Perspectives on youth-onset nonalcoholic fatty liver disease

Daily glucose variability is associated with intrahepatic fat content, β cell sensitivity, and biomarkers of glycolysis in youth with obesity

OBJECTIVE

Pediatric obesity is associated with insulin resistance, which, in turn, impacts glucose and lipid metabolism. This study sought to assess how glucose variability relates to intrahepatic fat content, β cell insulin sensitivity, and glycolysis in youth with obesity.

METHODS

A total of 27 youth with obesity (11 girls, BMI percentile, median [25th-75th percentiles]: 99.0 [97.9-99.0]) wore a continuous glucose monitoring device for 10 days and underwent a 3-h oral glucose tolerance test. β cell function was assessed using the oral minimal model, and liver proton density fat fraction was measured by magnetic resonance imaging.

RESULTS

Average sensor-derived glucose and glucose standard deviation (STDEV) and coefficient of variation (CV) were associated with liver proton density fat fraction (p = 0.0130, p = 0.0005, and p = 0.0028, respectively). First-phase insulin secretion, basal insulin secretion, and insulin sensitivity were associated with STDEV (p = 0.0344, p = 0.0091, and p = 0.0031, respectively) and CV (p = 0.0128, p = 0.0012, and p = 0.0022, respectively). STDEV and CV were also associated with 2-h glucose (p = 0.0067 and p = 0.0324, respectively) and plasma lactate (p = 0.0030 and p = 0.0123, respectively).

CONCLUSIONS

Daily glucose variability is associated with the degree of intrahepatic fat content, postprandial glucose, and plasma lactate concentrations.

Adipose tissue insulin resistance in children and adolescents: linking glucose and free fatty acid metabolism to hepatic injury markers

Obesity is one of the leading causes of the development of insulin resistance, diabetes, and metabolic dysfunction-associated steatotic liver disease (MASLD) in children. With the progression of insulin resistance, both glucose and free fatty acid (FFA) plasma levels are elevated, leading to cardiometabolic complications such as impaired glucose tolerance (IGT), type 2 diabetes, and liver fat accumulation. In this study, oral minimal models were used to estimate insulin sensitivity indexes (SI and SIFFA) in 375 adolescents with obesity. Differences between normal glucose tolerance (NGT) and IGT were assessed by using Mann-Whitney U test, while the relationship between insulin sensitivities and plasma alanine transaminase (ALT) was assessed using Spearman correlation and linear regression model of the log-transformed variables. Also, 48 youths repeated the oral glucose tolerance test and the measurement of liver function test after ∼1.3 yr of follow-up. SI was statistically different between NGT and IGT (P < 10-6) and correlated with each other (ρ = 0.7, P < 10-6). Lipolysis was completely suppressed after 30 min in NGT, compared with 120 min in IGT. SI and SIFFA were both statistically correlated with ALT (ρ = -0.19, P < 10-3). Also, the percentages of variation of SIFFA and ALT between the first and second visits correlated significantly (ρ = -0.47, P = 0.002). FFA minimal model can be used to estimate adipose tissue lipolysis in youths with obesity. The relationship of SI and SIFFA with ALT, along with the progression of the impairment of adipose tissue insulin sensitivity, shows that systemic insulin resistance underlies the relationship of glucose and FFA metabolism with hepatic damage.NEW & NOTEWORTHY In this study, we applied glucose, Cpeptide, and FFA minimal models to assess insulin sensitivities, insulin secretion, and lipolytic flux in NGT and IGT in adolescents with obesity. The results show that glucose and adipose tissue insulin sensitivities are strongly correlated with each other and with ALT plasma level. The longitudinal results show that changes in FFA insulin sensitivity are inversely associated with changes of beta cell secretion and with biomarkers of metabolic dysfunction-associated steatohepatitis.

Modelling and assessment of glucose-lactate kinetics in youth with overweight, obesity and metabolic dysfunction-associated steatotic liver disease: A pilot study

AIM

In this study, we investigated glucose and lactate kinetics during a 75 g oral glucose tolerance test (OGTT) in 23 overweight and obese adolescents and assessed putative differences among participants with and without metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

We enrolled 23 young people (six girls) with obesity [body mass index 33 (29-37)]. Glucose-lactate kinetics parameters (disposal glucose insulin sensitivity, SID; fraction of glucose converted into lactate, fr; fractional lactate clearance rate, kL) and lactate production rate (LPR) were estimated using the oral glucose-lactate minimal model. MASLD presence was assessed using the proton density fat fraction. We analysed glucose, lactate and LPR time to peak, peak values and area under the curve and evaluated differences using the Wilcoxon test. MASLD and no-MASLD participants were compared using the Mann-Whitney test. Correlations between parameters were assessed using the Spearman correlation coefficient (ρ). We also tested the performance of two (4 or 3 h OGTT) protocols in estimating oral glucose-lactate minimal model and LPR parameters.

