Toward More Accurate Nomenclature for Fatty Liver Diseases

NAFLD-associated hepatocellular carcinoma (HCC) - A compelling case for repositioning of existing mTORc1 inhibitors

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) is a growing concern for the high incidence rate of hepatocellular carcinoma (HCC) globally. The progression of NAFLD to HCC is heterogeneous and non-linear, involving intermediate stages of non-alcoholic steatohepatitis (NASH), liver fibrosis, and cirrhosis. There is a high unmet clinical need for appropriate diagnostic, prognostic, and therapeutic options to tackle this emerging epidemic. Unfortunately, at present, there is no validated marker to identify the risk of developing HCC in patients suffering from NAFLD or NASH. Additionally, the current treatment protocols for HCC don't differentiate between viral infection or NAFLD-specific etiology of the HCC and have a limited success rate. The mammalian target of rapamycin complex 1 (mTORc1) is an important protein involved in many vital cellular processes like lipid metabolism, glucose homeostasis, and inflammation. These cellular processes are highly implicated in NAFLD and its progression to severe liver manifestations. Additionally, hyperactivation of mTORc1 is known to promote cell proliferation, which can contribute to the genesis and progression of tumors. Many mTORc1 inhibitors are being evaluated for different types of cancers under various phases of clinical trials. This paper deliberates on the strong pathological implication of the mTORc1 signaling pathway in NAFLD and its progression to NASH and HCC and advocates for a systematic investigation of known mTORc1 inhibitors in suitable pre-clinical models of HCC having NAFLD/NASH-specific etiology.

Epidemiology and diagnosis of metabolic dysfunction-associated fatty liver disease

The most common chronic liver illness worldwide is metabolic dysfunction linked to fatty liver disease (MAFLD), which is poorly understood by doctors and patients. Many people with this disease develop steatohepatitis, cirrhosis and its consequences, as well as extrahepatic manifestations; these conditions are particularly common if they are linked to diabetes mellitus or obesity. A breakthrough with numerous benefits is the switch from NAFLD to MAFLD in terms of terminology and methodology. The diagnosis of MAFLD is based on affirmative criteria; unlike NAFLD, it is no longer based on exclusion. The diagnosis of MAFLD and the evaluation of steatosis and fibrosis is achieved using liver biopsy and non-invasive laboratory or radiographic techniques. We briefly address the most recent developments in MAFLD epidemiology and diagnosis.

Review article: Hepatic steatosis and its associations with acute and chronic liver diseases

BACKGROUND

Hepatic steatosis is a common finding in liver histopathology and the hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), whose global prevalence is rising.

AIMS

To review the histopathology of hepatic steatosis and its mechanisms of development and to identify common and rare disease associations.

METHODS

We reviewed literature on the basic science of lipid droplet (LD) biology and clinical research on acute and chronic liver diseases associated with hepatic steatosis using the PubMed database.

RESULTS

A variety of genetic and environmental factors contribute to the development of chronic hepatic steatosis or steatotic liver disease, which typically appears macrovesicular. Microvesicular steatosis is associated with acute mitochondrial dysfunction and liver failure. Fat metabolic processes in hepatocytes whose dysregulation leads to the development of steatosis include secretion of lipoprotein particles, uptake of remnant lipoprotein particles or free fatty acids from blood, de novo lipogenesis, oxidation of fatty acids, lipolysis and lipophagy. Hepatic insulin resistance is a key feature of MASLD. Seipin is a polyfunctional protein that facilitates LD biogenesis. Assembly of hepatitis C virus takes place on LD surfaces. LDs make important, functional contact with the endoplasmic reticulum and other organelles.

CONCLUSIONS

Diverse liver pathologies are associated with hepatic steatosis, with MASLD being the most important contributor. The biogenesis and dynamics of LDs in hepatocytes are complex and warrant further investigation. Organellar interfaces permit co-regulation of lipid metabolism to match generation of potentially toxic lipid species with their LD depot storage.

MAFLD: an ideal framework for understanding disease phenotype in individuals of normal weight

The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) is significant, impacting almost one-third of the global population. MAFLD constitutes a primary cause of end-stage liver disease, liver cancer and the need for liver transplantation. Moreover, it has a strong association with increased mortality rates due to various extrahepatic complications, notably cardiometabolic diseases. While MAFLD is typically correlated with obesity, not all individuals with obesity develop the disease and a significant percentage of MAFLD occurs in patients without obesity, termed lean MAFLD. The clinical features, progression and underlying physiological mechanisms of patients with lean MAFLD remain inadequately characterized. The present review aims to provide a comprehensive summary of current knowledge on lean MAFLD and offer a perspective on defining MAFLD in individuals with normal weight. Key to this process is the concept of metabolic health and flexibility, which links states of dysmetabolism to the development of lean MAFLD. This perspective offers a more nuanced understanding of MAFLD and its underlying mechanisms and highlights the importance of considering the broader metabolic context in which the disease occurs. It also bridges the knowledge gap and offers insights that can inform clinical practice.

Relevant Aspects of Combined Protocols for Prevention of N(M)AFLD and Other Non-Communicable Diseases

Obesity is a global health issue characterized by the excessive fat accumulation, leading to an increased risk of chronic noncommunicable diseases (NCDs), including metabolic dysfunction-associated fatty liver disease (MAFLD), which can progress from simple steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved pharmacological protocols for prevention/treatment of MAFLD, and due the complexity lying beneath these mechanisms, monotherapies are unlikely to be efficacious. This review article analyzes the possibility that NCDs can be prevented or attenuated by the combination of bioactive substances, as they could promote higher response rates, maximum reaction results, additive or synergistic effects due to compounds having similar or different mechanisms of action and/or refraining possible side effects, related to the use of lower doses and exposures times than monotherapies. Accordingly, prevention of mouse MAFLD is observed with the combination of the omega-3 docosahexaenoic acid with the antioxidant hydroxytyrosol, whereas attenuation of mild cognitive impairment is attained by folic acid plus cobalamin in elderly patients. The existence of several drawbacks underlying published monotherapies or combined trials, opens space for adequate and stricter experimental and clinical tryouts to achieve meaningful outcomes with human applicability.

Prevalence of steatotic liver disease, MASLD, MetALD and significant fibrosis in people with HIV in the United States

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) has recently been proposed as a replacement term for NAFLD.

AIMS

To assess the effects of this new nomenclature on the prevalence and distribution of different SLD categories in people with HIV (PWH) and identified factors associated with MASLD and clinically significant fibrosis (CSF).

METHODS

PWH were prospectively enrolled from 9 US centres and underwent clinical evaluation and vibration-controlled transient elastography for controlled attenuation parameter (CAP) and liver stiffness measurement (LSM). SLD was defined as CAP ≥ 263 dB/m, CSF as LSM of ≥8 kPa, and advanced fibrosis (AF) as LSM ≥ 12 kPa. The prevalence of SLD, MASLD, metabolic dysfunction and alcohol-associated liver disease (MetALD), ALD, cryptogenic (cSLD), CSF and AF were determined. Uni- and multivariate logistic regression models were used to assess factors associated with MASLD and CSF risk.

RESULTS

Of 1065 participants, 74% were male, mean (SD) age 51.6 ± 11.9 years, 46% non-Hispanic Black and 74% with undetectable HIV RNA. The prevalence of SLD was 52%, MASLD 39%, MetALD 10%, ALD 3%, CSF 15% and AF 4%. Only 0.6% had cSLD. Black race was protective whereas obesity, ALT and AST levels were associated with increased risk of MASLD and CSF in MASLD. HIV or antiretroviral therapy did not affect MASLD risk.

CONCLUSIONS

MASLD and MetALD are the dominant causes of SLD in PWH, affecting almost half. Application of the new nomenclature resulted in minimal change in the proportion of patients with MASLD who would have been diagnosed previously with NAFLD.

