Pediatric Nonalcoholic Fatty Liver Disease in New York City: An Autopsy Study

Metabolic dysfunction-associated steatotic liver disease (MASLD) in children with obesity: An Obesity Medicine Association (OMA) and expert joint perspective 2025

Introduction

This Obesity Medicine Association (OMA) Expert Joint Perspective examines steatotic liver disease (SLD), which is composed of metabolic dysfunction-associated steatotic liver disease (MASLD), and metabolic dysfunction-associated steatohepatitis (MASH) in children with obesity. The prevalence of obesity is increasing, rates have tripled since 1963 from 5 % to now 19 % of US children affected in 2018. MASLD, is the most common liver disease seen in children, can be a precursor to the development of Type 2 Diabetes (T2DM) and is the primary reason for liver transplant listing in young adults. We must be vigilant in prevention and treatment of MASLD in childhood to prevent further progression.

Methods

This joint clinical perspective is based upon scientific evidence, peer and clinical expertise. The medical literature was reviewed via PubMed search and appropriate articles were included in this review. This work was formulated from the collaboration of eight hepatologists/gastroenterologists with MASLD expertise and two physicians from the OMA.

Results

The authors who are experts in the field, determined sentinel questions often asked by clinicians regarding MASLD in children with obesity. They created a consensus and clinical guideline for clinicians on the screening, diagnosis, and treatment of MASLD associated with obesity in children.

Conclusions

Obesity and the comorbidity of MASLD is increasing in children, and this is a medical problem that needs to be addressed urgently. It is well known that children with metabolic associated chronic disease often continue to have these chronic diseases as adults, which leads to reduced life expectancy, quality of life, and increasing healthcare needs and financial burden. The authors of this paper recommend healthy weight reduction not only through lifestyle modification but through obesity pharmacotherapy and bariatric surgery. Therefore, this guidance reviews available therapies to achieve healthy weight reduction and reverse MASLD to prevent progressive liver fibrosis, and metabolic disease.

Global Epidemiological Impact of PNPLA3 I148M on Liver Disease

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) has increased exponentially over the past three decades, in parallel with the global rise in obesity and type 2 diabetes. It is currently the most common cause of liver-related morbidity and mortality. Although obesity has been identified as a key factor in the increased prevalence of MASLD, individual differences in susceptibility are significantly influenced by genetic factors. PNPLA3 I148M (rs738409 C>G) is the variant with the greatest impact on the risk of developing progressive MASLD and likely other forms of steatotic liver disease. This variant is prevalent across the globe, with the risk allele (G) frequency exhibiting considerable variation. Here, we review the contribution of PNPLA3 I148M to global burden and regional differences in MASLD prevalence, focusing on recent evidence emerging from population-based sequencing studies and prevalence assessments. We calculated the population attributable fraction (PAF) as a means of quantifying the impact of the variant on MASLD. Furthermore, we employ quantitative trait locus (QTL) analysis to ascertain the associations between rs738409 and a range of phenotypic traits. This analysis suggests that these QTLs may underpin pleiotropic effects on extrahepatic traits. Finally, we outline potential avenues for further research and identify key areas for investigation in future studies.

Association of blood manganese and selenium levels with hepatic steatosis among adolescents: a nationwide cross-sectional analysis

Objective

This study aimed to investigate the association between blood manganese and selenium levels and hepatic steatosis among adolescents, using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2023.

Methods

A cross-sectional analysis was conducted using data from 2,459 adolescents (aged 12-19 years) with complete data on liver ultrasound transient elastography, blood manganese, and selenium levels. Hepatic steatosis was defined as a controlled attenuation parameter (CAP) score of ≥248 dB/m, a measure of liver steatosis, which is a primary characteristic and a less severe stage of hepatic steatosis, assessed by vibration-controlled transient elastography (VCTE). Multivariate logistic regression models were used to assess the associations between blood manganese and selenium levels and hepatic steatosis, while restricted cubic splines (RCS) were employed to examine the dose-response relationships.

Results

The mean age of the participants was 15.37 years, with 52.22% boy. Higher blood manganese and selenium levels were significantly associated with an increased prevalence of hepatic steatosis. In the fully adjusted model, adolescents in the highest quartile of blood manganese had more than twice the odds of hepatic steatosis compared to those in the lowest quartile (OR = 2.41, 95% CI: 1.55-3.75, P < 0.01). Similarly, the highest quartile of blood selenium was associated with a 57% increase in hepatic steatosis prevalence compared to the lowest quartile (OR = 1.57, 95% CI: 1.19-2.08, P < 0.01). RCS analysis confirmed a linear association between both blood manganese and selenium levels and hepatic steatosis prevalence. Subgroup analyses did not reveal statistically significant interactions by age, sex, or obesity status, although associations appeared stronger in younger adolescents.

Conclusion

Elevated blood manganese and selenium levels are associated with a higher prevalence of hepatic steatosis in adolescents. These findings suggest a potential role of trace elements in the development of hepatic steatosis, highlighting the need for further research to better understand the underlying mechanisms involved in liver fat accumulation in this population.

