The Health Impact of MAFLD, a Novel Disease Cluster of NAFLD, Is Amplified by the Integrated Effect of Fatty Liver Disease-Related Genetic Variants

Proteogenomic Analysis Identifies a Causal Association between Plasma Apolipoprotein B Levels and Liver Cancer Risk

Liver oncogenesis is accompanied by discernible protein changes in the bloodstream. By employing plasma proteomic profiling, we can delve into the molecular mechanisms of liver cancer and pinpoint potential biomarkers. In this nested case-control study, we applied liquid chromatography-tandem mass spectrometry for proteome profiling in baseline plasma samples. Differential protein expression was determined and was subjected to functional enrichment, network, and Mendelian randomization (MR) analyses. We identified 193 proteins with notable differential levels between the groups. Of these proteins, MR analysis offered a compelling negative association between apolipoprotein B (APOB) and liver cancer. This association was further corroborated in the UK Biobank cohort: genetically predicted APOB levels were associated with a 31% (95% CI 19-42%) decreased risk of liver cancer; and phenotypic analysis indicated an 11% (95% CI 8-14%) decreased liver cancer risk for every 0.1 g/L increase of circulating APOB levels. Multivariable MR analysis suggested that the hepatic fat content might fully mediate the APOB-liver cancer connection. In summary, we identified some plasma proteins, particularly APOB, as potential biomarkers of liver cancer. Our findings underscore the intricate link between lipid metabolism and liver cancer, offering hints for targeted prophylactic strategies and early detection.

Synergistic association of sodium-glucose cotransporter-2 inhibitor and metformin on liver and non-liver complications in patients with type 2 diabetes mellitus and metabolic dysfunction-associated steatotic liver disease

OBJECTIVE

Type 2 diabetes mellitus and metabolic dysfunction-associated steatotic liver disease (diabetic MASLD) frequently coexist and worsen liver and non-liver outcomes, but effective pharmacological therapies are limited. We aimed to evaluate the long-term effect of sodium-glucose cotransporter-2 inhibitor (SGLT-2i) on liver and non-liver outcomes among patients with diabetic MASLD.

DESIGN

This population-based cohort study retrieved patients with diabetic MASLD from Merative Marketscan Research Databases (April 2013 and December 2021). The active comparator was other glucose-lowering drugs (oGLDs). Primary outcomes were liver complications including hepatocellular carcinoma (HCC) and liver cirrhosis, as well as non-liver complications including cardiovascular disease (CVD), chronic kidney disease (CKD) and non-liver cancer. Propensity score matching was applied and Cox regression models were conducted.

RESULTS

Compared with oGLD, SGLT-2i users had significantly lower risk of HCC (HR 0.76, 95% CI 0.62 to 0.93), liver cirrhosis (HR 0.80, 95% CI 0.76 to 0.84), CVD (HR 0.82, 95% CI 0.79 to 0.85) and CKD (HR 0.66, 95% CI 0.62 to 0.70), non-liver cancer (HR 0.81, 95% CI 0.76 to 0.86). Compared with patients without metformin and SGLT-2i, a stepwise decreasing risk was observed in users of either metformin or SGLT-2i (HRs 0.76-0.97) and in users of both medications (HRs 0.58-0.79). The lower risk also was shown in liver decompensation, compensated cirrhosis, major CVD, end-stage renal disease and specific common cancers (HRs 0.61-0.84).

CONCLUSION

In a nationwide cohort, SGLT-2i users were associated with a substantially lower risk of liver and non-liver complications than oGLD users among patients with diabetic MASLD. The risk was further reduced with concomitant metformin use.

Opportunities and barriers in omics-based biomarker discovery for steatotic liver diseases

The rising prevalence of liver diseases related to obesity and excessive use of alcohol is fuelling an increasing demand for accurate biomarkers aimed at community screening, diagnosis of steatohepatitis and significant fibrosis, monitoring, prognostication and prediction of treatment efficacy. Breakthroughs in omics methodologies and the power of bioinformatics have created an excellent opportunity to apply technological advances to clinical needs, for instance in the development of precision biomarkers for personalised medicine. Via omics technologies, biological processes from the genes to circulating protein, as well as the microbiome - including bacteria, viruses and fungi, can be investigated on an axis. However, there are important barriers to omics-based biomarker discovery and validation, including the use of semi-quantitative measurements from untargeted platforms, which may exhibit high analytical, inter- and intra-individual variance. Standardising methods and the need to validate them across diverse populations presents a challenge, partly due to disease complexity and the dynamic nature of biomarker expression at different disease stages. Lack of validity causes lost opportunities when studies fail to provide the knowledge needed for regulatory approvals, all of which contributes to a delayed translation of these discoveries into clinical practice. While no omics-based biomarkers have matured to clinical implementation, the extent of data generated has enabled the hypothesis-free discovery of a plethora of candidate biomarkers that warrant further validation. To explore the many opportunities of omics technologies, hepatologists need detailed knowledge of commonalities and differences between the various omics layers, and both the barriers to and advantages of these approaches.

Sleep patterns, genetic susceptibility, and risk of cirrhosis among individuals with nonalcoholic fatty liver disease

BACKGROUND

The associations between sleep patterns or behaviors and the risk of cirrhosis and the influence of genetic susceptibility on these associations among NAFLD participants remain inadequately elucidated.

METHODS

This study conducted a prospective follow-up of 112,196 NAFLD participants diagnosed at baseline from the UK Biobank cohort study. Five sleep behaviors were collected to measure a healthy sleep score. Five genetic variants were used to construct a polygenic risk score. We used Cox proportional hazard model to assess hazard ratios (HR) and 95% confidence intervals (CIs) for incidence of cirrhosis.

RESULTS

During the follow-up, 592 incident cirrhosis cases were documented. Healthy sleep pattern was associated with reduced risk of cirrhosis in a dose-response manner (ptrend < 0.001). Participants with favourable sleep score (versus unfavourable sleep score) had an HR of 0.55 for cirrhosis risk (95% CI 0.39-0.78). Multivariable-adjusted HRs (95% CIs) of cirrhosis incidence for NAFLDs with no frequent insomnia, sleeping for 7-8 h per day, and no excessive daytime dozing behaviors were 0.73 (0.61-0.87), 0.79 (0.66-0.93), and 0.69 (0.50-0.95), respectively. Compared with participants with favourable sleep pattern and low genetic risk, those with unfavourable sleep pattern and high genetic risk had higher risks of cirrhosis incidence (HR 3.16, 95% CI 1.88-5.33). In addition, a significant interaction between chronotype and genetic risk was detected for the incidence of cirrhosis (p for multiplicative interaction = 0.004).

CONCLUSION

An association was observed between healthy sleep pattern and decreased risk of cirrhosis among NAFLD participants, regardless of low or high genetic risk.

Polygenic risk score of metabolic dysfunction-associated steatotic liver disease amplifies the health impact on severe liver disease and metabolism-related outcomes

BACKGROUND

Although the inherited risk factors associated with fatty liver disease are well understood, little is known about the genetic background of metabolic dysfunction-associated steatotic liver disease (MASLD) and its related health impacts. Compared to non-alcoholic fatty liver disease (NAFLD), MASLD presents significantly distinct diagnostic criteria, and epidemiological and clinical features, but the related genetic variants are yet to be investigated. Therefore, we conducted this study to assess the genetic background of MASLD and interactions between MASLD-related genetic variants and metabolism-related outcomes.

METHODS

Participants from the UK Biobank were grouped into discovery and replication cohorts for an MASLD genome-wide association study (GWAS), and base and target cohorts for polygenic risk score (PRS) analysis. Autosomal genetic variants associated with NAFLD were compared with the MASLD GWAS results. Kaplan-Meier and Cox regression analyses were used to assess associations between MASLD and metabolism-related outcomes.

RESULTS

Sixteen single-nucleotide polymorphisms (SNPs) were identified at genome-wide significance levels for MASLD and duplicated in the replication cohort. Differences were found after comparing these SNPs with the results of NAFLD-related genetic variants. MASLD cases with high PRS had a multivariate-adjusted hazard ratio of 3.15 (95% confidence interval, 2.54-3.90) for severe liver disease (SLD), and 2.81 (2.60-3.03) for type 2 diabetes mellitus. The high PRS amplified the impact of MASLD on SLD and extrahepatic outcomes.