Global trends and hotspots of treatment for nonalcoholic fatty liver disease: A bibliometric and visualization analysis (2010-2023)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is chronic, with its progression leading to liver fibrosis and end-stage cirrhosis. Although NAFLD is increasingly common, no treatment guideline has been established. Many mechanistic studies and drug trials have been conducted for new drug development to treat NAFLD. An up-to-date overview on the knowledge structure of NAFLD through bibliometrics, focusing on research hotspots, is necessary to reveal the rational and timely directions of development in this field.

AIM

To research the latest literature and determine the current trends in treatment for NAFLD.

METHODS

Publications related to treatment for NAFLD were searched on the Web of Science Core Collection database, from 2010 to 2023. VOSviewers, CiteSpace, and R package "bibliometrix" were used to conduct this bibliometric analysis. The key information was extracted, and the results of the cluster analysis were based on network data for generating and investigating maps for country, institution, journal, and author. Historiography analysis, bursts and cluster analysis, co-occurrence analysis, and trend topic revealed the knowledge structure and research hotspots in this field. GraphPad Prism 9.5.1.733 and Microsoft Office Excel 2019 were used for data analysis and visualization.

RESULTS

In total, 10829 articles from 120 countries (led by China and the United States) and 8785 institutions were included. The number of publications related to treatment for NAFLD increased annually. While China produced the most publications, the United States was the most cited country, and the United Kingdom collaborated the most from an international standpoint. The University of California-San Diego, Shanghai Jiao Tong University, and Shanghai University of Traditional Chinese Medicine produced the most publications of all the research institutions. The International Journal of Molecular Sciences was the most frequent journal out of the 1523 total journals, and Hepatology was the most cited and co-cited journal. Sanyal AJ was the most cited author, the most co-cited author was Younossi ZM, and the most influential author was Loomba R. The most studied topics included the epidemiology and mechanism of NAFLD, the development of accurate diagnosis, the precise management of patients with NAFLD, and the associated metabolic comorbidities. The major cluster topics were "emerging drug," "glucagon-like peptide-1 receptor agonist," "metabolic dysfunction-associated fatty liver disease," "gut microbiota," and "glucose metabolism."

CONCLUSION

The bibliometric study identified recent research frontiers and hot directions, which can provide a valuable reference for scholars researching treatments for NAFLD.

The bidirectional impacts of alcohol consumption and MAFLD for progressive fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), once considered a benign condition, has been associated with several cardiometabolic complications over the past two decades. The worldwide prevalence of NAFLD is as high as 30%. NAFLD requires the absence of a "significant alcohol intake." Conflicting reports have suggested that moderate alcohol consumption may be protective; therefore, the diagnosis of NAFLD previously relied on negative criteria. However, there has been a significant increase in alcohol consumption globally. Apart from the rise in alcohol-related liver disease (ARLD), alcohol, a major toxin, is associated with an increased risk of several cancers, including hepatocellular carcinoma. Alcohol misuse is a significant contributor to disability-adjusted life years. Recently, the term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed instead of NAFLD to include the metabolic dysfunction responsible for the major adverse outcomes in patients with fatty liver disease. MAFLD, dependent on the "positive diagnostic criteria" rather than previous exclusion criteria, may identify individuals with poor metabolic health and aid in managing patients at increased risk of all-cause and cardiovascular mortality. Although MAFLD is less stigmatizing than NAFLD, excluding alcohol intake may increase the risk of already existing underreported alcohol consumption in this subgroup of patients. Therefore, alcohol consumption may increase the prevalence of fatty liver disease and its associated complications in patients with MAFLD. This review discusses the effects of alcohol intake and MAFLD on fatty liver disease.

Concomitant western diet and chronic-binge alcohol dysregulate hepatic metabolism

BACKGROUND AND AIMS

There is significant overlap between non-alcoholic fatty liver disease (NAFLD) and alcohol-associated liver disease (ALD) with regards to risk factors and disease progression. However, the mechanism by which fatty liver disease arises from concomitant obesity and overconsumption of alcohol (syndrome of metabolic and alcohol-associated fatty liver disease; SMAFLD), is not fully understood.

METHODS

Male C57BL6/J mice were fed chow diet (Chow) or high-fructose, high-fat, high-cholesterol diet (FFC) for 4 weeks, then administered either saline or ethanol (EtOH, 5% in drinking water) for another 12 weeks. The EtOH treatment also consisted of a weekly 2.5 g EtOH/kg body weight gavage. Markers for lipid regulation, oxidative stress, inflammation, and fibrosis were measured by RT-qPCR, RNA-seq, Western blot, and metabolomics.

RESULTS

Combined FFC-EtOH induced more body weight gain, glucose intolerance, steatosis, and hepatomegaly compared to Chow, EtOH, or FFC. Glucose intolerance by FFC-EtOH was associated with decreased hepatic protein kinase B (AKT) protein expression and increased gluconeogenic gene expression. FFC-EtOH increased hepatic triglyceride and ceramide levels, plasma leptin levels, hepatic Perilipin 2 protein expression, and decreased lipolytic gene expression. FFC and FFC-EtOH also increased AMP-activated protein kinase (AMPK) activation. Finally, FFC-EtOH enriched the hepatic transcriptome for genes involved in immune response and lipid metabolism.

CONCLUSIONS

In our model of early SMAFLD, we observed that the combination of an obesogenic diet and alcohol caused more weight gain, promoted glucose intolerance, and contributed to steatosis by dysregulating leptin/AMPK signaling. Our model demonstrates that the combination of an obesogenic diet with a chronic-binge pattern alcohol intake is worse than either insult alone.

Metabolic Dysfunction-Associated Fatty Liver Disease and Mortality: A Population-Based Cohort Study

BACKGROUND

We investigated whether metabolic dysfunction-associated fatty liver disease (MAFLD) is associated with an elevated risk of all-cause and cardiovascular mortality using a large-scale health examination cohort.

METHODS

A total of 394,835 subjects in the Kangbuk Samsung Health Study cohort were enrolled from 2002 to 2012. Participants were categorized by the presence of nonalcoholic fatty liver disease (NAFLD) and MAFLD as follows: normal subjects; patients with both NAFLD and MAFLD; patients with NAFLD only; and patients with MAFLD only. Cox proportional hazards models were used to analyze the risk of mortality.

RESULTS

During a median 5.7 years of follow-up, 20.69% was patients with both NAFLD and MAFLD, 1.51% was patients with NAFLD only, and 4.29% was patients with MAFLD only. All-cause and cardiovascular death was higher in patients with MAFLD than those without MAFLD (P<0.001, respectively). In patients with MAFLD only, the hazard ratio (HR) of all-cause and cardiovascular death was 1.35 (95% confidence interval [CI], 1.13 to 1.60) and 1.90 (95% CI, 1.26 to 2.88) after adjusting for age, which lost its statistical significance by multivariable adjustments. Compared to patients with less than two components of metabolic dysfunction, patients with more than two components of metabolic dysfunction were a higher risk of cardiovascular death (HR, 2.05; 95% CI, 1.25 to 3.38) and only women with more than two components of metabolic dysfunction were a higher risk of all-cause death (HR, 1.44; 95% CI, 1.02 to 2.03).

CONCLUSION

MAFLD criteria could identify a high-risk group for all-cause and cardiovascular death.

Evaluation of Liver Metabolism Biomarkers in Metabolic Associated Fatty Liver Disease According to Obesity Phenotype

OBJECTIVE

To analyze the relationship between the biochemical markers of liver metabolism in different stages of Metabolic Associated Fatty Liver Disease (MAFLD) according to the obesity phenotype.

METHODOLOGY

This is a cross-sectional study with individuals with class III obesity classified according to the obesity phenotypes proposed by the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. Biochemical and anthropometric variables were analyzed according to the staging of MAFLD and obesity phenotype.

