Limited data have prevented routine genetic testing from being integrated into clinical practice in metabolic dysfunction-associated steatotic liver disease (MASLD). We aimed to quantify the effect of genetic variants on changes in fibrosis severity per decade in MASLD.

This cross-sectional study included prospectively recruited adults with MASLD aged 18-70 who underwent magnetic resonance elastography (MRE) and genotyping for PNPLA3, TM6SF2, MBOAT7, GCKR, and HSD17B13. A genetic risk score (GRS) was calculated as the sum of established risk alleles in PNPLA3 minus protective variants in HSD17B13 (0=low risk, 1=high risk). We also estimated the polygenic risk score-hepatic fat content (PRS-HFC) and the adjusted version (PRS-5). The primary endpoint was the age-related change in liver stiffness measurement (LSM) on MRE by GRS. Findings were validated using an external cohort from Latin America.

Among 570 participants, the median age was 57 [49-64] years, 56.8% were women, and 34.2% were Hispanic. Median MRE was 2.4 [2.1-3.0] kPa, and 51% had high GRS. High GRS was independently associated with increased LSM (β=0.28 kPa, 95%CI:0.12-0.44, p=0.001) per 10-year age increase, while the low GRS group showed no significant difference. Similar findings were observed using PRS-HFC and PRS-5. PNPLA3 genotype alone also predicted higher LSM (C/G: β=0.32 kPa, 95%CI:0.02-0.61, p=0.034; G/G: β=0.87 kPa, 95%CI:0.52-1.22, p<0.0001) and G/G genotype was associated with significantly higher LSM by age 44, which was consistent in the validation population.

GRS, PRS-HFC, PRS-5, and PNPLA3 genotypes alone are associated with greater fibrosis per decade, resulting in divergent disease trajectories starting in midlife. Assessing genetic risk in MASLD will identify high-risk patients who require more frequent monitoring.

This study provides granular evidence that genetic predisposition, particularly the PNPLA3 G/G genotype, significantly influences the trajectory of liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), with a more pronounced impact emerging after the fourth decade of life. These findings highlight the importance of incorporating genetic risk assessment into MASLD management, as it allows for the early identification of high-risk individuals who may benefit from more frequent monitoring and targeted interventions. Given the rising global burden of MASLD, clinicians, researchers, and policymakers should consider integrating genetic stratification into existing risk assessment frameworks to refine screening and surveillance strategies. By optimizing patient selection for non-invasive fibrosis assessment and potential therapeutic interventions, this approach could enhance precision medicine efforts and may improve long-term outcomes.

Patatin-like phospholipase domain-containing 3 (PNPLA3) was the first gene identified through genome-wide association studies to be linked to hepatic fat accumulation. A missense variant, encoding the PNPLA3-148M allele, has since been shown to increase the risk for the full spectrum of steatotic liver disease (SLD), from simple steatosis to steatohepatitis, cirrhosis, and hepatocellular carcinoma. Despite extensive validation of this association and ongoing research into its pathogenic role, the precise mechanisms by which PNPLA3-148M contributes to the progression of SLD remain poorly understood. In this review, we evaluate preclinical in vitro and in vivo models used to investigate PNPLA3 and its involvement in SLD, with particular emphasis on metabolic dysfunction-associated steatotic liver disease. We assess the strengths and limitations of these models, as well as the challenges arising from species differences in PNPLA3 expression and function between human and murine systems.

Advances in nucleic acid delivery have positioned the liver as a key target for gene therapy, with adeno-associated virus vectors showing long-term effectiveness in treating hemophilia. Steatotic liver disease (SLD), the most common liver condition globally, primarily results from metabolic dysfunction-associated and alcohol-associated liver diseases. In some individuals, SLD progresses from simple steatosis to steatohepatitis, cirrhosis, and eventually hepatocellular carcinoma, driven by a complex interplay of genetic, metabolic, and environmental factors. Genetic variations in various lipid metabolism-related genes, such as patatin-like phospholipase domain-containing protein 3 (PNPLA3), 17β-hydroxysteroid dehydrogenase type 13 (HSD17B13), and mitochondrial amidoxime-reducing component 1 (MTARC1), impact the progression of SLD and offer promising therapeutic targets. This review largely focuses on genes identified through clinical association studies, as they are more likely to be effective and safe for therapeutic intervention. While preclinical research continues to deepen our understanding of genetic factors, early-stage clinical trials involving gene-based SLD therapies, including transient antisense and small-molecule approaches, are helping prioritize therapeutic targets. Meanwhile, hepatocyte gene editing technologies are advancing rapidly, offering alternatives to transient methods. As such, gene-based therapies show significant potential for preventing the progression of SLD and enhancing long-term liver health.

