Lack of efficacy of ursodeoxycholic acid for the treatment of liver abnormalities in obese children

Pediatric metabolic (dysfunction)-associated fatty liver disease: current insights and future perspectives

The historical use of the term non-alcoholic fatty liver disease (NAFLD) in obese/overweight children has been controversial as to the appropriateness of this terminology in children, and lately, in adults too. Newer game-changer terminology, metabolic (dysfunction)-associated fatty liver disease (MAFLD), for this condition signifies a positive step forward that addresses the limitations of the previous definition for both adults and children. The prevalence of MAFLD has surged in tandem with the global rise in obesity rates, establishing itself as a predominant cause of chronic liver disease in both adult and pediatric populations. The adoption of the recently proposed nomenclature reflects a more encompassing comprehension of the disease and its etiology compared to its predecessor, NAFLD. Notably, the revised terminology facilitates the recognition of MAFLD as an autonomous condition while acknowledging the potential coexistence of other systemic fatty liver disorders. Particularly in children, this includes various paediatric-onset genetic and inherited metabolic disorders, necessitating thorough exclusion, especially in cases where weight loss interventions yield no improvement or in the absence of obesity. MAFLD presents as a multifaceted disorder; evidence suggests its origins lie in a complex interplay of nutritional, genetic, hormonal, and environmental factors. Despite advancements, current non-invasive diagnostic biomarkers exhibit limitations in accuracy, often necessitating imaging and histological evaluations for definitive diagnosis. While dietary and lifestyle modifications stand as cornerstone measures for MAFLD prevention and management, ongoing evaluation of therapeutic agents continues. This article provides an overview of the latest developments and emerging therapies in the realm of paediatric MAFLD.

Defining paediatric metabolic (dysfunction)-associated fatty liver disease: an international expert consensus statement

The term non-alcoholic fatty liver disease (NAFLD), and its definition, have limitations for both adults and children. The definition is most problematic for children, for whom alcohol consumption is usually not a concern. This problematic definition has prompted a consensus to rename and redefine adult NAFLD associated with metabolic dysregulation to metabolic (dysfunction)-associated fatty liver disease (MAFLD). Similarities, distinctions, and differences exist in the causes, natural history, and prognosis of fatty liver diseases in children compared with adults. In this Viewpoint we, an international panel, propose an overarching framework for paediatric fatty liver diseases and an age-appropriate MAFLD definition based on sex and age percentiles. The framework recognises the possibility of other coexisting systemic fatty liver diseases in children. The new MAFLD diagnostic criteria provide paediatricians with a conceptual scaffold for disease diagnosis, risk stratification, and improved clinical and multidisciplinary care, and they align with a definition that is valid across the lifespan.

The pharmacological treatment of nonalcoholic fatty liver disease in children

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in childhood/adolescence. It comprises a broad spectrum of liver disease severity ranging from simple steatosis to steatohepatitis and fibrosis. To date lifestyle modifications, diet and physical activity represent the main option for the management of pediatric NAFLD, but numerous treatments classified depending on the mechanism of action, have been introduced. In keeping with, bariatric surgery, insulin sensitizers, antioxidants, probiotic and dietary supplementations have been evaluated in pediatric clinical trials.

AREAS COVERED

This review describes, after a search in PubMed/MEDLINE database, the current pediatric NAFLD non-pharmacological and pharmacological treatments and their effects on biochemical and histological features. We report not only the efficacy of the diet coupled with regular exercise but also advantages of the pharmacological treatments used in combination with lifestyle interventions in pediatric NAFLD.

EXPERT OPINION

Since pharmacological and non-pharmacological interventions have demonstrated variable effects in pediatric NAFLD, it is clear that safe and specific and efficient therapeutic strategies have not yet been identified. Therefore, large and long-term clinical trials in children are needed to find a way to reverse the liver tissue damage and the NAFLD-related long-term morbidity and mortality.

Non-alcoholic fatty liver infiltration in children: an underdiagnosed evolving disease

Non-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease, one that is still underdiagnosed in pediatric populations (as well as in the general population), this due to the progressive increase in childhood obesity observed both in developed and developing countries during the last few decades. The pathophysiology of the disease has not been thoroughly clarified yet. The condition displays common pathways in adults and children; however, there are age-related differences. Unlike adults, children with NAFLD require extensive laboratory analysis, because underlying pathologies other than obesity may contribute to the evolution of the disease. Despite the presence of several serum markers and imaging techniques that contribute to NAFLD diagnosis, liver biopsy remains the gold standard diagnostic procedure. Early intervention and obesity prevention are mandatory, as NAFLD is reversible at an early stage. If left undiagnosed and untreated, NAFLD can progress to steatohepatitis (NASH) and subsequent liver failure, a potentially lethal complication. Of note, there are no treatment options when advanced liver fibrosis occurs. This review summarizes literature data on NAFLD in childhood indicating that this is an evolving disease and a significant component of the metabolic syndrome. Pediatricians should be aware of this entity, screening children at high risk and providing appropriate early management, in collaboration with pediatric subspecialists.

Non-Alcoholic Fatty Liver Disease in Children and Adolescents: Lifestyle Change - a Systematic Review and Meta-Analysis

INTRODUCTION AND AIM

This manuscript seeks to analyze the impact of lifestyle changes on body mass index (BMI), aminotransferases and steatosis in children and adolescents with nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

A review of PubMed, BIREME, Scopus, EMBASE, Medline and Web of Science databases 2015 was performed seeking studies addressing the impact of lifestyle interventions on children and/or adolescents with NAFLD. Inclusion were manuscripts written in Portuguese, English and Spanish, as well as age less than 18 years. Two reviewers performed the data extraction independently and differences were resolved by consensus. Outcome measures were BMI, serum aminotransferase levels and the presence of hepatic steatosis.