RESULTS

A total of 50 subjects with MAFLD, 62% (n = 31) with steatosis and 38% (n = 19) with steatohepatitis without fibrosis; 36% were classified as metabolically healthy obesity (MHO) and 64% as metabolically unhealthy obesity (MUHO), respectively. Mean values of alkaline phosphatase were 85.44 ± 27.27 vs. 61.92 ± 17.57 (p = 0.006); gamma-glutamyl transpeptidase, 25.77 ± 15.36 vs. 30.63 ± 19.49 (p = 0.025); and albumin, 3.99 ± 0.34 vs. 4.24 ± 0.23 (p = 0.037), were lower and statistically significant in the MHO group with steatosis. The results show when considering individuals with IR, only AP is a predictor of unhealthy phenotype (B-0.934, 0.848- 1.029, p = 0.031).

CONCLUSION

MHO individuals with steatosis present lower severe changes related to markers of liver damage and function and AP is considered the predictor of MUHO phenotype.

Fatty Liver Disease-Alcoholic and Non-Alcoholic: Similar but Different

In alcohol-induced liver disease (ALD) and in non-alcoholic fatty liver disease (NAFLD), there are abnormal accumulations of fat in the liver. This phenomenon may be related to excessive alcohol consumption, as well as the combination of alcohol consumption and medications. There is an evolution from simple steatosis to steatohepatitis, fibrosis and cirrhosis leading to hepatocellular carcinoma (HCC). Hepatic pathology is very similar regarding non-alcoholic fatty liver disease (NAFLD) and ALD. Initially, there is lipid accumulation in parenchyma and progression to lobular inflammation. The morphological changes in the liver mitochondria, perivenular and perisinusoidal fibrosis, and hepatocellular ballooning, apoptosis and necrosis and accumulation of fibrosis may lead to the development of cirrhosis and HCC. Medical history of ethanol consumption, laboratory markers of chronic ethanol intake, AST/ALT ratio on the one hand and features of the metabolic syndrome on the other hand, may help in estimating the contribution of alcohol intake and the metabolic syndrome, respectively, to liver steatosis.

Hepatic Disorders and COVID-19: From Pathophysiology to Treatment Strategy

Following the SARS-CoV-2 outbreak and the subsequent development of the COVID-19 pandemic, organs such as the lungs, kidneys, liver, heart, and brain have been identified as priority organs. Liver diseases are considered a risk factor for high mortality from the COVID-19 pandemic. Besides, liver damage has been demonstrated in a substantial proportion of patients with COVID-19, especially those with severe clinical symptoms. Furthermore, antiviral medications, immunosuppressive drugs after liver transplantation, pre-existing hepatic diseases, and chronic liver diseases such as cirrhosis have also been implicated in SARS-CoV-2-induced liver injury. As a result, some precautions have been taken to prevent, monitor the virus, and avoid immunocompromised and susceptible individuals, such as liver and kidney transplant recipients, from being infected with SARS-CoV-2, thereby avoiding an increase in mortality. The purpose of this review was to examine the impairment caused by SARS-CoV-2 infection and the impact of drugs used during the pandemic on the mortality range and therefore the possibility of preventive measures in patients with liver disease.

NAFLD: genetics and its clinical implications

Worldwide non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of liver disease and its burden increasing at an alarming rate. NAFLD entails steatosis, fibrosis, cirrhosis, and, finally, hepatocellular carcinoma (HCC). The substantial inter-patient variation during disease progression is the hallmark of individuals with NAFLD. The variability of NAFLD development and related complications among individuals is determined by genetic and environmental factors. Genome-wide association studies (GWAS) have discovered reproducible and robust associations between gene variants such as PNPLA3, TM6SF2, HSD17B13, MBOAT7, GCKR and NAFLD. Evidences have provided the new insights into the NAFLD biology and underlined potential pharmaceutical targets. Ideally, the candidate genes associated with the hereditability of NAFLD are mainly involved in assembly of lipid droplets, lipid remodeling, lipoprotein packing and secretion, redox status mitochondria, and de novo lipogenesis. In recent years, the ability to translate genetics into a clinical context has emerged substantially by combining genetic variants primarily associated with NAFLD into polygenic risk scores (PRS). These score in combination with metabolic factors could be utilized to identify the severe liver diseases in patients with the gene regulatory networks (GRNs). Hereby, we even have highlighted the current understanding related to the schedule therapeutic approach of an individual based on microbial colonization and dysbiosis reversal as a therapy for NAFLD. The premise of this review is to concentrate on the potential of genetic factors and their translation into the design of novel therapeutics, as well as their implications for future research into personalized medications using microbiota.

Metabolic (dysfunction)-associated fatty liver disease in individuals of normal weight

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) affects up to a third of the global population; its burden has grown in parallel with rising rates of type 2 diabetes mellitus and obesity. MAFLD increases the risk of end-stage liver disease, hepatocellular carcinoma, death and liver transplantation and has extrahepatic consequences, including cardiometabolic disease and cancers. Although typically associated with obesity, there is accumulating evidence that not all people with overweight or obesity develop fatty liver disease. On the other hand, a considerable proportion of patients with MAFLD are of normal weight, indicating the importance of metabolic health in the pathogenesis of the disease regardless of body mass index. The clinical profile, natural history and pathophysiology of patients with so-called lean MAFLD are not well characterized. In this Review, we provide epidemiological data on this group of patients and consider overall metabolic health and metabolic adaptation as a framework to best explain the pathogenesis of MAFLD and its heterogeneity in individuals of normal weight and in those who are above normal weight. This framework provides a conceptual schema for interrogating the MAFLD phenotype in individuals of normal weight that can translate to novel approaches for diagnosis and patient care.

Current status and challenges in the drug treatment for fibrotic nonalcoholic steatohepatitis

Currently, nonalcoholic steatohepatitis (NASH) is one of the most common forms of chronic hepatitis, increasing the burden of health care worldwide. In patients with NASH, the fibrosis stage is the most predictive factor of long-term events. However, there are still no drugs approved by the Food and Drug Administration of the United States for treating biopsy-proven NASH with fibrosis or cirrhosis. Although some novel drugs have shown promise in preclinical studies and led to improvement in terms of hepatic fat content and steatohepatitis, a considerable proportion of them have failed to achieve histological endpoints of fibrosis improvement. Due to the large number of NASH patients and adverse clinical outcomes, the search for novel drugs is necessary. In this review, we discuss current definitions for the evaluation of treatment efficacy in fibrosis improvement for NASH patients, and we summarize novel agents in the pipeline from different mechanisms and phases of trial. We also critically review the challenges we face in the development of novel agents for fibrotic NASH and NASH cirrhosis.

Metabolic dysfunction-associated fatty liver disease: a year in review

PURPOSE OF REVIEW

In 2020, a novel comprehensive redefinition of fatty liver disease was proposed by an international panel of experts. This review aims to explore current evidence regarding the impact of this new definition on the current understanding of the epidemiology, pathogenesis, diagnosis, and clinical trials for fatty liver disease.

RECENT FINDINGS

The effectiveness of metabolic dysfunction-associated fatty liver disease (MAFLD) was compared to the existing criteria for nonalcoholic fatty liver disease (NAFLD). Recent data robustly suggest the superior utility of MAFLD in identifying patients at high risk for metabolic dysfunction, the hepatic and extra-hepatic complications, as well as those who would benefit from genetic testing, including patients with concomitant liver diseases. This change in name and criteria also appears to have improved disease awareness among patients and physicians.

SUMMARY

The transformation in name and definition from NAFLD to MAFLD represents an important milestone, which indicates significant tangible progress towards a more inclusive, equitable, and patient-centred approach to addressing the profound challenges of this disease. Growing evidence has illustrated the broader and specific contexts that have tremendous potential for positively influencing the diagnosis and treatment. In addition, the momentum accompanying this name change has included widespread public attention to the unique burden of this previously underappreciated disease.