Pediatric Non-Alcoholic Fatty Liver Disease (NAFLD): Trends, Mortality, and Socioeconomic Disparities in the U.S., 1998-2020

BACKGROUND/OBJECTIVES

We aim to describe the changing inpatient epidemiology of NAFLD in the U.S. and identify major risk factors associated with mortality in the disease among hospitalized pediatric patients.

METHODS

Hospitalization data from the 1998-2020 National Inpatient Sample were utilized. ICD-9 and ICD-10 codes were used to identify pediatric patients (age less than 18 years old) with NAFLD, and risk factors for mortality were analyzed by logistic regression.

RESULTS

We identified 68,869 pediatric hospitalizations involving NAFLD. Among those, 970 (1.4%) died during hospitalization. Hospitalization rates have been rapidly increasing from 1998 to 2020 (incidence rate ratio (IRR): 1.07; 95% CI: 1.06-1.07; p < 0.001). There was a significant difference in mortality based on the type of hospital (rural, non-teaching urban, or teaching urban) in pediatric patients with NAFLD (p < 0.05). Coagulopathy was significantly associated with increased odds of mortality, while age ≥ 12 years, diabetes and obesity were associated with decreased odds of mortality (p < 0.05). Sex, race/ethnicity, hepatitis B, hepatitis C, HIV, and IV drug use were not significantly associated with mortality.

CONCLUSIONS

Our study has shown ever increasing hospitalization rates for NAFLD in pediatric populations and well as significant risk factors associated with mortality. Further studies should be performed as more data on this patient population are collected.

Non-alcoholic fatty liver disease and the gut microbiota in adolescents: is there a relationship?

BACKGROUND

Despite the increasing prevalence of nonalcoholic fatty liver disease (NAFLD), the pathophysiology is still not fully understood. Recent evidence suggests that the gut microbiota may play a role in the pathophysiology of NAFLD and may also offer new therapeutic options.

METHODS

This prospective cross-sectional study included 100 consecutive newly diagnosed obese patients (BMI ≥ 95th percentile), aged 14-18 years with NAFLD (confirmed by ultrasound), persistently elevated levels of alanine aminotransferase (ALT) greater than 60 U/L for 1-6 months, and 100 healthy controls. We evaluated changes in the gut microbiota in NAFLD adolescents compared with healthy controls.

RESULTS

According to the multiple logistic regressions, the variables associated with NAFLD were the presence of Clostridium difficile, the presence of Salmonella spp., a greater abundance of Bifidobacterium and Prevotella, and a lower abundance of Lactobacillus.

CONCLUSION

Changes in the gut microbiota occur in adolescents with NAFLD compared with healthy individuals, which may be useful for identifying youths who are amenable to gut microbiota-based interventions.

CLINICAL TRIAL NUMBER

Not applicable.

Converging Pathways between Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and Diabetes in Children

In the past thirty years, childhood obesity rates have risen significantly worldwide, affecting over 340 million children in affluent nations. This surge is intricately tied to metabolic disorders, notably insulin resistance, type 2 diabetes mellitus (T2DM), and the continually evolving spectrum of metabolic-associated (dysfunction) steatotic liver disease (MASLD). This review underscores the alarming escalation of childhood obesity and delves comprehensively into the evolving and dynamic changes of nomenclature surrounding diverse conditions of hepatic steatosis, from the initial recognition of non-alcoholic fatty liver disease (NAFLD) to the progressive evolution into MASLD. Moreover, it emphasizes the crucial role of pediatric endocrinologists in thoroughly and accurately investigating MASLD onset in children with T2DM, where each condition influences and exacerbates the progression of the other. This review critically highlights the inadequacies of current screening strategies and diagnosis, stressing the need for a paradigm shift. A proposed solution involves the integration of hepatic magnetic resonance imaging assessment into the diagnostic arsenal for children showing insufficient glycemic control and weight loss post-T2DM diagnosis, thereby complementing conventional liver enzyme testing. This holistic approach aims to significantly enhance diagnostic precision, fostering improved outcomes in this vulnerable high-risk pediatric population.

Prevalence of metabolic dysfunction-associated steatotic liver disease and steatohepatitis in Türkiye: A forensic autopsy study

Background and aims

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global epidemic in Türkiye and worldwide. The aim of this study was to evaluate the prevalence and predictors of MASLD and steatohepatitis among adults who died of unnatural causes including sudden death and non-burn trauma.

Method

We conducted a prospective review of all consecutive adult forensic autopsies for natural (sudden unexpected) and non-natural (Suicidal, homicidal and accidental) suspicious deaths carried out at the Istanbul Council of Forensic Medicine from February to May 2022. Four wedge biopsies were extracted from sagittal sectioned liver specimens. A liver pathologist with 20 years of experience examined each case for steatosis, ballooning, inflammation, and fibrosis.