CONCLUSIONS

High PRS of MASLD GWAS amplified the impact of MASLD on SLD and metabolism-related outcomes, thereby refining the process of identification of individuals at high risk of MASLD. Supplementation of this process with relevant genetic backgrounds may lead to more effective MASLD prevention and management.

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.

Editorial: The tsunami of steatotic liver disease in India, the Asia-Pacific region and the world

This article is linked to Prabhakar et al papers. To view these articles, visit https://doi.org/10.1111/apt.17892 and https://doi.org/10.1111/apt.17921

The Global Epidemic of Metabolic Fatty Liver Disease

PURPOSE OF REVIEW

The objective of this manuscript is to examine the current literature on the epidemiology of metabolic dysfunction-associated steatotic liver disease (MASLD), its correlation with cardiovascular disease (CVD) outcomes, as well as to evaluate the update in nomenclature from non-alcoholic liver disease (NAFLD).

RECENT FINDINGS

The update of diagnostic criteria from NAFLD to MASLD reduces the stigma associated with alcohol consumption and poor health choices. It also shines a light on the crucial role of cardiometabolic risk factors in disease pathophysiology. The incidence and prevalence of MASLD are projected to increase significantly in the future as the population burden of cardiometabolic risk factors rises. MASLD is also a potent risk factor for developing CVD that should be tackled by using a multi-disciplinary team with a holistic approach. As the new nomenclature for metabolic liver disease is adopted on a global scale, more research is needed to investigate the applicability of findings from previous trials focusing on NAFLD. It is anticipated that the epidemic of MASLD will continue to increase globally, hence the urgent need for therapeutic approaches to reverse this trend.

Effects of weight loss on metabolic dysfunction-associated fatty liver disease in Japanese people: Non-alcoholic fatty liver disease in the Gifu area, longitudinal analysis study

AIM

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a major health concern. This cohort study aimed to evaluate the association between weight loss and remission of MAFLD in the Japanese population to aid the development of efficient treatment strategies.

METHODS

This retrospective cohort study was conducted at a Japanese health screening center. Participants included 3309 individuals diagnosed with baseline MAFLD between 2004 and 2016. Logistic regression analysis was used to assess the association between MAFLD remission from baseline to 5 years and weight change.

RESULTS

After 5 years, 671 participants achieved MAFLD remission. Weight loss was associated with MAFLD remission for every 1 kg of weight loss over 5 years; the odds ratio for MAFLD remission was 1.24 (95% CI 1.15-1.34) for participants with type 2 diabetes, 1.40 (95% CI 1.35-1.45) for overweight participants, and 1.51 (95% CI 1.33-1.72) for non-overweight participants with metabolic dysfunctions. The cutoff values for weight loss for MAFLD remission were 1.9 kg for all participants, 3.0 kg for participants with type 2 diabetes, 1.9 kg for overweight participants, and 0.8 kg for non-overweight participants with metabolic dysfunctions.

CONCLUSIONS

Among participants diagnosed with MAFLD, weight loss was associated with MAFLD remission regardless of the type of metabolic dysfunction in MAFLD. The results of this study may contribute to the development of novel approaches to achieve MAFLD remission.

Association between metabolic dysfunction-associated fatty liver disease and abdominal aortic aneurysm

BACKGROUND AND AIMS

Abdominal aortic aneurysm (AAA) is the second most common aortic pathological manifestation. Metabolic dysfunction-associated fatty liver disease (MAFLD) has a wide impact on the cardiovascular system and may be a risk factor for AAA. The aim of this study was to investigate whether MAFLD is associated with the risk of AAA.

METHODS AND RESULTS

We used data from the prospective UK Biobank cohort study. MAFLD is defined as hepatic steatosis plus metabolic abnormality, type 2 diabetes, or overweight/obesity. AAA is collected by ICD-10 code. Cox regression was established to analyze the association between MAFLD and AAA. A total of 370203 participants were included; the average age of the participants was 56.7 ± 8.0 years, and 134649 (36.4 %) were diagnosed with MAFLD. During the 12.5 years of follow-up, 1561 (0.4 %) participants developed AAA. After fully adjusting for confounding factors, individuals with MAFLD had a significantly increased risk of AAA (HR 1.521, 95 % CI 1.351-1.712, p < 0.001). Importantly, the risk of AAA increases with the severity of MAFLD as assessed by fibrosis scores. These associations were consistent according to sex, weight, and alcohol consumption but weaker in elderly or diabetics (P for interaction <0.05). The association between the MAFLD phenotype and AAA was independent of the polygenic risk score. Additionally, MAFLD was not associated with thoracic aortic aneurysm or aortic dissection events.

CONCLUSIONS

There was a significant relationship between MAFLD and AAA. These findings strongly recommend early prevention of AAA by intervening in MAFLD.

Exposure to ambient air pollution and metabolic dysfunction-associated fatty liver disease: Findings from over 2.7 million adults in Northwestern China

Ambient air pollutants exposures may lead to aggravated Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD). However, there is still a scarcity of empirical studies that have rigorously estimated this association, especially in regions where air pollution is severe. To fill in the literature gap, we conducted a cross-sectional study involving 2711,207 adults living in five regions of southern Xinjiang Uyghur Autonomous Region in 2021. Using a Space-Time Extra-Trees model, we assessed the four-year (2017-2020) average concentrations of particulate matter with aerodynamic diameter ≤1 µm (PM1), particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5), particulate matter with aerodynamic diameter ≤10 µm (PM10), ozone (O3), sulfur dioxide (SO2), and carbon monoxide (CO), and then assigned these values to the participants. Generalized linear mixed models were employed to examine the relationships between air pollutants and the prevalence of MAFLD, with adjustment for multiple confounding factors. The odds ratios and 95% confidence intervals of MAFLD were 2.002 (1.826-2.195), 1.133 (1.108-1.157), 1.034 (1.027-1.040), 1.077 (1.023-1.134), 2.703 (2.322-3.146) and 1.033 (1.029-1.036) per 10 µg/m3 increase in the 4-year average PM1, PM2.5, PM10, O3, SO2 and CO exposures, respectively. The robustness of the findings was confirmed by a series of sensitivities. In summary, long-term exposure to ambient air pollutants was associated with increased odds of MAFLD, particularly in males and individuals with unhealthy lifestyles.

Metabolic-associated fatty liver disease: a selective review of pathogenesis, diagnostic approaches, and therapeutic strategies

Background

Metabolic associated fatty liver disease (MAFLD) is a novel terminology introduced in 2020 to provide a more accurate description of fatty liver disease associated with metabolic dysfunction. It replaces the outdated term nonalcoholic fatty liver disease (NAFLD) and aims to improve diagnostic criteria and tailored treatment strategies for the disease. NAFLD, the most prevalent liver disease in western industrialized nations, has been steadily increasing in prevalence and is associated with serious complications such as cirrhosis and hepatocellular carcinoma. It is also linked to insulin resistance syndrome and cardiovascular diseases. However, current studies on NAFLD have limitations in meeting necessary histological endpoints.

Objective

This literature review aims to consolidate recent knowledge and discoveries concerning MAFLD, integrating the diverse aspects of the disease. Specifically, it focuses on analyzing the diagnostic criteria for MAFLD, differentiating it from NAFLD and alcoholic fatty liver disease (AFLD), and exploring the epidemiology, clinical manifestations, pathogenesis, and management approaches associated with MAFLD. The review also explores the associations between MAFLD and other conditions. It discusses the heightened mortality risk associated with MAFLD and its link to chronic kidney disease (CKD), showing that MAFLD exhibits enhanced diagnostic accuracy for identifying patients with CKD compared to NAFLD. The association between MAFLD and incident/prevalent CKD is supported by cohort studies and meta-analyses.

Conclusion

This literature review highlights the importance of MAFLD as a distinct terminology for fatty liver disease associated with metabolic dysfunction. The review provides insights into the diagnostic criteria, associations with CKD, and management approaches for MAFLD. Further research is needed to develop more accurate diagnostic tools for advanced fibrosis in MAFLD and to explore the underlying mechanisms linking MAFLD with other conditions. This review serves as a valuable resource for researchers and healthcare professionals seeking a comprehensive understanding of MAFLD.

Bidirectional Association Between Cardiovascular Disease and Lung Cancer in a Prospective Cohort Study

INTRODUCTION

The study aimed to prospectively investigate the bidirectional association between cardiovascular disease (CVD) and lung cancer, and whether this association differs across genetic risk levels.

