion (P < 0.001), whereas centrilobular fibrosis was associated with lobular inflammation (P = 0.026) and ballooning (P = 0.001). Before intervention, six adults (10.7%) had atypical fibrosis including 3 (5.4%) with a previously unrecognized pattern of very fine, non-zonal sinusoidal fibrosis. Despite improvements in steatosis and inflammation, more patients developed this unusual pattern after intervention with most having had surgery (9 of 10 adults; P < 0.001).

CONCLUSION

Differing associations with portal and centrilobular fibrosis in children and atypical fibrosis patterns in adults suggest that multiple fibrogenic pathways exist in NAFLD. This has implications for therapy and understanding pathogenesis.

Alterations in adipocytokines and cGMP homeostasis in morbid obesity patients reverse after bariatric surgery

OBJECTIVE

Obesity-associated nonalcoholic fatty liver disease (NAFLD), covering from simple steatosis to nonalcoholic steatohepatitis (NASH), is a common cause of chronic liver disease. Aberrant production of adipocytokines seems to play a main role in most obesity-associated disorders. Changes in adipocytokines in obesity could be mediated by alterations in cyclic GMP (cGMP) homeostasis. The aims of this work were: (1) to study the role of altered cGMP homeostasis in altered adipocytokines in morbid obesity, (2) to assess whether these alterations are different in simple steatosis or NASH, and (3) to assess whether these changes reverse in obese patients after bariatric surgery.

DESIGN AND METHODS

In 47 patients with morbid obesity and 45 control subjects, the levels in blood of adipocytokines, cGMP, nitric oxide (NO) metabolites, and atrial natriuretic peptide (ANP) were studied. Whether weight loss after a bariatric surgery reverses the changes in these parameters was evaluated.

RESULTS

NO metabolites and leptin increase (and adiponectin decreases) similarly in patients with steatosis or NASH, suggesting that these changes are due to morbid obesity and not to liver disease. Inflammation and cGMP homeostasis are affected both by morbid obesity and by liver disease. The increases in interleukin 6 (IL-6), interleukin 18 (IL-18), plasma cGMP, ANP, and the decrease in cGMP in lymphocytes are stronger in patients with NASH than with steatosis. All these changes reverse completely after bariatric surgery and weight loss, except IL-18.

CONCLUSION

Altered cGMP homeostasis seems to contribute more than inflammation to changes in leptin and adiponectin in morbid obesity.

Nonalcoholic fatty liver disease: an emerging threat to obese and diabetic individuals

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the Western world and its incidence is increasing rapidly. NAFLD is a spectrum ranging from simple steatosis, which is relatively benign hepatically, to nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis. Obesity, insulin resistance, type 2 diabetes mellitus, and dyslipidemia are the most important risk factors for NAFLD. Due to heavy enrichment with metabolic risk factors, individuals with NAFLD are at significantly higher risk for cardiovascular disease. Individuals with NAFLD have higher incidence of type 2 diabetes. The diagnosis of NAFLD requires imaging evidence of hepatic steatosis in the absence of competing etiologies including significant alcohol consumption. Liver biopsy remains the gold standard for diagnosing NASH and for determining prognosis. Weight loss remains a cornerstone of treatment. Weight loss of ∼5% is believed to improve steatosis, whereas ∼10% weight loss is necessary to improve steatohepatitis. A number of pharmacologic therapies have been investigated to treat NASH, and agents such as vitamin E and thiazolidinediones have shown promise in select patient subgroups.

Nonalcoholic fatty liver disease and the metabolic syndrome: clinical implications and treatment

The prevalence of nonalcoholic fatty liver disease (NAFLD) is expected to rise along with the global obesity epidemic. As NAFLD is the most common cause of chronic liver disease in the United States, it has become a major health concern. It affects all ethnicities, with the highest prevalence among the Hispanic population. Individuals with nonalcoholic steatohepatitis (NASH), the more serious form of NAFLD, are at increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Since NAFLD is intricately associated with the metabolic syndrome and insulin resistance, increased risk of cardiovascular disease and mortality become a real concern. It has recently been shown that current nutrition trends, such as increased consumption of high-fructose corn syrup and certain types of fats, may have an important role in the increased NAFLD prevalence. As there are no ideal treatment options available for NAFLD, a multifaceted treatment approach should be tailored to each individual patient.