The classification of steatotic liver disease (SLD) has evolved, incorporating all conditions characterized by hepatic lipid accumulation. SLD represents a continuum of disorders that are shaped by the dynamic factors of alcohol intake and cardiometabolic risk factors. This updated classification has profound implications for both the management and research of SLD, especially with the new distinct category of patients with both metabolic and alcohol-related liver disease. In this Perspective, we highlight the pivotal role of alcohol within the SLD framework. We introduce the 'SLD burden paradox': a concept illustrating the disparity in which metabolic dysfunction-associated steatotic liver disease is more prevalent, yet individuals with SLD and excessive alcohol intake (such as in metabolic and alcohol-related liver disease and in alcohol-related liver disease) account for greater global liver-related morbidity and mortality. We explore strategies to mitigate the effect of SLD on morbidity and mortality, emphasizing the importance of early detection and reducing stigma associated with alcohol intake. Our discussion extends to methods for assessing and monitoring alcohol intake together with the critical role of managing cardiometabolic risk factors in patients across the SLD spectrum. Conclusively, we advocate for a coordinated care framework that adopts a person-centric approach when managing SLD, aiming to improve outcomes and patient care.

Little is known about the interplay between patatin-like phospholipase domain-containing protein 3 (PNPLA3 rs738409 C>G), environmental factors, and the risk of liver-related death.

A total of 4,361 adults were selected from NHANES III, 1991-1994. All participants were linked to the National Death Index until 2019 (mean follow-up: 23.2 years). Liver-related death was the study outcome. Associations of PNPLA3, diet, light alcohol intake, smoking, and BMI (kg/m2) with liver-related death were examined using competing risk regression models.

The PNPLA3 G-allele was significantly associated with liver-related death (adjusted subhazard ratio [adj.sHR] 2.9, 95% CI 1.4-5.8). Light alcohol intake (adj.sHR 2.2, 95% CI 1.1-4.5), top quartiles of monounsaturated fat (adj.sHR 0.43, 95% CI 0.12-0.99) and cholesterol (adj.sHR 2.6, 95% CI 1.00-8.8), coffee intake ≥3 cups/day (adj.sHR 0.05, 95% CI 0.06-0.10), former/current smoking (adj.sHR 1.8, 95% CI 1.2-2.6), BMI (adj.sHR 1.1, 95% CI 1.03-1.2), and healthy eating index (adj.sHR 0.96, 95% CI 0.93-0.98) were associated with liver-related death. Joint effects between PNPLA3 and environmental factors showed that the risk of liver-related death was significantly increased in carriers of the G-allele with light alcohol intake (adj.sHR 3.7), higher consumption (top quartile) of cholesterol (adj.sHR 4.1), former (adj.sHR 4.3) or current (adj.sHR 3.5) smoking, or BMI ≥30 (adj.sHR 4.0) kg/m2. The effects of the G-allele on the risk of LRD were significantly attenuated in those with top quartile consumption of monounsaturated fat (adj.sHR 0.5) or coffee intake ≥3 cups/day (adj.sHR 0.09). Healthy eating index was inversely associated with liver-related death across all PNPLA3 genotypes (adj.sHR 0.94, 0.96, and 0.97 for CC, CG, and GG, respectively).

PNPLA3 is associated with liver-related death and this relationship is significantly modified by anthropometric and environmental factors.

Light alcohol intake, dietary factors (healthy eating index, monounsaturated fat, cholesterol), coffee intake, smoking status, and BMI are independently associated with the risk of liver-related death. The increased inherited risk of liver-related death associated with PNPLA3 rs738409 appears to be attenuated by healthy eating index, monounsaturated fat, and coffee intake, and exacerbated by light alcohol intake, smoking, and BMI. Reducing harmful environmental exposures and increasing healthy eating habits may help mitigate the risk of liver-specific mortality even in those with high genetic risk.

In this position statement, we explore the intricate relationship between alcohol intake and metabolic dysfunction in the context of the 2023 nomenclature update for steatotic liver disease (SLD). Recent and lifetime alcohol use should be accurately assessed in all patients with SLD to facilitate classification of alcohol use in grams of alcohol per week. Alcohol biomarkers (i.e., phosphatidylethanol), use of validated questionnaires (i.e. AUDIT-C [alcohol use disorders identification test consumption]), and collateral information from friends and relatives could help facilitate differentiation between alcohol-related liver disease (ALD) per se and liver disease with both metabolic and alcohol-related components (MetALD). Heavy alcohol use can contribute to cardiometabolic risk factors such as high blood pressure, hypertriglyceridaemia, and hyperglycaemia. As a result, caution should be exercised in the application of only one metabolic dysfunction criterion to diagnose MASLD, as suggested in the 2023 nomenclature document, particularly in individuals exceeding weekly alcohol use thresholds of 140 g for women and 210 g for men. This is particularly important in those individuals with isolated high blood pressure, hypertriglyceridaemia, or hyperglycaemia, where the disease process may be driven by alcohol itself. Additionally, metabolic dysfunction and alcohol use should be reassessed over time, especially after periods of change in risk factor exposure. This approach could ensure a more accurate prognosis and effective management of SLD, addressing both metabolic and alcohol-related factors.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common chronic liver disease that is heterogenous in nature with various drivers and modifiers such as metabolic dysfunction and genetic factors. MASLD and the progressive subtype, metabolic dysfunction-associated steatohepatitis (MASH) represent the most rapidly increasing cause of liver-related mortality. There are limited treatment options for patients living with MASLD and MASH, various treatments with an array of different targets are under investigation and one therapeutic has been approved since the initiation of this study. Clinical trials investigating treatments for MASLD and MASH are associated with a high screen failure rate, driven largely by the regulatory required histological inclusion criteria for clinical trial eligibility. Other available clinically utilized biomarkers, typically referred to as non-invasive tests (NITs), can assess both the presence of steatosis and the severity of liver fibrosis in patients with MASLD and MASH in the clinic but are not yet approved over histological changes as endpoints for pivotal trials. However, the use of NITs have been demonstrated to increase the likelihood of meeting clinical trial entry criteria. All-Liver Interventional Global Network (ALIGN) is the first described multi-centre global observational screening study aimed at identifying individuals with a high likelihood of MASLD/MASH interested in participating in therapeutic clinical trials using non-invasive methodologies and genetic testing. This study represents a valuable prototype for industry and academic groups looking to evaluate large populations for MASH eligibility and interest in clinical trial participation.

