Role of gut-liver axis and glucagon-like peptide-1 receptor agonists in the treatment of metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease(MAFLD)is a hepatic manifestation of the metabolic syndrome.It is one of the most common liver diseases worldwide and shows increasing prevalence rates in most countries.MAFLD is a progressive disease with the most severe cases presenting as advanced fibrosis or cirrhosis with an increased risk of hepatocellular carcinoma.Gut microbiota play a significant role in the pathogenesis and progression of MAFLD by disrupting the gut-liver axis.The mechanisms involved in maintaining gut-liver axis homeostasis are complex.One critical aspect involves preserving an appropriate intestinal barrier permeability and levels of intestinal lumen metabolites to ensure gutliver axis functionality.An increase in intestinal barrier permeability induces metabolic endotoxemia that leads to steatohepatitis.Moreover,alterations in the absorption of various metabolites can affect liver metabolism and induce liver steatosis and fibrosis.Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)are a class of drugs developed for the treatment of type 2 diabetes mellitus.They are also commonly used to combat obesity and have been proven to be effective in reversing hepatic steatosis.The mechanisms reported to be involved in this effect include an improved regulation of glycemia,reduced lipid synthesis,β-oxidation of free fatty acids,and induction of autophagy in hepatic cells.Recently,multiple peptide receptor agonists have been introduced and are expected to increase the effectiveness of the treatment.A modulation of gut microbiota has also been observed with the use of these drugs that may contribute to the amelioration of MAFLD.This review presents the current understanding of the role of the gutliver axis in the development of MAFLD and use of members of the GLP-1 RA family as pleiotropic agents in the treatment of MAFLD.

Muscle strength and non-alcoholic fatty liver disease/metabolicassociated fatty liver disease

This editorial comments on an article published in a recent issue of World Journal of Gastroenterology,entitled“Association of low muscle strength with metabolic dysfunction-associated fatty liver disease:A nationwide study”.We focused on the association between muscle strength and the incidence of non-alcoholic fatty liver disease(NAFLD)and metabolic-associated fatty liver disease(MAFLD),as well as the mechanisms underlying the correlation and related clinical applications.NAFLD,which is now redefined as MAFLD,is one of the most common chronic liver diseases globally with an increasing prevalence and is characterized by malnutrition,which may contribute to decreased muscle strength.Reduction of muscle strength reportedly has a pathogenesis similar to that of NAFLD/MAFLD,including insulin resistance,inflammation,sedentary behavior,as well as insufficient vitamin D.Multiple studies have focused on the relationship between sarcopenia or muscle strength and NAFLD.However,studies investigating the relationship between muscle strength and MAFLD are limited.Owing to the shortage of specific medications for NAFLD/MAFLD treatment,early detection is essential.Furthermore,the relationship between muscle strength and NAFLD/MAFLD suggests that improvements in muscle strength may have an impact on disease prevention and may provide novel insights into treatments including dietary therapy,as well as tailored physical activity.

Screening for metabolic dysfunction-associated fatty liver disease:Time to discard the emperor’s clothes of normal liver enzymes?

Metabolic dysfunction-associated fatty liver disease(MAFLD)is the most prevalent chronic liver condition worldwide.Current liver enzyme-based screening methods have limitations that may missed diagnoses and treatment delays.Regarding Chen et al,the risk of developing MAFLD remains elevated even when alanine aminotransferase levels fall within the normal range.Therefore,there is an urgent need for advanced diagnostic techniques and updated algorithms to enhance the accuracy of MAFLD diagnosis and enable early intervention.This paper proposes two potential screening methods for identifying individuals who may be at risk of developing MAFLD:Lowering these thresholds and promoting the use of noninvasive liver fibrosis scores.

Metabolic dysfunction-associated fatty liver disease and low muscle strength: A comment

The diagnosis of non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease only on the basis of laboratory parameter score such as Hepatic Steatosis Index which includes liver enzymes,gender,basal metabolic index,and presence of diabetic mellitus is not sufficient to exclude other causes of deranged liver enzymes especially medications and autoimmune related liver diseases.As the guideline suggests ultrasound is the preferred first-line diagnostic procedure for imaging of NAFLD,as it provides additional diagnostic information and the combination of biomarkers/scores and transient elastography might confer additional diagnostic accuracy and evident from previous similar studies too.

