Effect of vitamin E or metformin for treatment of nonalcoholic fatty liver disease in children and adolescents: the TONIC randomized controlled trial

Role of the diet as a link between oxidative stress and liver diseases

Oxidative stress is caused by an imbalance between the production of reactive oxygen (free radicals) and the body's ability (antioxidant capacity) to readily detoxify the reactive intermediates or easily repair the resulting damage. An adequate diet, characterized by daily intake of foods associated with improvements in the total antioxidant capacity of individuals and reduced incidence of diseases related to oxidation, can modulate the degree of oxidative stress. In fact, diet-derived micronutrients may be direct antioxidants, or are components of antioxidant enzymes, leading to improvement of some indicators of hepatic function. However, although their increased dietary intake might be beneficial, literature data are still controversial. This review summarizes what is known about the effects of diet nutrients on oxidative stress, inflammation and liver function. Moreover, we have analyzed: (1) the main nutritional components involved in the production and/or removal of free radicals; and (2) the role of free radicals in the pathogenesis of several hepatic diseases and related comorbidities.

A concise review of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and the incidence of which is rising rapidly due to the increasing epidemic of obesity in both adults and children. The initial accumulation of fat followed by subsequent inflammation is central to the development of liver damage, and is critically influenced by host factors including age, gender, presence of diabetes, genetic polymorphisms and more recently by the gut microbiome. An increasing body of data suggest that NAFLD is also an independent risk factor of cardiovascular disease, which remains the commonest cause of mortality in such patients. This review focusses on the pathogenesis of NAFLD, and the evolution of new approaches to the management and treatment of NAFLD.

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND

Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established.

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease.

DATA SOURCES

We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists.

METHODS

We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted.

RESULTS

Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822.

LIMITATIONS

A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments.

CONCLUSIONS

Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Vitamin E has a beneficial effect on nonalcoholic fatty liver disease: a meta-analysis of randomized controlled trials

OBJECTIVES

Vitamin E is often used in the treatment of nonalcoholic fatty liver disease (NAFLD), including nonalcoholic steatohepatitis (NASH); however, the magnitude of treatment response associated with vitamin E in improving liver function and histology in NAFLD/NASH has not, to our knowledge, been quantified systematically. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs) using vitamin E in the treatment of NAFLD/NASH.

METHODS

PubMed, Medline, and Cochrane Library Full Text Database, and Japan Medical-Literature Database (Igaku Chuo Zasshi) were searched until March 2014, and five RCTs were identified for meta-analysis.

RESULTS

According to a random effect model analysis of the five studies, vitamin E significantly reduced aspartate transaminase (AST) by -19.43 U/L, alanine aminotransferase (ALT) by -28.91 U/L, alkaline phosphatase (ALP) by -10.39 U/L, steatosis by -0.54 U/L, inflammation by -0.20 U/L, and hepatocellular ballooning by -0.34 U/L compared with the control group. Vitamin E treatment with NASH adult patients showed obvious reductions in not only AST of -13.91 U/L, ALT by -22.44 U/L, steatosis of -0.67 U/L, inflammation of -0.20 U/L, but also fibrosis of -0.30 U/L compared to the control treatment.

CONCLUSIONS

Vitamin E significantly improved liver function and histologic changes in patients with NAFLD/NASH.

Nonalcoholic steatohepatitis and insulin resistance in children

Various pathological conditions can cause fatty liver in children. Nonalcoholic steatohepatitis (NASH) in children has been known since 1983. However, NASH diagnosed in childhood does not have a favorable outcome. The pathological characteristics of NASH are significantly different between children and adults. Nonalcoholic fatty liver disease (NAFLD)/NASH is accompanied by insulin resistance, which plays a pivotal role in its pathophysiology in both children and adults. In NASH, a “two-hit” model involving triglyceride accumulation (first hit) and liver damage (second hit) has been accepted. Insulin resistance was found to correlate with changes in fat levels; however, it did not correlate with fibrosis or NAFLD activity score in children. Therefore, insulin resistance may be important in the first hit. Because there is obvious familial clustering in NASH, genetic predisposition as well as environmental factors including diet might be the second hit of NAFLD/NASH.

Possible role of tocopherols in the modulation of host microRNA with potential antiviral activity in patients with hepatitis B virus-related persistent infection: a systematic review

Hepatitis B virus (HBV) infection represents a serious global health problem and persistent HBV infection is associated with an increased risk of cirrhosis, hepatocellular carcinoma and liver failure. Recently, the study of the role of microRNA (miRNA) in the pathogenesis of HBV has gained considerable interest as well as new treatments against this pathogen have been approved. A few studies have investigated the antiviral activity of vitamin E (VE) in chronic HBV carriers. Herein, we review the possible role of tocopherols in the modulation of host miRNA with potential anti-HBV activity. A systematic research of the scientific literature was performed by searching the MEDLINE, Cochrane Library and EMBASE databases. The keywords used were 'HBV therapy', 'HBV treatment', 'VE antiviral effects', 'tocopherol antiviral activity', 'miRNA antiviral activity' and 'VE microRNA'. Reports describing the role of miRNA in the regulation of HBV life cycle, in vitro and in vivo available studies reporting the effects of VE on miRNA expression profiles and epigenetic networks, and clinical trials reporting the use of VE in patients with HBV-related chronic hepatitis were identified and examined. Based on the clinical results obtained in VE-treated chronic HBV carriers, we provide a reliable hypothesis for the possible role of this vitamin in the modulation of host miRNA profiles perturbed by this viral pathogen and in the regulation of some cellular miRNA with a suggested potential anti-HBV activity. This approach may contribute to the improvement of our understanding of pathogenetic mechanisms involved in HBV infection and increase the possibility of its management and treatment.

Relationship between changes in serum levels of keratin 18 and changes in liver histology in children and adults with nonalcoholic fatty liver disease

BACKGROUND & AIMS

Cross-sectional studies have associated serum levels of the keratin 18 (K18) fragment with histologic features of liver in individuals with nonalcoholic fatty liver disease (NAFLD). We investigated the relationship between changes in serum levels of K18 and changes in liver histology in adults and children with NAFLD.

METHODS

We measured levels of K18 in stored serum samples collected at baseline and various time points from 231 adults with nonalcoholic steatohepatitis and 152 children with NAFLD who participated in 2 separate prospective randomized clinical trials. Liver biopsy specimens collected at baseline and week 96 were reviewed centrally.