Results

Among 1797 autopsies, 62 met inclusion criteria. Overall, 43.3 % (n = 26) of autopsies showed evidence of steatotic liver disease, with a distribution of steatosis severity as: Grade I (28.3 %), Grade II (6.6 %), and Grade III (8.3 %). All these cases met at least one cardiometabolic criteria and diagnosed with MASLD. Ballooning was observed in 20.0 % of cases (5 cases grades 1 and 7 cases grade 2), and Inflammation was present in 51.7 % (9 cases with grade 0-1, 12 with 1-2, 7 with 2-3, and 3 with 5-6). Notably, 46.1 % (n = 12) of MASLD cases and 20.0 % (n = 12) of all cases were diagnosed with steatohepatitis, with three cases exhibiting delicate perisinusoidal fibrosis and one case showing portal fibrosis.

Conclusion

The histopathological findings from this autopsy study confirmed the markedly high prevalence of MASLD and steatohepatitis within the general adult population, highlighting the concerning burden of steatotic liver disease in Türkiye.

Metabolic complications of obesity in children and adolescents

The global prevalence of childhood and adolescent obesity, exacerbated by the coronavirus disease 2019 pandemic, affects school-aged children and preschoolers. Early-onset obesity, which carries a high risk of metabolic complications, may contribute to a lower age at the onset of cardiovascular disease. As metabolic diseases such as diabetes, dyslipidemia, and nonalcoholic fatty liver disease observed in adulthood are increasingly recognized in the pediatric population, there is an emphasis on moving disease susceptibility assessments from adulthood to childhood to enable early detection. However, consensus is lacking regarding the definition of metabolic diseases in children. In response, various indicators such as the pediatric simple metabolic syndrome score, continuous metabolic syndrome score, single-point insulin sensitivity estimator, and fatty liver index have been proposed in several studies. These indicators may aid the early detection of metabolic complications associated with pediatric obesity, although further validation studies are needed. Obesity assessments are shifting in perspective from visual obesity to metabolic health and body composition considerations to fill the gap in health impact assessments. Sarcopenic obesity, defined as the muscle- to-fat ratio, has been proposed in pediatric populations and is associated with metabolic health in children and adolescents. The National Health Screening Program for Children in Korea has expanded but still faces limitations in laboratory testing. These tests facilitate timely intervention by identifying groups at a high risk of metabolic complications. Early detection and intervention through comprehensive health screening are critical for mitigating long-term complications of childhood obesity.

Prevalence of Elevated ALT in Adolescents in the US 2011-2018

OBJECTIVE

The objective of this study is to characterize suspected nonalcoholic fatty liver disease (NAFLD) using elevated alanine aminotransferase (ALT) in a diverse and nationally representative cohort of adolescents and to characterize higher ALT elevation in adolescents with obesity.

METHODS

Data from the National Health and Nutrition Examination Survey 2011-2018 were analyzed for adolescents 12-19 years. Participants with causes for elevated ALT other than NAFLD were excluded. Race and ethnicity, sex, body mass index (BMI), and ALT were examined. Elevated ALT was defined as >22 U/L (females) and >26 U/L (males) using the biologic upper normal limit (ULN). Elevated ALT thresholds up to 2X-ULN were examined among adolescents with obesity. Multivariable logistic regression was used to determine the association of race/ethnicity and elevated ALT, adjusting for age, sex, and BMI.

RESULTS

Prevalence of elevated ALT in adolescents was 16.5% overall and 39.5% among those with obesity. For White, Hispanic, and Asian adolescents, prevalence was 15.8%, 21.8%, and 16.5% overall, 12.8%, 17.7%, and 27.0% in those with overweight, and 43.0%, 43.5%, and 43.1% in those with obesity, respectively. Prevalence was much lower in Black adolescents (10.7% overall, 8.4% for overweight, 20.7% for obesity). Prevalence of ALT at 2X-ULN was 6.6% in adolescents with obesity. Hispanic ethnicity, age, male sex, and higher BMI were independent predictors of elevated ALT.

CONCLUSIONS

Prevalence of elevated ALT in U.S. adolescents is high, affecting 1 in 6 adolescents during 2011-2018. The risk is highest in Hispanic adolescents. Asian adolescents with elevated BMI may comprise an emerging risk group for elevated ALT.

Low bone mineral density is associated with fatty liver disease and respiratory illness in a pediatric mortality sample

This study finds that fatty liver disease is associated with low bone density in a pediatric mortality sample. Since non-alcoholic fatty liver disease has increased in prevalence over the past few decades among children, a better understanding of the disease's impacts on bone health is of significance to clinicians.

PURPOSE

Chronic illness leads to decreased bone modeling and remodeling. This can be especially problematic during childhood and adolescence, since the majority of an individual's peak bone mass is achieved by the age of 20. In this study, we examine relationships between chronic illness and low bone mineral density (BMD) in a pediatric mortality sample (aged 0.5 to 20.9 years) from New Mexico. We also test whether low BMD is related to decelerated linear growth by examining its relationship to growth stunting and arrest (Harris lines).