Validity of fatty liver prediction scores for diagnosis of fatty liver by Fibroscan

Background:The Korea National Health and Nutrition Examination Survey nonalcoholic fatty liver disease(K-NAFLD)score was recently developed with the intent to operationally define nonalcoholic fatty liver disease(NAFLD).However,there remained an external validation that confirmed its diagnostic performance,especially in patients with alcohol consumption or hepatitis virus infection.Methods:Diagnostic accuracy of the K-NAFLD score was evaluated in a hospital-based cohort consisting of 1388 participants who received Fibroscan®.Multivariate-adjusted logistic regression models and the contrast estimation of receiver operating characteristic curves were used for validation of the K-NAFLD score,fatty liver index(FLI),and hepatic steatosis index(HSI).Results:K-NAFLD-moderate[adjusted odds ratio(aOR)=2.53,95%confidence interval(CI):1.13-5.65]and K-NAFLD-high(aOR=4.14,95%CI:1.69-10.13)groups showed higher risks of fatty liver compared to the K-NAFLD-low group after adjustments for demographic and clinical characteristics,and FLI-moderate and FLI-high groups revealed aORs of 2.05(95%CI:1.22-3.43)and 1.51(95%CI:0.78-2.90),respectively.In addition,the HSI was less predictive for Fibroscan®-defined fatty liver.Both K-NAFLD and FLI also demonstrated high accuracy in the prediction of fatty liver in patients with alcohol consumption and chronic hepatitis virus infection,and the adjusted area under curve values were comparable between K-NAFLD and FLI.Conclusions:Externally validation of the K-NAFLD and FLI showed that these scores may be a useful,noninvasive,and non-imaging modality for the identification of fatty liver.In addition,these scores also predicted fatty liver in patients with alcohol consumption and chronic hepatitis virus infection.

Metabolic-associated fatty liver disease and sarcopenia:A double whammy

The prevalence of metabolic-associated fatty liver disease(MAFLD)has increased substantially in recent years because of the global obesity pandemic.MAFLD,now recognized as the number one cause of chronic liver disease in the world,not only increases liver-related morbidity and mortality among sufferers but also worsens the complications associated with other comorbid conditions such as cardiovascular disease,type 2 diabetes mellitus,obstructive sleep apnoea,lipid disorders and sarcopenia.Understanding the interplay between MAFLD and these comorbidities is important to design optimal therapeutic strategies.Sarcopenia can be either part of the disease process that results in MAFLD(e.g.,obesity or adiposity)or a consequence of MAFLD,especially in the advanced stages such as fibrosis and cirrhosis.Sarcopenia can also worsen MAFLD by reducing exercise capacity and by the production of various muscle-related chemical factors.Therefore,it is crucial to thoroughly understand how we deal with these diseases,especially when they coexist.We explore the pathobiological interlinks between MAFLD and sarcopenia in this comprehensive clinical update review article and propose evidence-based therapeutic strategies to enhance patient care.

Changes in the terminology and diagnostic criteria of non-alcoholic fatty liver disease:Implications and opportunities

Fatty liver disease(FLD)is a highly prevalent pathological liver disorder.It has many and varied etiologies and has heterogeneous clinical course and outcome.Its proper nomenclature and classification have been problematic since its initial recognition.Traditionally,it was divided into two main categories:Alcoholassociated liver disease and nonalcoholic FLD(NAFLD).Among these,the latter condition has been plagued with nomenclature and classification issues.The two main objections to its use have been the use of negative(non-alcoholic)and stigmatizing(fatty)terms in its nomenclature.Numerous attempts were made to address these issues but none achieved universal acceptance.Just recently,NAFLD has received a new nomenclature from an international collaborative effort based on a rigorous scientific methodology.FLD has been renamed steatotic liver disease(SLD),and NAFLD as metabolic dysfunction-associated SLD.Metabolic dysfunction-associated steatohepatitis was chosen as the replacement terminology for non-alcoholic steatohepatitis.This is a significant positive change in the nomenclature and categorization of FLD and will likely have a major impact on research,diagnosis,treatment,and prognosis of the disease in the future.