Estimating Global Prevalence of Metabolic Dysfunction-Associated Fatty Liver Disease in Overweight or Obese Adults

BACKGROUND & AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a new terminology updated from non-alcoholic fatty liver disease (NAFLD). In this study, we aim to estimate the global prevalence of MAFLD specifically in overweight and obese adults from the general population by performing a systematic review and meta-analysis through mining the existing epidemiological data on fatty liver disease.

METHODS

We searched Medline, Embase, Web of Science, Cochrane and google scholar database from inception to November, 2020. DerSimonian-Laird random-effects model with Logit transformation was performed for data analysis. Sensitivity analysis and meta-regression were used to explore predictors of MAFLD prevalence in pooled statistics with high heterogeneity.

RESULTS

We identified 116 relevant studies comprised of 2,667,052 participants in general population with an estimated global MAFLD prevalence as 50.7% (95% CI 46.9-54.4) among overweight/obese adults regardless of diagnostic techniques. Ultrasound was the most commonly used diagnostic technique generating prevalence rate of 51.3% (95% CI, 49.1-53.4). Male (59.0%; 95% CI, 52.0-65.6) had a significantly higher MAFLD prevalence than female (47.5%; 95% CI, 40.7-54.5). Interestingly, MAFLD prevalence rates are comparable based on classical NAFLD and non-NAFLD studies in general population. The pooled estimate prevalence of comorbidities such as type 2 diabetes and metabolic syndrome was 19.7% (95% CI, 12.8-29.0) and 57.5% (95% CI, 49.9-64.8), respectively.

CONCLUSIONS

MAFLD has an astonishingly high prevalence rate in overweight and obese adults. This calls for attention and dedicated action from primary care physicians, specialists, health policy makers and the general public alike.

Biomarkers of Metabolic (Dysfunction)-associated Fatty Liver Disease: An Update

The prevalence of metabolic (dysfunction)-associated fatty liver disease (MAFLD) is rapidly increasing and affects up to two billion individuals globally, and this has also resulted in increased risks for cirrhosis, hepatocellular carcinoma, and liver transplants. In addition, it has also been linked to extrahepatic consequences, such as cardiovascular disease, diabetes, and various types of cancers. However, only a small proportion of patients with MAFLD develop these complications. Therefore, the identification of high-risk patients is paramount. Liver fibrosis is the major determinant in developing these complications. Although, liver biopsy is still considered the gold standard for the assessment of patients with MAFLD. Because of its invasive nature, among many other limitations, the search for noninvasive biomarkers for MAFLD remains an area of intensive research. In this review, we provide an update on the current and future biomarkers of MAFLD, including a discussion of the associated genetics, epigenetics, microbiota, and metabolomics. We also touch on the next wave of multiomic-based biomarkers.

Synergistic and Detrimental Effects of Alcohol Intake on Progression of Liver Steatosis

Nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) are the most common liver disorders worldwide and the major causes of non-viral liver cirrhosis in the general population. In NAFLD, metabolic abnormalities, obesity, and metabolic syndrome are the driving factors for liver damage with no or minimal alcohol consumption. ALD refers to liver damage caused by excess alcohol intake in individuals drinking more than 5 to 10 daily units for years. Although NAFLD and ALD are nosologically considered two distinct entities, they show a continuum and exert synergistic effects on the progression toward liver cirrhosis. The current view is that low alcohol use might also increase the risk of advanced clinical liver disease in NAFLD, whereas metabolic factors increase the risk of cirrhosis among alcohol risk drinkers. Therefore, special interest is now addressed to individuals with metabolic abnormalities who consume small amounts of alcohol or who binge drink, for the role of light-to-moderate alcohol use in fibrosis progression and clinical severity of the liver disease. Evidence shows that in the presence of NAFLD, there is no liver-safe limit of alcohol intake. We discuss the epidemiological and clinical features of NAFLD/ALD, aspects of alcohol metabolism, and mechanisms of damage concerning steatosis, fibrosis, cumulative effects, and deleterious consequences which include hepatocellular carcinoma.

Metabolic Risks Are Increasing in Non-B Non-C Early-Stage Hepatocellular Carcinoma: A 10-Year Follow-Up Study

Background

Non-B, non-C hepatocellular carcinoma (NBNC-HCC) may be related to metabolic syndrome, and the incidence of this tumor type is increasing annually. The definition of metabolic-associated fatty liver disease (MAFLD) proposed in 2020 may help to more accuratelyassess the association between metabolic syndrome and NBNC-HCC. However, this new concept has not yet been applied in NBNC-HCC research. Therefore, this study aimed to compare the clinicopathological characteristics of patients with NBNC-HCC and CHB-HCC diagnosed between 2009-13 and 2014-18, focusing on metabolic risk factors and the new concept of MAFLD.

Method

Patients with BCLC-0/A-HCC who received curative hepatectomy between January 2009 and December 2018 were retrospectively assessed; the associations between clinicopathological characteristics and clinical outcomes of NBNC-HCC and CHB-HCC were analyzed by multivariate analysis.

Result

Compared to patients diagnosed in 2009-13, the frequency of metabolic disorders in NBNC-HCC was significantly higher in 2014-18 [DM (p=0.049), HTN (p=0.004), BMI (p=0.017) and MAFLD (p=0.003)]; there was no significant change in patients with CHB-HCC. Moreover, CHB-HCC was an independent risk factor for HCC recurrence (HR, 1.339; 95% CI, 1.010-1.775, p=0.043) and death (HR, 1.700; 95% CI, 1.017-2.842, p=0.043) compared to NBNC-HCC.

Conclusions

Therisk of MAFLD, obesity, DM, and hypertension in patients with early-stage NBNC have significantly increased in recent years, thus metabolic syndrome should be monitored in this special population. Moreover, NBNC-HCC tend to had a better prognosis than CHB-HCC, probably due to their distinct clinicopathological features.

From MAFLD to hepatocellular carcinoma and everything in between

Metabolic (dysfunction) associated fatty liver disease (MAFLD), previously known as non-alcoholic fatty liver disease, is the most common cause of chronic liver disease worldwide. Many risk factors contribute to the pathogenesis of MAFLD with metabolic dysregulation being the final arbiter of its development and progression. MAFLD poses a substantial economic burden to societies, which based on current trends is expected to increase over time. Numerous studies have addressed various aspects of MAFLD from its risk associations to its economic and social burden and clinical diagnosis and management, as well as the molecular mechanisms linking MAFLD to end-stage liver disease and hepatocellular carcinoma. This review summarizes current understanding of the pathogenesis of MAFLD and related diseases, particularly liver cancer. Potential therapeutic agents for MAFLD and diagnostic biomarkers are discussed.

Bdh1 overexpression ameliorates hepatic injury by activation of Nrf2 in a MAFLD mouse model

In 2020, a group of experts officially suggested metabolic dysfunction associated with fatty liver disease "MAFLD" as a more appropriate overarching term than NAFLD, indicating the key role of metabolism in fatty liver disease. Bdh1, as the rate-limiting enzyme of ketone metabolism, acts as an important metabolic regulator in liver. However, the role of Bdh1 in MAFLD is unclear. In this study, we used the transgenic db/db mice as a MAFLD mouse model and observed the downregulated expression of Bdh1 in fatty liver. In addition, expression of Bdh1 was also reduced by palmitic acid (PA) treatment in LO2 cells. Bdh1 knockdown led to ROS overproduction and ROS-induced inflammation and apoptosis in LO2 cells, while Bdh1 overexpression protected LO2 cells from lipotoxicity by inhibiting ROS overproduction. Mechanistically, Bdh1-mediated βOHB metabolism inhibits ROS overproduction by activation of Nrf2 through enhancement of metabolic flux composed of βOHB-AcAc-succinate-fumarate. Notably, adeno-associated virus (AAV)-mediated Bdh1 overexpression successfully reversed the hepatic function indexes, fibrosis, inflammation, and apoptosis in fatty livers from db/db mice. In conclusion, our study revealed a Bdh1-mediated molecular mechanism in pathogenesis of metabolic dysfunction related liver disease and identified Bdh1 as a novel potential therapeutic target for MAFLD.