METHODS

Hounsfield units (HU), a proxy for trabecular BMD, were obtained at the fourth lumbar vertebra and the femoral neck from postmortem CT scans. Linear regression was used to examine associations between z-standardized HU and age, sex, medical conditions, Harris lines, and growth stunting.

RESULTS

We find that lumbar HU is significantly lower for individuals with fatty liver disease and respiratory illness; femoral HU is significantly lower in individuals with Harris lines.

CONCLUSION

The mechanisms of low BMD in individuals with fatty liver disease and respiratory illness are likely multifactorial and involve vitamin D deficiency (malnutrition, malabsorption), systemic inflammation, and sedentary lifestyles. However, better awareness of this relationship can provide clinicians with the ability to introduce nutritional and behavioral interventions early to mitigate deleterious effects on bone. Harris lines, on the other hand, mark temporary growth cessation due to physiological stress followed by a rapid resumption of growth. Low BMD in these individuals may be due to bone mineralization lagging behind relatively rapid linear growth.

Review article: the epidemiologic burden of non-alcoholic fatty liver disease across the world

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing in parallel with obesity and type 2 diabetes.

AIM

To review the global epidemiology of NAFLD METHODS: We retrieved articles from PubMed using search terms of NAFLD, epidemiology, prevalence, incidence, and comorbidities.

RESULTS

Over 250 articles were reviewed. In 2016, the global NAFLD prevalence was 25%; this increased to >30% in 2019. Prevalence in Asia, Latin America and Middle East-North Africa (MENA) was 30.8%, 34.5% and 42.6%, respectively. Prevalence increased with age. Although prevalence was higher in men, prevalence in post-menopausal women was similar. NAFLD prevalence was higher in certain subpopulations, especially among the obese and those with metabolic syndrome (MS). However, the prevalence of lean NAFLD was 11.2%. The global prevalence of non-alcoholic steatohepatitis (NASH) is estimated between 2% and 6% in the general population. Approximately 7% of patients with NAFLD have advanced fibrosis; rates were between 21% and 50% among patients with NASH. Overall mortality related to NAFLD was 15-20 per 1000 person-years, and increased substantially in patients with NASH, especially in those with components of MS. Recent data suggest mortality/morbidity from NAFLD is increasing globally but NAFLD awareness remains low among patients and healthcare providers.

CONCLUSIONS

NAFLD poses a global public health problem with a very high disease burden in Asia, MENA and Latin America. Research is needed to better quantify the full impact of NAFLD and to develop strategies to improve awareness and risk stratification.

The accuracy of fatty liver index for the screening of overweight and obese children for non-alcoholic fatty liver disease in resource limited settings

Background

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease among children with a higher prevalence among obese. Fatty liver index (FLI), an algorithm derived to screen NAFLD using the waist circumference, body mass index, triglyceride and gamma glutamyl-transferase concentration was rarely investigated in Asian paediatric population. Since each component is routinely measured in clinical practice, it is feasible to measure FLI even in resource limited settings. Hence, we determined the accuracy of FLI for the screening of NAFLD in obese children in Southern Sri Lanka.

Methods

A descriptive cross sectional study was conducted on ninety five children (56 boys) aged 5–15 years with BMI ≥ 85th percentile for age and gender based on CDC 2000 growth charts recruited from the nutrition clinic at the Teaching Hospital, Karapitiya, Sri Lanka. NAFLD was diagnosed by ultrasonography. Factors associated with ultrasonographic fatty liver such as biochemical parameters and fatty liver index in either sex or the whole population were determined by a multivariate analysis. The ability of FLI to screen NAFLD was determined by the analysis of area under the receiver operator characteristic curve (AUROC) and the maximum Youden index analysis.

Results

Overweight and obese children with ultrasonographic fatty liver had a significantly higher FLI than those without fatty liver according to the multivariate analysis performed (Odds ratio 3.524; 95% CI 1.104–11.256, P = 0.033). AUROC of FLI for NAFLD was 0.692 (95% CI; 0.565–0.786) and the optimal cut off value for the screening of NAFLD was 30 (Maximum Youden index 0.2782, Sensitivity, 58.33%; Specificity, 69.49%).

Conclusion

FLI could accurately be used in resource limited community settings and in epidemiological studies to screen overweight and obese children for NAFLD.

The burden and sexual dimorphism with nonalcoholic fatty liver disease in Asian children: A systematic review and meta-analysis

BACKGROUND

Despite substantial attention paid to the epidemic of nonalcoholic fatty liver disease (NAFLD) in adults, data on the burden and sexual dimorphism of NAFLD in Asian children have not yet been synthesized.

METHODS

We conducted a literature search of 735 references up to April 2021. Pooled analyses, stratified analyses and meta-regression were all performed.