RESULTS

The literature search identified 71,012 articles. After excluding 46,397 duplicates and other clearly irrelevant studies, 89 publications were reviewed in detail. Another 55 studies were excluded at this stage. Subsequently, 18 were excluded due to lack of data and three new articles were found in the review of the references of previously identified manuscripts. Therefore, 19 studies that had evaluated 923 subjects (477 boys and 446 girls) aged 6-18 years were included in the review. In most studies, the intervention included aerobic exercise and diet. In nine studies, BMI improved significantly following the intervention. The vast majority of studies reported a benefit from the intervention on aminotransferase levels. Lifestyle changes also had a significant impact on steatosis, reducing the risk by 61%.

CONCLUSIONS

Lifestyle changes lead to significant improvements in BMI, aminotransferase levels and hepatic steatosis in children and adolescents with NAFLD.

Nonalcoholic Fatty Liver Disease in Children: Not a Small Matter

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased substantially in the past two decades and NAFLD has now become the most common cause of chronic liver disease in children and adolescents. NAFLD is a broad clinicopathologic spectrum ranging from simple steatosis to varying degrees of necroinflammation called nonalcoholic steatohepatitis (NASH), leading to fibrosis and subsequently to cirrhosis. Despite the increasing prevalence and progressive nature of NAFLD even among children, therapy for NAFLD in both adults and children are limited. Weight loss remains the only consistently effective therapy for NAFLD. Pharmacologic options are even more limited in children than in adults with NAFLD. Vitamin E has been shown to be effective in improving histology in children with NASH. Few pharmacologic options such as metformin, probiotics, omega-3 fatty acids, and cysteamine bitartrate have been studied in children, with limited beneficial effects. However, these studies are limited by small sample size and heterogeneity of outcome assessment after treatment. Recent studies show promising results with bariatric surgery with regards to weight loss and improvement in liver histology in adolescents with NAFLD. In this review article, we discuss epidemiology, pathophysiology, and extrahepatic comorbidities of pediatric NAFLD and review existing therapeutic options for children with NAFLD. We also review novel therapeutic strategies studied in adults that could potentially be studied in children in the future.

The pharmacological management of NAFLD in children and adolescents

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) represents a spectrum, including 'simple' steatosis, non-alcoholic steatohepatitis (NASH), and fibrosis. Increasing prevalence of NAFLD has followed the international rise in obesity and lifestyle modification is the mainstay therapy for children. To date, pharmacological trials have had varying efficacy but a large number of new agents are in early phase trials for adults. Areas covered: This review explores the effect of current and potential future paediatric NAFLD treatments in terms of histological and biochemical endpoints. The potential for the extension of adult treatments to children is discussed, as well as what limits the use of certain agents in children. Expert commentary: No drugs have yet to be licenced for NAFLD. Trial heterogeneity makes comparison of drugs between studies challenging. FXR agonists are yet to be trialled in children but may represent a safe and potentially efficacious therapy. Future treatments would likely encompass a multimodal approach that may include bariatric surgery.

NASPGHAN Clinical Practice Guideline for the Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease in Children: Recommendations from the Expert Committee on NAFLD (ECON) and the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN)

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease that occurs in the setting of insulin resistance and increased adiposity. It has rapidly evolved into the most common liver disease seen in the pediatric population and is a management challenge for general pediatric practitioners, subspecialists, and for health systems. In this guideline, the expert committee on NAFLD reviewed and summarized the available literature, formulating recommendations to guide screening and clinical care of children with NAFLD.

Omega-3 fatty acids as a treatment for non-alcoholic fatty liver disease in children: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The most typical chronic liver disease in children and adolescents is non-alcoholic fatty liver disease (NAFLD). The dietary addition of ω-3 polyunsaturated fatty acids (PUFAs) provides a promising therapy for children with NAFLD due to its convenience and safety; however, several studies suggested contradictory results for PUFA supplementation in children. Hence, we performed a systematic review and meta-analysis to evaluate the effectiveness of PUFA supplementation in children with NAFLD.

METHODS

Published randomized controlled trials (RCTs) that evaluated the effectiveness of the dietary addition of PUFA in children with NAFLD were considered. The primary result was the alteration in hepatic steatosis grade on ultrasound after treatment. The secondary outcomes included alanine aminotransferase (ALT), aspartate aminotransferase (AST), C-reactive protein (CRP) and components of metabolic syndrome. Predefined sensitivity analysis was also performed to explore possible explanations for heterogeneity in the evaluations.

RESULTS

In total, 4 studies with 263 subjects were identified. PUFA supplementation was associated with significantly improved hepatic steatosis grade on ultrasound (risk difference: 25%, 95% CI: 12-38%), without heterogeneity (P = 0.27, I² = 24%). Sensitivity analysis confirmed the robustness of our findings. PUFA supplementation could decrease AST levels after 6 months, but could only reduce ALT levels after 12 months. PUFA did not have a significant effect on most components of metabolic syndrome and the CRP level.

CONCLUSION

ω-3 PUFA supplementation can improve liver steatosis and liver functions, and it is a potential food supplementation to treat NAFLD in children.