US Attenuation for Liver Fat Quantification: An AIUM-RSNA QIBA Pulse-Echo Quantitative Ultrasound Initiative

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with an estimated prevalence of up to 30% in the general population and higher in people with type 2 diabetes. The assessment of liver fat content is essential to help identify patients with or who are at risk for NAFLD and to follow their disease over time. The American Institute of Ultrasound in Medicine-RSNA Quantitative Imaging Biomarkers Alliance Pulse-Echo Quantitative Ultrasound Initiative was formed to help develop and standardize acquisition protocols and to better understand confounding factors of US-based fat quantification. The three quantitative US parameters explored by the initiative are attenuation, backscatter coefficient, and speed of sound. The purpose of this review is to present the current state of attenuation imaging for fat quantification and to provide expert opinion on examination performance and interpretation. US attenuation methods that need further study are outlined.

From NAFLD to MAFLD: Aligning Translational In Vitro Research to Clinical Insights

Although most same-stage non-alcoholic fatty liver disease (NAFLD) patients exhibit similar histologic sequelae, the underlying mechanisms appear to be highly heterogeneous. Therefore, it was recently proposed to redefine NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) in which other known causes of liver disease such as alcohol consumption or viral hepatitis do not need to be excluded. Revised nomenclature envisions speeding up and facilitating anti-MAFLD drug development by means of patient stratification whereby each subgroup would benefit from distinct pharmacological interventions. As human-based in vitro research fulfils an irrefutable step in drug development, action should be taken as well in this stadium of the translational path. Indeed, most established in vitro NAFLD models rely on short-term exposure to fatty acids and use lipid accumulation as a phenotypic benchmark. This general approach to a seemingly ambiguous disease such as NAFLD therefore no longer seems applicable. Human-based in vitro models that accurately reflect distinct disease subgroups of MAFLD should thus be adopted in early preclinical disease modeling and drug testing. In this review article, we outline considerations for setting up translational in vitro experiments in the MAFLD era and allude to potential strategies to implement MAFLD heterogeneity into an in vitro setting so as to better align early drug development with future clinical trial designs.

Metabolic-Associated Fatty Liver Disease Is Highly Prevalent in the Postacute COVID Syndrome

Background

A proposal has recently been advanced to change the traditional definition of nonalcoholic fatty liver disease to metabolic-associated fatty liver disease (MAFLD), to reflect the cluster of metabolic abnormalities that may be more closely associated with cardiovascular risk. Long coronavirus disease 2019 (COVID-19) is a smoldering inflammatory condition, characterized by several symptom clusters. This study aims to determine the prevalence of MAFLD in patients with postacute COVID syndrome (PACS) and its association with other PACS-cluster phenotypes.

Methods

We included 235 patients observed at a single university outpatient clinic. The diagnosis of PACS was based on ≥1 cluster of symptoms: respiratory, neurocognitive, musculoskeletal, psychological, sensory, and dermatological. The outcome was prevalence of MAFLD detected by transient elastography during the first postdischarge follow-up outpatient visit. The prevalence of MAFLD at the time of hospital admission was calculated retrospectively using the hepatic steatosis index.

Results

Of 235 patients, 162 (69%) were men (median age 61). The prevalence of MAFLD was 55.3% at follow-up and 37.3% on admission (P < .001). Insulin resistance (odds ratio [OR] = 1.5; 95% confidence interval [CI], 1.14–1.96), body mass index (OR = 1.14; 95% CI, 1.04–1.24), and the metabolic syndrome (OR = 2.54; 95% CI, 1.13–5.68) were independent predictors of MAFLD. The number of PACS clusters was inversely associated with MAFLD (OR = 0.86; 95% CI, .76–0.97). Thirty-one patients (13.2%) had MAFLD with no other associated PACS clusters. All correlations between MAFLD and other PACS clusters were weak.

Conclusions

Metabolic-associated fatty liver disease was highly prevalent after hospital discharge and may represent a specific PACS-cluster phenotype, with potential long-term metabolic and cardiovascular health implications.

The egyptian clinical practice guidelines for the diagnosis and management of metabolic associated fatty liver disease

The landscape of chronic liver disease in Egypt has drastically changed over the past few decades. The prevalence of metabolic-associated fatty liver disease (MAFLD) has risen to alarming levels. Despite the magnitude of the problem, no regional guidelines have been developed to tackle this disease. This document provides the clinical practice guidelines of the key Egyptian opinion leaders on MAFLD screening, diagnosis, and management, and covers various aspects in the management of MAFLD. The document considers our local situations and the burden of clinical management for the healthcare sector and is proposed for daily clinical practical use. Particular reference to special groups was done whenever necessary.

Potential screening indicators for early diagnosis of NAFLD/MAFLD and liver fibrosis: Triglyceride glucose index-related parameters

IMPORTANCE

Homeostatic model assessment for insulin resistance (HOMA-IR) and triglyceride glucose (TyG) index-related parameters [TyG index, triglyceride glucose-waist circumference (TyG-WC), triglyceride glucose-waist-to-height ratio (TyG-WHtR), and triglyceride glucose-body mass index (TyG-BMI)] are gradually considered as convenient and alternative indicators for insulin resistance in various metabolic diseases, but the specific diagnostic capacity and the comparison of the parameters in non-alcoholic fatty liver disease (NAFLD), metabolic-associated fatty liver disease (MAFLD), and liver fibrosis remain uncertain.

OBJECTIVE

To comprehensively assess and compare the diagnostic accuracy of the above parameters in NAFLD, MAFLD, and liver fibrosis and identify the appropriate indicators.

METHODS

A total of 1,727 adults were enrolled from the 2017-2018 National Health and Nutrition Examination Surveys. Logistic regressions were used to identify the parameters significantly associated with NAFLD, MAFLD, and liver fibrosis; receiver operating characteristic (ROC) curves were used to evaluate and compare their diagnostic capacity. Subgroup analyses were conducted to validate the concordance, and the optimal cutoff values were determined according to the Youden's indexes.

RESULTS

Significant differences were observed between quartile-stratified HOMA-IR and TyG index-related parameters across the NAFLD, MAFLD, and liver fibrosis (P < 0.05). All variables were significantly predictive of different disease states (P < 0.05). The top three AUC values are TyG-WC, TyG-WHtR, and TyG-BMI with AUCs of 0.815, 0.809, and 0.804 in NAFLD. The optimal cutoff values were 822.34, 4.94, and 237.77, respectively. Similar values and the same trend of the above three indexes could be observed in MAFLD and liver fibrosis. Subgroup analyses showed consistent results with the primary research, despite some heterogeneity.

CONCLUSIONS

TyG-WC, TyG-WHtR, and TyG-BMI can be used for early screening of NAFLD and MAFLD. These three parameters and HOMA-IR were more suitable for assessing metabolic risks and monitoring disease progression in patients with NAFLD.

Design of Hepatic Targeted Drug Delivery Systems for Natural Products: Insights into Nomenclature Revision of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), recently renamed metabolic-dysfunction-associated fatty liver disease (MAFLD), affects a quarter of the worldwide population. Natural products have been extensively utilized in treating NAFLD because of their distinctive advantages over chemotherapeutic drugs, despite the fact that there are no approved drugs for therapy. Notably, the limitations of many natural products, such as poor water solubility, low bioavailability in vivo, low hepatic distribution, and lack of targeted effects, have severely restricted their clinical application. These issues could be resolved via hepatic targeted drug delivery systems (HTDDS) that boost clinical efficacy in treating NAFLD and decrease the adverse effects on other organs. Herein an overview of natural products comprising formulas, single medicinal plants, and their crude extracts has been presented to treat NAFLD. Also, the clinical efficacy and molecular mechanism of active monomer compounds against NAFLD are systematically discussed. The targeted delivery of natural products via HTDDS has been explored to provide a different nanotechnology-based NAFLD treatment strategy and to make suggestions for natural-product-based targeted nanocarrier design. Finally, the challenges and opportunities put forth by the nomenclature update of NAFLD are outlined along with insights into how to improve the NAFLD therapy and how to design more rigorous nanocarriers for the HTDDS. In brief, we summarize the up-to-date developments of the NAFLD-HTDDS based on natural products and provide viewpoints for the establishment of more stringent anti-NAFLD natural-product-targeted nanoformulations.