RESULTS

Glucose peaks 30 min earlier than lactate (p = .0019). This pattern was present in the no-MASLD group (p < .001). LPR peaks 30 min later in the MASLD group (p = .02). LPR and kL were higher in MASLD, suggesting higher glycolysis and lactate utilization. SID and fr correlate significantly (ρ = -0.55, p = .008). SID and fr were also correlated with the body mass index, (ρ = -0.45, p = .04; and ρ = 0.45; p = .03). The protocol duration did not influence the estimates of the parameters.

DISCUSSION

Youth with MASLD showed a delayed glucose metabolism, possibly because of greater utilization of the underlying substrates. A 3-h OGTT may be used to assess lactate metabolism effectively.

Unveiling the cancer risk nexus of the steatotic liver

Steatotic liver, characterized by the accumulation of fat in the liver, poses significant health risks including metabolic dysfunction-associated steatotic liver disease (MASLD) and an elevated risk of primary liver cancer. Emerging evidence indicates a robust association between steatotic liver and increased susceptibility to extrahepatic primary cancers and their metastases. The deposition of fat induces dynamic changes in hepatic microenvironments, thereby fostering inflammation and immune responses that enhance liver metastasis from extrahepatic primary cancers. This review explores the impact of steatotic liver on hepatic carcinogenesis and metastasis from extrahepatic cancers, with a specific focus on hepatocyte-derived factors and the immune microenvironment. By emphasizing novel conclusions, this article underscores the timely relevance of understanding these intricate connections.

Risk factors and cardio-metabolic outcomes associated with metabolic-associated fatty liver disease in childhood

Background

Non-Alcoholic Fatty Liver Disease (NAFLD) is defined as increased liver fat percentage, and is the most common chronic liver disease in children. Rather than NAFLD, Metabolic-Associated Fatty Liver Disease (MAFLD), defined as increased liver fat with presence of adverse cardio-metabolic measures, might have more clinical relevance in children. We assessed the prevalence, risk-factors and cardio-metabolic outcomes of MAFLD at school-age.

Methods

This cross-sectional analysis was embedded in an ongoing population-based prospective cohort study started in 2001, in the Netherlands. In 1910 children of 10 years, we measured liver fat fraction by magnetic resonance imaging (MRI), body mass index (BMI), blood pressure, and lipids, insulin, and glucose concentrations. Childhood lifestyle factors were obtained through questionnaires. MAFLD was defined as ≥2% liver fat in addition to excess adiposity (BMI or visceral adiposity), presence of metabolic risk (blood pressure, triglycerides and HDL-concentrations) or prediabetes (glucose).

Findings

Of all children, 49.6% had ≥2% liver fat, and 25.2% fulfilled the criteria of MAFLD. Only non-European descent was associated with increased odds of MAFLD at nominal significance (Odds Ratio 1.38, 95% Confidence Interval 1.04, 1.82). Compared to children with <2% liver fat, those with MAFLD had increased odds of cardio-metabolic-risk-factor clustering (Odds Ratio 7.65, 95% Confidence Interval 5.04, 11.62).

Interpretation

In this study, no NAFLD-associated childhood risk factors were associated with increased odds of childhood MAFLD, yet the findings suggest that ethnicity could be, despite mostly explained by socio-economic factors. Use of MAFLD criteria, rather than NAFLD, may identify children at risk for impaired cardio-metabolic health.

Funding

Erasmus University MC, the Netherlands Organisation for Health Research and Development, the Ministry of Health, Welfare, and Sport, and the European Research Council.

Liver Transplant Outcomes in Young Adults with Cirrhosis Related to Nonalcoholic Fatty Liver Disease

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NASH) and cryptogenic cirrhosis (CC) is constantly increasing in adolescents and young adults (AYAs).

METHODS

In a retrospective UNOS database evaluation, we analyzed postoperative outcomes of AYAs with nonalcoholic NASH/CC undergoing LT between January 1st, 2003 and March 5th, 2021. After exclusions, 85,970 LT recipients, 393 (47.1%) AYAs with NASH/CC and 441 (52.9%) AYAs with other metabolic conditions, were analyzed.