RESULTS

There were greater decreases in serum levels of K18 in adults with histologic improvement at week 96 than in those without histologic improvement at week 16 (decrease, 193 ± 293 vs 139 ± 467 U/L; P < .001), week 48 (decrease, 232 ± 360 vs 113 ± 425 U/L; P < .001), or week 96 (decrease, 269 ± 368 vs 97 ± 400 U/L; P < .001). There were greater decreases in serum levels of K18 in children with histologic improvements than in those without histologic improvements at week 48 (decrease, 197 ± 467 vs 47 ± 350 U/L; P = .005) and week 96 (decrease, 206 ± 432 vs 2 ± 474 U/L; P < .001). However, reductions in serum levels of K18 were not better than reductions in levels of alanine aminotransferase in identifying adults with histologic improvement (area under the receiver operator characteristic [AUROC], 0.71; 95% confidence interval [CI], 0.63-0.80; vs AUROC, 0.68; 95% CI, 0.61-0.79; P = .34) or children (AUROC, 0.72; 95% CI, 0.63-0.81; vs AUROC, 0.79; 95% CI, 0.70-0.87; P = .42).

CONCLUSIONS

Decreases in serum levels of K18 are associated strongly with improved liver histologies in adults or children with NAFLD. However, reductions in K18 do not perform better than those in alanine aminotransferase level in identifying histologic changes in NAFLD.

Longitudinal assessment of high blood pressure in children with nonalcoholic fatty liver disease

Objective

Nonalcoholic fatty liver disease (NAFLD) affects 9.6% of children and may put these children at elevated risk of high blood pressure and subsequent cardiovascular morbidity and mortality. Therefore, we sought to determine the prevalence of and risk factors for high blood pressure in children with NAFLD.

Methods

Cohort study performed by the NIDDK NASH Clinical Research Network. There were 484 children with NAFLD ages 2 to 17 at enrollment; 382 children were assessed both at enrollment and 48 weeks afterwards. The main outcomes were high blood pressure at baseline and persistent high blood pressure at both baseline and 48 weeks.

Results

Prevalence of high blood pressure at baseline was 35.8% and prevalence of persistent high blood pressure was 21.4%. Children with high blood pressure were significantly more likely to have worse steatosis than children without high blood pressure (mild 19.8% vs. 34.2%, moderate 35.0% vs. 30.7%, severe 45.2% vs. 35.1%; P = 0.003). Higher body mass index, low-density lipoprotein, and uric acid were independent risk factors for high blood pressure (Odds Ratios: 1.10 per kg/m², 1.09 per 10 mg/dL, 1.25 per mg/dL, respectively). Compared to boys, girls with NAFLD were significantly more likely to have persistent high blood pressure (28.4% vs.18.9%; P = 0.05).

Conclusions

In conclusion, NAFLD is a common clinical problem that places children at substantial risk for high blood pressure, which may often go undiagnosed. Thus blood pressure evaluation, control, and monitoring should be an integral component of the clinical management of children with NAFLD.

Gut-liver axis and probiotics: Their role in non-alcoholic fatty liver disease

The incidence of obesity and its related conditions, including non-alcoholic fatty liver disease (NAFLD), has dramatically increased in all age groups worldwide. Given the health consequences of these conditions, and the subsequent economic burden on healthcare systems, their prevention and treatment have become major priorities. Because standard dietary and lifestyle changes and pathogenically-oriented therapies (e.g., antioxidants, oral hypoglycemic agents, and lipid-lowering agents) often fail due to poor compliance and/or lack of efficacy, novel approaches directed toward other pathomechanisms are needed. Here we present several lines of evidence indicating that, by increasing energy extraction in some dysbiosis conditions or small intestinal bacterial overgrowth, specific gut microbiota and/or a “low bacterial richness” may play a role in obesity, metabolic syndrome, and fatty liver. Under conditions involving a damaged intestinal barrier (“leaky gut”), the gut-liver axis may enhance the natural interactions between intestinal bacteria/bacterial products and hepatic receptors (e.g., toll-like receptors), thus promoting the following cascade of events: oxidative stress, insulin-resistance, hepatic inflammation, and fibrosis. We also discuss the possible modulation of gut microbiota by probiotics, as attempted in NAFLD animal model studies and in several pilot pediatric and adult human studies. Globally, this approach appears to be a promising and innovative add-on therapeutic tool for NAFLD in the context of multi-target therapy.

A non-invasive prediction model for non-alcoholic steatohepatitis in paediatric patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease encompasses a spectrum of diseases that range from simple steatosis to the aggressive form of non-alcoholic steatohepatitis. Non-alcoholic steatohepatitis is currently diagnosed through liver biopsy.

AIM

To develop a non-invasive predictive model of non-alcoholic steatohepatitis in children with non-alcoholic fatty liver disease.

METHODS

Anthropometric, laboratory, and histologic data were obtained in a cohort of children with biopsy-proven non-alcoholic fatty liver disease. Multivariable logistic regression analysis was employed to create a nomogram predicting the risk of non-alcoholic steatohepatitis. Internal validation was performed by bootstrapping.

RESULTS

Three hundred and two children were included in this analysis with a mean age of 12.3 ± 3.1 years, a mean body mass index percentile of 94.3 ± 6.9, and non-alcoholic steatohepatitis was present in 67%. Following stepwise variable selection, total cholesterol, waist circumference percentile, and total bilirubin were included as variables in the model, with good discrimination with an area under the receiver operating characteristic curve of 0.737.

CONCLUSIONS

A nomogram was constructed with reasonable accuracy that can predict the risk of non-alcoholic steatohepatitis in children with non-alcoholic fatty liver disease. If validated externally, this tool could be utilized as a non-invasive method to diagnose non-alcoholic steatohepatitis in children with non-alcoholic fatty liver disease.

Review article: the management of paediatric nonalcoholic fatty liver disease

BACKGROUND

Paediatric nonalcoholic fatty liver disease (NAFLD) is a major public health concern given the recent increase in its prevalence and link to obesity and other metabolic comorbidities. Current treatment strategies involve lifestyle changes. Other surgical and pharmacologic interventions have been proposed; however, limited randomised controlled trials (RCTs) in the paediatric population restrict their use.