METHODS

This study prospectively followed 455,804 participants from the United Kingdom Biobank cohort who were free of lung cancer at baseline. Cox proportional hazard models were used to estimate the hazard ratio (HR) for incident lung cancer according to CVD status. In parallel, similar approaches were used to assess the risk of incident CVD according to lung cancer status among 478,756 participants free of CVD at baseline. The bidirectional causal relations between these conditions were assessed using Mendelian randomization analysis. Besides, polygenic risk scores were estimated by integrating genome-wide association studies identified risk variants.

RESULTS

During 4,007,477 person-years of follow-up, 2006 incident lung cancer cases were documented. Compared with participants without CVD, those with CVD had HRs (95% confidence interval [CI]) of 1.49 (1.30-1.71) for NSCLC, 1.80 (1.39-2.34) for lung squamous cell carcinoma (LUSC), and 1.25 (1.01-1.56) for lung adenocarcinoma (LUAD). After stratification by smoking status, significant associations of CVD with lung cancer risk were observed in former smokers (HR = 1.44, 95% CI: 1.20-1.74) and current smokers (HR = 1.38, 95% CI: 1.13-1.69), but not in never-smokers (HR = 0.98, 95% CI: 0.60-1.61). In addition, CVD was associated with lung cancer risk across each genetic risk level (pheterogeneity = 0.336). In the second analysis, 32,974 incident CVD cases were recorded. Compared with those without lung cancer, the HRs (95% CI) for CVD were 2.33 (1.29-4.21) in NSCLC, 3.66 (1.65-8.14) in LUAD, and 1.98 (0.64-6.14) in LUSC. In particular, participants with lung cancer had a high risk of incident CVD at a high genetic risk level (HR = 3.79, 95% CI: 1.57-9.13). No causal relations between these conditions were observed in Mendelian randomization analysis.

CONCLUSIONS

CVD is associated with an increased risk of NSCLC including LUSC and LUAD. NSCLC, particularly LUAD, is associated with a higher CVD risk. Awareness of this bidirectional association may improve prevention and treatment strategies for both diseases. Future clinical demands will require a greater focus on cardiac oncology.

Association of MBOAT7 rs641738 polymorphism with hepatocellular carcinoma susceptibility: A systematic review and meta-analysis

BACKGROUND

The MBOAT7 rs641738 single-nucleotide polymorphism (SNP) has been proven to influence various liver diseases, but its association with hepatocellular carcinoma (HCC) susceptibility has been debated. To address this discrepancy, we conducted the current systematic review and meta-analysis.

AIM

To perform a systematic review and meta-analysis on association of MBOAT7 SNP and HCC susceptibility.

METHODS

We performed a systematic review in PubMed, Web of Science, Scopus, and EMBASE; applied specific inclusion and exclusion criteria; and extracted the data. Meta-analysis was conducted with the meta package in R. Sensitivity and subgroup analyses were also performed. This meta-analysis was registered in PROSPERO (CRD42023458046).

RESULTS

Eight studies were included in the systematic review, and 12 cohorts from 6 studies were included in the meta-analysis. Our meta-analysis revealed an association between the MBOAT7 SNP and HCC susceptibility in both the dominant [odds ratio (OR): 1.14, 95% confidence interval (95%CI): 1.02-1.26, P = 0.020] and recessive (OR: 1.21, 95%CI: 1.05-1.39, P = 0.008) models. Subgroup analysis revealed that stratification of the included patients by geographical origin showed a significant association in Asia (OR: 1.20, 95%CI: 1.03-1.39).

CONCLUSION

This meta-analysis underscores the contribution of the MBOAT7 rs641738 SNP to hepatocarcinogenesis, especially in Asian populations, which warrants further investigation.

Prediction model of hepatitis B virus-related hepatocellular carcinoma in patients receiving antiviral therapy

Chronic hepatitis B virus (HBV) infection, which ultimately leads to liver cirrhosis, hepatic decompensation, and hepatocellular carcinoma (HCC), remains a significant disease burden worldwide. Despite the use of antiviral therapy (AVT) using oral nucleos(t)ide analogs (NUCs) with high genetic barriers, the risk of HCC development cannot be completely eliminated. Therefore, bi-annual surveillance of HCC using abdominal ultrasonography with or without tumor markers is recommended for at-risk populations. For a more precise assessment of future HCC risk at the individual level, many HCC prediction models have been proposed in the era of potent AVT with promising results. It allows prognostication according to the risk of HCC development, for example, low-vs. intermediate-vs. high-risk groups. Most of these models have the advantage of high negative predictive values for HCC development, allowing exemption from biannual HCC screening. Recently, non-invasive surrogate markers for liver fibrosis, such as vibration-controlled transient elastography, have been introduced as integral components of the equations, providing better predictive performance in general. Furthermore, beyond the conventional statistical methods that primarily depend on multi-variable Cox regression analyses based on the previous literature, newer techniques using artificial intelligence have also been applied in the design of HCC prediction models. Here, we aimed to review the HCC risk prediction models that were developed in the era of potent AVT and validated among independent cohorts to address the clinical unmet needs, as well as comment on future direction to establish the individual HCC risk more precisely.

Multi-system diseases and death trajectory of metabolic dysfunction-associated fatty liver disease: findings from the UK Biobank

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a newly defined condition encompassing hepatic steatosis and metabolic dysfunction. However, the relationship between MAFLD and multi-system diseases remains unclear, and the time-dependent sequence of these diseases requires further clarification.

METHODS

After propensity score matching, 163,303 MAFLD subjects and 163,303 matched subjects were included in the community-based UK Biobank study. The International Classification of Diseases, Tenth Revision (ICD-10), was used to reclassify medical conditions into 490 and 16 specific causes of death. We conducted a disease trajectory analysis to map the key pathways linking MAFLD to various health conditions, providing an overview of their interconnections.

RESULTS

Participants aged 59 (51-64) years, predominantly males (62.5%), were included in the study. During the 12.9-year follow-up period, MAFLD participants were found to have a higher risk of 113 medical conditions and eight causes of death, determined through phenome-wide association analysis using Cox regression models. Temporal disease trajectories of MAFLD were established using disease pairing, revealing intermediary diseases such as asthma, diabetes, hypertension, hypothyroid conditions, tobacco abuse, diverticulosis, chronic ischemic heart disease, obesity, benign tumors, and inflammatory arthritis. These trajectories primarily resulted in acute myocardial infarction, disorders of fluid, electrolyte, and acid-base balance, infectious gastroenteritis and colitis, and functional intestinal disorders. Regarding death trajectories of MAFLD, malignant neoplasms, cardiovascular diseases, and respiratory system deaths were the main causes, and organ failure, infective disease, and internal environment disorder were the primary end-stage conditions. Disease trajectory analysis based on the level of genetic susceptibility to MAFLD yielded consistent results.

CONCLUSIONS

Individuals with MAFLD have a risk of a number of different medical conditions and causes of death. Notably, these diseases and potential causes of death constitute many pathways that may be promising targets for preventing general health decline in patients with MAFLD.

MAFLD: an optimal framework for understanding liver cancer phenotypes

Hepatocellular carcinoma has a substantial global mortality burden which is rising despite advancements in tackling the traditional viral risk factors. Metabolic (dysfunction) associated fatty liver disease (MAFLD) is the most prevalent liver disease, increasing in parallel with the epidemics of obesity, diabetes and systemic metabolic dysregulation. MAFLD is a major factor behind this sustained rise in HCC incidence, both as a single disease entity and often via synergistic interactions with other liver diseases. Mechanisms behind MAFLD-related HCC are complex but is crucially underpinned by systemic metabolic dysregulation with variable contributions from interacting disease modifiers related to environment, genetics, dysbiosis and immune dysregulation. MAFLD-related HCC has a distinct clinical presentation, most notably its common occurrence in non-cirrhotic liver disease. This is just one of several major challenges to effective surveillance programmes. The response of MAFLD-related HCC to immune-checkpoint therapy is currently controversial, and is further complicated by the high prevalence of MAFLD in individuals with HCC from viral aetiologies. In this review, we highlight the current data on epidemiology, clinical characteristics, outcomes and screening controversies. In addition, concepts that have arisen because of the MAFLD paradigm such as HCC in MAFLD/NAFLD non-overlapping groups, dual aetiology tumours and MAFLD sub-phenotypes is reviewed.