RESULTS

During the study period, the number of LTs performed for AYAs with NASH/CC increased from 4%-7% but decreased from 6.6%-5.3% compared to LTs performed for NASH/CC in all ages. In comparison to AYAs with other metabolic conditions, AYA LT recipients with NASH/CC had a higher prevalence of metabolic syndrome (MetS) components, including diabetes and increased body mass index (P < .0001 for both). Patient and graft survival in AYAs with NASH/CC were significantly lower in comparison to AYAs transplanted for other metabolic conditions (P < .0001) (Hazard Ratio = 1.93, P < .001). Patient survival in AYAs with NASH/CC was significantly better in comparison to older (40-65-year-old) patients with the same diagnosis (P = .01).

CONCLUSIONS

Our study found that the overall number of LTs in AYAs with NASH increased significantly, but to a lesser degree compared to the older population with the same diagnosis. Outcomes after LT in AYAs with NASH/CC were worse compared to LT for other metabolic conditions, but significantly better in comparison to older patients. The prevalence of LT for NASH/CC in AYAs is growing. MetS may contribute to worse outcomes in AYAs.

Liver Fibrosis Markers Represent Central Venous Pressure in Post-pubertal Patients With Congenital Heart Disease

Background Central venous pressure (CVP) is one of the most important hemodynamic parameters in patients with congenital heart disease (CHD). In adults, it is well-known that liver fibrosis markers reflect CVP, but this is not well-understood in children. We investigated the liver fibrosis markers in pediatric CHD patients and their ability to predict CVP. Methods We studied 160 patients who underwent cardiac catheterization in our hospital between January 2017 and December 2020. The levels of the fibrotic markers, including type IV collagen 7s, procollagen type III peptide, and hyaluronic acid, were measured. Results Procollagen type III peptide was markedly elevated in infants younger than one year of age. From one to 15 years of age, it was slightly lower than in the infant group, with a peak at around 10 years of age. In the age group of 16 years and older, most of its values were generally high. Type IV collagen 7s and hyaluronic acid levels were high in infants, with no significant differences at later ages. Procollagen type III peptide and hyaluronic acid showed no significant correlation with CVP in any of the age groups, whereas type IV collagen 7s significantly correlated with CVP in the age group above one year old. Conclusions We found that elevated liver fibrosis markers, particularly type IV collagen 7s, correlated with central venous pressure in CHD patients older than one year. Measurement of liver fibrosis markers may allow the early detection of changes in CVP and liver function in patients with CHD.

Metabolic-Associated Fatty Liver Disease in Childhood and Adolescence

Metabolic-associated fatty liver disease (MAFLD) has become the most common cause for chronic liver disease among children and adolescents globally. Although liver biopsy remains the gold standard for diagnosis, emerging technology, like velocity controlled transient elastography, a noninvasive method, is being utilized to evaluate degree of fibrosis in these patients. The discovery of multiple gene polymorphisms has brought new hope for possible treatment targets. However, this research is still ongoing, making lifestyle changes and weight reduction the current mainstay of treatment. This review briefly reviews the most recent data regarding the epidemiology, pathophysiology, diagnostic modalities, and treatment of pediatric MAFLD.

Obesity Pillars roundtable: Metabolic and bariatric surgery in children and adolescents

Background

Obesity is a chronic disease which frequently begins in childhood and requires a life-long multidisciplinary approach. Metabolic-bariatric surgery (MBS) is a key component of the treatment of severe obesity in children, adolescents and adults. Children and adolescents who have class II obesity and a complication of obesity or have class III obesity should be considered for MBS, regardless of age, race, sex, or gender. Children and adolescents with cognitive disabilities, a history of mental illness, a treated eating disorder, immature bone growth, or low Tanner Stage should not be denied treatment. Early intervention can reduce the risk of persistent obesity, end organ damage, and sequelae from long-standing complications of obesity.

Methods

This roundtable discussion includes three pediatric obesity specialists with experience in the medical and surgical management of children and adolescents with obesity. Included are citations regarding metabolic-bariatric surgery in children and adolescents.

Results

MBS in pediatric patients is increasingly recognized as an essential part of managing the disease of obesity in combination with medication, nutrition, behavioral training, and physical activity. Vertical sleeve gastrectomy or Roux-en-Y gastric bypass in patients meeting criteria for severe obesity should be considered, especially when children have complications such as poor quality of life, orthopedic disease, idiopathic intracranial hypertension, type 2 diabetes mellitus, obstructive sleep apnea, or cardiovascular risk. Children and adolescents with autism, developmental delay, or syndromic obesity should be considered for MBS on a case-by-case basis. Early intervention may result in improved long-term outcomes, and referral for MBS should not be conditional based on stage of pubertal development (Tanner Staging), bone age, or prior weight loss attempts.