AIM

To review the current management of paediatric NAFLD, including lifestyle and pharmacologic interventions, and to formulate recommendations for study design for future studies.

METHODS

A MEDLINE, Pubmed and Cochrane Review database search used a combination of keywords, including NAFLD, nonalcoholic steatohepatitis (NASH), paediatric, treatments, lifestyle changes, bariatric surgery, orlistat, metformin, thiazolidinediones, vitamin E, cysteamine bitartrate, ursodeoxycholic acid (UDCA), probiotics, omega-3 fatty acids, pentoxyfylline, farnesoid X receptor agonist and toll-like receptor modifiers. The articles were selected based on their relevance to the review.

RESULTS

Lifestyle interventions involving diet and exercise remain first-line treatment for paediatric NAFLD. Bariatric surgery, orlistat, insulin sensitisers and UDCA have been evaluated but are not recommended as first or second-line therapy. Medications such as cysteamine bitartrate, probiotics, polyunsaturated fats and pentoxyfilline share beneficial effects in trials, however, there is a paucity of adequately powered RCTs in which liver histology is evaluated. Vitamin E has been shown to be effective and safe in improving NASH histology in children.

CONCLUSIONS

Lifestyle intervention should be first-line treatment for paediatric NAFLD. Vitamin E should be considered for those with biopsy-proven NASH or borderline NASH failing first-line therapy. Other therapeutics show promising results but require larger RCTs with convincing endpoints. Improved screening techniques, objective validated inclusion criteria and outcome measures as well as rigour in study design are necessary for propelling therapeutic discovery.

Non-alcoholic fatty liver disease in children: focus on nutritional interventions

With increasing prevalence of childhood obesity, non-alcoholic fatty liver disease (NAFLD) has emerged as the most common cause of liver disease among children and adolescents in industrialized countries. It is generally recognized that both genetic and environmental risk factors contribute to the pathogenesis of NAFLD. Recently, there has been a growing body of evidence to implicate altered gut microbiota in the development of NAFLD through the gut-liver axis. The first line of prevention and treatment of NAFLD in children should be intensive lifestyle interventions such as changes in diet and physical activity. Recent advances have been focused on limitation of dietary fructose and supplementation of antioxidants, omega-3 fatty acids, and prebiotics/probiotics. Convincing evidences from both animal models and human studies have shown that reduction of dietary fructose and supplement of vitamin E, omega-3 fatty acids, and prebiotics/probiotics improve NAFLD.

Review of nonalcoholic fatty liver disease in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-aged women. Women with PCOS frequently have metabolic complications including insulin resistance (IR), early diabetes, hypertension and dyslipidemia. Recent studies have demonstrated an association between PCOS and another metabolic complication: nonalcoholic fatty liver disease (NAFLD). NAFLD occurs as a result of abnormal lipid handling by the liver, which sensitizes the liver to injury and inflammation. It can progress to nonalcoholic steatohepatitis (NASH), which is characterized by hepatocyte injury and apoptosis. With time and further inflammation, NASH can progress to cirrhosis. Thus, given the young age at which NAFLD may occur in PCOS, these women may be at significant risk for progressive hepatic injury over the course of their lives. Many potential links between PCOS and NAFLD have been proposed, most notably IR and hyperandrogenemia. Further studies are needed to clarify the association between PCOS and NAFLD. In the interim, clinicians should be aware of this connection and consider screening for NAFLD in PCOS patients who have other metabolic risk factors. The optimal method of screening is unknown. However, measuring alanine aminotransferase and/or obtaining ultrasound on high-risk patients can be considered. First line treatment consists of lifestyle interventions and weight loss, with possible pharmacologic interventions in some cases.

Non-alcoholic fatty liver disease: What has changed in the treatment since the beginning?

Non-alcoholic fatty liver disease (NAFLD) is an umbrella term to describe the entire spectrum of this common liver disease. In patients with NAFLD, especially those with non-alcoholic steatohepatitis (NASH), most often have one or more components of the metabolic syndrome, but this is not universal. Although most patients with NAFLD share many clinical features, only a subset of patients develops significant liver inflammation and progressive fibrosis. On the other hand, not all patients with NASH exhibit insulin resistance. NASH can be seen in patients who are lean and have no identifiable risk factors. Many clinical studies have tried numerous drugs and alternative medicine, however, investigators have failed to identify a safe and effective therapy for patients with NASH. As summarized, the heterogeneity of pathogenic pathways in individual patients with NASH may warrant the development of an individualized treatment according to the underlying pathogenic pathway. The differentiation of pathogenetic targets may require the development of diagnostic and prognostic biomarkers, and the identification of genetic susceptibilities. At present, evidence-based medicine provides only a few options including life-style modifications targeting weight loss, pioglitazone and vitamin E in non-diabetic patients with biopsy-proven NASH.

Branched-Chain Amino Acid-Rich Supplements Containing Microelements Have Antioxidant Effects on Nonalcoholic Steatohepatitis in Mice

BACKGROUND

The aim of the present study was to elucidate whether the administration of antioxidant-rich nutrients, including branched-chain amino acids (BCAAs), microelements, and vitamins, both alone and in combination, has a positive impact on liver function in a nonalcoholic steatohepatitis (NASH) mouse model and identify the mechanisms underlying these effects.

METHODS

Seven-week-old male KKAy mice fed a methionine- and choline-deficient diet (MCD) for 4 weeks were divided into 7 groups and fed the following planned diets for another 4 weeks: group A (normal diet), group B (MCD; control), group C (MCD with rich microelements), group D (MCD with rich BCAAs), group E (MCD with rich microelements and BCAAs), and group F (MCD with rich microelements, BCAAs, and vitamins). We then conducted biochemical assays, histological analyses, immunohistochemistry for 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxy-2'-nonenal (4-HNE), and Western blotting for insulin glucose signaling, lipid metabolism, and endoplasmic reticulum (ER) stress-related signaling in liver specimens obtained from mice in each group.

RESULTS

The morphometric grades of all NASH-related findings and the mean degree of 8-OHdG immunolocalization in groups D-F were significantly lower than those observed in group B. The expression levels of insulin receptor β subunit (IRβ) and p-elF in groups E and F and those of phosphatidyl-inositol 3 kinase (PI3K85), p-AcelCoA, and PERK in group F were similar to those noted in group A.