Associations of MAFLD and MAFLD subtypes with the risk of the incident myocardial infarction and stroke

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a condition characterized by liver fat accumulation and metabolic abnormalities. Given the potential impact of MAFLD on patient health, it is important to understand its association with major adverse cardiovascular events (MACE) such as myocardial infarction (MI) and stroke. In the prospective UK Biobank cohort, we sought to elucidate the association of MAFLD and its subtypes with incident MI and stroke. In this study, we analyzed the data of 325,129 participants in the UK Biobank and calculated relative risks for MI and stroke using Cox regression analysis. Among 325,129 participants over a median duration of 12.8 years follow-up, participants with MAFLD were significantly more likely to experience a MI (hazard ratio [HR] = 1.35, 95% confidence interval [CI: 1.29;1.41] P < 0.001) or a stroke (HR = 1.26 [1.18-1.33] P < 0.001) compared to those without MAFLD. In addition, diabetic, overweight with metabolic dysfunction (MD), and lean MAFLD subtypes were significantly associated with an increased risk for MI and stroke, whereas overweight without MD subtype did not appear to be associated with this risk. Our findings also revealed graded associations between liver fibrosis scores and risk of MI and stroke in MAFLD patients. However, only diabetic, and overweight patients with MD subtypes exhibited graded associations between liver fibrosis score and the risk of MI and stroke among the MAFLD subtypes. Furthermore, the risk alleles traits of fatty liver did not enhance the effect of MAFLD on the risk of MI and stroke. In conclusion, a diagnosis of MAFLD is associated with an increased risk of MI or stroke, and the assessment of MAFLD and its subtypes should be a component of the cardiovascular risk assessment.

Lean Metabolic-Associated Fatty Liver Disease

Since the nomenclature change from nonalcoholic fatty liver disease (NAFLD) to metabolic-associated fatty liver disease (MAFLD), much work has been undertaken to establish the clinical characteristics as well as the hepatic and extrahepatic complications of the different MAFLD subtypes. Currently, there has been significant work performed to evaluate previously acknowledged evidence in the lean NAFLD population to determine its applicability to the new entity. This article examines recently published data on lean MAFLD cohorts to highlight the prevalence, pathophysiological characteristics, associated liver fibrosis, genetics, hepatic and extrahepatic complications, prognosis, treatment, and research into this unique subtype of MAFLD.

Differential risk of 23 site-specific incident cancers and cancer-related mortality among patients with metabolic dysfunction-associated fatty liver disease: a population-based cohort study with 9.7 million Korean subjects

INTRODUCTION

Although an association between metabolic dysfunction-associated fatty liver disease (MAFLD) and cardiovascular disease or overall mortality has been reported, it is unclear whether there is an association between MAFLD and cancer incidence or mortality. We aimed to investigate the differential risk of all- and site-specific cancer incidence and mortality according to MAFLD subgroups categorized by additional etiologies of liver disease.

METHODS

Using the Korean National Health Insurance Service database, we stratified the participants into three groups: (1) single-etiology MAFLD (S-MAFLD) or MAFLD of pure metabolic origin; (2) mixed-etiology MAFLD (M-MAFLD) or MAFLD with additional etiological factor(s) (i.e., concomitant liver diseases and/or heavy alcohol consumption); and (3) non-MAFLD. Hepatic steatosis and fibrosis were defined using the fatty liver index and the BARD score, respectively. Cox proportional hazards regression was performed to estimate the risk of cancer events.

RESULTS

Among the 9,718,182 participants, the prevalence of S-MAFLD and M-MAFLD was 29.2% and 6.7%, respectively. During the median 8.3 years of follow-up, 510,330 (5.3%) individuals were newly diagnosed with cancer, and 122,774 (1.3%) cancer-related deaths occurred among the entire cohort. Compared with the non-MAFLD group, the risk of all-cancer incidence and mortality was slightly higher among patients in the S-MAFLD group (incidence, adjusted hazard ratio [aHR] = 1.03; 95% confidence interval [CI]: 1.02-1.04; mortality, aHR = 1.06; 95% CI: 1.04-1.08) and highest among patients with M-MAFLD group (incidence, aHR = 1.31; 95% CI: 1.29-1.32; mortality, aHR = 1.45; 95% CI: 1.42-1.48, respectively). The M-MAFLD with fibrosis group (BARD score ≥ 2) showed the highest relative risk of all-cancer incidence (aHR = 1.38, 95% CI = 1.36-1.39), followed by the M-MAFLD without fibrosis group (aHR = 1.09, 95% CI = 1.06-1.11). Similar trends were observed for cancer-related mortality.

CONCLUSIONS

MAFLD classification, by applying additional etiologies other than pure metabolic origin, can be used to identify a subgroup of patients with poor cancer-related outcomes.

Blood lactate levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease in type 2 diabetes: a real-world study

Aim

To investigate the association between blood lactate levels and metabolic dysfunction-associated fatty liver disease (MAFLD) in type 2 diabetes mellitus (T2DM).

Methods

4628 Chinese T2DM patients were divided into quartiles according to blood lactate levels in this real-world study. Abdominal ultrasonography was used to diagnosis MAFLD. The associations of blood lactate levels and quartiles with MAFLD were analyzed by logistic regression.

Results

There were a significantly increased trend in both MAFLD prevalence (28.9%, 36.5%, 43.5%, and 54.7%) and HOMA2-IR value (1.31(0.80-2.03), 1.44(0.87-2.20), 1.59(0.99-2.36), 1.82(1.15-2.59)) across the blood lactate quartiles in T2DM patients after adjustment for age, sex, diabetic duration, and metformin use (all p<0.001 for trend). After correcting for other confounding factors, not only increased blood lactate levels were obviously associated with MAFLD presence in the patients with (OR=1.378, 95%CI: 1.210-1.569, p<0.001) and without taking metformin (OR=1.181, 95%CI: 1.010-1.381, p=0.037), but also blood lactate quartiles were independently correlated to the increased risk of MAFLD in T2DM patients (p<0.001 for trend). Compared with the subjects in the lowest blood lactate quartiles, the risk of MAFLD increased to 1.436-, 1.473-, and 2.055-fold, respectively, in those from the second to the highest lactate quartiles.

Conclusions

The blood lactate levels in T2DM subjects were independently associated with an increased risk of MAFLD, which was not affected by metformin-taking and might closely related to insulin resistance. Blood lactate levels might be used as a practical indicator for assessing the risk of MAFLD in T2DM patients.

The Inter-Organ Crosstalk Reveals an Inevitable Link between MAFLD and Extrahepatic Diseases

Fatty liver is known to be associated with extra-hepatic diseases including atherosclerotic cardiovascular disease and extra-hepatic cancers, which affect the prognosis and quality of life of the patients. The inter-organ crosstalk is mediated by metabolic abnormalities such as insulin resistance and visceral adiposity. Recently, metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed as a new definition for fatty liver. MAFLD is characterized by the inclusion criteria of metabolic abnormality. Therefore, MAFLD is expected to identify patients at high risk of extra-hepatic complications. In this review, we focus on the relationships between MAFLD and multi-organ diseases. We also describe the pathogenic mechanisms of the inter-organ crosstalk.

Association of MAFLD with end-stage kidney disease: a prospective study of 337,783 UK Biobank participants

INTRODUCTION

Metabolic dysfunction-associated fatty liver (MAFLD) has been found to be associated with the prevalence of chronic kidney disease (CKD). However, it is unknown whether MAFLD is associated with CKD development and the incidence of end-stage kidney disease (ESKD). We aimed to clarify the association between MAFLD and incident ESKD in the prospective UK Biobank cohort.

METHODS

We analyzed the data of 337,783 UK Biobank participants and relative risks for the ESKD were calculated by using the Cox regression analysis.

RESULTS

Among 337,783 participants over a median duration of 12.8 years follow-up, a total of 618 ESKD cases were diagnosed. Participants with MAFLD were twice likely to develop ESKD (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.68-2.46, p < 0.001). The association of MAFLD with ESKD risk remained significant in both non-CKD and CKD participants. Our results also showed that there were graded associations between liver fibrosis scores and the risk of ESKD in MAFLD cases. Compared to non-MAFLD individuals, the adjusted HRs for incident ESKD in MAFLD patients with increasing levels of NAFLD fibrosis score were 1.23 (95% CI 0.96-1.58), 2.45 (1.98-3.03) and 7.67 (5.48-10.73), respectively. Furthermore, the risking alleles of PNPLA3 rs738409, TM6SF2 rs58542926, GCKR rs1260326 and MBOAT7 rs641738 amplified the MAFLD effect on ESKD risk. In conclusion, MAFLD is associated with incident ESKD.