Conclusions

Children and adolescents who suffer from severe obesity need the entire spectrum of treatment modalities available to achieve a healthy weight and control obesity-related complications. This treatment spectrum should include MBS. These children and adolescents should be cared for by a pediatric weight management team prepared to care for them until they transition to adult care.

Development of a prediction protocol for the screening of metabolic associated fatty liver disease in children with overweight or obesity

BACKGROUND

The early detection and management of children with metabolic associated fatty liver disease (MAFLD) is challenging.

OBJECTIVE

To develop a non-invasive and accurate prediction protocol for the identification of MAFLD among children with overweight/obesity candidates to confirmatory diagnosis.

METHODS

A total of 115 children aged 8-12 years with overweight/obesity, recruited at a primary care, were enrolled in this cross-sectional study. The external validation was performed using a cohort of children with overweight/obesity (N = 46) aged 8.5-14.0 years. MAFLD (≥5.5% hepatic fat) was diagnosed by magnetic resonance imaging (MRI). Fasting blood biochemical parameters were measured, and 25 candidates' single nucleotide polymorphisms (SNPs) were determined. Variables potentially associated with the presence of MAFLD were included in a multivariate logistic regression.

RESULTS

Children with MAFLD (36%) showed higher plasma triglycerides (TG), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), alanine aminotransferase (ALT), aspartate transaminase (AST), glutamyl-transferase (GGT) and ferritin (p < 0.05). The distribution of the risk-alleles of PPARGrs13081389, PPARGrs1801282, HFErs1800562 and PNLPLA3rs4823173 was significantly different between children with and without MAFLD (p < 0.05). Three biochemical- and/or SNPs-based predictive models were developed, showing strong discriminatory capacity (AUC-ROC: 0.708-0.888) but limited diagnostic performance (sensitivity 67%-82% and specificity 63%-69%). A prediction protocol with elevated sensitivity (72%) and specificity (84%) based on two consecutive steps was developed. The external validation showed similar results: sensitivity of 70% and specificity of 85%.

CONCLUSIONS

The HEPAKID prediction protocol is an accurate, easy to implant, minimally invasive and low economic cost tool useful for the early identification and management of paediatric MAFLD in primary care.

Insights from shotgun metagenomics into bacterial species and metabolic pathways associated with NAFLD in obese youth

Nonalcoholic fatty liver disease (NAFLD) is the most common form of liver disease and is often the precursor for more serious liver conditions such as nonalcoholic steatohepatitis and cirrhosis. Although the gut microbiome has been implicated in the development of NAFLD, the strong association of obesity with NAFLD and its effect on microbiome structure has made interpreting study outcomes difficult. In the present study, we examined the taxonomic and functional differences between the microbiomes of youth with obesity and with and without NAFLD. Shotgun metagenome sequencing was performed to profile the microbiomes of 36 subjects, half of whom were diagnosed with NAFLD using abdominal magnetic resonance imaging. Beta diversity analysis showed community-wide differences between the groups (p = 0.002). Specific taxonomic differences included increased relative abundances of the species Fusicatenibacter saccharivorans (p = 0.042), Romboutsia ilealis (p = 0.046), and Actinomyces sp. ICM47 (p = 0.0009), and a decrease of Bacteroides thetaiotamicron (p = 0.0002), in the NAFLD group as compared with the non-NAFLD group. At the phylum level, Bacteroidetes (p < 0.0001) was decreased in the NAFLD group. Functionally, branched-chain amino acid (p = 0.01343) and aromatic amino acid (p = 0.01343) synthesis pathways had increased relative abundances in the NAFLD group along with numerous energy use pathways, including pyruvate fermentation to acetate (p = 0.01318). Conclusion: Community-wide differences were noted based on NAFLD status, and individual bacterial species along with specific metabolic pathways were identified as potential drivers of these differences. The results of the present study support the idea that the NAFLD phenotype displays a differentiated microbial and functional signature from the obesity phenotype.

Metabolic dysfunction-associated fatty liver disease in obese youth with insulin resistance and type 2 diabetes

PURPOSE OF REVIEW

The aim of this review is to present the new definition of the disease, defining the epidemiology, risk factors with a particular attention to the role of insulin resistance (IR) and to define the main treatments explored.