CONCLUSIONS

The administration of a combination of antioxidant-rich nutrients, including BCAAs and microelements, is likely to suppress the progression of NASH by reducing oxidative stress, primarily via the downregulation of the ER stress pathway.

Obesity and the liver: nonalcoholic fatty liver disease

The increasing prevalence of nonalcoholic fatty liver disease (NAFLD) parallels the rise of obesity and its complications. NAFLD is a common cause of cirrhosis and a leading indication for liver transplant. Genetic susceptibility, dietary composition, and exercise habits influence the development of NAFLD, and insulin resistance results in widespread metabolic perturbations with a net effect of triglyceride accumulation in the liver. Some patients will develop hepatocyte cellular injury and fibrosis of the liver, which can progress to cirrhosis and require liver transplant. Treatments targeting the pathophysiological mechanisms of NAFLD exist, but carry some potential risk and are not universally effective. Weight loss and lifestyle changes remain the most effective and safest approach, but sustainable change is difficult for most patients to achieve. Future work will continue to focus on developing effective and safe interventions to prevent the development of advanced liver disease, whereas efforts in the public health domain continue to combat obesity.

Effect of Vitamin E and Metformin on Fatty Liver Disease in Obese Children- Randomized Clinical Trial

BACKGROUND

We evaluated the effect of vitamin E and metformin on fatty liver disease in obese children.

METHODS

This interventional study has been done on 119 children with Non-alcoholic fatty liver disease (based on sonography results). Patients were divided into four treatment groups; they received metformin 1gr daily (age< 12 years), metformin 1.5 gr daily (age> 12 years), vitamin E 800 U daily and vitamin E 400 U daily. Liver sonography was performed for patients for two periods of two months. This trial was registered in Iranian Registry of Clinical Trials (IRCT), No.IRCT2013021012421N1.

RESULTS

The study group comprised 119 individuals (62 females, 57 males). The mean age was 10± 3.19 yr. There was no significant difference in terms of sex and BMI between the groups. Overall liver sonography showed normal liver in 66 patients (55.46%), 66.63% after two months and 33.37% after four months. After two months, the most therapeutic response observed in the group which received vitamin E 800 u daily (48.1%) and the least therapeutic response was in the group which received vitamin E 400 u daily (14.3%). After four months, the greater response was seen in vitamin E 400 u daily group (45.8%) and the least response in the metformin 1 gram daily group (19%).

CONCLUSION

In comparison with metformin, vitamin E is more influential in remission; however both are efficient in treatment of fatty liver. Vitamin E 400 u daily responses better in four-month treatment.

Non-alcoholic fatty liver disease: a practical approach to treatment

Non-alcoholic fatty liver disease (NAFLD) affects up to a third of the population in many developed countries. Between 10% and 30% of patients with NAFLD have non-alcoholic steatohepatitis (NASH) that can progress to cirrhosis. There are metabolic risk factors common to both NAFLD and cardiovascular disease, so patients with NASH have an increased risk of liver-related and cardiovascular death. Management of patients with NAFLD depends largely on the stage of disease, emphasising the importance of careful risk stratification. There are four main areas to focus on when thinking about management strategies in NAFLD: lifestyle modification, targeting the components of the metabolic syndrome, liver-directed pharmacotherapy for high risk patients and managing the complications of cirrhosis.

Non-alcoholic fatty liver disease in obese adults: clinical aspects and current management strategies

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder whose prevalence is strongly linked to the current epidemic of obesity in many western countries. The prevalence of NAFLD is two to four times higher in populations with pre-existing metabolic comorbidities than in the general population. The diagnosis of primary NAFLD involves establishing the presence of hepatic steatosis or steatohepatitis by imaging or histology, along with establishing the non-alcoholic nature of the disease process and excluding competing aetiologies for hepatic steatosis. Among the indirect serum biomarkers, the NAFLD fibrosis score can help to identify patients with NAFLD and with higher likelihood of having fibrosis or cirrhosis. A liver biopsy should be considered in NAFLD patients at increased risk for steatohepatitis/advanced fibrosis and in cases where a liver biopsy is necessary to exclude co-existing chronic liver diseases and other aetiologies for hepatic steatosis. The treatment and management recommendations for obesity-associated NAFLD are aimed towards weight reduction. The currently available interventions employed to promote weight loss and improve the metabolic responses in NAFLD include lifestyle modification, pharmacotherapy and bariatric surgery.

Cell death and cell death responses in liver disease: mechanisms and clinical relevance

Hepatocellular death is present in almost all types of human liver disease and is used as a sensitive parameter for the detection of acute and chronic liver disease of viral, toxic, metabolic, or autoimmune origin. Clinical data and animal models suggest that hepatocyte death is the key trigger of liver disease progression, manifested by the subsequent development of inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma. Modes of hepatocellular death differ substantially between liver diseases. Different modes of cell death such as apoptosis, necrosis, and necroptosis trigger specific cell death responses and promote progression of liver disease through distinct mechanisms. In this review, we first discuss molecular mechanisms by which different modes of cell death, damage-associated molecular patterns, and specific cell death responses contribute to the development of liver disease. We then review the clinical relevance of cell death, focusing on biomarkers; the contribution of cell death to drug-induced, viral, and fatty liver disease and liver cancer; and evidence for cell death pathways as therapeutic targets.

Nonalcoholic fatty liver disease: A comprehensive review of a growing epidemic

Nonalcoholic fatty liver disease (NAFLD) is quickly becoming one of the most prominent causes of liver disease worldwide. The increasing incidence of NAFLD is tied to the obesity epidemic and the subsequent metabolic derangements brought along with it. Current efforts to elucidate the mechanism and causes of the disease have answered some questions, but much remains unknown about NAFLD. The aim of this article is to discuss the current knowledge regarding the pathogenesis of the disease, as well as the current and future diagnostic, preventative, and therapeutic options available to clinicians for the management of NAFLD.

Management of nonalcoholic fatty liver disease: an evidence-based clinical practice review

AIM

To build a consensus among Chilean specialists on the appropriate management of patients with nonalcoholic fatty liver disease (NAFLD) in clinical practice.

METHODS

NAFLD has now reached epidemic proportions worldwide. The optimal treatment for NAFLD has not been established due to a lack of evidence-based recommendations. An expert panel of members of the Chilean Gastroenterological Society and the Chilean Hepatology Association conducted a structured analysis of the current literature on NAFLD therapy. The quality of the evidence and the level of recommendations supporting each statement were assessed according to the recommendations of the United States Preventive Services Task Force. A modified three-round Delphi technique was used to reach a consensus among the experts.