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects up to 30% of Western populations. While obesity is a recognized risk factor, MASLD does not develop in all obese individuals, highlighting the need to understand genetic and environmental interactions. The PNPLA3 I148M variant has been identified as a key genetic risk factor, significantly increasing the likelihood of MASLD development and progression.

We reviewed current literature on the role of PNPLA3 I148M in MASLD, focusing on gene-environment interactions involving diet, physical activity, obesity, and insulin resistance. We included studies analysing ethnic differences in PNPLA3 I148M prevalence and its association with MASLD. Additionally, we reviewed data on how PNPLA3 I148M influences the response to therapies, including lipid-lowering medications and GLP-1 agonists.

The PNPLA3 I148M variant markedly heightens MASLD risk, particularly in Hispanic populations, where a higher prevalence of MASLD is observed. Lifestyle factors such as high sugar intake, alcohol consumption, and physical inactivity exacerbate MASLD risk among I148M carriers. Evidence shows that insulin resistance amplifies MASLD risk associated with the I148M variant, especially in non-diabetic individuals. Moreover, the PNPLA3 I148M variant interacts with other genetic loci, further modifying MASLD risk and disease course. The variant also influences treatment response, with variability observed in effectiveness of lipid-lowering therapies and GLP-1 agonists among carriers.

The interplay between PNPLA3 I148M and environmental factors underscores the need for personalized MASLD prevention and treatment strategies. Targeting both genetic and lifestyle contributors may enhance MASLD management, offering a tailored approach to reducing disease burden.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a heterogenous clinical and histopathological entity, where multiple metabolic co-factors are intertwined with high interindividual variability. The impact and severity of each factor (including obesity and type 2 diabetes) define a systemic dysmetabolism that can lead to either advanced liver disease and its complication (including hepatocellular carcinoma and clinical events related to portal hypertension) or extrahepatic events: incident cardiovascular disease, chronic kidney disease and extrahepatic cancers. The balance between environmental factors and genetic susceptibility has unique implications in MASLD: the intermittent injury of metabolic co-factors, their fluctuation over time and their specific management, are counterbalanced by the presence of gene variants that can significantly impact the disease at multiple levels. The I148M variant in the PNPLA3 gene is the most investigated genetic susceptibility that induces a more severe steatohepatitis, enhanced fibrogenesis and can shape the incidence of long-term clinical events regardless of, or worsened by, other metabolic risk factors.

In this review, we will summarise the updated evidence on the natural history of MASLD accounting for classical metabolic risk factors, the role of PNPLA3 in clinical sub-phenotyping (e.g., 'lean MASLD'), impact on disease severity and fibrosis progression, as well as its role for prognostication, alone or in combination with non-invasive tools into polygenic risk scores.

The PNPLA3-rs738409-G variant was the first common variant associated with hepatic fat accumulation and progression of metabolic dysfunction-associated steatotic liver disease (MASLD). Nevertheless, to date, the clinical translation of this discovery has been minimal because it has not yet been clearly demonstrated where the genetic information may play an independent and additional role in clinical risk prediction. In this mini-review, we will discuss the most relevant evidence regarding the potential integration of the PNPLA3 variant into scores and algorithms for liver disease diagnostics and risk stratification, specifically focusing on MASLD but also extending to liver diseases of other etiologies. The PNPLA3 variant adds little in diagnosing the current state of the disease, whether in terms of presence/absence of metabolic dysfunction-associated steatohepatitis or the stage of fibrosis. While it can play an important role in prediction, allowing for the early definition of risk profiles that enable tailored monitoring and interventions over time, this is most valuable when applied to populations with relatively high pre-test probability of having significant fibrosis based on either non-invasive tests (e.g. Fibrosis-4) or demographics (e.g. diabetes). Indeed, in this context, integrating FIB4 with the PNPLA3 genotype can refine risk stratification, though there is still no evidence that genetic information adds to liver stiffness determined by elastography. Similarly, in patients with known liver cirrhosis, knowing the PNPLA3 genotype can play a role in predicting the risk of hepatocellular carcinoma, while more doubts remain about the risk of decompensation.