RESULTS

Thirty-three study populations were finally included. Nine of them comprising 20 595 children showed an overall NAFLD prevalence of 5.53% (95% CI 3.46%-8.72%), in which, 36.64% (95% CI, 27.99%-46.26%) NAFLD subjects had elevated levels of ALT. The prevalence rate of NAFLD increased about 1.6-fold from 2004 to 2010 to the last decade. Male predominant trends were observed in paediatric NAFLD (boys: 8.18%, 95% CI 4.93%-13.26%; girls: 3.60%, 95% CI 1.60%-7.87%). Moreover, meta-analysis showed that after 10 years of age, boys were more prone to have NAFLD than girls (OR = 1.75; P = .0012). In addition, the pooled prevalence of NAFLD increased sequentially in normal-weight (1.49%, 95% CI 0.88%-2.51%, n = 2610), overweight (16.72%, 95% CI 7.07%-34.65%, n = 1265) and obese children (50.13%, 95% CI 41.99%-58.27%, n = 6434 individuals). After full covariate adjustment, the multivariate meta-regression also showed that boy percentage (P = .0396) and body mass index (P < .0001) were positively correlated with prevalent NAFLD.

CONCLUSIONS

In Asia, paediatric NAFLD is becoming prevalent over the recent decades, particularly among obese children and boys after 10 years old. The hormonal and chromosomal origins of paediatric NAFLD dimorphism need further investigation.

Nonalcoholic Steatohepatitis in Children

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in children. Although environmental factors are major contributors to early onset, children have both shared and unique genetic risk alleles as compared with adults with NAFLD. Treatment relies on reducing environmental risk factors, but many children have persistent diseases. No medications are approved specifically for the treatment of NAFLD, but some anti-obesity or diabetes treatments may be beneficial. Pediatric NAFLD increases the risk of diabetes and other cardiovascular risk factors. Long-term prospective studies are needed to determine the long-term risk of hepatic and non-hepatic morbidity and mortality in adulthood.

Ethnic disparities in liver fat accumulation in school-aged children

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) has a different prevalence in adults from different ethnic groups. This study examined whether these ethnic differences originate in early life and could be explained by early-life factors.

METHODS

This observational study was embedded in a population-based prospective cohort study from fetal life onward among 2,570 children born in Rotterdam, the Netherlands. Information about prepregnancy, pregnancy, and childhood factors, as well as childhood BMI, was obtained from questionnaires and physical examinations. Liver fat was assessed by magnetic resonance imaging at age 10 years.

RESULTS

Median liver fat fraction was 2.0% (95% CI: 1.2%-5.3%), and NAFLD prevalence was 2.8%. Children from a Turkish background had the highest median liver fat percentage (2.5%, 95% CI: 1.2%-10.7%) and NAFLD prevalence (9.1%). Children of Cape Verdean, Dutch Antillean, Surinamese-Creole, or Turkish background had a higher total liver fat fraction compared with children with a Dutch background (p < 0.05). After controlling for early-life factors, these differences persisted only in children with a Turkish background.

CONCLUSIONS

Prevalence of liver fat accumulation and NAFLD differs between ethnic subgroups living in the Netherlands, especially for those with a Turkish background. Early-life factors have a strong influence on these associations and may hold clues for future preventive strategies.

Unique Cardiovascular Disease Risk Factors in Hispanic Individuals

Purpose of Review

This review summarizes contemporary data on unique cardiovascular disease (CVD) risk factors in Hispanic individuals in the USA, and how addressing these factors is important in addressing health equity.

Recent Findings

Recent studies have shown high rates of traditional CVD risk factors in Hispanic individuals such as obesity, hypertension, diabetes, hyperlipidemia, and emerging CVD risk factors like hypertensive disorders of pregnancy, psychological stress, and occupational exposures. However, most studies fail to consider the significant heterogeneity in risk factor burden and outcomes in atherosclerotic CVD by Hispanic subgroup. Heart failure and rhythm disorders are less well studied in Hispanic adults, making risk assessment for these conditions difficult. High levels of CVD risk factors in Hispanic youth given an aging Hispanic population overall highlight the importance of risk mitigation among these individuals.

Summary

In brief, these data highlight the significant, unique burden of CVD risk among Hispanic individuals in the USA and predict a rising burden of disease among this growing and aging population. Future CVD research should focus on including robust, diverse Hispanic cohorts as well as specifically delineating results for disaggregated Hispanic groups across CVDs. This will allow for better risk assessment, prevention, and treatment decisions to promote health equity for Hispanic patients.

The Prevalence of Elevated Alanine Aminotransferase Levels Meeting Clinical Action Thresholds in Children with Obesity in Primary Care Practice

Using a clinically actionable threshold for alanine aminotransferase to define suspected nonalcoholic fatty liver disease in US children with obesity, the risk of suspected nonalcoholic fatty liver disease was highest for Asian and Hispanic race/ethnicity, male sex, and severe obesity.

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.