Caveolin‑1 is critical for hepatic iron storage capacity in the development of nonalcoholic fatty liver disease

Background:Nonalcoholic fatty liver disease(NAFLD)is associated with disordered lipid and iron metabolism.Our previous study has substantiated the pivotal role of Caveolin-1(Cav-1)in protecting hepatocytes and mediating iron metabolism in the liver.This study aimed to explore the specific mechanisms underlying the regulation of iron metabolism by Cav-1 in NAFLD.Methods:Hepatocyte-specific Cav-1 overexpression mice and knockout mice were used in this study.Cav-1-knockdown of RAW264.7 cells and mouse primary hepatocytes were performed to verify the changes in vitro.Moreover,a high-fat diet and palmitic acid plus oleic acid treatment were utilized to construct a NAFLD model in vivo and in vitro,respectively,while a high-iron diet was used to construct an in vivo iron overload model.Besides,iron concentration,the expression of Cav-1 and iron metabolism-related proteins in liver tissue or serum were detected using iron assay kit,Prussian blue staining,Western blotting,immunofluorescence staining,immunohistochemical staining and ELISA.The related indicators of lipid metabolism and oxidative stress were evaluated by the corresponding reagent kit and staining.Results:Significant disorder of lipid and iron metabolism occurred in NAFLD.The expression of Cav-1 was decreased in NAFLD hepatocytes(P<0.05),accompanied by iron metabolism disorder.Cav-1 enhanced the iron storage capacity of hepatocytes by activating the ferritin light chain/ferritin heavy chain pathway in NAFLD,subsequently alleviating the oxidative stress induced by excess ferrous ions in the liver.Further,CD68^(+) CD163^(+) macrophages expressing Cav-1 were found to accelerate iron accumulation in the liver,which was contrary to the effect of Cav-1 in hepatocytes.Positive correlations were also observed between the serum Cav-1 concentration and the serum iron-related protein levels in NAFLD patients and healthy volunteers(P<0.05).Conclusions:These findings confirm that Cav-1 is an essential target protein that regulates iron and lipid metabolic homeostasis.It is a pivotal molecule for predicting and protecting against the development of NAFLD.

Lactiplantibacillus plantarum FRT4 attenuates high-energy low-protein dietinduced fatty liver hemorrhage syndrome in laying hens through regulating gut-liver axis

Background Fatty liver hemorrhage syndrome(FLHS)becomes one of the most major factors resulting in the laying hen death for caged egg production.This study aimed to investigate the therapeutic effects of Lactiplantibacillus plan-tarum(Lp.plantarum)FRT4 on FLHS model in laying hen with a focus on liver lipid metabolism,and gut microbiota.Results The FLHS model of laying hens was established by feeding a high-energy low-protein(HELP)diet,and the treatment groups were fed a HELP diet supplemented with differential proportions of Lp.plantarum FRT4.The results indicated that Lp.plantarum FRT4 increased laying rate,and reduced the liver lipid accumulation by regulating lipid metabolism(lipid synthesis and transport)and improving the gut microbiota composition.Moreover,Lp.plan-tarum FRT4 regulated the liver glycerophospholipid metabolism.Meanwhile,“gut-liver”axis analysis showed that there was a correlation between gut microbiota and lipid metabolites.Conclusions The results indicated that Lp.plantarum FRT4 improved the laying performance and alleviated FLHS in HELP diet-induced laying hens through regulating“gut-liver”axis.Our findings reveal that glycerophospholipid metabolism could be the underlying mechanism for the anti-FLHS effect of Lp.plantarum FRT4 and for future use of Lp.plantarum FRT4 as an excellent additive for the prevention and mitigation of FLHS in laying hens.

Loss of LBP triggers lipid metabolic disorder through H3K27 acetylation-mediated C/EBPβ-SCD activation in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets.

Necroptosis contributes to non-alcoholic fatty liver disease pathoetiology with promising diagnostic and therapeutic functions

Nonalcoholic fatty liver disease(NAFLD)is the most prevalent type of chronic liver disease.However,the disease is underappreciated as a remarkable chronic disorder as there are rare managing strategies.Several studies have focused on determining NAFLD-caused hepatocyte death to elucidate the disease pathoe-tiology and suggest functional therapeutic and diagnostic options.Pyroptosis,ferroptosis,and necroptosis are the main subtypes of non-apoptotic regulated cell deaths(RCDs),each of which represents particular characteristics.Considering the complexity of the findings,the present study aimed to review these types of RCDs and their contribution to NAFLD progression,and subsequently discuss in detail the role of necroptosis in the pathoetiology,diagnosis,and treatment of the disease.The study revealed that necroptosis is involved in the occurrence of NAFLD and its progression towards steatohepatitis and cancer,hence it has potential in diagnostic and therapeutic approaches.Nevertheless,further studies are necessary.