Chronic liver disease (CLD) is a leading cause of death worldwide, with alcohol consumption and metabolic risk factors accounting for the majority of cases of CLD in many developed countries. Currently, specific strategies for the early diagnosis of CLD are lacking and consequently most cases are diagnosed at an advanced stage, which is associated with negative consequences for disease management and prognosis. Screening for CLD is based on either detection of chronic viral hepatitis B and C, or detection of liver fibrosis in patients with steatotic liver disease related to alcohol or metabolic dysfunction. Non-invasive tools, including serological and imaging-based tests, can be used to detect liver fibrosis. Clinical practice guidelines recommend screening for liver fibrosis using algorithms that combine different non-invasive tests, with widely available but low accuracy tests, such as FIB-4, recommended as a first screening step in the primary care setting, and other tests with lower availability but higher accuracy, such as transient elastography or the enhanced liver fibrosis test, recommended as a second step. There are different pathways for early detection of patients with CLD from primary to specialised care, with primary care providers being key for early detection, management and referral of patients. In addition, interventions targeting metabolic risk factors and alcohol consumption should be carried out in collaboration between specialists and primary care. In this review, we describe liver fibrosis from the community perspective, highlighting gaps in knowledge on how to define the optimal combination of tests, target population, the ideal pathway of care for CLD, and how to increase implementation of programmes for early diagnosis of liver diseases in clinical practice.

The discovery of PNPLA3 as a genetic risk factor for liver disease has transformed our understanding of the pathogenesis of alcohol-related liver disease (ALD). The recent reclassification of fatty liver disease as steatotic liver disease (SLD), introducing metabolic dysfunction and alcohol-related liver disease (MetALD), has highlighted how genetic and environmental factors synergistically drive liver damage. The PNPLA3 rs738409 variant stands as a paradigmatic example of gene-environment interaction, where its effect on liver disease is dramatically amplified by alcohol consumption, obesity and type 2 diabetes. Understanding these interactions has revealed novel pathogenic mechanisms. The robust genetic evidence and a growing understanding of molecular mechanisms have made PNPLA3 an attractive therapeutic target. Several compounds targeting PNPLA3 are now in clinical development. While initial trials have focused on metabolic dysfunction-associated SLD, the recognition that almost all individuals with excessive alcohol consumption have metabolic comorbidities provides an unprecedented opportunity to evaluate these genetically informed therapies in MetALD. In this review, we examine the role of PNPLA3 in ALD, focusing on gene-environment interactions and therapeutic implications in the context of the new disease classification framework.

Heavy alcohol intake induces a wide spectrum of liver diseases ranging from steatosis, steatohepatitis, cirrhosis, and HCC. Although alcohol consumption is a well-known risk factor for the development, morbidity, and mortality of HCC globally, alcohol-associated hepatocellular carcinoma (A-HCC) is poorly characterized compared to viral hepatitis-associated HCC. Most A-HCCs develop after alcohol-associated cirrhosis (AC), but the direct carcinogenesis from ethanol and its metabolites to A-HCC remains obscure. The differences between A-HCC and HCCs caused by other etiologies have not been well investigated in terms of clinical prognosis, genetic or epigenetic landscape, molecular mechanisms, and heterogeneity. Moreover, there is a huge gap between basic research and clinical practice due to the lack of preclinical models of A-HCC. In the current review, we discuss the pathogenesis, heterogeneity, preclinical approaches, epigenetic, and genetic profiles of A-HCC, and discuss the current insights into and the prospects for future research on A-HCC. The potential effect of alcohol on cholangiocarcinoma and liver metastasis is also discussed.

Alcohol-associated liver disease (ALD), as highlighted in this narrative review, is a major public health concern, increasingly impacting global disease burden and premature mortality. In 2019, ALD accounted for the loss of 11 million life-years worldwide. The rising number of deaths and disability-adjusted life-years attributed to ALD, particularly pronounced in the United States, are alarming. Projections suggest that the economic impact of ALD, as seen in the United States, could potentially double by 2040. ALD is increasingly prevalent among younger adults (20-45 y) and has become the leading cause of liver transplantation in both United States and Europe. During the COVID-19 pandemic, the existing trend was further amplified as high-risk drinking patterns coincided with a rise in hospital admissions for alcohol-associated hepatitis and increased ALD-related mortality. The prevalence of ALD is estimated at 3.5% in the general population, 26.0% among hazardous drinkers, and 55.1% among those with alcohol use disorders. Alarmingly, 5-year mortality rates for patients with ALD exceed 50%, with even higher rates in more advanced disease stages. Methodological challenges, such as underreporting, diagnostic difficulties, and variability in registry data quality, complicate the accurate assessment of the impact of ALD. Additionally, the contribution of alcohol to the progression of other liver diseases is often under acknowledged in health care registries, leading to a significant underestimation of its broader implications for liver health. Addressing the growing ALD concern requires robust public health initiatives, heightened awareness, refined diagnostic techniques, and comprehensive epidemiological studies. These measures are vital to tackle the increasing prevalence of ALD and mitigate its extensive impact on individuals and health care systems.

Cirrhosis is a leading cause of liver-related mortality and a multifactorial disease. To date, the complex genetic architecture of non-viral cirrhosis has not been fully explored. Cross-trait genetic correlations can elucidate the common genetic etiology of genetically correlated phenotypes. This study aims to identify polygenic and pleiotropic traits associated with cirrhosis using the linkage disequilibrium score regression analysis.