Health disparities in cardiometabolic risk among Black and Hispanic youth in the United States

Cardiometabolic risk factors in children and adolescents track into adulthood and are associated with increased risk of atherosclerotic cardiovascular disease. The purpose of this review is to examine the pervasive race and ethnic disparities in cardiometabolic risk factors among Black and Hispanic youth in the United States. We focus on three traditional cardiometabolic risk factors (obesity, type 2 diabetes mellitus, and dyslipidemia) as well as on the emerging cardiometabolic risk factor of non-alcoholic fatty liver disease. Additionally, we highlight interventions aimed at improving cardiometabolic health among these minority pediatric populations. Finally, we advocate for continued research on effective prevention strategies to reduce cardiometabolic risk and avert further disparities in cardiovascular morbidity and mortality.

Alanine Aminotransferase and Gamma-Glutamyl Transpeptidase Predict Histologic Improvement in Pediatric Nonalcoholic Steatohepatitis

BACKGROUND AND AIMS

Predictive, noninvasive tools are needed to monitor key features of nonalcoholic fatty liver disease (NAFLD) in children that relate to improvement in liver histology. The purpose of this study was to evaluate the relationship between liver chemistries and liver histology using data from the CyNCh (Cysteamine Bitartrate Delayed-Release for the Treatment of NAFLD in Children) clinical trial.

APPROACH AND RESULTS

This study included 146 children. Improvement in liver histology, defined as decrease in nonalcoholic fatty liver disease (NAFLD) Activity Score ≥2 points without worsening of fibrosis, occurred in 43 participants (30%). There were 46 participants with borderline zone 1 nonalcoholic steatohepatitis (NASH) at baseline, with resolution in 28% (12 of 46). Multivariate models were constructed using baseline and change in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) at 52 weeks, for improvement in (1) liver histology primary outcome, (2) borderline zone 1 NASH, and (3) fibrosis. For improvement in histology, the model (P < 0.0001) retained baseline and change in GGT (area under the receiver operating characteristic [AUROC], 0.79; 95% confidence interval [CI], 0.71-0.87). For borderline zone 1 NASH, the model (P = 0.0004) retained baseline and change in ALT (AUROC, 0.80; 95% CI, 0.67-0.93). For fibrosis, the model (P < 0.001) retained baseline and change in ALT (AUROC, 0.80; 95% CI, 0.67-0.93). Additional clinical parameters were added to the models using Akaike's information criterion selection, and significantly boosted performance: improvement in histology with AUROC of 0.89 (95% CI, 0.82-0.95), borderline zone 1 NASH with AUROC of 0.91 (95% CI, 0.83-0.99), and fibrosis with AUROC of 0.89 (95% CI, 0.82-0.94). Models were validated using data from the TONIC (Treatment of Nonalcoholic Fatty Liver Disease in Children) trial.

CONCLUSIONS

In children with NAFLD, dynamic changes in serum ALT and GGT are associated with change in liver histology and appear to be powerful indicators of histological response.

Advances in the Epidemiology, Diagnosis, and Management of Pediatric Fatty Liver Disease

PURPOSE

Nonalcoholic fatty liver (NAFL) is a major contributor to pediatric liver disease. This review evaluated the current literature on prevalence, screening, diagnosis, and management of NAFL in children and explored recent advances in the field of pediatric NAFL.

METHODS

A PubMed search was performed for manuscripts describing disease burden, diagnosis, and management strategies in pediatric NAFL published within the past 15 years. Systematic reviews, clinical practice guidelines, randomized controlled trials, and cohort and case-control studies were reviewed for the purpose of this article.

FINDINGS

The prevalence of NAFL in children is increasing. It is a leading cause of liver-related morbidity and mortality in children. Screening and diagnosis of NAFL in children are a challenge. Lifestyle changes and exercise are the cornerstones of the management of NAFL.

IMPLICATIONS

Further research is needed to develop better screening and diagnostic tools for pediatric NAFL, including noninvasive diagnostics. NAFL therapeutics is another area of much-needed, ongoing research.

Incidence of Nonalcoholic Fatty Liver Disease in Children: 2009-2018

BACKGROUND AND OBJECTIVES

In 2007, the American Academy of Pediatrics recommended that children with obesity should be screened for nonalcoholic fatty liver disease (NAFLD). Population epidemiology reveals that NAFLD is common in children; however, little is known about rates of clinical diagnosis. In this study, we aim to determine screening practices, annual incidence, and clinical characteristics of NAFLD in children within an integrated community health system.

METHODS

Using electronic health records, we identified patients newly diagnosed (aged 5-18) with NAFLD on the basis of diagnostic codes from the 9th and 10th revisions of the International Classification of Diseases. We calculated screening rates and annual incidence rates of NAFLD from January 1, 2009, to December 31, 2018.

RESULTS

In this study, we evaluated 7 884 844 patient-years. Screening was performed in 54.0% of children with obesity and 24.0% of children with overweight. The results revealed 36 658 children aged 9 to 18 with overweight or obesity and alanine aminotransferase >30 U/L. Of these children, 12.3% received further workup for NAFLD. The incidence of an NAFLD diagnosis significantly increased over time, with 36.0 per 100 000 in 2009 and 58.2 per 100 000 in 2018 (P < .0001).