Prevalence and risk factors for impaired renal function among Asian patients with nonalcoholic fatty liver disease

Background:Nonalcoholic fatty liver disease(NAFLD)is associated with impaired renal function,and both diseases often occur alongside other metabolic disorders.However,the prevalence and risk factors for impaired renal function in patients with NAFLD remain unclear.The objective of this study was to identify the prevalence and risk factors for renal impairment in NAFLD patients.Methods:All adults aged 18-70 years with ultrasound-diagnosed NAFLD and transient elastography examination from eight Asian centers were enrolled in this prospective study.Liver fibrosis and cirrhosis were assessed by FibroScan-aspartate aminotransferase(FAST),Agile 3+and Agile 4 scores.Impaired renal function and chronic kidney disease(CKD)were defined by an estimated glomerular filtration rate(eGFR)with value of<90 mL/min/1.73 m^(2) and<60 mL/min/1.73 m^(2),respectively,as estimated by the CKD-Epidemiology Collaboration(CKD-EPI)equation.Results:Among 529 included NAFLD patients,the prevalence rates of impaired renal function and CKD were 37.4%and 4.9%,respectively.In multivariate analysis,a moderate-high risk of advanced liver fibrosis and cirrhosis according to Agile 3+and Agile 4 scores were independent risk factors for CKD(P<0.05).Furthermore,increased fasting plasma glucose(FPG)and blood pressure were significantly associated with impaired renal function after controlling for the other components of metabolic syndrome(P<0.05).Compared with patients with normoglycemia,those with prediabetes[FPG≥5.6 mmol/L or hemoglobin A1c(HbA1c)≥5.7%]were more likely to have impaired renal function(P<0.05).Conclusions:Agile 3+and Agile 4 are reliable for identifying NAFLD patients with high risk of CKD.Early glycemic control in the prediabetic stage might have a potential renoprotective role in these patients.

Reorganization of 3D genome architecture provides insights into pathogenesis of early fatty liver disease in laying hens

Background Fatty liver disease causes huge economic losses in the poultry industry due to its high occurrence and lethality rate.Three-dimensional(3D)chromatin architecture takes part in disease processing by regulating tran-scriptional reprogramming.The study is carried out to investigate the alterations of hepatic 3D genome and H3K27ac profiling in early fatty liver(FLS)and reveal their effect on hepatic transcriptional reprogramming in laying hens.Results Results show that FLS model is constructed with obvious phenotypes including hepatic visible lipid deposi-tion as well as higher total triglyceride and cholesterol in serum.A/B compartment switching,topologically associat-ing domain(TAD)and chromatin loop changes are identified by high-throughput/resolution chromosome conforma-tion capture(HiC)technology.Targeted genes of these alternations in hepatic 3D genome organization significantly enrich pathways related to lipid metabolism and hepatic damage.H3K27ac differential peaks and differential expres-sion genes(DEGs)identified through RNA-seq analysis are also enriched in these pathways.Notably,certain DEGs are found to correspond with changes in 3D chromatin structure and H3K27ac binding in their promoters.DNA motif analysis reveals that candidate transcription factors are implicated in regulating transcriptional reprogram-ming.Furthermore,disturbed folate metabolism is observed,as evidenced by lower folate levels and altered enzyme expression.Conclusion Our findings establish a link between transcriptional reprogramming changes and 3D chromatin struc-ture variations during early FLS formation,which provides candidate transcription factors and folate as targets for FLS prevention or treatment.

Circulating microRNA expression and nonalcoholic fatty liver disease in adolescents with severe obesity