RECENT FINDINGS

Nonalcoholic fatty liver disease (NAFLD) was previously considered a primary liver disease, but it would be more correct to consider it a component of the metabolic syndrome (MetS) in which IR might play a key role. Based on these findings, it has been recently proposed to modify the classic term of NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) that better reflects the pathophysiology of this complex disease.

SUMMARY

Currently, no treatments approved in childhood are available, thus the only recommended approach is the prevention and correction of the known risk factors, and particularly of IR. However, further studies are needed to better clarify the pathogenetic mechanisms of NAFLD in order to establish more tailored therapies.

Alarming increase of NASH as cause of liver cancer

A very interesting recent article by Huang and colleagues evaluated the global epidemiology of liver cancer from 2010 to 2019 and showed that non-alcoholic steatohepatitis (NASH) is the fastest growing cause of hepatocellular carcinoma (HCC).¹

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.

Neonatal Oral Administration of Chrysin Prevents Long-Term Development of Non-Alcoholic Fatty Liver Disease in a Sexually Dimorphic Manner in Fructose Nurtured Sprague Dawley Rats

High-fructose diets are linked with the development of non-alcoholic fatty liver disease (NAFLD), the management of which is a burden to society. Interventions with phytochemicals in the early postnatal period may prevent fructose-induced NAFLD later in adulthood. We investigated the protective potential of chrysin against fructose-induced NAFLD. Four-day-old male and female suckling Sprague Dawley rats (N = 112) were randomly grouped and orally gavaged daily with distilled water (negative Control-Cn + W), chrysin(Chr-100 mg/kg), fructose-solution (Fr-20% w/v), and Chr + Fr between postnatal day (PND) 4 and 21 and then weaned onto normal rat chow and plain drinking water to PND 55. From PND 56 to 130, half of the rats continued on plain water, and the rest had Fr as drinking fluid. Terminally, the liver tissue was collected, and the lipid content was determined and histologically assessed for NAFLD. Dietary Fr induced an increased hepatic lipid content (p = 0.0001 vs. Cn + W) both sexes, and it was only attenuated by neonatal Chr in female rats (p < 0.05). Histologically, there was increased microvesicular steatosis (p = 0.0001 vs. Cn + W) in both sexes, and it was prevented by neonatal Chr (p > 0.05). Fr caused macrovesicular steatosis (p = 0.01 vs. Cn + W) in females only, and chrysin did not prevent it (p > 0.05). Fr induced hepatocellular hypertrophy, and inflammation was observed in females only (p = 0.01 vs. Cn + W), and this was prevented by Chr (p > 0.05). The collagen area fraction was increased by Fr (p = 0.02 (males) and p = 0.04 (females) vs. Cn + W, respectively; however, chrysin did not prevent this (p > 0.05). Neonatal chrysin prevented some of the deleterious effects of the high-fructose diet on the liver, suggesting that chrysin should be further explored as a strategic prophylactic neonatal intervention against high-fructose-diet-induced NAFLD.

Young adults with nonalcoholic fatty liver disease, defined using the fatty liver index, can be at increased risk of myocardial infarction or stroke

AIM

To investigate the relationship between nonalcoholic fatty liver disease (NAFLD) and cardiovascular events among a nationally representative sample of young adults in Korea.

METHODS AND RESULTS

This population-based cohort study from the Korean National Health Insurance Service included adults who were aged 20 to 39 years when they underwent a health examination between 2009 and 2012. NAFLD was defined as a fatty liver index (FLI) ≥60, and participants were divided into three groups according to FLI (<30, 30-59 and ≥60) to investigate the dose-dependent effect of FLI score. Among 5 324 410 participants, 9.8% had an FLI ≥60. There were 13 051 myocardial infarctions (MIs; 0.39%) and 8573 strokes (0.26%) during a median follow-up of 8.4 years. In multivariable analysis, NAFLD was associated with a higher risk of MI and stroke (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.61-1.77 and HR  1.73, 95% CI 1.63-1.84, respectively). MI and stroke had dose-dependent relationships with FLI (HR 1.28 in participants with FLI 30-59 and 1.73 in those with FLI ≥60 for MI and HR 1.18 in participants with FLI 30-59 and 1.41 in those with FLI ≥60 for stroke, respectively).

CONCLUSIONS

Nonalcholic fatty liver disease was an independent predictor of MI and stroke in young adults. These results suggest that primary prevention of cardiovascular disease should be emphasized in young adults with NAFLD.