CONCLUSIONS

Our study of a large integrated health care system in southern California revealed that the incidence of NAFLD in children is increasing, although many children may remain undiagnosed.

Perspectives on youth-onset nonalcoholic fatty liver disease

BACKGROUND

The prevalence and incidence of youth-onset nonalcoholic fatty liver disease (NAFLD) far exceeds other paediatric chronic liver diseases and represents a considerable public health issue globally.

METHODS

Here, we performed a narrative review of current knowledge regarding the epidemiology of paediatric NAFLD, selected concepts in pathogenesis, comorbidities, diagnosis, and management, and issues related to the transition to adulthood.

RESULTS

Paediatric NAFLD has become increasingly more prevalent, especially in certain subgroups, such as children with obesity and certain races/ethnicities. The pathophysiology of paediatric NAFLD is complex and multifactorial, driven by an interaction of environmental and genetic factors. Once developed, NAFLD in childhood is associated with type 2 diabetes, hypertension, increased cardiovascular disease risk, and end-stage liver disease. This predicts an increased burden of morbidity and mortality in adolescents and young adults. Early screening and diagnosis are therefore crucial, and the development of noninvasive biomarkers remains an active area of investigation. Currently, treatment strategies are focused on lifestyle changes, but there is also research interest in pharmacological and surgical options. In the transition from paediatric to adult care, there are several potential challenges/barriers to treatment and research is needed to understand how best to support patients during this time.

CONCLUSIONS

Our understanding of the epidemiology and pathophysiology of paediatric NAFLD has increased considerably over recent decades, but several critical knowledge gaps remain and must be addressed in order to better mitigate the short-term and long-term risks of youth-onset NAFLD.

Effect of TSH on Non-Alcoholic Fatty Liver Disease (NAFLD) independent of obesity in children of predominantly Hispanic/Latino ancestry by causal mediation analysis

Background

Nonalcoholic Fatty Liver Disease (NAFLD) is a common co-morbidity of obesity. Elevated TSH levels (eTSH), also associated with obesity, may contribute to the dysmetabolic state that predisposes to NAFLD.

Objective

To assess the relationship between TSH levels and NAFLD in children with biopsy-proven NAFLD compared to controls.

Design and methods

In this retrospective study of children with biopsy-proven NAFLD and age-matched controls, the association of eTSH with NAFLD was investigated and the role of TSH as a mediator between obesity and NAFLD was assessed.

Results

Sixty-six cases and 4067 controls (69.7 vs 59% Hispanic/Latino ancestry, p = 0.1) of the same age range seen in the same time duration at an urban Children’s Hospital were studied. Children with NAFLD were more likely to be male (74.6 vs 39.4%, p < 0.001), have higher modified BMI-z scores (median 2.4 (IQR 1.7) vs 1.9 (IQR 1.7), p < 0.001), and abnormal metabolic parameters (TSH, ALT, HDL-C, non-HDL-C, and TG). Multivariate analyses controlling for age, sex and severity of obesity showed significant association between the 4^th quartile of TSH and NAFLD. Causal mediation analysis demonstrates that TSH mediates 33.8% of the effect of modified BMI-z score on NAFLD. This comprises of 16.0% (OR = 1.1, p = 0.002) caused by the indirect effect of TSH and its interaction with modified BMI-z, and 17.7% (OR = 1.1, p = 0.05) as an autonomous effect of TSH on NAFLD. Overall, 33.8% of the effect can be eliminated by removing the mediator, TSH (p = 0.001).

Conclusions

The association of eTSH and biopsy-proven NAFLD is demonstrated in children of Hispanic/Latino ancestry. Further, a causal mediation analysis implicates an effect of TSH on NAFLD, independent of obesity.

Recent advances in understanding and managing pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of disease that can range from isolated macrovesicular hepatocellular steatosis to nonalcoholic steatohepatitis (NASH) with or without fibrosis to cirrhosis. The prevalence of NAFLD has increased over several decades, mirroring the global obesity pandemic. NAFLD currently represents the most common etiology of chronic liver disease in children and adolescents worldwide. Disease presentation in childhood strongly suggests that these children may have unique susceptibilities and more severe long-term consequences. Emerging data demonstrate that the pathogenesis of early-onset NAFLD is secondary to a complex interplay involving genetic, metabolic, environmental, and microbiological factors. Such influences may begin in utero. Dietary and lifestyle modifications remain the primary effective therapeutic interventions, although long-term efficacy is limited by poor adoption or adherence. Advances in the development and validation of non-invasive biomarkers and imaging modalities will facilitate diagnosis for affected children and adolescents and facilitate long-term natural history studies and the development of therapeutic interventions.

Nonalcoholic Fatty Liver Disease in Children: Unique Considerations and Challenges

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence in concert with the global epidemic of obesity and is being diagnosed at increasingly younger ages. The unique histologic features and early presentation of disease in pediatrics suggest that children and adults may differ with regard to etiopathogenesis, with children displaying a greater vulnerability to genetic and environmental factors. Of significant relevance to pediatrics, in utero and perinatal stressors may alter the lifelong health trajectory of a child, increasing the risk of NAFLD and other cardiometabolic diseases. The development and progression of disease in childhood is likely to carry increased risk of long-term morbidity. Novel biomarkers and therapeutic agents are needed to avoid the otherwise inevitable health and societal consequences of this rapidly expanding pediatric population.