CONCLUSION

MAFLD may help identify the subjects at high risk of ESKD development and MAFLD interventions should be encouraged to slow down CKD progression.

Metabolic dysfunction-associated fatty liver disease and liver function markers are associated with Crohn's disease but not Ulcerative Colitis: a prospective cohort study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is recently recognized as a condition featured with metabolic dysfunctions in liver. It has been supposed that MAFLD might contribute to the development of IBD, but evidence from prospective cohort studies is lacking and inconclusive.

METHODS

A total of 221,546 females and 183,867 males from the UK Biobank cohort enrolled in 2006-2010 were included to examine whether MAFLD and liver function markers were related to incident IBD. MAFLD was identified based on hepatic steatosis defined by fatty liver index plus the prevalence of overweight, type 2 diabetes mellitus, or at least two metabolic abnormalities. Biomarker related to liver function (albumin [ALB], alkaline phosphatase [ALP], alanine transaminase [ALT], aspartate transaminase [AST]; gamma-glutamyl transferase [GGT], total bilirubin [TB], total protein [TP]) was measured using colorimetric or enzymatic assays. The incidence of IBD was ascertained based on primary care and inpatient records. Cox proportional hazard model was used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for the magnitude of their associations.

RESULTS

With a mean follow-up of 12.1 years, 2228 incident IBD cases were documented. We identified 150,385 individuals with MAFLD at baseline and 86% participants' circulating liver function markers were within the normal range. Participants with MAFLD were associated with a 12% (HR 1.12, 95% CI 1.03, 1.23, p = 0.012) increased risk of IBD compared with those without MAFLD at baseline; the association was stronger (p-_{Heterogeneity} = 0.006) with Crohn's disease (HR 1.35, 95% CI 1.15, 1.59, p < 0.001) than ulcerative colitis (HR 1.03, 95% CI 0.93, 1.15, p = 0.57). As for the serum liver function markers, the HRs of IBD for per 1-SD increment in ALB, ALP, AST, and TB concentration were 0.86 (95% CI 0.83, 0.90, p < 0.001), 1.18 (95% CI 1.13, 1.24, p < 0.001), 0.95 (95% CI 0.91, 0.99, p = 0.027), 0.92 (95% CI 0.87, 0.96, p < 0.001), respectively. We did not observe significant associations of GGT and TP with IBD.

CONCLUSIONS

Individuals with MAFLD were at increased risk of developing IBD, especially CD, but not UC. Circulating levels of liver function biomarkers as the surrogate indicators of MAFLD were also associated with IBD risk.

Liver fibrosis is closely related to metabolic factors in metabolic associated fatty liver disease with hepatitis B virus infection

This case-control study aimed to identify the clinical characteristics and explore the risk factors for liver fibrosis in metabolic associated fatty liver disease (MAFLD) patients with hepatitis B virus (HBV) infection. The patients were grouped into MAFLD + HBV and MAFLD (without HBV infection). Propensity score matching (PSM) was used to match baseline features between the groups. We included 401 patients with biopsy-proven MAFLD, 179 of whom had HBV infection. A total of 83 pairs were successfully matched via PSM, and steatosis scores and ballooning in the MAFLD + HBV group were lower than those in the MAFLD group, while the inflammation scores and liver fibrosis stages were higher. After adjusted for confounding factors, HBV infection was associated with a higher risk of significant liver fibrosis in patients with MAFLD [odds ratio (OR): 3.140, P = 0.003]. Overall, 43.58% (78/179) of patients in the MAFLD + HBV group had significant liver fibrosis. Further multivariate regression analysis, hypertension (OR: 2.640; P = 0.031), type 2 diabetes (OR: 4.939; P = 0.035), and elevated glutamyl-transferase levels (OR: 3.980; P = 0.001) were risk factors for liver fibrosis in the MAFLD + HBV group. This suggests metabolic rather than viral factors are more closely associated with liver fibrosis in MAFLD patients with HBV infection.

The relationship between metabolic dysfunction-associated fatty liver disease and the incidence rate of extrahepatic cancer

BACKGROUND

The associations between metabolic dysfunction-associated fatty liver disease (MAFLD) and cancer development, especially extrahepatic cancers, are unknown. The aims of the current study were to investigate the cancer incidence rates of MAFLD and analyze the associations between MAFLD and the development of cancers.

METHODS

This historical cohort study included participants who underwent ultrasonographic detection of hepatic steatosis at a tertiary hospital in China from January 2013 to October 2021. MAFLD was diagnosed in accordance with The International Expert Consensus Statement. Cox proportional hazards regression modeling was used to assess the associations between MAFLD and the development of cancers.

RESULTS

Of the 47,801 participants, 16,093 (33.7%) had MAFLD. During the total follow-up of 175,137 person-years (median 3.3 years), the cancer incidence rate in the MAFLD group was higher than that in the non-MAFLD group [473.5 vs. 255.1 per 100,000 person-years; incidence rate ratio 1.86; 95% confidence interval (CI) 1.57-2.19]. After adjustment for age, gender, smoking status, and alcohol status, MAFLD was moderately associated with cancers of the female reproductive system/organs (labium, uterus, cervix, and ovary) [hazard ratio (HR) 2.24; 95% CI 1.09-4.60], thyroid (HR 3.64; 95% CI 1.82-7.30), and bladder (HR 4.19; 95% CI 1.15-15.27) in the total study cohort.

CONCLUSION

MAFLD was associated with the development of cancers of the female reproductive system/organs (labium, uterus, cervix, and ovary), thyroid, and bladder in the total study cohort.

Metabolic-Associated Fatty Liver Disease, Hepatitis B Surface Antigen Seroclearance, and Long-Term Risk of Hepatocellular Carcinoma in Chronic Hepatitis B

The value of metabolic-associated fatty liver disease (MAFLD) and its ability to assess hepatocellular carcinoma (HCC) risk remains uncertain for chronic hepatitis B (CHB). We evaluated the impacts of MAFLD and its coincidental metabolic abnormalities and related genetic predisposition on HCC incidence and mortality outcomes in CHB. We analyzed data from 1453 HBsAg-positive men (median age = 49.2 years at baseline) from a cohort of civil servants recruited from 1989−1992. MAFLD was defined as hepatic steatosis on ultrasound with obesity, diabetes, or metabolic dysfunction at baseline. During follow-up (median = 19.3 years), 105 HCC events occurred. MAFLD was not associated with HCC (adjusted hazard ratio (aHR) = 1.02) but was associated with a higher HBsAg seroclearance rate (aHR = 1.43). In mediation analysis, HBsAg seroclearance driven by hepatic steatosis explained 31.6% of the association between MAFLD and HCC. Antiviral treatment or fatty liver disease-associated genetic variants did not influence the MAFLD−HCC association. In contrast, even after adjustment for MAFLD and the other metabolic abnormalities, diabetes (aHR = 2.28), obesity (aHR = 1.72), and metabolic dysfunction (aHR = 3.30) increased the risk of HCC (all p < 0.030). The risk of HCC increased with the number of metabolic abnormalities (vs 0: aHR = 2.05 and 5.72 for 2 and ≥ 3 metabolic abnormalities, respectively), and the cumulative effect of metabolic abnormalities was found across subgroups categorized by hepatic steatosis as well as in participants both with and without HBsAg seroclearance. In conclusion, MAFLD was not associated with increased HCC incidence in CHB. A more informative assessment of HCC risk can be obtained by taking into account the number of metabolic abnormalities.

Effect of metabolic dysfunction-associated fatty liver disease on liver cancer risk in a population with chronic hepatitis B virus infection: A nationwide study

BACKGROUND

The association between metabolic dysfunction-associated fatty liver disease (MAFLD) and hepatocellular carcinoma (HCC) lacks clinical validation in at-risk populations. We assessed this relationship among chronic hepatitis B (CHB) patients.