RESULTS

A group of thirteen experts was established. The survey included 17 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 93.8% in the first round and 100% in the second and third rounds. The final recommendations support the indication of lifestyle changes, including diet and exercise, for all patients with NAFLD. Proven pharmacological therapies include only vitamin E and pioglitazone, which can be used in nondiabetic patients with biopsy-proven nonalcoholic steatohepatitis (the progressive form of NAFLD), although the long-term safety and efficacy of these therapies have not yet been established.

CONCLUSION

Current NAFLD management is rapidly evolving, and new pathophysiology-based therapies are expected to be introduced in the near future. All NAFLD patients should be evaluated using a three-focused approach that considers the risks of liver disease, diabetes and cardiovascular events.

Vitamin E inadequacy in humans: causes and consequences

It is estimated that >90% of Americans do not consume sufficient dietary vitamin E, as α-tocopherol, to meet estimated average requirements. What are the adverse consequences of inadequate dietary α-tocopherol intakes? This review discusses health aspects where inadequate vitamin E status is detrimental and additional vitamin E has reversed the symptoms. In general, plasma α-tocopherol concentrations <12 μmol/L are associated with increased infection, anemia, stunting of growth, and poor outcomes during pregnancy for both the infant and the mother. When low dietary amounts of α-tocopherol are consumed, tissue α-tocopherol needs exceed amounts available, leading to increased damage to target tissues. Seemingly, adequacy of human vitamin E status cannot be assessed from circulating α-tocopherol concentrations, but inadequacy can be determined from “low” values. Circulating α-tocopherol concentrations are very difficult to interpret because, as a person ages, plasma lipid concentrations also increase and these elevations in lipids increase the plasma carriers for α-tocopherol, leading to higher circulating α-tocopherol concentrations. However, abnormal lipoprotein metabolism does not necessarily increase α-tocopherol delivery to tissues. Additional biomarkers of inadequate vitamin E status are needed. Urinary excretion of the vitamin E metabolite α-carboxy-ethyl-hydroxychromanol may fulfill this biomarker role, but it has not been widely studied with regard to vitamin E status in humans or with regard to health benefits. This review evaluated the information available on the adverse consequences of inadequate α-tocopherol status and provides suggestions for avenues for research.

Overweight and obesity in children and adolescents

Obesity among children, adolescents and adults has emerged as one of the most serious public health concerns in the 21st century. The worldwide prevalence of childhood obesity has increased remarkably over the past 3 decades. The growing prevalence of childhood obesity has also led to appearance of obesity-related comorbid disease entities at an early age. Childhood obesity can adversely affect nearly every organ system and often causes serious consequences, including hypertension, dyslipidemia, insulin resistance, dysglycemia, fatty liver disease and psychosocial complications. It is also a major contributor to increasing healthcare expenditures. For all these reasons, it is important to prevent childhood obesity as well as to identify overweight and obese children at an early stage so they can begin treatment and attain and maintain a healthy weight. At present, pharmacotherapy options for treatment of pediatric obesity are very limited. Therefore, establishing a comprehensive management program that emphasizes appropriate nutrition, exercise and behavioral modification is crucial. The physician's role should expand beyond the clinical setting to the community to serve as a role model and to advocate for prevention and early treatment of obesity.

Where are persons with intellectual disabilities in medical research? A survey of published clinical trials

BACKGROUND

Persons with intellectual disabilities (ID) are exposed to the same medical interventions as everyone else. Given the unique health profiles of many persons with ID, it cannot be assumed that they will react to medical treatments the same as persons without ID. It is not clear if medical clinical trials routinely include persons with ID. The purpose of this research survey was to examine the inclusion of persons with ID in medical research trials, and to determine whether accommodations and/or study modifications could have been made to promote greater inclusion in medical research.

METHOD

Three hundred randomised control and clinical trials published between 2007 and 2011 in the six highest impact medical journals were randomly selected. Each study was reviewed for inclusion of persons with ID, and possible accommodations that could have been put in place without compromising research integrity. Corresponding authors received a follow-up survey to determine whether persons with ID were included, but were not mentioned in the article.

RESULTS

Only 6 (2%) of 300 randomly chosen studies clearly included persons with ID. Over 90% of studies were designed in ways that would automatically exclude persons with ID from participating. The author survey revealed three additional studies including persons with ID. Most persons with ID could have participated in at least 70% of the studies with simple accommodations and/or minor procedural modifications.

DISCUSSION

The findings highlight the exclusion of persons with ID in medical research. Efforts are needed to increase inclusion through research policy initiatives and education.

Non-alcoholic Fatty liver disease in children

In the last years, there has been extremely much information which reveals an alarming increase of obesity in children and, at the same time, an increase of the incidence of non-alcoholic fatty liver disease (NAFLD). NAFLD implies a wide range of affections starting from simple hepatic steatosis to non-alcoholic steatohepatitis (NASH); the latter can evolve to cirrhosis and hepatic carcinoma. All these affections were noticed in children, too. The article presents data on the epidemiology, pathogeny, clinical and paraclinical findings, and treatment of NAFLD in children.

Non-alcoholic fatty liver disease, obesity and the metabolic syndrome

Nonalcoholic fatty liver disease (NAFLD) is now recognized as the most common cause of chronic liver disease worldwide. Its prevalence has increased to more than 30% of adults in developed countries and its incidence is still rising. The majority of patients with NAFLD have simple steatosis but in up to one third of patients, NAFLD progresses to its more severe form nonalcoholic steatohepatitis (NASH). NASH is characterized by liver inflammation and injury thereby determining the risk to develop liver fibrosis and cancer. NAFLD is considered the hepatic manifestation of the metabolic syndrome. However, the liver is not only a passive target but affects the pathogenesis of the metabolic syndrome and its complications. Conversely, pathophysiological changes in other organs such as in the adipose tissue, the intestinal barrier or the immune system have been identified as triggers and promoters of NAFLD progression. This article details the pathogenesis of NAFLD along with the current state of its diagnosis and treatment.

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.