Pediatric Non-alcoholic Fatty Liver Disease

Childhood obesity has reached epidemic proportions, and by 2012, more than one third of American children were overweight or obese. As a result, increasingly, children are developing complications of obesity including liver disease. In fact, non-alcoholic fatty liver disease is the most common form of chronic liver disease seen in children today. Recently, there has been a burgeoning literature examining the pathogenesis, genetic markers, and role of the microbiome in this disease. On the clinical front, new modalities of diagnosing hepatic steatosis and hepatic fibrosis are being developed to provide non-invasive methods of surveillance in children. Lastly, the mainstay of treatment of pediatric non-alcoholic fatty liver disease (NAFLD) has been largely through lifestyle interventions, namely, dieting and exercise. Currently, there are a number of clinical trials examining novel lifestyle and drug therapies for NAFLD that are registered with the US National Institutes of Health ClinicalTrials.gov website.

A Guide to Non-Alcoholic Fatty Liver Disease in Childhood and Adolescence

Non-Alcoholic Fatty Liver Disease (NAFLD) is now the most prevalent form of chronic liver disease, affecting 10%–20% of the general paediatric population. Within the next 10 years it is expected to become the leading cause of liver pathology, liver failure and indication for liver transplantation in childhood and adolescence in the Western world. While our understanding of the pathophysiological mechanisms underlying this disease remains limited, it is thought to be the hepatic manifestation of more widespread metabolic dysfunction and is strongly associated with a number of metabolic risk factors, including insulin resistance, dyslipidaemia, cardiovascular disease and, most significantly, obesity. Despite this, ”paediatric” NAFLD remains under-studied, under-recognised and, potentially, undermanaged. This article will explore and evaluate our current understanding of NAFLD in childhood and adolescence and how it differs from adult NAFLD, in terms of its epidemiology, pathophysiology, natural history, diagnosis and clinical management. Given the current absence of definitive radiological and histopathological diagnostic tests, maintenance of a high clinical suspicion by all members of the multidisciplinary team in primary and specialist care settings remains the most potent of diagnostic tools, enabling early diagnosis and appropriate therapeutic intervention.

Paediatric non-alcoholic fatty liver disease: an overview

Non-alcoholic fatty liver disease (NAFLD) is a progressive disease that encompasses a spectrum of liver diseases, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Data related to survival in children are scarce, but these data firmly associate NAFLD with higher risks of hepatic and non-hepatic morbidities and mortalities compared with the general population. More recently, the association between NAFLD and cardiovascular disease among children has increasingly been recognized. Given that obesity is a major risk factor for the disease, paediatric NAFLD is becoming a global issue, paralleling the dramatic rise in obesity worldwide. NASH, which is more common in obese children, has the potential to advance to liver fibrosis and failure. It is unclear why certain patients undergo such transformation but this susceptibility is likely related to an interaction between a genetically susceptible host and the surrounding environment. Currently, treatment is largely conservative and includes lifestyle modification, attainable through healthy weight reduction via diet and exercise. In this review, current knowledge about NAFLD in children is summarized. This review aims to increase the awareness of the medical community about a hidden public health issue and to identify current gaps in the literature while providing directions for future research.

Effects of ursodeoxycholic acid therapy on carotid intima media thickness, apolipoprotein A1, apolipoprotein B, and apolipoprotein B/A1 ratio in nonalcoholic steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a prevalent liver disease that is increasingly being associated with cardiovascular disease. Ursodeoxycholic acid (UDCA) may have antioxidant and anti-inflammatory activities, and may reduce liver injury in NASH. To date, no studies have assessed the efficacy of UDCA in carotid intima media thickness (CIMT), serum lipids, apolipoprotein A1 (apo A), apolipoprotein B (apo B), and apolipoprotein B/A1 (apo B/A1) ratios in patients with NASH.

PATIENTS AND METHODS

In this prospective study, 30 patients with biopsy-proven NASH and 25 healthy adults as a control group were evaluated. None of the participants had diabetes, hypertension, or hyperlipidemia. Patients with NASH received UDCA 15 mg/kg/day for 6 months. BMI, waist circumference, homeostasis model assessment, lipids, apo A1, apo B, apo B/A1 ratios, and CIMT were analyzed before and after the treatment period.

RESULTS

At the end of the study, there were no statistically significant changes in BMI or waist circumference. Liver enzymes decreased gradually. The homeostasis model assessment decreased from 3.4 ± 1.89 to 2.06 ± 1.68 (P < 0.001). No significant changes in the mean triglyceride, total cholesterol, low-density lipoprotein, or apo B levels were observed. The mean high-density lipoprotein (42.9 ± 7.1 vs. 45.5 ± 9.8; P = 0.037) and apo A1 (127.6 ± 17.7 vs. 135.9 ± 22.2; P = 0.02) increased significantly. Apo B/A1 ratios tended to decrease, but this decrease was not statistically significant. The mean CIMT decreased significantly (0.56 ± 0.15 vs. 0.47 ± 0.12; P = 0.001).

CONCLUSION

UDCA treatment in NASH patients resulted in statistically significant reductions in the mean CIMT over a 6-month period. We believe that this benefit of UDCA may have resulted from decreased insulin resistance and increased serum high-density lipoprotein-apo A1 levels. However, larger, longer-term studies are needed to confirm this effect of UDCA in NASH.

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.

Pediatric non-alcoholic fatty liver disease: an increasing public health issue

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial condition that encompasses a wide spectrum of liver abnormalities ranging from simple liver steatosis to steatohepatitis (non-alcoholic steatohepatitis), which may be associated with fibrosis and progress to cirrhosis and end-stage liver disease. NAFLD has recently become the most common cause of chronic liver disease in children and adolescents. NAFLD prevalence, alongside obesity, continues to increase among pediatric patients. Obesity is believed to represent a major risk factor for NAFLD, which is considered to be the liver presentation of the metabolic syndrome. Although the pathogenesis of NAFLD is not fully understood, the notion that multiple factors affect disease development and progression is widely accepted. Both genetic background and environmental factors contribute to NAFLD development. A more complete understanding of the pathogenesis may aid in developing non-invasive diagnostic tools and identifying new therapeutic targets. Liver biopsy currently remains the gold standard for NAFLD diagnosis and staging. Although lifestyle and diet modifications are key in NAFLD treatment, the development of new pharmacological therapies is crucial for patients who are unresponsive to first-line therapy.