Early-Life Exposure to Famine and Risk of Metabolic Associated Fatty Liver Disease in Chinese Adults

Background: Early-life exposure to the Chinese famine has been related to the risk of obesity, type 2 diabetes, and nonalcoholic fatty liver disease later in life. Nevertheless, the long-term impact of famine exposure on metabolic associated fatty liver disease (MAFLD), a recently proposed term to describe liver disease associated with known metabolic dysfunction, remains unknown. The aim of our study was to explore the relationship between early famine exposure and MAFLD in adulthood. Methods: A total of 26,821 participants (10,994 men, 15,827 women) were recruited from a cohort study of Chinese adults in Shanghai. We categorized participants into four famine exposure subgroups based on the birth year as nonexposed (1963–1967), fetal-exposed (1959–1962), childhood-exposed (1949–1958), and adolescence-exposed (1941–1948). MAFLD was defined as liver steatosis detected by ultrasound plus one of the following three criteria: overweight/obesity, type 2 diabetes, or evidence of metabolic dysregulation. Multivariable logistic regression models were performed to examine the association between famine exposure and MAFLD. Results: The mean ± standard deviation age of the participants was 60.8 ± 6.8 years. The age-adjusted prevalence of MAFLD was 38.3, 40.8, 40.1, and 36.5% for the nonexposed, fetal-exposed, childhood-exposed, and adolescence-exposed subgroups, respectively. Compared with nonexposed participants, fetal-exposed participants showed an increased risk of adulthood MAFLD (OR = 1.10, 95% CI 1.00–1.21). The significant association between fetal famine exposure and MAFLD was observed in women (OR = 1.22, 95% CI 1.08–1.37), but not in men (OR = 0.88, 95% CI 0.75–1.03). In age-balanced analyses combining pre-famine and post-famine births as the reference, women exposed to famine in the fetal stage still had an increased risk of MAFLD (OR = 1.15, 95% CI 1.05–1.26). Conclusions: Prenatal exposure to famine showed a sex-specific association with the risk of MAFLD in adulthood.

Assessment of chronic liver disease by multiparametric ultrasound: results from a private practice outpatient facility

PURPOSE

To assess chronic liver disease (CLD) using multiparametric US in a private practice setting in a cohort of patients with increased skin-to-liver distance.

METHODS

110 consecutive patients with increased skin-to-liver distance scheduled for US assessment of CLD were reviewed for study completion time, liver stiffness values (LS), attenuation imaging, and shear wave dispersion slope. The ROI was placed 2 cm below the liver capsule. The study included patients with NAFLD/NASH (68), hepatitis C (30), prior Fontan surgery (1), elevated liver function tests (5), alcohol abuse (3), hepatitis B (2), and primary biliary cirrhosis (1). IQR/M values were obtained. Comparison of less experienced sonographers (LES) and more experienced sonographers (MES) were evaluated through Student's t test for independent data. Pearson coefficient r of correlation among quantitative variables was calculated.

RESULTS

The mean time to perform the exam was 129.7 ± 62.1 s. There was a statistically significant difference between LES and MES. The mean IQR/M for LS was 12.3 ± 5.5% m/s. Overall, in a cohort of difficult patients, 4.5% of LS values were not reliable. Fat quantification using attenuation imaging had a mean value of 0.60 ± 0.15 dB/cm/MHz (range 0.35-0.98 cm/dB/MHz) with an IQR/M of 14.7 ± 9.2%. Less reliable measurements of steatosis were obtained in 4.5% of patients. The mean shear wave dispersion slope was 12.74 ± 4.05 (m/s)/kHz (range 7.7-27.5 (m/s)/kHz) with an IQR/M of 38.7 ± 20.2% (range 3-131%). 20.9% of patients had values suggestive of compensated advanced chronic liver disease (cACLD).

CONCLUSION

Multiparametric US can provide assessment of CLD in less than 3 min in most patients and identify patients at risk for cACLD.

Metabolic Disorders Combined with Noninvasive Tests to Screen Advanced Fibrosis in Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is associated with metabolic disorders. This study aimed to explore the role of metabolic disorders in screening advanced fibrosis in NAFLD patients.

METHODS

A total of 246 histologically-proven NAFLD patients were enrolled across 14 centers. We compared the severity of fibrosis in patients with different components of metabolic disorders. Based on standard noninvasive tests and metabolic disorders, we developed new algorithms to identify advanced fibrosis.

RESULTS

Metabolic syndrome (MetS) was frequent in NAFLD patients (133/246, 54%). Patients with MetS had a higher proportion of significant fibrosis (p=0.014) and higher LSM values (9.2 kPa, vs. 7.4 kPa, p=0.002) than those without MetS. Patients with more metabolic disorders had higher fibrosis stages (p=0.017). Reduced high-density lipoprotein cholesterol (odds ratio [OR]: 2.241, 95% confidence interval [CI]: 1.004-5.002, p=0.049) and raised fasting glucose (OR: 4.500, 95% CI: 2.083-9.725, p<0.001) were significantly associated with advanced fibrosis. Using these two metabolic disorders as a screening tool, a sensitivity, specificity and accuracy of 92%, 81% and 83% was achieved, respectively. With the new algorithms combining metabolic disorders with noninvasive measurements, the number of patients requiring liver biopsy was reduced, especially in combination with the Fibrosis-4 score and metabolic disorders (36% to 17%, p<0.001). In addition, this stepwise algorithm could achieve a high accuracy (85%) and high negative predictive value (93%).

CONCLUSIONS

Metabolic disorders should be taken into consideration in the diagnosis of advanced fibrosis. With further validation and investigation, new algorithms could be recommended in primary care units to spare patients from unnecessary referral and liver biopsies.

An update on drug development for the treatment of metabolic (dysfunction) associated fatty liver disease: Progress and opportunities

Despite the rising health burden of metabolic (dysfunction) associated fatty liver disease (MAFLD), there are no approved pharmacotherapies for MAFLD currently. This situation led to a significant escalation in drug development and randomized controlled trials for MAFLD, particularly as novel information about its molecular pathogenesis unfolds. Currently, there are numerous investigational candidate drugs for MAFLD in various stages of clinical development that act on different pathophysiological processes, such as metabolism/steatosis, inflammation or fibrosis. Here, we provide an update on drug development for the treatment of MAFLD and discuss the prospects and challenges for improving and accelerating the nonalcoholic fatty liver disease drug discovery pipeline.

The Chinese Society of Hepatology position statement on the redefinition of fatty liver disease

Fatty liver disease associated with metabolic dysfunction is of increasing concern in mainland China, the world's most populous country. The incidence of fatty liver disease is highest in China, surpassing the incidence in European countries and the USA. An international consensus panel recently published an influential report recommending a novel definition of fatty liver disease associated with metabolic dysfunction. This recommendation includes a switch in name from non-alcoholic fatty liver disease (NAFLD) to metabolic (dysfunction)-associated fatty liver disease (MAFLD) and adoption of a set of positive criteria for disease diagnosis that are independent of alcohol intake or other liver diseases. Given the unique importance of this proposal, the Chinese Society of Hepatology (CSH) invited leading hepatologists and gastroenterologists representing their respective provinces and cities to reach consensus on alternative definitions for fatty liver disease from a national perspective. The CSH endorses the proposed change from NAFLD to MAFLD (supported by 95.45% of participants). We expect that the new definition will result in substantial improvements in health care for patients and advance disease awareness, public health policy, and political, scientific and funding outcomes for MAFLD in China.