Nonalcoholic fatty liver disease and cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD) are two diseases that are common in the general population. To date, many studies have been conducted and demonstrate a direct link between NAFLD and CVD, but the exact mechanisms for this complex relationship are not well established. A systematic search of the PubMed database revealed that several common mechanisms are involved in many of the local and systemic manifestations of NAFLD and lead to an increased cardiovascular risk. The possible mechanisms linking NAFLD and CVD include inflammation, oxidative stress, insulin resistance, ectopic adipose tissue distribution, dyslipidemia, endothelial dysfunction, and adiponectin, among others. The clinical implication is that patients with NAFLD are at an increased risk of CVD and should undergo periodic cardiovascular risk assessment.

Modern approach to the clinical management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common and emerging form of chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to steatohepatitis, which may progress to cirrhosis, liver cancer, and liver mortality. Common metabolic diseases, which are well established cardiovascular risk factors, have been associated to NAFLD and cardiovascular disease is the single most important cause of morbidity and mortality in this patient population. The pathogenesis of NAFLD appears multifactorial and many mechanisms have been proposed as possible causes of fatty liver infiltration. Management of fatty liver has become a major challenge to healthcare systems as the consequence of the increasing rates of obesity worldwide. First-line management focuses on lifestyle modifications. Moderate weight reduction either by dietary restriction or by increased habitual physical activity is safe and highly recommended. Several therapeutic interventions have been proposed. These include insulin sensitizer agents, lipid lowering drugs, antioxidants such as vitamin E and supplementation of vitamin D₃. However, therapeutic strategies have been largely empirical so far, and experimental trials have mostly been carried out in uncontrolled settings with small sample sizes. Metabolic conditions such as diabetes mellitus, obesity, hypertension and hyperlipidemia, should be strongly considered and a multidisciplinary approach should be personalized for individual patients. Treatment of co-morbidities should be regarded as of paramount importance in the management of these patients. The purpose of this review is to examine different approaches for the clinical management of non-alcoholic fatty liver disease.

L-carnitine prevents progression of non-alcoholic steatohepatitis in a mouse model with upregulation of mitochondrial pathway

Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease characterized by lobular inflammation, hepatocellular ballooning, and fibrosis with an inherent risk for progression to cirrhosis and hepatocellular carcinoma (HCC). Mitochondrial dysfunction appears to play a role in the progression from simple steatosis to NASH. L-carnitine (L-b-hydroxy-g-N-trimethylaminobutyric acid), an essential nutrient that converts fat into energy in mitochondria, has been shown to ameliorate liver damage. The aim of the present study was to explore the preventive and therapeutic effect of L-carnitine in NASH model mice. Eight-week-old male STAM mice, a NASH-cirrhosis-hepatocarcinogenic model, were divided into 3 experimental groups and fed as follows: 1) high-fat diet (HFD) (control group); 2) HFD mixed with 0.28% L-carnitine (L-carnitine group); and 3) HFD mixed with 0.01% α-tocopherol (α-tocopherol group). After 4 or 8 weeks, mice were sacrificed. Blood samples and livers were collected, and hepatic tumors were counted and measured. Livers were subjected to histological study, immunohistochemical staining of 4-hydroxynonenal and ferritin, determination of 8-OHdG levels, mRNA and protein expressions for multiple genes, and metabolomic analysis. The intestinal microbiome was also analyzed. L-carnitine increased hepatic expression of genes related to long-chain fatty acid transport, mitochondrial β-oxidation, and antioxidant enzymes following suppression of hepatic oxidative stress markers and inflammatory cytokines in NASH, and mice treated with L-carnitine developed fewer liver tumors. Although α-tocopherol resulted in NASH improvement in the same manner as L-carnitine, it increased periodontitis-related microbiotic changes and hepatic iron transport-related gene expression and led to less effective for anti-hepatocarcinogenesis.

Conclusion

L-carnitine prevents progression of non-alcoholic steatohepatitis in a mouse model by upregulating the mitochondrial β-oxidation and redox system.

Effect of carnitine-orotate complex on glucose metabolism and fatty liver: a double-blind, placebo-controlled study

BACKGROUND AND AIM

Effective medicines have not been introduced for insulin resistance-related fatty liver. The efficacy and safety of treatment between a combination of metformin and carnitine-orotate complex and metformin alone in a 12-week, double-blind, randomized, placebo-controlled study on drug-naïve patients with impaired glucose metabolism and fatty liver were compared.

METHODS

Fifty-two patients with fasting glucose 100-240 mg/dL or glycosylated hemoglobin (HbA1c) ≥ 6.0% and alanine aminotransferase (ALT) 40-250 IU/L were randomized to receive metformin (250 mg t.i.d.), or metformin (250 mg t.i.d.) and carnitine-orotate complex (300 mg t.i.d.) for 12 weeks (n = 26 per group). The primary end-point was a change from baseline ALT level. Secondary end-points were changes in fasting glucose, HbA1c, aspartate aminotransferase levels, mitochondrial DNA (mtDNA) copy number in the peripheral blood, and urinary output of 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress.

RESULTS

The combined treatment reduced ALT level significantly more than metformin alone (-51.5 ± 33.2 IU/L vs -16.7 ± 31.3 IU/L, P = 0.001). The HbA1c levels also decreased significantly in both groups but there was no significant difference between them (-0.9% ± 1.0% vs -0.7% ± 0.9%). Treatment with the complex decreased the urinary 8-hydroxy-2'-deoxyguanosine level and increased mtDNA copy number significantly compared with metformin alone (both P < 0.05). No severe adverse events were observed.

CONCLUSION

A 12-week treatment with metformin and carnitine-orotate complex significantly improved liver function enzyme levels. This was associated with changes in oxidative stress and mtDNA copy number compared with metformin alone in patients with impaired glucose metabolism and fatty liver (clinical trial number: KCT0000193).

OxNASH score correlates with histologic features and severity of nonalcoholic fatty liver disease

BACKGROUND AND AIM

Oxidative stress is a core abnormality responsible for disease progression in nonalcoholic fatty liver disease (NAFLD). By employing a highly sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) approach we recently were able to define the circulating profile of bioactive lipid peroxidation products characteristic of patients with nonalcoholic steatohepatitis (NASH) and developed the OxNASH score for NASH diagnosis. The aims of this study were to assess the utility of OxNASH as a predictor of NASH and study the association between OxNASH and specific histologic features of NAFLD.