CONCLUSION

Pediatric NAFLD is an increasing public health issue that remains underdiagnosed. A large-scale screening in the high-risk population, especially among the overweight pediatric patients, should be considered, including measurement of serum transaminases and liver ultrasound. It is crucial to treat this condition as soon as possible in order to avoid the progression to end-stage liver disease.

A 360-degree overview of paediatric NAFLD: recent insights

Non-alcoholic fatty liver disease (NAFLD) is a multi-faceted disorder, which ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) with/without fibrosis. The effects of specific risk factors, such as obesity and sedentary lifestyle, on predisposing genetic settings eventually lead to the development of NAFLD in children. The complex interplay between genes and environment in NAFLD pathogenesis is sustained by multiple mechanisms that involve liver crosstalk with other organs and tissues, especially gut and adipose tissue. Unfortunately, natural history of paediatric NAFLD is lacking, and the etiopathogenesis is still in the process of being defined. Potential early predictors and suitable non-invasive diagnostic tools can be discovered based on the pathogenetic mechanisms and histological patterns. This will also help design novel treatments and a comprehensive and successful management strategy for patients. In this review, we discuss the recent advances made in genetics, etiopathogenesis, diagnosis, and therapeutic management of NAFLD, focusing especially on the obesity-related steatotic liver condition.

Paediatric nonalcoholic fatty liver disease

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is a multicluster disease ranging from intrahepatic simple steatosis to nonalcoholic steatohepatitis (NASH). During the last decade, NAFLD has reached epidemic proportions in overweight/obese children. In this manuscript, we review all recent advances in paediatric NAFLD.

RECENT FINDINGS

Paediatric NAFLD displays some common aspects with the adult form of disease. However, recent findings have demonstrated that regarding development of NAFLD in children, due to the absence of long-time confounding factors, it may be more appropriate to investigate genetic and pathogenetic origins of the disease. Furthermore, as the histological pattern of paediatric NAFLD is different from those observed in adults, specific diagnostic/management programmes and diagnostic scores have been recently developed. Accordingly, several studies demonstrated that both lifestyle intervention and pharmacological treatments should be adequate to the specific pattern of NAFLD in children.

SUMMARY

Results of this year's investigations further elucidated the histological features and genetic background that characterize paediatric NAFLD; the closed association of disease development with the cross-talk between different cells and organs; limitations of diagnostic tools borrowed from adult studies and the need of further clinical trial.

[Non-alcoholic fatty liver disease in obese children and adolescents]

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in children and adolescents in industrialized countries. Recent studies have demonstrated a prevalence rate of NAFLD in overweight and obese children and adolescents in Germany of up to 30%. The spectrum of NAFLD ranges from pure fatty infiltration (simple steatosis) to inflammation (steatohepatitis, synonymous NASH) to fibrosis and cirrhosis. Age, gender, ethnicity, insulin resistance, and sex steroids are implicated in the pathogenesis of NAFLD in childhood and adolescence. Moreover, NAFLD in the pediatric age group is associated with marked cardiovascular comorbidities. This review focuses on current data regarding epidemiology, pathophysiology, comorbidities, and treatment of NAFLD in children and adolescents.

Nonalcoholic fatty liver in children and adolescents: an overview

Nonalcoholic fatty liver disease is rapidly becoming one of the most common liver diseases in the pediatric population in industrialized countries because of the growing prevalence of obesity and overweight. For this reason, there is a keen and broad interest among researchers to identify new diagnostic noninvasive tools and novel treatment modalities for this condition. Unfortunately, to date, liver biopsy remains the imperfect gold standard for diagnosis. In addition, available noninvasive markers are not fully satisfactory for the diagnosis of fatty liver. Although in recent years many pharmacological agents, on the basis of pathogenetic mechanism of the disease, have been attempted, to date, the guidelines for the management of fatty liver are still lacking. Establishing effective therapeutic strategies to treat the disease represents the challenge for pediatric hepatologists in the near future. In this article, we briefly review the current knowledge and ideas concerning pediatric nonalcoholic fatty liver disease, and discuss the new perspective therapies.

Nonalcoholic fatty liver disease in pediatric patients

Nonalcoholic fatty liver disease is a spectrum of liver disease ranging from simple hepatic steatosis to steatohepatitis, hepatic fibrosis, and cirrhosis. It is highly associated with obesity and insulin resistance, and with the dramatic increase in childhood and adolescent obesity, it has become the most common form of chronic liver disease in these age groups. Genetic and environmental factors both appear to play a role in the development of nonalcoholic fatty liver disease. There is currently no established effective therapy, and decreasing the prevalence of this disorder will require a reduction in the current obesity epidemic.

Non-alcoholic fatty liver disease in children now: lifestyle changes and pharmacologic treatments

Over the past decade, non-alcoholic fatty liver disease (NAFLD) has become one of most common chronic liver diseases in children. A greater understanding about the risk factors and molecular pathogenesis of NAFLD suggests that lifestyle interventions aiming to decrease obesity/body mass index and metabolic derangement are the first line of treatments adopted in children affected by this disease. However, because these therapeutic options are often at the beginning misjudged by the patients and their parents, the use of pharmacologic agents may help to protect the liver and other organs from further irreversible tissue damage. Pharmacologic therapies against one or more specific factors and/or molecules involved in the development of NAFLD (i.e., insulin resistance, free fatty acid lipid toxicity, and oxidative stress) also might slow the progression of this increasingly prevalent pediatric disorder. On this basis, insulin sensitizers, antioxidants, cytoprotective agents, and dietary supplementations have been evaluated in pediatric clinical trials. In this review, we discuss the efficacy of the dietary approaches, possibly coupled with regular exercise, on decreasing the metabolic and histologic damage in pediatric NAFLD. We also emphasize several advantages of the pharmacologic treatments adopted or adoptable in combination with lifestyle interventions in children with NAFLD.