We conducted genome-wide association analysis of 9,622,842 imputed SNPs on 3,368 non-viral cirrhosis cases and 258,258 controls, and cross-trait analysis between non-viral cirrhosis and various polygenic and pleiotropic traits using the UK Biobank cohort study. We further performed sensitivity analyses by removing genomic regions of alcohol intake, smoking behaviors, and obesity. We observed multiple traits showing robust genetic correlations (rg) with non-viral cirrhosis.

We found strong genetic correlations between the genetic architectures of non-viral cirrhosis and clinical/physiologic factors, including BMI (rg=0.82), alanine aminotransferase (0.71), diabetes (0.70), number of cigarettes currently smoked daily (0.67), amount of alcohol drunk on a typical drinking day (0.60), insomnia (0.59), gout (0.57), depression (0.50), apoliprotein-A (-0.33), HDL cholesterol (-0.49). Exclusion of genomic regions associated with alcohol intake, smoking behaviors, and obesity demonstrated consistent directions and persistent associations in genetic patterns. The inheritability of cirrhosis on the observed scale showed 0.56%.

This study provides a comprehensive assessment of the shared genetic architecture of non-viral cirrhosis predisposition and numerous polygenic and pleiotropic traits, most notably BMI, alanine aminotransferase, and diabetes. These findings provide new information on underlying comorbid conditions that can increase the non-viral cirrhosis risk.

Alcohol consumption is a global phenomenon and a major contributor to alcohol-associated liver disease (ALD). Detecting individuals at risk of ALD has been challenging, with only a small fraction of patients being identified at early stages compared to other chronic liver diseases. In response to this challenge, non-invasive tests (NITs) have become essential tools for the detection of ALD, offering opportunities for early identification and intervention to mitigate the disease burden. Noninvasive alcohol consumption biomarkers are crucial in estimating individuals' recent alcohol intake, providing valuable insights into their drinking patterns. Various NITs have been investigated for the initial screening of asymptomatic individuals at risk of ALD, as well as for identifying specific stages of the disease. These NITs are applied in 2 main clinical scenarios: population-based stratification for identifying and predicting liver-related symptoms and diagnosing and prognosticating compensated cirrhosis or advanced chronic liver disease in secondary or tertiary care settings. Moreover, NITs play a significant role in the prognostic assessment of patients with various manifestations of ALD, including alcohol-associated hepatitis (AH), decompensated cirrhosis, and metabolic-associated and ALD. These tests guide appropriate treatment decisions and predict outcomes. In this review, various NITs for the early detection and monitoring of alcohol consumption were discussed. Additionally, the evaluation of NITs for screening and predicting ALD and liver complications was addressed comprehensively. Future perspectives of NITs for ALD were explored, alongside a thorough discussion of the opportunities and challenges associated with NITs for ALD screening.

The growing recognition of the role of the gut microbiome's impact on alcohol-associated diseases, especially in alcohol-associated liver disease, emphasizes the need to understand molecular mechanisms involved in governing organ-organ communication to identify novel avenues to combat alcohol-associated diseases. The gut-liver axis refers to the bidirectional communication and interaction between the gut and the liver. Intestinal microbiota plays a pivotal role in maintaining homeostasis within the gut-liver axis, and this axis plays a significant role in alcohol-associated liver disease. The intricate communication between intestine and liver involves communication between multiple cellular components in each organ that enable them to carry out their physiological functions. In this review, we focus on novel approaches to understanding how chronic alcohol exposure impacts the microbiome and individual cells within the liver and intestine, as well as the impact of ethanol on the molecular machinery required for intraorgan and interorgan communication.

Most current studies use body mass index (BMI) or waist circumference (WC) to define obesity, and BMI, which reflects subcutaneous fat independent of visceral fat, is the most commonly used indicator of obesity. WC reflects subcutaneous and visceral fat. This research aims to investigate the effect of obesity on mortality in people with digestive diseases. According to BMI and WC, we divided patients with obesity into the following four groups: general obesity, abdominal obesity, combined obesity, and non-obese. The effects of different obesity types on mortality in a population with digestive diseases were analysed via Cox regression and inverse probability-weighted Cox regression. Our research employed multivariate imputation via the chained equations method to interpolate missing values. A total of 254,445 participants, with a mean age of 57.8 ± 7.8 years, were included in the analysis. Of these participants, 227,111 (89.3%) participants were censored, and 27,334 (10.7%) participants died. Abdominal obesity and combined obesity were independent predictors of mortality in patients with digestive diseases. The combination of BMI and WC was valuable and significant for considering the type of obesity. In addition, our study revealed that sex, socioeconomic status, lifestyle habits, and physical activity were also associated with death in people with digestive disorders. Combined obesity, which is determined by both BMI and WC, is an important factor that influences mortality in a population with digestive diseases, and it plays a stronger role than abdominal obesity alone. These modifiable risk factors for mortality can provide guidance to populations with digestive diseases to avoid poor lifestyles and prolong survival time.