Glomerular Biomechanical Stress and Lipid Mediators during Cellular Changes Leading to Chronic Kidney Disease

Hyperfiltration is an important underlying cause of glomerular dysfunction associated with several systemic and intrinsic glomerular conditions leading to chronic kidney disease (CKD). These include obesity, diabetes, hypertension, focal segmental glomerulosclerosis (FSGS), congenital abnormalities and reduced renal mass (low nephron number). Hyperfiltration-associated biomechanical forces directly impact the cell membrane, generating tensile and fluid flow shear stresses in multiple segments of the nephron. Ongoing research suggests these biomechanical forces as the initial mediators of hyperfiltration-induced deterioration of podocyte structure and function leading to their detachment and irreplaceable loss from the glomerular filtration barrier. Membrane lipid-derived polyunsaturated fatty acids (PUFA) and their metabolites are potent transducers of biomechanical stress from the cell surface to intracellular compartments. Omega-6 and ω-3 long-chain PUFA from membrane phospholipids generate many versatile and autacoid oxylipins that modulate pro-inflammatory as well as anti-inflammatory autocrine and paracrine signaling. We advance the idea that lipid signaling molecules, related enzymes, metabolites and receptors are not just mediators of cellular stress but also potential targets for developing novel interventions. With the growing emphasis on lifestyle changes for wellness, dietary fatty acids are potential adjunct-therapeutics to minimize/treat hyperfiltration-induced progressive glomerular damage and CKD.

Association Between Non-invasive Diagnostic Methods of Liver Fibrosis and Type 2 Diabetes in Pediatric Patients With Non-alcoholic Fatty Liver Disease

BACKGROUND AND PURPOSE

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children has been increasing associated with insulin resistance. However, there is a scarcity of related studies in children with NAFLD with type 2 diabetes mellitus (T2DM) compared to adults. We conducted this study to investigate the association between non-invasive diagnostic methods of liver fibrosis and T2DM in pediatric patients with NAFLD.

METHODS

We enrolled a total of 152 patients aged <18 years with NAFLD, and compared their data according to the presence of T2DM. We evaluated fibrosis by transient elastography (TE, FibroScan®), and calculated the following fibrosis scores for each patient: NAFLD fibrosis score (NFS), AST: platelet ratio index (APRI), Fibrosis-4 (FIB-4) index, and pediatric NAFLD fibrosis index (PNFI).

RESULTS

In the NAFLD-T2DM group, the NFS and mean controlled attenuation parameter in FibroScan were significantly higher than those in the nondiabetic group. The receiver operating characteristic (ROC) curve values for predicting the presence of T2DM were 0.78 for NFS, 0.64 for FIB-4, 0.62 for PNFI, and 0.61 for APRI. The cutoff HbA1c levels for predicting fibrosis progression in APRI, NFS, and PNFI were 5.7% [area under the curve (AUC) 0.74], 6.4% (AUC 0.71), and 6.4% (AUC 0.55), respectively. In the multivariate analysis, hepatosteatosis on abdomen sonography, NFS, FibroScan F, and APRI were independently associated with T2DM risk.

CONCLUSIONS

We significantly characterized non-invasive fibrosis markers and elastography in pediatric NAFLD with T2DM compared with the nondiabetic group. We suggest evaluating the progression of fibrosis in the prediabetic stage in children using a combination of these non-invasive methods.

Metabolic Fatty Liver Disease in Children: A Growing Public Health Problem

Metabolic-associated fatty liver disease (MAFLD), previously called nonalcoholic fatty liver diseases (NAFLD), is one of the most important causes of chronic liver disease worldwide and will likely become the leading cause of end-stage liver disease in the decades ahead. MAFLD covers a continuum of liver diseases from fatty liver to nonalcoholic steatohepatitis (NASH), liver fibrosis/cirrhosis and hepatocellular cancer. Importantly, the growing incidence of overweight and obesity in childhood, 4% in 1975 to 18% in 2016, with persisting obesity complications into adulthood, is likely to be harmful by increasing the incidence of severe MAFLD at an earlier age. Currently, MAFLD is the leading form of chronic liver disease in children and adolescents, with a global prevalence of 3 to 10%, pointing out that early diagnosis is therefore crucial. In this review, we highlight the current knowledge concerning the epidemiology, risk factors and potential pathogenic mechanisms, as well as diagnostic and therapeutic approaches, of pediatric MAFLD.