Metabolic syndrome in childhood from impaired carbohydrate metabolism to nonalcoholic fatty liver disease

Compelling evidence supports the concept that nonalcoholic fatty liver disease (NAFLD) represents the hepatic component of metabolic syndrome (MetS). Intrahepatic fat seems to predict more strongly than does visceral adiposity an individual's cardiovascular risk and the likelihood that metabolic abnormalities are present in youth. Young individuals with fatty liver are more insulin resistant and present with a higher prevalence of metabolic abnormalities than do individuals without intrahepatic fat accumulation. They also present with a certain endothelial dysfunction and greater carotid intima-media thickness. Conversely, youth with MetS seem to have an increased risk of developing liver inflammation, a condition termed nonalcoholic steatohepatitis (NASH), and fibrosis. In the context of MetS, the liver is central in that it can drive both hepatic and systemic insulin resistance, trigger low-grade inflammation, and promote atherogenic processes. In the context of MetS, NAFLD and altered carbohydrate metabolism track from childhood to adulthood. Thus, prevention, recognition, and effective treatment of these two abnormalities may limit the burden of morbidity and mortality associated with obesity and may delay onset of cardiovascular disease in early adulthood. The present review aims at systematically presenting evidence of the critical interplay of fatty liver and altered glucose metabolism in youth. It attempts to provide pathogenetic explanations for such an association and the rationale for its treatment, with particular regard to nutritional interventions. Key teaching points: Overweight and obese youth should be screened for fatty liver disease once after puberty by liver function tests and ultrasonography. Screening for fatty liver should be accurately performed in young patients with features of metabolic syndrome. Obese patients with fatty liver are at increased risk for altered glucose metabolism, thus they should undergo an oral glucose tolerance test. A nutritional and behavioral intervention aimed at achieving a permanent change of the lifestyle in patients and their parents is recommended.

Expert opinion on current therapies for nonalcoholic fatty liver disease

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming one of most common liver diseases in industrialized countries owing to the increasing prevalence of obesity and being overweight. Until now, loss of weight and physical activity have represented the cornerstone of treatment, but they are very difficult to achieve and to maintain. Therefore, new treatments based on pathogenetic mechanisms leading to NAFLD are under evaluation to establish an effective pharmacological therapy for this disorder.

AREAS COVERED

An overview of current therapeutic interventions to treat NAFLD is given. This review provides evidence of the efficacy of natural and pharmacological agents used so far in the treatment of both adult and pediatric NAFLD, on the basis of clinical trials published in the last 10 years.

EXPERT OPINION

In the last 10 years, many pharmacological agents on the basis of the pathogenetic mechanism of NAFLD have been attempted, but so far guidelines for the management of NAFLD are lacking. We believe that the advance in the understanding of pathogenesis and factors involved in the progression of the disease may disclose the way to defining new, solid, therapeutic strategies. A multidisciplinary approach considering the risk factors and comorbidities of fatty liver will represent in the future a successful therapeutic strategy for NAFLD.

Treatment options for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of abnormal liver enzymes in the last few decades and is among the most common forms of chronic liver disease in the Western world and across the globe. With the growing epidemic of obesity and diabetes, NAFLD is estimated to affect about one-quarter of the US population. Although most patients with NAFLD have nonprogressive bland steatosis, a minority of patients develop the histological subtype of nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis, hepatocellular carcinoma, and liver-related death. This is especially true when NASH patients have type 2 diabetes. Treatment of NAFLD should therefore be directed towards patients with established NASH. Sustained weight loss seems to improve insulin resistance and associated NASH. In fact, weight loss with bariatric surgery leads to biochemical and histological improvement in morbidly obese patients with NASH. Several pharmacologic agents have been studied in an effort to improve insulin resistance and pro-inflammatory mediators potentially responsible for the development and progression of NASH. While some studies have shown initial promise, none has established long-term efficacy using randomized clinical trials. This paper briefly reviews the epidemiology, natural history, and pathophysiology of NAFLD and NASH and then focuses on the clinical trials of various therapeutic modalities for NAFLD. These include weight loss agents, bariatric surgery, insulin-sensitizing agents, lipid-lowering agents, antioxidants, probiotics, anti-tumor necrosis factor agents, cytoprotective and other novel agents.

Fatty liver disease in children: eat now pay later

INTRODUCTION

With the recent epidemic in childhood obesity, nonalcoholic fatty liver disease (NAFLD) has become an emerging problem and a common cause of chronic liver disease in children.

METHODS

In this review, the most recent insights on the pathogenesis, diagnosis, natural history, and treatment of NAFLD in children are discussed.