Alcohol-associated liver disease (ALD) is a significant global health challenge, encompassing a spectrum from steatotic liver disease to cirrhosis and alcohol-associated hepatitis, and contributed to 25% of global cirrhosis deaths in 2019. The identification of both modifiable (e.g. heavy drinking, metabolic syndromes) and non-modifiable risk factors (e.g. genetic predispositions) is crucial for effective disease management. Alcohol use assessment and treatment, by using both behavioral therapy and pharmacotherapeutic modalities, nutrition support, and optimization of liver disease modifiers, form the cornerstone of management. Advances in medical therapies, such as fecal microbiota transplantation and novel agents such as IL-22, are being explored for their therapeutic potential. A unifying theme in ALD care is the need for a personalized approach to management, accounting for the spectrum of the disease and individual patient characteristics, to tailor interventions effectively. Finally, it is essential to address the challenges to effective ALD treatment, including socioeconomic, logistical, and stigma-related barriers, to improve patient outcomes. This review discusses the current knowledge on ALD, including epidemiology, pathophysiology, risk factors, and management strategies, highlighting the critical role of integrated care models.

Steatotic liver disease is the overarching term for conditions characterised by abnormal lipid accumulation in the liver (liver or hepatic steatosis). Steatotic liver disease encompasses what was previously termed non-alcoholic fatty liver disease (NAFLD), which is now called metabolic dysfunction-associated steatotic liver disease (MASLD). Additionally, steatotic liver disease includes alcohol-related liver disease (ALD) and MetALD, the new classification for the overlap between MASLD and ALD, and rare causes of liver steatosis. Cirrhosis is globally the 11th leading cause of death, and steatotic liver disease has become the leading cause of cirrhosis in the EU and USA. Steatotic liver disease affects around 30% of the global population and is mainly driven by obesity, type 2 diabetes, and alcohol intake, but only a minor proportion with steatotic liver disease progress to cirrhosis. The presence and progression of liver fibrosis led by hepatic inflammation is the main predictor of liver-related death across the entire spectrum of steatotic liver diseases. A combination of recent advancements of widely available biomarkers for early detection of liver fibrosis together with considerable advancements in therapeutic interventions offer the possibility to reduce morbidity and mortality in patients with steatotic liver disease. This Seminar covers the recent reclassification of steatotic liver disease and how it reflects clinical practice and prognosis. For early detection of liver fibrosis, we propose a collaborative diagnostic framework between primary care and liver specialists. Lastly, we discuss current best practices for managing steatotic liver disease, we explore therapeutic targets across the spectrum of steatotic liver diseases, and we review the pipeline of drugs in development for MASLD.

This review aims to synthesize the old issues and current understandings of the etiology of liver cancer, focusing on the diverse causative factors influenced by geographical, socioeconomic, and lifestyle variations across different regions.

We highlight significant geographic disparities in liver cancer risk factors. While hepatitis B and C viruses, aflatoxin exposure, and alcohol consumption remain globally established contributors; metabolic dysfunction-associated steatotic liver disease and metabolic syndromes are increasingly prominent in the West. Chronic HBV and aflatoxin continue to dominate as risk factors in Asia and Africa. Dietary factors, metabolic diseases like diabetes and obesity, genetic predispositions, environmental risk factors and lifestyle choices such as smoking and alcohol use play substantial roles in specific populations. Protective factors like coffee and tea consumption, along with aspirin use, vegetables and fruits have shown potential in reducing HCC risk, although findings vary by population and dietary habits. Liver cancer etiology is influenced by various factors that differ by region. Established risk factors include hepatitis B and C, aflatoxin, and alcohol. Emerging risks, such as metabolic dysfunction-associated steatotic liver disease, are more prevalent in Western countries, while aflatoxin and HBV remains significant in Asia and Africa. Diet, metabolic conditions like diabetes and obesity, genetic predispositions, and lifestyle choices also play crucial roles. Coffee, tea, aspirin, vegetables, and fruits may reduce HCC risk, but effectiveness varies. Future research should integrate epidemiology, genetics, and nutrition, with global cooperation and data sharing essential for effective cancer control strategies.

The 2023 nomenclature defined criteria for steatotic liver disease (SLD), including metabolic dysfunction-associated SLD (MASLD), alcohol-associated liver disease (ALD), and the overlapping MASLD/ALD (MetALD). We aimed to assess racial and ethnic disparities in the SLD prevalence among United States (US) adults based on this new nomenclature.

We undertook a cross-sectional study employing the 2017-2018 National Health and Nutrition Examination Survey (NHANES) database. We identified SLD according to a controlled attenuation parameter ≥288 dB/m, liver stiffness ≥7.2 kPa, or elevated aminotransferase levels. Alcohol use thresholds were established according to the updated SLD definition. We estimated prevalences using the complex design of the NHANES survey. Multivariable logistic regressions with complex design weights were employed.

A total of 5532 individuals are included. The mean age is 45.4 years, and 50.9% are women. The adjusted estimated prevalence of MASLD is 42.4% (95% CI: 41.1-43.8%), MetALD 1.7% (95% CI: 1.3-2.0%), and ALD 0.6% (95% CI: 0.3-0.8%). Hispanics exhibit a higher prevalence of SLD, but there are no significant differences in advanced fibrosis prevalence due to SLD among racial/ethnic groups. In MASLD, men, individuals aged 40-64 and ≥65 years, Hispanics, those with health insurance, higher BMI, diabetes, hypertension, hypertriglyceridemia, and low high-density lipoprotein (HDL) cholesterol or use of lipid-lowering agents are independently associated with a higher risk, while Blacks have the lowest risk. In MetALD, men and higher BMI are independently associated with a higher risk of MetALD in adjusted multivariable analysis. In ALD, the adjusted multivariable analysis shows that only health insurance is independently associated with a lower ALD risk.