METHODS

Data was collected from the National Health Insurance System database in South Korea. Chronic hepatitis B patients aged over 40 years receiving health examinations between 2011 and 2012 were recruited. The primary outcome was HCC. Metabolic dysfunction-associated fatty liver disease was defined as hepatic steatosis in combination with at least one of the following: (i) overweight, (ii) diabetes, or (iii) lean/normal weight with two or more metabolic components. Multivariable Cox regression analysis was used to estimate adjusted hazard ratios (aHRs).

RESULTS

Of 197 346 participants, 66 149 had MAFLD; 19 149, 44 475, and 2525 fulfilled diabetes (regardless of overweight), overweight alone, and lean/normal weight with two or more metabolic components, respectively. During follow-up (median 7 years), 13 771 developed HCC. Metabolic dysfunction-associated fatty liver disease was independently associated with increased risk of HCC, with aHR of 1.36 (p < 0.001). Propensity score matching confirmed the same phenomena, with aHR of 1.37 (p < 0.001). Furthermore, when stratified by liver cirrhosis and/or antiviral therapy, independent significances of MAFLD for HCC risk were maintained (all p < 0.001). Compared with the persistent non-MAFLD subgroup during the entire follow-up, diagnosis of MAFLD from at least one health examination significantly increased HCC risk with aHRs of 1.41, 1.37, and 1.14 among subgroups with persistent MAFLD, MAFLD to non-MAFLD, and non-MAFLD to MAFLD, respectively (all p < 0.05).

CONCLUSIONS

Metabolic dysfunction-associated fatty liver disease consistently increases HCC risk among CHB patients. Further studies are needed to develop an effective preventive strategy through control of metabolic health.

Contribution of a genetic risk score to ethnic differences in fatty liver disease

BACKGROUND AND AIMS

Susceptibility to fatty liver disease (FLD) varies among individuals and between racial/ethnic groups. Several genetic variants influence FLD risk, but whether these variants explain racial/ethnic differences in FLD prevalence is unclear. We examined the contribution of genetic risk factors to racial/ethnic-specific differences in FLD.

METHODS

A case-control study comparing FLD patients (n = 1194) and population-based controls (n = 3120) was performed. Patient characteristics, FLD risk variants (PNPLA3-rs738409 + rs6006460, TM6SF2-rs58542926, HSD17B13-rs80182459 + rs72613567, MBOAT7/TMC4-rs641738, and GCKR-rs1260326) and a multi-locus genetic risk score (GRS) were examined. The odds of FLD for individuals with different risk factor burdens were determined.

RESULTS

Hispanics and Whites were over-represented (56% vs. 38% and 36% vs. 29% respectively) and Blacks under-represented (5% vs. 23%) among FLD patients, compared to the population from which controls were selected (p < .001). Among cases and controls, Blacks had a lower and Hispanics a greater, net number of risk alleles than Whites (p < .001). GRS was associated with increased odds of FLD (OR_Q5vsQ1  = 8.72 [95% CI = 5.97-13.0], p = 9.8 × 10^-28 ), with the association being stronger in Hispanics (OR_Q5vsQ1  = 14.8 [8.3-27.1]) than Blacks (OR_Q5vsQ1  = 3.7 [1.5-11.5], P-interaction = 0.002). After accounting for GRS, the odds of FLD between Hispanics and Whites did not differ significantly (OR = 1.06 [0.87-1.28], p = .58), whereas Blacks retained much lower odds of FLD (OR = 0.21, [0.15-0.30], p < .001).

CONCLUSIONS

Blacks had a lower and Hispanics a greater FLD risk allele burden than Whites. These differences contributed to, but did not fully explain, racial/ethnic differences in FLD prevalence. Identification of additional factors protecting Blacks from FLD may provide new targets for prevention and treatment of FLD.

Molecular Advances in MAFLD—A Link between Sphingolipids and Extracellular Matrix in Development and Progression to Fibrosis

Metabolic-Associated Fatty Liver Disease (MAFLD) is a major cause of liver diseases globally and its prevalence is expected to grow in the coming decades. The main cause of MAFLD development is changed in the composition of the extracellular matrix (ECM). Increased production of matrix molecules and inflammatory processes lead to progressive fibrosis, cirrhosis, and ultimately liver failure. In addition, increased accumulation of sphingolipids accompanied by increased expression of pro-inflammatory cytokines in the ECM is closely related to lipogenesis, MAFLD development, and its progression to fibrosis. In our work, we will summarize all information regarding the role of sphingolipids e.g., ceramide and S1P in MAFLD development. These sphingolipids seem to have the most significant effect on macrophages and, consequently, HSCs which trigger the entire cascade of overproduction matrix molecules, especially type I and III collagen, proteoglycans, elastin, and also tissue inhibitors of metalloproteinases, which as a result cause the development of liver fibrosis.

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.

Adipose tissue insulin resistance and lipidome alterations as the characterizing factors of non-alcoholic steatohepatitis

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) is now 25% in the general population but increases to more than 55% in subjects with obesity and/or type 2 diabetes. Simple steatosis (NAFL) can develop into more severe forms, that is non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma leading to death.

METHODS

In this narrative review, we have discussed the current knowledge in the pathophysiology of fatty liver disease, including both metabolic and non-metabolic factors, insulin resistance, mitochondrial function, as well as the markers of liver damage, giving attention to the alterations in lipid metabolism and production of lipotoxic lipids.

RESULTS

Insulin resistance, particularly in the adipose tissue, is the main driver of NAFLD due to the excess release of fatty acids. Lipidome analyses have shown that several lipids, including DAGs and ceramides, and especially if they contain saturated lipids, act as bioactive compounds, toxic to the cells. Lipids can also affect mitochondrial function. Not only lipids, but also amino acid metabolism is impaired in NAFL/NASH, and some amino acids, as branched-chain and aromatic amino acids, glutamate, serine and glycine, have been linked to impaired metabolism, insulin resistance and severity of NAFLD and serine is a precursor of ceramides.

CONCLUSIONS

The measurement of lipotoxic species and adipose tissue dysfunction can help to identify individuals at risk of progression to NASH.

Single Nucleotide Polymorphism of Genes Associated with Metabolic Fatty Liver Disease

Aims

The present study aimed to reveal the relationship between single nucleotide polymorphism (SNP) of PNPLA3, TM6SF2, MBOAT7, GATAD2A, and STAT3 genes and metabolism-related fatty liver disease (MAFLD), so as to provide a research basis for further exploring the diagnosis and treatment of diseases at the molecular level.

Methods

A total of 564 patients were included in the physical examination center of Xinjiang Karamay People's Hospital. They were divided into an MAFLD case group and a healthy control group. The whole blood DNA of each sample was extracted by a whole blood genomic DNA extraction kit, and the genotypes of PNPLA3 rs738409, MBOAT7 rs64173, STAT3 rs744166, TM6SF2 rs58542926, and GATAD2A rs4808199 were performed; after adjusting for confounding factors, the additive model, dominant model, and recessive model of each gene were analyzed by multivariate logistic regression.

Results

The CC genotype of the PNPLA3 gene rs738409 and the TT genotype of the MBOAT7 gene rs64173 are risk factors in the occurrence of MAFLD. The AA genotype of the STAT3 gene rs744166 is a protective factor of MAFLD, while TM6SF2 rs58542926 and GATAD2A rs4808199 show no significant correlation with MAFLD.

Metabolic dysfunction-associated fatty liver disease and the risk of 24 specific cancers

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a significant health issue closely associated with multiple metabolic dysfunctions. The association between MAFLD and cancer risk is yet unknown.

METHODS

UK Biobank study participants were diagnosed for the presence of MAFLD at baseline. A multivariable Cox regression model was performed to examine the associations of MAFLD with incident events in 24 specific cancers.

RESULTS

We included 352,911 individuals (37.2% with MAFLD), among whom 23,345 developed cancers. Compared with non-MAFLD, MAFLD was significantly associated with 10 of the 24 examined cancers, including corpus uteri (hazard ratio [HR] = 2.36, 95% CI 1.99-2.80), gallbladder (2.20, 1.14-4.23), liver (1.81, 1.43-2.28), kidney (1.77, 1.49-2.11), thyroid (1.69, 1.20-2.38), esophagus (1.48, 1.25-1.76), pancreas (1.31, 1.10-1.56), bladder (1.26, 1.11-1.43), breast (1.19, 1.11-1.27), and colorectal and anus cancers (1.14, 1.06-1.23). The associations of MAFLD with liver, esophageal, pancreatic, colorectal and anal and bladder cancers and malignant melanoma were strengthened in males, and associations with kidney, thyroid, and lung cancers were increased in females. The associations of MAFLD with the risk of liver, kidney, and thyroid cancers remained significant after further adjusting for the waist circumference or body mass index and the number of metabolic syndrome components based on the main models. The risk-increasing allele of PNPLA3 rs738409 significantly amplified the association of MAFLD with the risk of liver and kidney cancers.