Pediatric non-alcoholic fatty liver disease: Preventive and therapeutic value of lifestyle intervention

Nonalcoholic fatty liver disease (NAFLD), ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), and eventually cirrhosis and liver failure, is seen to be increasing amongst Western children. NAFLD rates are rising in parallel with the epidemic of childhood obesity, and in particular, fatty liver evolves more easily in NASH when poor dietary habits and sedentary lifestyle are combined. In fact, its general prevalence in the child population varies between 2.6% and 10%, but increases up to 80% in obese children. Since NASH is expected to become the most common cause of pediatric chronic liver disease in the near future, there is broad interest amongst clinical researchers to move forward, both in diagnosis and treatment. Unfortunately, to date, the expensive and invasive procedure of liver biopsy is seen as the gold standard for NASH diagnosis and few noninvasive diagnostic methods can be applied successfully. Moreover, there are still no approved pharmacological interventions for NAFLD/NASH. Therefore, current management paradigms are based upon the presence of associated risk factors and aims to improve an individual’s quality of life, thus reducing NAFLD-associated morbidity and mortality. Today, lifestyle intervention (diet and exercise) is the treatment of choice for NAFLD/NASH. Thus far, no study has evaluated the potential preventive effect of lifestyle intervention on children at risk of NAFLD/NASH. Future studies will be required in this area with the perspective of developing a national program to promote nutrition education and increase physical activity as means of preventing the disease in individuals at risk. Here, we outline the clinical course, pathogenesis and management of NAFLD in children, highlighting the preventive and therapeutic value of lifestyle intervention.

Identification and treatment of metabolic complications in pediatric obesity

Metabolic consequences of obesity including insulin resistance, type 2 diabetes mellitus, hyperlipidemia, hypertension, polycystic ovarian syndrome, and non-alcoholic fatty liver infiltration are rapidly emerging in the pediatric population. Identifying effective strategies for identifying and treating these obesity related comorbidities in children are crucial to the prevention of future cardiovascular disease and poor health outcomes.This review discusses the pathophysiologic connections between obesity, metabolic disease and cardiovascular risk. Current evidence and recommendations for screening and treatment for the metabolic consequences of pediatric obesity are reviewed.

The metabolic syndrome and nonalcoholic fatty liver disease in children

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent in pediatric-age individuals, in parallel with increasing obesity, and can lead to liver inflammation, fibrosis, and even cirrhosis. NAFLD appears tightly linked with features of the metabolic syndrome (MetS). This review aims to reconsider the clinical presentation, laboratory and pathologic assessment, and treatment of NAFLD, with a focus on its relationship with the MetS.

RECENT FINDINGS

NAFLD occurs with a high prevalence and severity in obese, insulin-resistant adolescents, especially Hispanic males. Pediatric NAFLD may improve with lifestyle therapy and agents that improve insulin sensitivity. In youth, NAFLD appears tightly correlated with components of the MetS, especially visceral fat, which appears to predict fibrosis as well as liver fat. In addition, noninvasive techniques such as transient elastography may help provide data on fibrosis in youth with NAFLD and avoid biopsy.

SUMMARY

The close association between NAFLD and the MetS supports screening for other comorbidities associated with the MetS. Further research is urgently required to best identify effective therapies to prevent and treat NAFLD, but its close association with MetS argues for a focus on strategies designed to improve insulin resistance and components of the MetS.

Pharmacological interventions for nonalcoholic fatty liver disease in adults and in children: a systematic review

BACKGROUND

Uncertainty exists regarding the treatment of patients with nonalcoholic fatty liver disease (NAFLD) who are unable to lose weight and/or change lifestyle. The present study assesses the effectiveness and safety of pharmacological and dietary supplement interventions for NAFLD.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched for randomized controlled trials (RCTs) both in adults and in children.

RESULTS

Fifteen (2 pediatric patients and 13 adults) RCTs met the inclusion criteria. A significant effect on normalization of alanine transaminase was found in patients treated with metformin compared with vitamin E, and in those treated with high-dose (3 g) carnitine vs diet. In contrast, there was no difference in patients treated with pioglitazone combined with vitamin E versus vitamin E alone, ursodeoxycholic acid (UDCA) combined with vitamin E or alone versus placebo, or UDCA versus combination of vitamin E and vitamin C, and in patients treated with vitamin E, probucol, N-acetylcysteine, low doses of carnitine, or Yo Jyo Shi Ko compared with placebo. Aspartate aminotransferase normalization was significantly higher in those treated with UDCA combined with vitamin E versus UDCA alone or placebo, and in those treated with metformin. Small number of subjects, high drop-out rates, and numerous interventions in 1 study limit the value of many studies. Only 7 RCTs analyzed biopsy specimens, but most of them have significant methodological limitations. Pioglitazone had reduced liver necrosis and inflammation in 1 large study.

CONCLUSIONS

Limited data do not allow one to draw firm conclusions on the efficacy of various treatments for NAFLD.

Nonviral Hepatitis

Chronic liver diseases are a significant cause of death worldwide. Cirrhosis is most frequently caused by hepatitis C or alcohol abuse, but other nonviral etiologies are now recognized as important contributors to the development of hepatitis. Nonalcoholic fatty liver disease, caused by abnormal accumulation of lipids in hepatocytes, can progress from simple steatosis to necroimflammation and cirrhosis. It is estimated to occur in up to 40% of the general population, and its pathophysiology is closely linked to features of metabolic syndrome. There is currently no proven treatment for nonalcoholic fatty liver disease. Management strategies largely address identification and treatment of associated risk factors and include drug therapy for obesity, insulin resistance (eg, metformin, thiazolidinediones), and dyslipidemia (eg, fibrates, HMG-CoA reductase inhibitors). Autoimmune hepatitis is characterized by necroinflammation mediated by autoantibody attack against liver antigens in genetically predisposed patients. It is considered a rare form of chronic liver disease but can progress to cirrhosis if unrecognized and untreated. Autoimmune hepatitis usually responds well to long-established immunosuppressive regimens with prednisone and azathioprine; however, new approaches are required for those patients who do not achieve or sustain desired outcomes or are intolerant to standard therapy.