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases in children and adolescents.NAFLD ranges in severity from isolated hepatic steatosis to nonalcoholic steatohepatitis(NASH),wherein hepatocellular inflammation and/or fibrosis coexist with steatosis.Circulating microRNA(miRNA)levels have been suggested to be altered in NAFLD,but the extent to which miRNA are related to NAFLD features remains unknown.This analysis tested the hypothesis that plasma miRNAs are significantly associated with histological features of NAFLD in adolescents.AIM To investigate the relationship between plasma miRNA expression and NAFLD features among adolescents with NAFLD.METHODS This study included 81 adolescents diagnosed with NAFLD and 54 adolescents without NAFLD from the Teen-Longitudinal Assessment of Bariatric Surgery study.Intra-operative core liver biopsies were collected from participants and used to characterize histological features of NAFLD.Plasma samples were collected during surgery for miRNA profiling.A total of 843 plasma miRNAs were profiled using the HTG EdgeSeq platform.We examined associations of plasma miRNAs and NAFLD features using logistic regression after adjusting for age,sex,race,and other key covariates.Ingenuity Pathways Analysis was used to identify biological functions of miRNAs that were associated with multiple histological features of NAFLD.RESULTS We identified 16 upregulated plasma miRNAs,including miR-193a-5p and miR-193b-5p,and 22 downregulated plasma miRNAs,including miR-1282 and miR-6734-5p,in adolescents with NAFLD.Moreover,52,16,15,and 9 plasma miRNAs were associated with NASH,fibrosis,ballooning degeneration,and lobular inflammation,respectively.Collectively,16 miRNAs were associated with two or more histological features of NAFLD.Among those miRNAs,miR-411-5p was downregulated in NASH,ballooning,and fibrosis,while miR-122-5p,miR-1343-5p,miR-193a-5p,miR-193b-5p,and miR-7845-5p were consistently and positively associated with all histological features of NAFLD.Pathway analysis revealed that most common pathways of miRNAs associated with multiple NAFLD features have been associated with tumor progression,while we also identified linkages between miR-122-5p and hepatitis C virus and between miR-199b-5p and chronic hepatitis B.CONCLUSION Plasma miRNAs were associated with NAFLD features in adolescent with severe obesity.Larger studies with more heterogeneous NAFLD phenotypes are needed to evaluate miRNAs as potential biomarkers of NAFLD.

Management of non-alcoholic fatty liver disease:Lifestyle changes

In this editorial,we commented on a recently released manuscript by Zeng et al in the World Journal of Gastroenterology.We focused specifically on lifestyle changes in patients with non-alcoholic fatty liver disease(NAFLD).NAFLD is a hepatic manifestation of the metabolic syndrome,which ultimately leads to advanced hepatic fibrosis,cirrhosis,and hepatocellular carcinoma and affects more than 25%of the population globally.Existing therapeutic strategies against NAFLD such as pharmacologic therapies focus on liver protection,anti-inflammation,and regulating disease-related metabolic disorder symptoms.Although several drugs are in late-stage development,potent drugs against the diseases are lacking.Additionally,existing surgical approaches such as bariatric surgery are not routinely used to treat NAFLD.Intervening in patients’unhealthy lifestyles,such as weight loss through dietary changes and exercises to ameliorate patientassociated metabolic disorders and metabolic syndrome,is the first-line treatment for patients with NAFLD.With sufficient intrinsic motivation and adherence,the management of unhealthy lifestyles can reduce the severity of the disease,improve the quality of life,and increase the survival expectancy of patients with NAFLD.

Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is the most common liver disease worldwide,affecting about 1/4th of the global population and causing a huge global economic burden.To date,no drugs have been approved for the treatment of NAFLD,making the correction of unhealthy lifestyles the principle method of treatment.Identifying patients with poor adherence to lifestyle correction and attempting to improve their adherence are therefore very important.AIM To develop and validate a scale that can rapidly assess the adherence of patients with NAFLD to lifestyle interventions.METHODS The Exercise and Diet Adherence Scale(EDAS)was designed based on com-pilation using the Delphi method,and its reliability was subsequently evaluated.Demographic and laboratory indicators were measured,and patients completed the EDAS questionnaire at baseline and after 6 months.The efficacy of the EDAS was evaluated in the initial cohort.Subsequently,the efficacy of the EDAS was internally verified in a validation cohort.RESULTS The EDAS consisted of 33 items in six dimensions,with a total of 165 points.Total EDAS score correlated significantly with daily number of exercise and daily reduction in calorie intake(P<0.05 each),but not with overall weight loss.A total score of 116 was excellent in predicting adherence to daily reduction in calorie intake(>500 kacl/d),(sensitivity/specificity was 100.0%/75.8%),while patients score below 97 could nearly rule out the possibility of daily exercise(sensitivity/specificity was 89.5%/44.4%).Total EDAS scores≥116,97-115,and<97 points were indicative of good,average,and poor adherence,respectively,to diet and exercise recommendations.CONCLUSION The EDAS can reliably assess the adherence of patients with NAFLD to lifestyle interventions and have clinical application in this population.