Differences between current clinical guidelines for screening, diagnosis and management of nonalcoholic fatty liver disease and real-world practice: a targeted literature review

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease and is associated with obesity and metabolic comorbidities. Liver steatosis can progress to nonalcoholic steatohepatitis (NASH) exhibiting a relevant risk of fibrosis and ultimately liver failure. To date, no approved treatment for NASH to reduce its clinical and humanistic burden has been developed.

AREAS COVERED

We undertook a literature review to identify English language, national and international clinical guidelines for NAFLD regarding diagnosis, assessment and management, and determined their points of agreement and difference. Additionally, we investigated published literature relating to real-world management of NAFLD and NASH.

EXPERT OPINION

National (China, England/Wales, Italy, the USA) and international society (Asia-Pacific, Europe, World Gastroenterology Organization) guidelines were identified and analyzed. All guidelines addressed identifying and diagnosing subjects with likely NAFLD, as well as assessment and management of individuals with risk factors for advanced disease, including fibrosis. Real-world practice reveals widespread suboptimal awareness and implementation of guidelines. In the absence of proven therapeutics, such gaps risk failure to recognize patients in need of specialist care and monitoring, highlighting the need for clear, easy-to-apply care pathways to aid in reducing the clinical and humanistic burden of NAFLD and NASH.

NAFLD and renal function in children: is there a genetic link?

Introduction: Over the past decades, a large amount of both adult and pediatric data has shown relationship between Nonalcoholic Fatty Liver Disease (NAFLD) and chronic kidney disease (CKD), resulting in an overall increased cardiometabolic burden. In view of the remarkable role of the genetic background in the NAFLD pathophysiology, a potential influence of the major NAFLD polymorphisms (e.g. the I148M variant of the Patatin-like phospholipase containing domain 3 (PNPLA3) gene, the E167K allele of the Transmembrane 6 superfamily member 2 (TM6SF2), the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13), and the Membrane bound O-acyltransferase domain containing 7-transmembrane channel-like 4 (MBOAT7-TMC4) genes) on renal function has been supposed. A shared metabolic and proinflammatory pathogenesis has been hypothesized, but the exact mechanism is still unknown.Areas covered: We provide a comprehensive review of the potential genetic link between NAFLD and CKD in children. Convincing both adult and pediatric evidence supports this association, but there is some dispute especially in childhood.Expert opinion: Evidence supporting a potential genetic link between NAFLD and CKD represents an intriguing aspect with a major clinical implication because of its putative role in improving strategy programs to counteract the higher cardiometabolic risk of these patients.

A Review of the Increasing Prevalence of Metabolic-Associated Fatty Liver Disease (MAFLD) in Children and Adolescents Worldwide and in Mexico and the Implications for Public Health

Non-alcoholic fatty liver disease (NAFLD) affects almost a quarter of the world’s population and is the most common cause of chronic liver disease in children and adolescents. The recent proposal to replace the terminology of NAFLD with metabolic-associated fatty liver disease (MAFLD) aims to reflect the pathophysiology and risk factors for this disease. Importantly, the risk factors for MAFLD may be prenatal, such as genetic factors, or postnatal, such as obesity and insulin resistance. MAFLD is increasingly recognized in children and adolescents. Early diagnosis and identification of high-risk individuals with type 2 diabetes mellitus and metabolic syndrome is important. The diagnosis and management of MAFLD in children and adolescents should follow international clinical guidelines, such as those from the American Diabetes Association (ADA) and the International Society for Pediatric and Adolescent Diabetes (ISPAD). Current guidelines recommend lifestyle and dietary modifications, exercise, screening, individualized patient assessment, and multidisciplinary patient management. This review assesses the revised terminology and discusses the epidemiology, risk factors, pathophysiology, diagnosis, and prevention of MAFLD in children and adolescents worldwide and in Mexico, and also considers the implications for public health.

Non-Alcoholic Fatty Liver Disease in Children

Background and Objectives: The prevalence of pediatric non-alcoholic fatty liver disease is increasing. A lot of new data are published regularly. Materials and Methods: Original clinical studies, review articles, and guidelines in children were searched for and the most relevant included in this review. Results: A total of 138 retrieved papers were classified into pathogenesis, epidemiology, diagnosis, and treatment. Pathogenesis is currently explained with the "multi hit hypothesis", with complex interactions of genetic and environmental factors which trigger inflammation in steatotic liver. The prevalence is rising. A diagnosis can be made with laboratory tests, imaging, and liver biopsy after the exclusion of other causes of liver steatosis. The mainstay of treatment is lifestyle modification consisting of dietary intervention and increased physical activity. The progression to liver cirrhosis can occur even in children. Conclusions: Non-alcoholic fatty liver disease in children is a part of a metabolic syndrome in the majority of patients. Due to its complex etiology and high prevalence, multidisciplinary teams, together with public health professionals, should be involved in its treatment.