METHODS

Our cohort consisted of 122 patients undergoing liver biopsy for clinical suspicion of NAFLD. The NAFLD activity score (NAS) was calculated for each patient. Levels of fatty acid oxidation products were quantified using stable isotope dilution LC/MS/MS, and OxNASH was calculated.

RESULTS

The mean age of our patients was 49.3 (±11.6) years, and the mean body mass index was 31.5 (±4.8) kg/m(2). The majority of patients were Caucasian (82 %) and 48 % were female. OxNASH correlated with NAS and with the individual histologic features of NAFLD, namely, steatosis, inflammation, and ballooning (P < 0.05), with the strongest association being with inflammation [rho (ρ) 0.40, 95 % confidence interval 0.23, 0.57, P < 0.001]. There was also a correlation between the stage of fibrosis and OxNASH (P = 0.001). These associations remained statistically significant after adjustment for multiple confounders.

CONCLUSIONS

Based on our results, in adult patients with NAFLD, OxNASH correlates with histologic features of NASH and appears to be a promising noninvasive marker.

Management of fatty liver disease with the metabolic syndrome

Non-alcoholic fatty liver disease (NAFLD) is the liver disease of this century, increasing in parallel with obesity, insulin resistance and the metabolic syndrome. NAFLD can be seen as a component of the metabolic syndrome, and as such, contributing as a risk factor for cardiovascular disease. In fact, these patients die more often from cardiovascular disease than from direct consequences of liver disease. In this review, we will summarize the data that link NAFLD as a central player in this dysmetabolism, as well as the evidence for appropriate therapy, in order to improve not only liver disease prognosis, but also the overall prognosis and risk of mortality, with particular focus on cardiovascular risk.

OCT1 is a high-capacity thiamine transporter that regulates hepatic steatosis and is a target of metformin

Organic cation transporter 1, OCT1 (SLC22A1), is the major hepatic uptake transporter for metformin, the most prescribed antidiabetic drug. However, its endogenous role is poorly understood. Here we show that similar to metformin treatment, loss of Oct1 caused an increase in the ratio of AMP to ATP, activated the energy sensor AMP-activated kinase (AMPK), and substantially reduced triglyceride (TG) levels in livers from healthy and leptin-deficient mice. Conversely, livers of human OCT1 transgenic mice fed high-fat diets were enlarged with high TG levels. Metabolomic and isotopic uptake methods identified thiamine as a principal endogenous substrate of OCT1. Thiamine deficiency enhanced the phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase. Metformin and the biguanide analog, phenformin, competitively inhibited OCT1-mediated thiamine uptake. Acute administration of metformin to wild-type mice reduced intestinal accumulation of thiamine. These findings suggest that OCT1 plays a role in hepatic steatosis through modulation of energy status. The studies implicate OCT1 as well as metformin in thiamine disposition, suggesting an intriguing and parallel mechanism for metformin and its major hepatic transporter in metabolic function.

Randomised clinical trial: The beneficial effects of VSL#3 in obese children with non-alcoholic steatohepatitis

BACKGROUND

Gut microbiota modifiers may have beneficial effects of non-alcoholic fatty liver disease (NAFLD) but randomised controlled trials (RCT) are lacking in children.

AIM

To perform a double-blind RCT of VSL#3 vs. placebo in obese children with biopsy-proven NAFLD.

METHODS

Of 48 randomised children, 44 (22 VSL#3 and 22 placebo) completed the study. The main outcome was the change in fatty liver severity at 4 months as detected by ultrasonography. Secondary outcomes were the changes in triglycerides, insulin resistance as detected by the homoeostasis model assessment (HOMA), alanine transaminase (ALT), body mass index (BMI), glucagon-like peptide 1 (GLP-1) and activated GLP-1 (aGLP-1). Ordinal and linear models with cluster confidence intervals were used to evaluate the efficacy of VSL#3 vs. placebo at 4 months.

RESULTS

At baseline, moderate and severe NAFLD were present in 64% and 36% of PLA children and in 55% and 45% of VSL#3 children. The probability that children supplemented with VSL#3 had none, light, moderate or severe FL at the end of the study was 21%, 70%, 9% and 0% respectively with corresponding values of 0%, 7%, 76% and 17% for the placebo group (P < 0.001). No between-group differences were detected in triglycerides, HOMA and ALT while BMI decreased and GLP-1 and aGLP1 increased in the VSL#3 group (P < 0.001 for all comparisons).

CONCLUSIONS

A 4-month supplement of VSL#3 significantly improves NAFLD in children. The VSL#3-dependent GLP-1 increase could be responsible for these beneficial effects. Trial identifier: NCT01650025 (www.clinicaltrial.gov).

Metabolic syndrome and non-alcoholic fatty liver disease in liver surgery: The new scourges?

The aim of this topic highlight is to review relevant evidence regarding the influence of the metabolic syndrome (MS) and its associated liver manifestation, non-alcoholic fatty liver disease (NAFLD), on the development of liver cancer as well as their impact on the results of major liver surgery. MS and NAFLD, whose incidences are significantly increasing in Western countries, are leading to a changing profile of the patients undergoing liver surgery. A MEDLINE search was performed for relevant articles using the key words "metabolic syndrome", "liver resection", "liver transplantation", "non alcoholic fatty liver disease", "non-alcoholic steatohepatitis" and "liver cancer". On one hand, the MS favors the development of primary liver malignancies (hepatocellular carcinoma and cholangiocarcinoma) either through NAFLD liver parenchymal alterations (steatosis, steatohepatitis, fibrosis) or in the absence of significant underlying liver parenchyma changes. Also, the existence of NAFLD may have a specific impact on colorectal liver metastases recurrence. On the other hand, the postoperative period following partial liver resection and liver transplantation is at increased risk of both postoperative complications and mortality. These deleterious effects seem to be related to the existence of liver specific complications but also higher cardio-vascular sensitivity in a setting of MS/NAFLD. Finally, the long-term prognosis after curative surgery joins that of patients operated on with other types of underlying liver diseases. An increased rate of patients with MS/NAFLD referred to hepatobiliary units has to be expected. The higher operative risk observed in this subset of patients will require specific improvements in their perioperative management.