Nutritional supplementation for nonalcohol-related fatty liver disease: a network meta-analysis

BACKGROUND

The prevalence of non-alcohol-related fatty liver disease (NAFLD) varies between 19% and 33% in different populations. NAFLD decreases life expectancy and increases risks of liver cirrhosis, hepatocellular carcinoma, and the requirement for liver transplantation. Uncertainty surrounds relative benefits and harms of various nutritional supplements in NAFLD. Currently no nutritional supplement is recommended for people with NAFLD.

OBJECTIVES

• To assess the benefits and harms of different nutritional supplements for treatment of NAFLD through a network meta-analysis • To generate rankings of different nutritional supplements according to their safety and efficacy SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, the World Health Organization International Clinical Trials Registry Platform, and trials registers until February 2021 to identify randomised clinical trials in people with NAFLD.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) for people with NAFLD, irrespective of method of diagnosis, age and diabetic status of participants, or presence of non-alcoholic steatohepatitis (NASH). We excluded randomised clinical trials in which participants had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS using Bayesian methods whenever possible and calculated differences in treatments using hazard ratios (HRs), odds ratios (ORs), and rate ratios with 95% credible intervals (CrIs) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance.

MAIN RESULTS

We included in the review a total of 202 randomised clinical trials (14,200 participants). Nineteen trials were at low risk of bias. A total of 32 different interventions were compared in these trials. A total of 115 trials (7732 participants) were included in one or more comparisons. The remaining trials did not report any of the outcomes of interest for this review. Follow-up ranged from 1 month to 28 months. The follow-up period in trials that reported clinical outcomes was 2 months to 28 months. During this follow-up period, clinical events related to NAFLD such as mortality, liver cirrhosis, liver decompensation, liver transplantation, hepatocellular carcinoma, and liver-related mortality were sparse. We did not calculate effect estimates for mortality because of sparse data (zero events for at least one of the groups in the trial). None of the trials reported that they measured overall health-related quality of life using a validated scale. The evidence is very uncertain about effects of interventions on serious adverse events (number of people or number of events). We are very uncertain about effects on adverse events of most of the supplements that we investigated, as the evidence is of very low certainty. However, people taking PUFA (polyunsaturated fatty acid) may be more likely to experience an adverse event than those not receiving an active intervention (network meta-analysis results: OR 4.44, 95% CrI 2.40 to 8.48; low-certainty evidence; 4 trials, 203 participants; direct evidence: OR 4.43, 95% CrI 2.43 to 8.42). People who take other supplements (a category that includes nutritional supplements other than vitamins, fatty acids, phospholipids, and antioxidants) had higher numbers of adverse events than those not receiving an active intervention (network meta-analysis: rate ratio 1.73, 95% CrI 1.26 to 2.41; 6 trials, 291 participants; direct evidence: rate ratio 1.72, 95% CrI 1.25 to 2.40; low-certainty evidence). Data were sparse (zero events in all groups in the trial) for liver transplantation, liver decompensation, and hepatocellular carcinoma. So, we did not perform formal analysis for these outcomes. The evidence is very uncertain about effects of other antioxidants (antioxidants other than vitamins) compared to no active intervention on liver cirrhosis (HR 1.68, 95% CrI 0.23 to 15.10; 1 trial, 99 participants; very low-certainty evidence). The evidence is very uncertain about effects of interventions in any of the remaining comparisons, or data were sparse (with zero events in at least one of the groups), precluding formal calculations of effect estimates. Data were probably because of the very short follow-up period (2 months to 28 months). It takes follow-up of 8 to 28 years to detect differences in mortality between people with NAFLD and the general population. Therefore, it is unlikely that differences in clinical outcomes are noted in trials providing less than 5 to 10 years of follow-up.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about effects of nutritional supplementation compared to no additional intervention on all clinical outcomes for people with non-alcohol-related fatty liver disease. Accordingly, high-quality randomised comparative clinical trials with adequate follow-up are needed. We propose registry-based randomised clinical trials or cohort multiple randomised clinical trials (study design in which multiple interventions are trialed within large longitudinal cohorts of patients to gain efficiencies and align trials more closely to standard clinical practice) comparing interventions such as vitamin E, prebiotics/probiotics/synbiotics, PUFAs, and no nutritional supplementation. The reason for the choice of interventions is the impact of these interventions on indirect outcomes, which may translate to clinical benefit. Outcomes in such trials should be mortality, health-related quality of life, decompensated liver cirrhosis, liver transplantation, and resource utilisation measures including costs of intervention and decreased healthcare utilisation after minimum follow-up of 8 years (to find meaningful differences in clinically important outcomes).

Chronic hepatitis B infection with concomitant hepatic steatosis: Current evidence and opinion

With the increasing incidence of obesity and metabolic syndrome worldwide, concomitant nonalcoholic fatty liver disease (NAFLD) in patients with chronic hepatitis B (CHB) has become highly prevalent. The risk of dual etiologies, outcome, and mechanism of CHB with concomitant NAFLD have not been fully characterized. In this review, we assessed the overlapping prevalence of metabolic disorders and CHB, assessed the risk of advanced fibrosis/hepatocellular carcinoma in CHB patients concomitant with NAFLD, and discussed the remaining clinical issues to be addressed in the outcome of such patients. We also explored the possible roles of hepatitis B virus in the development of steatosis and discussed difficultiesof histological evaluation. For CHB patients, it is important to address concomitant NAFLD through lifestyle management and disease screening to achieve better prognoses. The assessment of progressive changes and novel therapies for CHB patients concomitant with NAFLD deserve further research.

Editorial: International Consensus Recommendations to Replace the Terminology of Non-Alcoholic Fatty Liver Disease (NAFLD) with Metabolic-Associated Fatty Liver Disease (MAFLD)

In 2020, international consensus guidelines recommended the renaming of non-alcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD), supported by diagnostic criteria. MAFLD affects up to 25% of the global population. However, the rates of MAFLD are likely to be underestimated due to the increasing prevalence of type 2 diabetes mellitus (T2DM) and obesity. Within the next decade, MAFLD has been projected to become a major cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide, as well as the most common indication for liver transplantation in the US. This transition in terminology and clinical criteria may increase momentum and clinical evidence at multiple levels, including patient diagnosis, management, and care, and provide the basis for new research areas and clinical development for therapeutics. The diagnostic criteria for MAFLD are practical, simple, and superior to the existing NAFLD criteria for identifying patients at increased risk of developing progressive liver disease. This Editorial aims to present the historical evolution of the terminology for fatty liver disease and the advantages of diagnosis, patient management, and future research on MAFLD.

Lifestyle modifications for nonalcohol-related fatty liver disease: a network meta-analysis

BACKGROUND

The prevalence of nonalcohol-related fatty liver disease (NAFLD) varies between 19% and 33% in different populations. NAFLD decreases life expectancy and increases the risks of liver cirrhosis, hepatocellular carcinoma, and requirement for liver transplantation. There is uncertainty surrounding the relative benefits and harms of various lifestyle interventions for people with NAFLD.

OBJECTIVES

To assess the comparative benefits and harms of different lifestyle interventions in the treatment of NAFLD through a network meta-analysis, and to generate rankings of the different lifestyle interventions according to their safety and efficacy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, World Health Organization International Clinical Trials Registry Platform, and trials registers until February 2021 to identify randomised clinical trials in people with NAFLD.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or status) in people with NAFLD, whatever the method of diagnosis, age, and diabetic status of participants, or presence of non-alcoholic steatohepatitis (NASH). We excluded randomised clinical trials in which participants had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We planned to perform a network meta-analysis with OpenBUGS using Bayesian methods and to calculate the differences in treatments using hazard ratios (HRs), odds ratios (ORs), and rate ratios (RaRs) with 95% credible intervals (CrIs) based on an available-participant analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance. However, the data were too sparse for the clinical outcomes. We therefore performed only direct comparisons (head-to-head comparisons) with OpenBUGS using Bayesian methods.