Impact of lifestyle interventions on pathogenesis of nonalcoholic fatty liver disease

This editorial builds on the article titled“Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease”by Zeng et al.We carried out a critical examination of nonalcoholic fatty liver disease(NAFLD)pathogenesis and how lifestyle interventions could facilitate disease resolution,particularly highlighting that non-alcoholic steatohepatitis(NASH)is a severe form of NAFLD.Our discussion details that weight loss is a pivotal factor in disease outcomes:A 3%-5%reduction is enough for resolution in 50%of non-obese individuals,while a 7%-10%reduction achieves similar benefits in obese individuals,as demonstrated by magnetic resonance spectroscopy.Additionally,the editorial underscores that such lifestyle changes are instrumental not only in resolving NAFLD but also in reversing hepatic steatosis and inflammation.These insights,derived from the research,emphasize the critical role of personalized lifestyle modifications in halting the progression of NAFLD to NASH and even reversing fibrosis,thus offering a template for effective patient management.

Fecal microbiota transplantation for treatment of non-alcoholic fatty liver disease:Mechanism,clinical evidence,and prospect

The population of non-alcoholic fatty liver disease(NAFLD)patients along with relevant advanced liver disease is projected to continue growing,because currently no medications are approved for treatment.Fecal microbiota transplantation(FMT)is believed a novel and promising therapeutic approach based on the concept of the gut-liver axis in liver disease.There has been an increase in the number of pre-clinical and clinical studies evaluating FMT in NAFLD treatment,however,existing findings diverge on its effects.Herein,we briefly summarized the mechanism of FMT for NAFLD treatment,reviewed randomized controlled trials for evaluating its efficacy in NAFLD,and proposed the prospect of future trials on FMT.

Interplay between metabolic dysfunction-associated fatty liver disease and renal function: An intriguing pediatric perspective

Over recent years,the nomenclature of non-alcoholic fatty liver disease has undergone significant changes.Indeed,in 2020,an expert consensus panel proposed the term“Metabolic(dysfunction)associated fatty liver disease”(MAFLD)to underscore the close association of fatty liver with metabolic abnormalities,thereby highlighting the cardiometabolic risks(such as metabolic syndrome,type 2 diabetes,insulin resistance,and cardiovascular disease)faced by these patients since childhood.More recently,this term has been further replaced with metabolic associated steatotic liver disease.It is worth noting that emerging evidence not only supports a close and independent association of MAFLD with chronic kidney disease in adults but also indicates its interplay with metabolic impairments.However,comparable pediatric data remain limited.Given the progressive and chronic nature of both diseases and their prognostic cardiometabolic implications,this editorial aims to provide a pediatric perspective on the intriguing relationship between MAFLD and renal function in childhood.

Portal hypertension in patients with nonalcoholic fatty liver disease:Current knowledge and challenges

Portal hypertension(PH)has traditionally been observed as a consequence of significant fibrosis and cirrhosis in advanced non-alcoholic fatty liver disease(NAFLD).However,recent studies have provided evidence that PH may develop in earlier stages of NAFLD,suggesting that there are additional pathogenetic mechanisms at work in addition to liver fibrosis.The early development of PH in NAFLD is associated with hepatocellular lipid accumulation and ballooning,leading to the compression of liver sinusoids.External compression and intraluminal obstacles cause mechanical forces such as strain,shear stress and elevated hydrostatic pressure that in turn activate mechanotransduction pathways,resulting in endothelial dysfunction and the development of fibrosis.The spatial distribution of histological and functional changes in the periportal and perisinusoidal areas of the liver lobule are considered responsible for the pre-sinusoidal component of PH in patients with NAFLD.Thus,current diagnostic methods such as hepatic venous pressure gradient(HVPG)measurement tend to underestimate portal pressure(PP)in NAFLD patients,who might decompensate below the HVPG threshold of 10 mmHg,which is traditionally considered the most relevant indicator of clinically significant portal hypertension(CSPH).This creates further challenges in finding a reliable diagnostic method to stratify the prognostic risk in this population of patients.In theory,the measurement of the portal pressure gradient guided by endoscopic ultrasound might overcome the limitations of HVPG measurement by avoiding the influence of the pre-sinusoidal component,but more investigations are needed to test its clinical utility for this indication.Liver and spleen stiffness measurement in combination with platelet count is currently the best-validated non-invasive approach for diagnosing CSPH and varices needing treatment.Lifestyle change remains the cornerstone of the treatment of PH in NAFLD,together with correcting the components of metabolic syndrome,using nonselective beta blockers,whereas emerging candidate drugs require more robust confirmation from clinical trials.