Genetic Risk Factors and Disease Modifiers of Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease is strongly associated with obesity and the metabolic syndrome, but genetic factors also contribute to disease susceptibility. Human genetic studies have identified several common genetic variants contributing to nonalcoholic fatty liver disease initiation and progression. These findings have provided new insights into the pathogenesis of nonalcoholic fatty liver disease and opened up new avenues for the development of therapeutic interventions. In this review, we summarize the current state of knowledge about the genetic determinants of nonalcoholic fatty liver disease, focusing on the most robustly validated genetic risk factors and on recently discovered modifiers of disease progression.

Designing Clinical Trials in Pediatric Nonalcoholic Steatohepatitis: Tips for Patient Selection and Appropriate Endpoints

Nonalcoholic fatty liver disease (NAFLD) is common in children and may progress to nonalcoholic steatohepatitis (NASH), advanced fibrosis, and even cirrhosis in childhood or early adulthood, indicating the need for pharmacologic treatment in this age group. Multiple trials are evaluating different therapeutic targets for NASH with fibrosis in adults, and the U.S. Food and Drug Administration has recently provided clear guidance to the pharmaceutical industry on developing drugs for the treatment of noncirrhotic NASH with liver fibrosis. Pediatric NAFLD has several unique aspects that distinguish it from the adult disease in terms of histology, our understanding of the natural history, and the utility of noninvasive tests. These differences have the potential to impact the design of clinical trials to test different drugs in the pediatric population. The aim of this article is to provide a review of common misconceptions regarding pediatric NAFLD and key differences from adult NAFLD. We have provided our recommendations on the design of early proof-of-concept and late phase 2 trials based on lessons learned from previous clinical trials. We believe that clinical drug development for children with NAFLD should happen in parallel with ongoing adult trials.

NAFLD in children: new genes, new diagnostic modalities and new drugs

Nonalcoholic fatty liver disease (NAFLD) has rapidly become the most common form of chronic liver disease in children and adolescents. Over the past 5 years, developments have revolutionized our understanding of the genetic factors, natural history, diagnostic modalities and therapeutic targets for this disease. New polymorphisms, such as those in PNPLA3, TM6SF2, MBOAT7 and GCKR, have been identified and used to predict the development and severity of NAFLD in both adults and children, and their interaction with environmental factors has been elucidated. Studies have demonstrated the true burden of paediatric NAFLD and its progression to end-stage liver disease in adulthood. In particular, nonalcoholic steatohepatitis can progress to advanced fibrosis and cirrhosis, emphasizing the importance of early diagnosis. Non-invasive imaging tests, such as transient elastography, will probably replace liver biopsy for the diagnosis of nonalcoholic steatohepatitis and the assessment of fibrosis severity in the near future. The therapeutic landscape is also expanding rapidly with the development of drugs that can modify liver steatosis, inflammation and fibrosis, indicating that pharmacotherapy for NAFLD will become available in the future. In this Review, we summarize current knowledge and new advances related to the pathogenesis and management of paediatric NAFLD.

Omega-3 fatty acids and nonalcoholic fatty liver disease in adults and children: where do we stand?

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic fatty liver disease worldwide. The incidence of NAFLD parallels the prevalence of obesity. Moreover, NAFLD can progress to nonalcoholic steatohepatitis (NASH), cirrhosis and primary hepatocellular cancer (HCC). As such, NAFLD has become a major public health concern. We discuss recent clinical trials and meta-analyses evaluating the efficacy of C20-22 ω3 polyunsaturated fatty acids (PUFA) to attenuate preexisting NAFLD in adults and children.

RECENT FINDINGS

Humans with NAFLD and NASH; and preclinical mouse models of NASH, have a high abundance of hepatic saturated (SFA) and monounsaturated (MUFA) fat, but a low abundance of hepatic C20-22 ω3 PUFA. This change in hepatic fat type and abundance is associated with hepatic lipotoxicity, inflammation, oxidative stress and fibrosis. Recent meta-analyses and clinical trials evaluated the capacity of C20-22 ω3 PUFA dietary supplementation to improve health outcomes in adults and children with preexisting NAFLD. Diets supplemented with docosahexaenoic acid (DHA, 22 : 6,ω3) alone or with eicosapentaenoic acid (EPA, 20 : 5,ω3) are tolerated and effective at lowering liver fat in NAFLD patients. However, outcomes are mixed with respect to C20-22 ω3 PUFA attenuation of more severe NAFLD markers, such as hepatic injury, inflammation and fibrosis.

SUMMARY

These studies suggest that dietary supplementation with C20-22 ω3 PUFA should be considered as a viable and effective option to lower liver fat in obese adults and children with NAFLD.