Review article: epidemiology, pathogenesis and potential treatments of paediatric non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of paediatric liver disease. Similar to NAFLD in adults, NAFLD in children is associated with obesity and insulin resistance and requires liver histology for diagnosis and staging. However, significant histological differences exist between adult and paediatric NAFLD to warrant caution in extrapolation of adult data.

AIM

To review the available data on the epidemiology, pathogenesis, diagnosis and treatment of paediatric NAFLD.

METHODS

Relevant articles were identified by Medline searches using the keywords: nonalcoholic fatty liver disease, steatohepatitis, obesity and children.

RESULTS

The rise in childhood obesity has been accompanied by an increase in paediatric NAFLD. Age, gender and race/ethnicity are significant determinants of risk, and sex hormones, insulin sensitivity and adipocytokines are implicated in the pathogenesis of paediatric NAFLD. There is no consensus for treatment of NAFLD; however, data suggest that diet, exercise and some pharmacological therapies may be of benefit.

CONCLUSIONS

To evaluate and effectively treat paediatric NAFLD, the pathophysiology and natural history of the disease should be clarified and non-invasive methods for screening, diagnosis, and longitudinal assessment developed. Randomized, controlled, double-blind trials of pharmacological therapies in children with biopsy-proven disease are necessary.

[Effectiveness of weight loss in the treatment of non-alcoholic steatohepatitis in an obese adolescent]

Childhood obesity is the most frequent nutritional disorder in developed countries and has been described as a global epidemic by the World Health Organization. In children, as in adults, obesity is the most significant risk factor for the development of non-alcoholic fatty liver disease. Therefore, it may become the most frequent chronic liver disease in children. However, pediatric publications on this disorder, which can progress to severe liver disease with risk of mortality, are scarce, with small series and few histological studies. The present article describes an obese adolescent who presented severe steatosis and steatohepatitis, which responded to weight loss with clinical and histological normalization. The risk of obesity comorbidity is increasing significantly in the pediatric population.

Nonalcoholic Fatty liver disease and obesity

Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized medical condition that may progress to hepatic cirrhosis with liver failure. The pathologic picture resembles that of alcohol-induced liver injury, but it occurs in patients who do not abuse alcohol. NAFLD is more common among patients with evidence of insulin resistance. NAFLD refers to a wide spectrum of liver damage, ranging from simple steatosis to steatohepatitis, fibrosis, and cirrhosis. The clinical implications of NAFLD are derived mostly from its common occurrence in the general population, specifically in obese individuals, and its potential to progress to cirrhosis and liver failure. It is difficult to propose a treatment strategy for NAFLD because its pathogenesis is poorly understood; however, the most commonly associated clinical features of obesity, diabetes mellitus, lipid disorders, and hypertension deserve therapeutic interventions independent of NAFLD. It is also not known if and how treatment of these other conditions affects the natural history of NAFLD, particularly in the long term.

Hypertension and fatty liver: guilty by association?

Essential hypertension is associated with the metabolic syndrome, insulin resistance and the development of fatty liver. Fatty liver disease is a spectrum of liver diseases ranging from simple hepatic steatosis through steato-hepatitis to cirrhosis and hepatoma. The purpose of this review is to discuss the evidence for an association between essential hypertension and non-alcoholic fatty liver disease, and to consider the diagnosis and management of non-alcoholic fatty liver disease. We conclude that it is important to consider the diagnosis of fatty liver disease in hypertensive patients, to measure the liver function tests at diagnosis and not to ignore minor elevations of serum aminotransferases. Hypertensive patients with raised liver enzymes should be referred for further assessment, particularly if risk factors for progressive liver disease, such as obesity and diabetes, are present.

Bile acids for non-alcoholic fatty liver disease and/or steatohepatitis

BACKGROUND

Non-alcoholic fatty liver disease is a condition characterised by fatty deposition in the hepatocytes of patients in patients with minimal or no alcohol intake. Some patients develop non-alcoholic steatohepatitis. Bile acids may potentially protect cellular structures and may be of benefit in patients with non-alcoholic fatty liver or steatohepatitis.

OBJECTIVES

To systematically evaluate the beneficial and harmful effects of bile acids versus no intervention, placebo, or other interventions for patients with non-alcoholic fatty liver or steatohepatitis.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (July 2005), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 2, 2005), MEDLINE (1966 to July 2005), EMBASE (1980 to July 2005), and The Chinese Biomedical Database (1978 to July 2005). No language restrictions were applied.

SELECTION CRITERIA

Randomised clinical trials evaluating any bile acids versus no intervention, placebo, or other interventions in patients with NAFLD.

DATA COLLECTION AND ANALYSIS

We extracted data from the identified trials as well as contacted authors. We evaluated the methodological quality of the randomised trials by assessing the generation of allocation sequence, allocation concealment, blinding, and follow-up. We made our analyses following the intention-to-treat method by imputing missing data.

MAIN RESULTS

We identified four randomised clinical trials randomising 279 patients. Only one of the trials was considered a low-bias risk trial. One of the trials reported a non-liver-related death in the bile acid group. No significant differences were found regarding mortality or improvement in liver function tests observed after treatment with ursodeoxycholic acid. Data on the radiological and histological responses were too scant to draw any definite conclusions. Adverse events were non-specific and considered of no major clinical relevance.

AUTHORS' CONCLUSIONS

Presently, there are insufficient data to support or refute the use of ursodeoxycholic acid for patients with non-alcoholic fatty liver or steatohepatitis. It may be advisable to carry out large randomised clinical trials on this topic.