MASLD prevalence is high in the US, especially in men, older individuals, and Hispanics. MetALD and ALD prevalence was substantial but could be underestimated.

In patients with cirrhosis, continued heavy alcohol consumption and obesity may increase risk of hepatocellular carcinoma (HCC). We examined whether germline susceptibility to hepatic steatosis not only independently predisposes to HCC but may also act synergistically with other risk factors.

We analyzed data from 1911 patients in 2 multicenter prospective cohort studies in the United States. We classified patients according to alcohol consumption (current heavy vs not current heavy), obesity (body mass index ≥30 vs <30 kg/m2), and PNPLA3 I148M variant status (carrier of at least one G risk allele vs noncarrier). We examined the independent and joint effects of these risk factors on risk of developing HCC using Cox regression with competing risks.

Mean age was 59.6 years, 64.3% were male, 28.7% were Hispanic, 18.3% were non-Hispanic Black, 50.9% were obese, 6.2% had current heavy alcohol consumption, and 58.4% harbored at least 1 PNPLA3 G-allele. One hundred sixteen patients developed HCC. Compared with PNPLA3 noncarriers without heavy alcohol consumption, HCC risk was 2.65-fold higher (hazard ratio [HR], 2.65; 95% confidence interval [CI], 1.20-5.86) for carriers who had current heavy alcohol consumption. Compared with noncarrier patients without obesity, HCC risk was higher (HR, 2.40; 95% CI, 1.33-4.31) for carrier patients who were obese. PNPLA3 and alcohol consumption effect was stronger among patients with viral etiology of cirrhosis (HR, 3.42; 95% CI, 1.31-8.90). PNPLA3 improved 1-year risk prediction for HCC when added to a clinical risk model.

The PNPLA3 variant may help refine risk stratification for HCC in patients with cirrhosis with heavy alcohol consumption or obesity who may need specific preventive measures.

The PNPLA3-rs738409-G, TM6SF2-rs58542926-T, and HSD17B13-rs6834314-A polymorphisms have been associated with cirrhosis, hepatic decompensation, and HCC. However, whether they remain associated with HCC and decompensation in people who already have cirrhosis remains unclear, which limits the clinical utility of genetics in risk stratification as HCC is uncommon in the absence of cirrhosis. We aimed to characterize the effects of PNPLA3, TM6SF2, and HSD17B13 genotype on hepatic decompensation, HCC, and liver-related mortality or liver transplant in patients with baseline compensated cirrhosis.

We conducted a single-center retrospective study of patients in the Michigan Genomics Initiative who underwent genotyping. The primary predictors were PNPLA3, TM6SF2, and HSD17B13 genotypes. Primary outcomes were either hepatic decompensation, HCC, or liver-related mortality/transplant. We conducted competing risk Fine-Gray analyses on our cohort.

We identified 732 patients with baseline compensated cirrhosis. During follow-up, 50% of patients developed decompensation, 13% developed HCC, 24% underwent liver transplant, and 27% died. PNPLA3-rs738409-G genotype was associated with risk of incident HCC: adjusted subhazard hazard ratio 2.42 (1.40-4.17), p=0.0015 for PNPLA3-rs738409-GG vs. PNPLA3-rs738409-CC genotype. The 5-year cumulative incidence of HCC was higher in PNPLA3-rs738409-GG carriers than PNPLA3-rs738409-CC/-CG carriers: 15.6% (9.0%-24.0%) vs. 7.4% (5.2%-10.0%), p<0.001. PNPLA3 genotype was not associated with decompensation or the combined outcome of liver-related mortality or liver transplant. TM6SF2 and HSD17B13 genotypes were not associated with decompensation or HCC.

The PNPLA3-rs738409-G allele is associated with an increased risk of HCC among patients with baseline compensated cirrhosis. People with cirrhosis and PNPLA3-rs738409-GG genotype may warrant more intensive HCC surveillance.

Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive form of metabolic dysfunction-associated steatotic liver disease, for which there is limited information about patient experience, including the patient journey.

In this study, we conducted interviews with patients with MASH to qualitatively evaluate the patient journey and help elucidate the experiences of this patient population. We also investigated if the patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M variant (non-Hispanic) or being of Hispanic ethnicity may influence patient experiences because these 2 subgroups develop advanced liver disease more frequently than other patient groups.

One-to-one interviews were conducted with 28 adults (with PNPLA3 I148M genetic variant, n = 10; Hispanic, n = 8) living in the United States who had been diagnosed with MASH with liver fibrosis. Patients were asked open-ended questions about their experiences before, at, and after their diagnosis. The data collected found that patients experienced a long process of misdiagnoses before their diagnosis of MASH, a lack of clear information provided by clinicians, and limited accessibility to support groups. Hispanic patients reported "impact on family/friends" (75%) and "fear of disease progression" (75%) more frequently than the other patient cohorts interviewed. This is the first report of "fear of progression" in patients with MASH. No patients who were White and had the PNPLA3 I148M variant reported nausea/vomiting, in contrast to other patient cohorts.