CONCLUSION

MAFLD is associated with an increased risk of a set of cancers, but the effect substantially varies by site. MAFLD deserves higher priority in the current scheme of cancer prevention.

Identification of 90 NAFLD GWAS loci and establishment of NAFLD PRS and causal role of NAFLD in coronary artery disease

The prevalence of non-alcoholic fatty liver disease (NAFLD), now also known as metabolic dysfunction-associated fatty liver disease (MAFLD), is rapidly increasing worldwide due to the ongoing obesity epidemic. However, currently the NALFD diagnosis requires non-readily available imaging technologies or liver biopsy, which has drastically limited the sample sizes of NAFLD studies and hampered the discovery of its genetic component. Here we utilized the large UK Biobank (UKB) to accurately estimate the NAFLD status in UKB based on common serum traits and anthropometric measures. Scoring all individuals in UKB for NAFLD risk resulted in 28,396 NAFLD cases and 108,652 healthy individuals at a >90% confidence level. Using this imputed NAFLD status to perform the largest NAFLD genome-wide association study (GWAS) to date, we identified 94 independent (R² < 0.2) NAFLD GWAS loci, of which 90 have not been identified before; built a polygenic risk score (PRS) model to predict the genetic risk of NAFLD; and used the GWAS variants of imputed NAFLD for a tissue-aware Mendelian randomization analysis that discovered a significant causal effect of NAFLD on coronary artery disease (CAD). In summary, we accurately estimated the NAFLD status in UKB using common serum traits and anthropometric measures, which empowered us to identify 90 GWAS NAFLD loci, build NAFLD PRS, and discover a significant causal effect of NAFLD on CAD.

Association Between Metabolic Dysfunction-Associated Fatty Liver Disease and the Risk of Cirrhosis in Patients with Chronic Hepatitis B-A Retrospective Cohort Study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a novel proposed concept that is being recognized worldwide. Both chronic hepatitis B (CHB) and MAFLD have been independently attributed to an increased risk of disease development to cirrhosis. However, it is still unclear whether MAFLD is associated with an increased risk of cirrhosis in CHB patients.

AIM

This study aimed to analyze the impact of MAFLD on the risk of cirrhosis in CHB patients.

METHODS

In this retrospective cohort study, consecutive CHB patients with or without MAFLD were enrolled from January 1st, 2007, to May 1st, 2020, in Guangdong Provincial Hospital of Chinese Medicine. Inverse probability treatment weighting (IPTW) was performed to balance the covariates across groups. The weighted Kaplan-Meier analysis and Cox regression analysis were used to compare both groups for the risk of cirrhosis.

RESULTS

A total of 1223 CHB patients were included in this study during the median follow-up of 5.25 years; of these patients, 355 were CHB-MAFLD patients. After IPTW, the weighted Kaplan-Meier analysis showed that the weighted cumulative incidence of cirrhosis was significantly higher in patients with MAFLD than that in patients without MAFLD (12.6% versus 7.1%, P=0.015). In the weighted multivariate Cox analysis, coexisting MAFLD was related to an increased risk of cirrhosis [adjusted weighted hazard ratio (HR) 1.790; P =0.020]. Age (>40 years, adjusted weighted HR, 1.950; P=0.015), diabetes mellitus (adjusted weighted HR, 1.883; P=0.041), non-antiviral treatment (adjusted weighted HR, 2.037; P=0.013), and baseline serum HBV DNA levels (>2.4 log¹⁰ IU/mL, adjusted weighted HR, 1.756; P=0.045) were significant risk factors for cirrhosis.

CONCLUSION

We found that MAFLD was associated with a higher risk of cirrhosis in CHB patients.

Metabolic dysfunction-associated fatty liver disease and cardiovascular disease: A meta-analysis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease [MAFLD, formerly known as nonalcoholic fatty liver disease (NAFLD)] is one of the most important causes of liver disease worldwide, while cardiovascular disease (CVD) is still one of the main causes of morbidity and mortality worldwide, and the two are closely related. This study aimed to investigate the risk of CVD incidence or CVD-related mortality (CVD mortality) in patients diagnosed with MAFLD under new concepts and new diagnostic criteria.

METHODS

We searched English databases PubMed, Web of Science, Embase, and Cochrane Library for relevant literature. The language was restricted to English.

RESULTS

By 22 January 2022, 556 published studies were obtained through preliminary retrieval, and 10 cohort studies were included in this study. All statistical analyses were performed using Review Manager 5.2 software. Compared with the control group, patients in the MAFLD group had a significantly higher relative risk of CVD incidence or CVD mortality during the follow-up, with an RR rate of 1.95 (95% CI 1.76-2.17, p < 0.01). The incidence of CVD in the MAFLD group was more than twice that in the control group (RR 2.26, 95% CI 2.00-2.54, p < 0.01). The mortality rate of CVD was 1.57 times higher than that in the control group (RR 1.57, 95% CI 1.42-1.72, p < 0.01).

CONCLUSIONS

Patients diagnosed with MAFLD alone had higher cardiovascular mortality than those diagnosed with NAFLD alone based on the available data.

Liver biomarkers, genetic and lifestyle risk factors in relation to risk of cardiovascular disease in Chinese

Background and aims

Liver biomarkers and metabolic associated fatty liver disease (MAFLD) have been shown to be associated with cardiovascular disease (CVD). However, there is limited evidence on CVD subtypes [myocardial infarction (MI), ischemic stroke (IS), and intracerebral hemorrhage (ICH)], especially in the Chinese population. We examined these associations overall, by genetic predisposition to non-alcoholic fatty liver disease (NAFLD), and by lifestyle risk factors.

Approach and results

This is a nested case-control study of CVD (10,298 cases and 5,388 controls) within the China Kadoorie Biobank. Cox regression was used to estimate adjusted hazard ratios (HRs) for CVD associated with liver biomarkers and MAFLD and by stratum of genetic risk and a combined high-risk lifestyle score. For liver enzymes, there were positive associations with MI and IS, but no associations with ICH or carotid plaque. There were positive associations of NAFLD with risks of MI, IS, and ICH (HR 1.43 [95% CI 1.30-1.57], 1.25 [1.16-1.35], and 1.12 [1.02-1.23]) as well as carotid plaque (odds ratio 2.36 [1.12-4.96]). The associations of NAFLD with CVD and carotid plaque were stronger among individuals with a high genetic risk (ICH: p-interaction < 0.05), while the associations with stroke were stronger among those with a favorable lifestyle (p-interaction < 0.05). The results for MAFLD mirrored those for NAFLD.

Conclusion

In Chinese adults, liver biomarkers and MAFLD were associated with risk of CVD, with different magnitudes of associations by CVD subtypes. Genetic predisposition to NAFLD and lifestyle factors modified the associations of fatty liver with stroke.

Epidemiology and Clinical Outcomes of Metabolic (Dysfunction)-associated Fatty Liver Disease

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) is currently the most common chronic liver disease and affects at least a quarter of the global adult population. It has rapidly become one of the leading causes of hepatocellular carcinoma and cirrhosis in Western countries. In this review, we discuss the nomenclature and definition of MAFLD as well as its prevalence and incidence in different geographical regions. Although cardiovascular disease remains the leading cause of death in MAFLD patients, the proportion of patients dying from hepatic complications increases sharply as the disease progresses to advanced liver fibrosis and cirrhosis. In addition, patients with MAFLD are at increased risk of various extrahepatic cancers. Although a causal relationship between MAFLD and extrahepatic cancers has not been established, clinicians should recognize the association and consider cancer screening (e.g., for colorectal cancer) as appropriate.