MAIN RESULTS

We included a total of 59 randomised clinical trials (3631 participants) in the review. All but two trials were at high risk of bias. A total of 33 different interventions, ranging from advice to supervised exercise and special diets, or a combination of these and no additional intervention were compared in these trials. The reference treatment was no active intervention. Twenty-eight trials (1942 participants) were included in one or more comparisons. The follow-up ranged from 1 month to 24 months. The remaining trials did not report any of the outcomes of interest for this review. The follow-up period in the trials that reported clinical outcomes was 2 months to 24 months. During this short follow-up period, clinical events related to NAFLD such as mortality, liver cirrhosis, liver decompensation, liver transplantation, hepatocellular carcinoma, and liver-related mortality were sparse. This is probably because of the very short follow-up periods. It takes a follow-up of 8 years to 28 years to detect differences in mortality between people with NAFLD and the general population. It is therefore unlikely that differences by clinical outcomes will be noted in trials with less than 5 years to 10 years of follow-up. In one trial, one participant developed an adverse event. There were no adverse events in any of the remaining participants in this trial, or in any of the remaining trials, which seemed to be directly related to the intervention.

AUTHORS' CONCLUSIONS

The evidence indicates considerable uncertainty about the effects of the lifestyle interventions compared with no additional intervention (to general public health advice) on any of the clinical outcomes after a short follow-up period of 2 months to 24 months in people with nonalcohol-related fatty liver disease. Accordingly, high-quality randomised clinical trials with adequate follow-up are needed. We propose registry-based randomised clinical trials or cohort multiple randomised clinical trials (a study design in which multiple interventions are trialed within large longitudinal cohorts of participants to gain efficiencies and align trials more closely to standard clinical practice), comparing aerobic exercise and dietary advice versus standard of care (exercise and dietary advice received as part of national health promotion). The reason for the choice of aerobic exercise and dietary advice is the impact of these interventions on indirect outcomes which may translate to clinical benefit. The outcomes in such trials should be mortality, health-related quality of life, decompensated liver cirrhosis, liver transplantation, and resource use measures including costs of intervention and decreased healthcare use after a minimum follow-up of eight years, to find meaningful differences in the clinically important outcomes.

Historical narrative from fatty liver in the nineteenth century to contemporary NAFLD - Reconciling the present with the past

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder worldwide. This historical narrative traces the evolution from basic descriptions of fatty liver in the nineteenth century to our contemporary understanding of NAFLD in the twentieth and twenty-first centuries. A detailed historiographic review of fatty liver from 1800s onwards was performed alongside a brief review of contemporary associations. Archived published literature dating back to the 1800s describe clinicopathological features of fatty liver. In the nineteenth century, doyens of medicine associated fatty liver with alcohol, malnutrition or wasting conditions, and subsequently adiposity, unhealthy diets and sedentary lifestyle. Microscopically, fatty liver was described when 5% or more hepatocytes were distended with fat. Recommendations to reverse fatty liver included reducing consumption of fat, sugar, starchy carbohydrates and alcohol, plus increasing physical exercise. Fatty liver was associated with liver fibrosis and cirrhosis in the late 1800s, and with diabetes in the early 1900s. The diagnostic labels NAFLD and non-alcoholic steatohepatitis (NASH) were introduced in the late 1900s. Metabolic dysfunction-associated fatty liver disease (MAFLD) was recently proposed to update the nosology of fatty liver, recognising the similar metabolic pathogenesis evident in individuals with typical NAFLD and those with heterogenous "secondary" co-factors including alcohol and other aetiologies. Fatty liver has emerged from being considered a disorder of nutritional extremes or alcohol excess to contemporary recognition as a complex metabolic disorder that risks progression to cirrhosis and hepatocellular carcinoma. The increasing prevalence of NAFLD and our growing understanding of its lifestyle and metabolic determinants justify the current exercise of re-examining the evolution of this common metabolic disorder.

A single-letter change in an acronym: signals, reasons, promises, challenges, and steps ahead for moving from NAFLD to MAFLD

Introduction: We are currently at the dawn of a revolution in the field of fatty liver diseases. Recently, a consensus recommended 'metabolic (dysfunction) associated fatty liver disease' (MAFLD) as a more appropriate name to describe fatty liver disease associated with metabolic dysfunction, ultimately suggesting that the old acronym nonalcoholic fatty liver disease (NAFLD) should be abandoned.Areas covered: In this viewpoint, we discuss the reasons and relevance of this semantic modification through five different conceptual domains, i.e., 1) signals, 2) reasons, 2) promises, 4) challenges and 5) steps ahead.Expert opinion: The road ahead will not be traveled without major challenges. Further research to evaluate the positive and negative impacts of the nomenclature change is warranted. However, this modification should encourage increased disease awareness among policymakers and stimulate public and private investments leading to more effective therapy development.

From NAFLD to MAFLD: Nurse and allied health perspective

Fatty liver disease associated with metabolic dysfunction is the most prevalent liver disease worldwide, though both patient and health professional still lack awareness of it. An international consensus panel has produced what is sure to be an influential report renaming the disease from non-alcoholic fatty liver disease (NAFLD) to metabolic (dysfunction) associated fatty liver disease (MAFLD) and suggesting how the disease should be diagnosed. This viewpoint explores the call from the perspective of nurse and allied health practitioners. This group have raised serious concerns on the existing nomenclature, which labels the disease as NAFLD, and its diagnostic criteria, including provoking nurse role confusion and representing a major barrier to various key aspects; patient-nurse communications, patient awareness, partnership working, motivation of patients to undertake lifestyle changes and multiple health behaviour change promotion and nurse-led clinics. Therefore, they are enthusiastically supportive of this call to reframe the disease that we believe will ultimately have a positive impact on nurse-patient communication, and through this, improve patient care and quality of life and reduce burden on health system.

Human Nonalcoholic Steatohepatitis on a Chip

Nonalcoholic steatohepatitis (NASH), an advanced stage of nonalcoholic fatty liver disease (NAFLD), is a rapidly growing and global health problem compounded by the current absence of specific treatments. A major limiting factor in the development of new NASH therapies is the absence of models that capture the unique cellular structure of the liver microenvironment and recapitulate the complexities of NAFLD progression to NASH. Organ-on-a-chip platforms have emerged as a powerful approach to dynamically model diseases and test drugs. Herein, we describe a NASH-on-a-chip platform. Four main types of human primary liver cells (hepatocytes [HCs], Kupffer cells, liver sinusoidal endothelial cells, and hepatic stellate cells [HSCs]) were cocultured under microfluidic dynamics. Our chip-based model successfully recapitulated a functional liver cellular microenvironment with stable albumin and urea secretion for at least 2 weeks. Exposing liver chips to a lipotoxic environment led to gradual development of NASH phenotypic characteristics, including intracellular lipid accumulation, hepatocellular ballooning, HSC activation, and elevation of inflammatory and profibrotic markers. Further, exposure of the chip to elafibranor, a drug under study for the therapy of NASH, inhibited the development of NASH-specific hallmarks, causing an ~8-fold decrease in intracellular lipids, a 3-fold reduction in number of ballooned HCs, a significant reduction in HSC activation, and a significant decrease in the levels of inflammatory and profibrotic markers compared with controls. Conclusion: We have successfully developed a microfluidic NASH-on-a-chip platform that recapitulates the main NASH histologic endpoints in a single chip and that can emerge as a powerful noninvasive, human-relevant, in vitro platform to study disease pathogenesis and develop novel anti-NASH drugs.