The impact of diet and nutrition in the prevention and progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. There is growing evidence for a chemopreventive role of nutrition in the development of HCC in at risk populations. Bibliographical searches were performed in PubMed for the terms 'nutrition and hepatocellular carcinoma', 'nutrition and liver cancer', 'nutrition and hepatic cancer', 'diet and hepatocellular carcinoma', 'diet and liver cancer'. High dietary sugar intake should be discouraged in at risk populations. Coffee, polyphenols, vanadium, dietary fibre, fruits and vegetables show encouraging results in terms of chemoprevention. Red meat intake may be associated with increased risk of HCC. The evidence for fatty acids is inconclusive, but they might exert anti-cancer effects. Inconclusive results are available on vitamins, selenium probiotics and prebiotics. There is increasing evidence that diet may play an important role in the development of HCC, and may also have a chemopreventive role in at risk populations.

State of the art: treatment of nonalcoholic steatohepatitis

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease is the most common cause of chronic liver disease in Western countries, and consists of a spectrum of histopathological changes that range in severity from simple steatosis to steatohepatitis to cirrhosis. The use of pharmacological agents as adjunctive therapy to lifestyle modification is crucial, because weight loss is often difficult to achieve and maintain. The purpose of this review is to analyze the most recent literature pertaining to current therapies for nonalcoholic steatohepatitis (NASH), as there are currently no Food and Drug Administration-approved medications.

RECENT FINDINGS

Recent studies suggest that vitamin E may improve liver histology in NASH without affecting insulin resistance; however, long-term risks remain to be studied. Pioglitazone is beneficial in improving liver histology and insulin resistance, but is associated with weight gain. Emerging data suggest that pentoxifylline may also be beneficial in improving serum aminotransferase and liver histology in patients with biopsy-proven NASH.

SUMMARY

Ongoing research evaluating potential pharmacological agents for NASH is critical, because these patients are at an increased risk for cirrhosis and hepatocellular carcinoma. The current therapies being used for the treatment of NASH include the use of vitamin E and pioglitazone, in addition to dietary counseling and regular exercise.

The α-tocopherol status and expression of α-tocopherol-related proteins in methionine-choline deficient rats treated with vitamin E

Non-alcoholic fatty liver disease is the most common liver disorder in developed countries, and its incidence is increasing in all population groups. As an antioxidant, vitamin E is effective in the treatment of non-alcoholic fatty liver disease, although the mechanism is still unclear. Methionine-choline deficient Wistar rats (n = 5) used as an experimental model of non-alcoholic fatty liver disease were fed a vitamin E-enriched diet (500 mg/kg) for 4 weeks. The effects were assessed by measuring lipid peroxidation, α-tocopherol levels, and the expression of α-tocopherol-related proteins in the liver. In vitamin E-treated methionine-choline deficient rats, lipid peroxidation was reduced, but liver histopathological changes were not improved. Hepatic α-tocopherol levels in these rats were significantly elevated compared to normal rats treated with vitamin E. Expression of liver α-tocopherol transfer protein in vitamin E-treated methionine-choline deficient rats was significantly repressed compared to methionine-choline deficient rats. The expression of liver cytochrome P450 4F2 and ATP-binding cassette transporter protein 1, involved in metabolism and transport of α-tocopherol, respectively, was significantly repressed in vitamin E-treated methionine-choline deficient rats. In methionine-choline deficient rats, vitamin E treatment altered the hepatic α-tocopherol-related protein expression, which may affect α-tocopherol status in the liver, leading to reduced lipid peroxidation.

Insulin sensitizers for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver disease in the Western world and is closely associated with metabolic syndrome, which includes hypertension, central obesity, dyslipidemia and insulin resistance. NAFLD includes a wide spectrum of liver alterations, ranging from simple hepatic steatosis to variable degrees of fibrosis, cirrhosis and even hepatocellular carcinoma. Although the etiology and progression of the disorder remain poorly understood, insulin resistance is considered to play a pivotal role in the pathogenesis. Insulin sensitizers such as biguanides, thiazolidinediones (TZDs), glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase 4 inhibitors have been studied as therapeutic approaches for NAFLD in recent years. Metformin improves insulin sensitivity and serum alanine transaminase and aspartate transaminase (ALT/AST) levels in the majority of subjects; however, it has no significant effect on liver histology. TZDs improve insulin sensitivity, serum ALT/AST levels and histology in some cases, but there are some concerns about the safety of long-term therapy. Selection of appropriate patients for avoiding side effects and the treatment of underlying disease are the main points. These drugs are the best choice for the treatment of NAFLD in patients with type 2 DM who are also candidates for treatment with an insulin sensitizer. The present review provides an overview of insulin sensitizers in the treatment of NAFLD.

Pediatric non-alcoholic fatty liver disease: New insights and future directions

One of the most common complications of childhood obesity is the non-alcoholic fatty liver disease (NAFLD), which is the most common form of liver disease in children. NAFLD is defined by hepatic fat infiltration > 5% hepatocytes, as assessed by liver biopsy, in the absence of excessive alcohol intake, viral, autoimmune and drug-induced liver disease. It encompasses a wide spectrum of liver diseases ranging from simple steatosis to non-alcoholic steatohepatitis, which, in turn, can evolve into cirrhosis and end stage liver disease. Obesity and insulin resistance are the main risk factors for pediatric NAFLD. In fact, NAFLD is strongly associated with the clinical features of insulin resistance especially the metabolic syndrome, prediabetes and type 2 diabetes mellitus (T2D). In particular, it has been clearly shown in obese youth that the prevalence of metabolic syndrome, pre-diabetes and type 2 diabetes increases with NAFLD severity progression. Evidence that not all of the obese patients develop NAFLD suggests that the disease progression is likely to depend on complex interplay between environmental factors and genetic predisposition. Recently, a non-synonymous SNP (rs738409), characterized by a C to G substitution encoding an isoleucine to methionine substitution at the amino acid position 148 in the patatin like phospholipase containing domain 3 gene (PNPLA3), has been associated with hepatic steatosis in a multiethnic cohort of adults as well as in children. Another important polymorphisms that acts with PNPLA3 to convey susceptibility to fatty liver in obese youths is the rs1260326 polymorphism in the glucokinase regulatory protein. The pharmacological approach in NAFLD children poorly adherent to or being unresponsive/partially responsive to lifestyle changes, is aimed at acting upon specific targets involved in the pathogenesis. There are some therapeutic approaches that are being studied in children. This article reviews the current knowledge regarding the pediatric fatty liver disease, the new insights and the future directions.