Analysis of Common Pathways and Markers From Non-Alcoholic Fatty Liver Disease to Immune-Mediated Diseases

Metabolic associated fatty liver disease (MAFLD) is the most prevalent form of liver disease worldwide, accounting for a high liver-related mortality and morbidity with extensive multi-organ involvement. This entity has displaced viral hepatitis as the main cause of severe forms of hepatic diseases, although the onset and transition of MAFLD stages still remains unclear. Nevertheless, innate and adaptive immune responses seem to play an essential role in the establishment and further progression of this disease. The immune system is responsible of safeguard and preserves organs and systems function, and might be altered under different stimuli. Thus, the liver suffers from metabolic and immune changes leading to different injuries and loss of function. It has been stablished that cell-cell crosstalk is a key process in the hepatic homeostasis maintenance. There is mounting evidence suggesting that MAFLD pathogenesis is determined by a complex interaction of environmental, genetic and host factors that leads to a full plethora of outcomes. Therefore, herein we will revisit and discuss the interplay between immune mechanisms and MAFLD, highlighting the potential role of immunological markers in an attempt to clarify its relationship.

MAFLD Enhances Clinical Practice for Liver Disease in the Asia-Pacific region

Fatty liver is now a major cause of liver disease in the Asia-Pacific region. Liver diseases in this region have distinctive characteristics. First, fatty liver is frequently observed in lean/normal-weight individuals. However, there is no standard definition of this unique phenotype. Second, fatty liver is often observed in patients with concomitant viral hepatitis. The exclusion of viral hepatitis from non-alcoholic fatty liver disease limits its value and detracts from the investigation and holistic management of coexisting fatty liver in patients with viral hepatitis. Third, fatty liver-associated hepatocellular carcinoma (HCC) is generally categorized as non-B non-C HCC. Fourth, the population is aging rapidly, and it is imperative to develop a practicable, low-intensity exercise program for elderly patients. Fifth, most patients and non-specialized healthcare professionals still lack an awareness of the significance of fatty liver both in terms of intrahepatic and extrahepatic disease and cancer. Recently, an international expert panel proposed a new definition of fatty liver: metabolic dysfunction-associated fatty liver disease (MAFLD). One feature of MAFLD is that metabolic dysfunction is a prerequisite for diagnosis. Pertinent to regional issues, MAFLD also provides its diagnostic criteria in lean/normal-weight individuals. Furthermore, MAFLD is independent of any concomitant liver disease, including viral hepatitis. Therefore, MAFLD may be a more suitable definition for fatty liver in the Asia-Pacific region. In this review, we introduce the regional characteristics of fatty liver and discuss the advantages of MAFLD for improving clinical practice for liver disease in the region.

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

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

Risk stratification using sarcopenia status among subjects with metabolic dysfunction-associated fatty liver disease

BACKGROUND

Sarcopenia is a significant indicator of the severity of non-alcoholic fatty liver disease. We investigated whether sarcopenia could identify subgroups with different risk of liver fibrosis and atherosclerotic cardiovascular disease (ASCVD) among subjects with metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

Subjects from the Korea National Health and Nutrition Examination Survey 2008-2011 were selected (n = 8361). Sarcopenia was defined using the sarcopenia index. Hepatic steatosis was defined as a fatty liver index ≥30. Significant liver fibrosis was defined as a fibrosis-4 index (FIB-4) ≥2.67 or the highest quartile of non-alcoholic fatty liver disease fibrosis score (NFS). High probability of ASCVD was defined as ASCVD risk score >10%.

RESULTS

The mean age was 48.5 ± 15.6 years, and 42.6% of subjects were male. The prevalence of MAFLD was 37.3% (n = 3116 of 8361), and the proportion of sarcopenic subjects was 9.9% among those with MAFLD. After adjusting for confounders, the risk of significant liver fibrosis significantly increased from non-sarcopenic subjects with MAFLD [odds ratio (OR) = 1.57 by FIB-4 and 2.13 by NFS] to sarcopenic subjects with MAFLD (OR = 4.51 by FIB-4 and 5.72 by NFS), compared with subjects without MAFLD (all P < 0.001). The risk for high probability of ASCVD significantly increased from non-sarcopenic subjects with MAFLD (OR = 1.47) to sarcopenic subjects with MAFLD (OR = 4.08), compared with subjects without MAFLD (all P < 0.001).

CONCLUSIONS

The risks of significant liver fibrosis and ASCVD differed significantly according to sarcopenic status among subjects with MAFLD. An assessment of sarcopenia might be helpful in risk stratification among subjects with MAFLD.

Metabolic-associated fatty liver disease and autoimmune hepatitis: an overlooked interaction

INTRODUCTION

Metabolic-associated fatty liver disease (MAFLD) is the most common liver disease globally, and affects about a quarter of the general population. Autoimmune hepatitis (AIH) is a severe (sometimes fatal) liver disease that affects children and adults, with a rising prevalence. Thus, not surprisingly, both conditions can frequently coexist, with potential synergistic impact on the course of the disease and response to therapy of both entities.

AREAS COVERED

In this work, the authors aimed to provide a narrative updated review on this interaction, diagnosis, and management of MAFLD/AIH and the current challenges.

EXPERT OPINION

Clarifying the nature of the complex interaction between the two diseases was hampered by a myriad of factors, particularly the previous diagnosis of exclusion for fatty liver disease associated with metabolic dysfunction. The recent redefinition of fatty liver disease that led to the development of positive diagnostic criteria for MAFLD has the premise to help in circumventing some of these challenges.

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.

From nonalcoholic fatty liver disease to metabolic-associated fatty liver disease: Big wave or ripple?

There is some dissatisfaction with the term "nonalcoholic fatty liver disease (NAFLD)," which overemphasizes alcohol and underemphasizes the importance of metabolic risk factors in this disease. Recently, a consensus recommended "metabolic (dysfunction)-associated fatty liver disease (MAFLD)" as a more appropriate term to describe fatty liver diseases (FLD) associated with metabolic dysfunction. During the definition change from NAFLD to MAFLD, subjects with FLD and metabolic abnormalities, together with other etiologies of liver diseases such as alcohol, virus, or medication who have been excluded from the NAFLD criteria, were added to the MAFLD criteria, while subjects with FLD but without metabolic abnormality, who have been included in the NAFLD criteria, were excluded from the MAFLD criteria. This means that there is an emphasis on the metabolic dysfunction in MAFLD which may underestimate the prognostic value of hepatic steatosis itself, whereas the MAFLD criteria might better identify subjects who are at a higher risk of hepatic or cardiovascular outcomes. However, non-metabolic risk NAFLD subjects who are excluded from the MAFLD criteria are missed from the diagnosis, and their potential risk can be the cause of future diseases. Although huge controversies remain, this review focused on summarizing recent studies that compared the clinical and prognostic characteristics between subjects with NAFLD and MAFLD.

Dermatological aspects of SARS-CoV-2 infection: mechanisms and manifestations

The human infection caused by the novel SARS-CoV-2 is a public health emergency of international concern. Although the disease associated to this virus, named COVID-19, mainly affects the lungs, the infection can spread to extrapulmonary tissues, causing multiorgan involvement in severely ill patients. The broad infective capacity of SARS-CoV-2 is related to the pattern of expression of the viral entry factors ACE2 and TMPRSS2 in human tissues. As such, the respiratory and gastrointestinal tracts are at high risk for SARS-CoV-2 infection due to their high expression of ACE2 and TMPRSS2, which explains the clinical phenotype described in the vast majority of infected patients that includes pneumonia and diarrhea. Recently, preoccupation about the potential of the virus to infect the skin has been raised by dermatologists due to the increasing observations of cutaneous manifestations in patients with SARS-CoV-2 infection. Although there is little evidence of the expression of ACE2 and TMPRSS2 in the normal skin, the dermatological findings observed among COVID-19 patients warrants further investigation to delineate the mechanisms of skin affection after SARS-CoV-2 infection. Here, we provide a summary of the dermatological findings observed among patients with laboratory-confirmed SARS-CoV-2 infection based on recent reports. In addition, we analyze possible mechanisms of skin injury in COVID-19 patients and discuss about the risk of individuals with chronic skin conditions for SARS-CoV-2 infection. The present review constitutes a useful informative tool to improve our understanding of the pathophysiological mechanisms of COVID-19 and the possible implications of the current pandemic in dermatology.

Imaging biomarkers of diffuse liver disease: current status

We are happy to introduce this special issue of Abdominal Radiology on "diffuse liver disease". We have invited imaging experts to discuss various topics pertaining to diffuse liver disease, covering a vast array of imaging techniques including ultrasound (US), CT, MRI and new molecular imaging agents. Below, we briefly discussed the current status, limitations, and future directions of imaging biomarkers of diffuse liver disease.