Nonalcoholic fatty liver disease (NAFLD): Approach in the adolescent patient

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver disease whose hallmark is the accumulation of large-droplet fat in hepatocytes. This metabolic disorder occurs mainly in overweight or obese individuals. The disease mechanism involves hyperinsulinemia and hepatic insulin resistance, not ethanol abuse. NAFLD may be the hepatic manifestation of the "metabolic syndrome" classically associated with type 2 diabetes mellitus and cardiovascular disease. NAFLD ranges from simple steatosis, which is the least rapidly progressing disorder, to nonalcoholic steatohepatitis to cirrhosis, which can evolve to chronic liver failure. The high prevalence of NAFLD in children has been recognized only in the past 5 to 10 years, as rates of childhood obesity have soared. Accordingly, the best strategies for diagnosis and treatment of childhood NAFLD are a work in progress and remain controversial. Weight reduction through a healthy diet and regular medium-intensity exercise is the mainstay of current treatment. Few research data are available to guide pharmacologic therapy. Certain points regarding management of childhood NAFLD require emphasis: It is a serious liver disease that requires detailed clinical investigation. Other liver diseases causing fatty liver and/or abnormal liver tests, notably Wilson disease and chronic viral hepatitis, need to be excluded. Liver biopsy can provide critical diagnostic and staging information. Associated genetic or endocrine disorders need to be identified. Treatment should begin with a low-glycemic index diet that provides adequate nutrients but is low in harmful fats and eliminates foods causing postprandial hyperglycemia. Initially, this can target two to three problem foods so that it is easy for the adolescent to follow. Regular exercise suited to the capabilities and interests of the teenager should be added to the daily routine. Where possible, a team approach, including a dietician and psychologist, should be utilized, as adolescents do better in a supportive atmosphere. Optimal drug treatment requires further research: current front-runners are vitamin E and metformin. The roles of drugs that alter appetite and bariatric surgery for adolescents with NAFLD have not been determined.

Pediatric nonalcoholic fatty liver disease: a critical appraisal of current data and implications for future research

Although population prevalence is very difficult to establish, nonalcoholic fatty liver disease (NAFLD) is probably the most common cause of liver disease in the preadolescent and adolescent age groups. There seems to be an increase in the prevalence of NAFLD, likely related to the dramatic rise in the incidence of obesity during the past 3 decades. Despite an increase in public awareness, overweight/obesity and related conditions, such as NAFLD, remain underdiagnosed by health care providers. Accurate diagnosis and staging of nonalcoholic steatohepatitis (NASH) requires liver biopsy. The development of noninvasive surrogate markers and the advancements in imaging technology will aid in the screening of large populations at risk for NAFLD. Two distinct histological patterns of NASH have been identified in the pediatric population, and discrete clinical and demographic features are observed in children with these 2 patterns. The propensity for NASH to develop in obese, insulin-resistant pubertal boys of Hispanic ethnicity or a non-Hispanic white race may provide clues to the pathogenesis of NAFLD in children. The natural history of pediatric NASH has yet to be defined, but most biopsies in this age group demonstrate some degree of fibrosis. In addition, cirrhosis can be observed in children as young as 10 years. While the optimal treatment of pediatric NAFLD has yet to be determined, lifestyle modification through diet and exercise should be attempted in children diagnosed with NAFLD. A large, multicenter trial of vitamin E and metformin is underway as part of the NASH clinical research network.

Alanine amino transferase concentrations are linked to folate intakes and methylenetetrahydrofolate reductase polymorphism in obese adolescent girls

OBJECTIVE

The objective of this study was to investigate the consequences of low dietary folate intake and the impact of the 677 C-->T methylenetetrahydrofolate reductase (MTHFR) common mutation on liver function in obese adolescents.

METHODS

Fifty-seven obese girls (BMI = 36.1 +/- 6.0 kg/m) aged 14.1 +/- 1.5 years were included before starting a weight reduction program. Dietary intakes for folate were assessed by means of an adapted food frequency questionnaire (n = 50). Liver enzymes, plasma lipids, glucose metabolism parameters, ferritin, homocysteine and erythrocyte folate content were measured in plasma or blood obtained under fasting conditions. The MTHFR 677 C-->T polymorphism, which is associated with decreased enzyme activity, was determined using PCR. Body composition was assessed using dual x-ray absorptiometry.

RESULTS

Twenty-three subjects were heterozygote (CT) for the mutation and 5 were homozygote (TT). An increase in alanine amino transferase (ALT) and ALT/aspartate aminotransferase ratio was associated with the mutation (F = 4.46, P = 0.016 and F = 5.92, P = 0.0049, respectively). Alanine amino transferase was correlated negatively to folate intake (r = -0.32, P = 0.024) (n = 50) and positively to homocysteine concentrations (r = 0.30, P = 0.025). Body composition was similar among the 3 genotypic groups. Ferritin was also correlated to ALT concentrations of the entire group (P = 0.009).

CONCLUSION

Our data suggest that folate intake and the MTHFR polymorphism represent a part of the link between antioxidant status and liver disease in obese adolescent girls.

Nonalcoholic fatty liver disease in children

Nonalcoholic fatty liver disease (NAFLD) is likely to reach epidemic proportions in children worldwide in the next decade. NAFLD may be the hepatic aspect of the metabolic syndrome in adults and children. The entire range of liver involvement characterizing NAFLD can occur in children: hepatic macrovesicular steatosis without inflammation, steatosis with inflammation or fibrosis, and cirrhosis. NAFLD may be more severe in children from certain ethnic groups or in association with metabolic disorders characterized by abnormalities in insulin receptor structure and function. Treatment strategies focus on modifying risk factors because specific drug treatments are lacking. Overweight/obesity should be identified as early as possible. Comprehensive clinical management to normalize weight should be instituted immediately to avoid hepatic and nonhepatic complications.