Perinatal High-Salt Diet Induces Gut Microbiota Dysbiosis, Bile Acid Homeostasis Disbalance, and NAFLD in Weanling Mice Offspring

A perinatal high-salt (HS) diet was reported to elevate plasma triglycerides. This study aimed to investigate the hypothesis that a perinatal HS diet predisposed offspring to non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of abnormal lipid metabolism, and the possible mechanism. Female C57BL/6 mice were fed a control diet (0.5% NaCl) or HS diet (4% NaCl) during pregnancy and lactation and their offspring were sacrificed at weaning. The perinatal HS diet induced greater variation in fecal microbial beta-diversity (β-diversity) and increased bacteria abundance of Proteobacteria and Bacteroides. The gut microbiota dysbiosis promoted bile acid homeostasis disbalance, characterized by the accumulation of lithocholic acid (LCA) and deoxycholic acid (DCA) in feces. These alterations disturbed gut barrier by increasing the expression of tight junction protein (Tjp) and occludin (Ocln), and increased systemic lipopolysaccharide (LPS) levels and hepatic inflammatory cytokine secretion (TNF-α and IL-6) in the liver. The perinatal HS diet also inhibited hepatic expression of hepatic FXR signaling (CYP7A1 and FXR), thus triggering increased hepatic expression of pro-inflammatory cytokines (TNF-α and IL-6) and hepatic lipid metabolism-associated genes (SREBP-1c, FAS, ACC), leading to unique characteristics of NAFLD. In conclusion, a perinatal HS diet induced NAFLD in weanling mice offspring; the possible mechanism was related to increased bacteria abundance of Proteobacteria and Bacteroides, increased levels of LCA and DCA in feces, and increased expressions of hepatic FXR signaling.

Development and Internal Validation of Fatty Liver Prediction Models in Obese Children and Adolescents

To develop predictive models of fatty liver (FL), we performed a cross-sectional retrospective study of 1672 obese children with a median (interquartile range) age of 15 (13-16) years. The outcome variable was FL diagnosed by ultrasonography. The potential predictors were: (1) binary: sex; (2) continuous: age, body mass index (BMI), waist circumference (WC), alanine transaminase (ALT), aspartate transaminase, gamma-glutamyltransferase, glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), HDL-cholesterol, LDL-cholesterol, triglycerides, mean arterial pressure, uric acid, and c-reactive protein; (3) ordinal: Pubertal status. Bootstrapped multivariable logistic regression with fractional polynomials was used to develop the models. Two models were developed and internally validated, one using BMI and the other using WC as the anthropometric predictor. Both models included ALT, HOMA-IR, triglycerides, and uric acid as predictors, had similar discrimination (c-statistic = 0.81), and were similarly well calibrated as determined by calibration plots. These models should undergo external validation before being employed in clinical or research practice.

MAFLD in Obese Children: A Challenging Definition

BACKGROUND

Recently, the new definition of Metabolic (dysfunction) associated fatty liver disease (MAFLD) has gained remarkable scientific interest. We aimed to evaluate the effectiveness of MAFLD definition in selecting obese children at higher cardiovascular risk.

METHODS

A total of 954 obese children and adolescents was retrospectively enrolled. Clinical, biochemical, and metabolic evaluations were performed. Hepatic steatosis was assessed by liver ultrasound. According to the metabolic status, the population was divided in three groups. Group 1 included obese patients without both non-alcoholic fatty liver disease (NAFLD) and metabolic dysregulation; group 2 included patients with obesity and NAFLD (then encompassing one MAFLD criterion); group 3 included patients with obesity, NAFLD and evidence of metabolic dysregulation (then encompassing more than 1 MAFLD criteria).

RESULTS

Patients of Group 3 showed a worse cardiometabolic profile, as also proven by the higher percentage of prediabetes (defined as the presence of impaired fasting glucose or impaired glucose tolerance) compared to other groups (p = 0.001).

CONCLUSIONS

MAFLD criteria in obese children seem to be less accurate in identifying patients having an intrinsic higher cardiometabolic risk. This suggests the need for a more accurate definition in the context of pediatric obesity.