This qualitative study identified key aspects of the patient journey that are important for clinical providers and medical teams to recognize. We also propose a new algorithm that could be developed to help screen relatives of patients who are found to carry the PNPLA3 I148M variant.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a widespread global disease with significant health burden. Unhealthy lifestyle, obesity, diabetes mellitus (DM), insulin resistance, and genetics have been implicated in the pathogenesis of MASLD. A significant degree of heterogeneity exists among each of above-mentioned risk factors. Heterogeneity of these risk factors translates into the heterogeneity of MASLD. On the other hand, MASLD can itself lead to insulin resistance and DM. Such heterogeneity makes it difficult to assess the natural course of an individual with MASLD in clinical practice. At present MASLD is considered as one disease despite the variability of etiopathogenic processes, and we lack the consensus definitions of unique subtypes of MASLD. In this review, pathogenic processes of MASLD are discussed and a need of subtyping is recommended.

Liver disease poses a substantial burden in Latin America. This burden is primarily attributed to a high level of alcohol consumption and the increasing prevalence of risk factors associated with metabolic dysfunction-associated steatotic liver disease (MASLD), such as sedentary lifestyles, easy access to ultra-processed foods, obesity, and type 2 diabetes mellitus. These epidemiological trends are cause for concern, especially considering that there are significant challenges in addressing them due to disparities in access to liver disease screening and care. In this article, we aim to provide an overview of the current situation regarding liver disease in Latin America. We also discuss recent multinational proposals designed to address the growing MASLD burden via its integration into existing non-communicable diseases policies, at both local and global levels. Additionally, we emphasize the urgent need to establish effective public health policies that target both MASLD risk factors and excessive alcohol consumption. Furthermore, we discuss the development of liver transplantation programs, areas for improvement in medical education and research capabilities, and how the fostering of extensive collaboration among all stakeholders is crucial for addressing liver disease in the region.

High-dose methotrexate (HDMTX) therapy poses challenges in various neoplasms due to individualized pharmacokinetics and associated adverse effects. Our purpose is to identify early risk factors associated with HDMTX-induced toxicities, paving the way for personalized treatment.

A systematic review of PubMed and Cochrane databases was conducted for articles from inception to July 2023. Eligible studies included reviews, clinical trials, and real-world analyses. Irrelevant studies were excluded, and manual searches and citation reviews were performed. Factors such as MTX exposure, drug interactions, demographics, serum albumin, urine pH, serum calcium, and genetic polymorphisms affecting MTX transport (e.g. SLCO1B1), intracellular folate metabolism (MTHFR), cell development (ARID5B), metabolic pathways (UGT1A1, PNPLA3), as well as epigenetics were identified.

This comprehensive review aids researchers and clinicians in early identification of HDMTX toxicity risk factors. By understanding the multifaceted risk factors associated with hematologic malignancies, personalized treatment approaches can be tailored to optimize therapeutic outcomes.

Metabolic dysfunction-associated steatotic (fatty) liver disease (MASLD), previously termed non-alcoholic fatty liver disease, is a worldwide epidemic that can lead to hepatic inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The disease is typically a component of the metabolic syndrome that accompanies obesity, and is often overlooked because the liver manifestations are clinically silent until late-stage disease is present (i.e., cirrhosis). Moreover, Asian populations, including Koreans, have a higher fraction of patients who are lean, yet their illness has the same prognosis or worse than those who are obese. Nonetheless, ongoing injury can lead to hepatic inflammation and ballooning of hepatocytes as classic features. Over time, fibrosis develops following activation of hepatic stellate cells, the liver's main fibrogenic cell type. The disease is usually more advanced in patients with type 2 diabetes mellitus, indicating that all diabetic patients should be screened for liver disease. Although there has been substantial progress in clarifying pathways of injury and fibrosis, there no approved therapies yet, but current research seeks to uncover the pathways driving hepatic inflammation and fibrosis, in hopes of identifying new therapeutic targets. Emerging molecular methods, especially single cell sequencing technologies, are revolutionizing our ability to clarify mechanisms underlying MASLD-associated fibrosis and HCC.

Alcohol-associated liver disease (ALD) is a major cause of chronic liver disease worldwide, and comprises a spectrum of several different disorders, including simple steatosis, steatohepatitis, cirrhosis, and superimposed hepatocellular carcinoma. Although tremendous progress has been made in the field of ALD over the last 20 years, the pathogenesis of ALD remains obscure, and there are currently no FDA-approved drugs for the treatment of ALD. In this Review, we discuss new insights into the pathogenesis and therapeutic targets of ALD, utilizing the study of multiomics and other cutting-edge approaches. The potential translation of these studies into clinical practice and therapy is deliberated. We also discuss preclinical models of ALD, interplay of ALD and metabolic dysfunction, alcohol-associated liver cancer, the heterogeneity of ALD, and some potential translational research prospects for ALD.

Nonalcoholic fatty liver disease (NAFLD) and alcohol-related liver disease (ALD) are the leading causes of chronic liver disease worldwide. NAFLD and ALD share pathophysiological, histological and genetic features and both alcohol and metabolic dysfunction coexist as aetiological factors in many patients with hepatic steatosis. A diagnosis of NAFLD requires the exclusion of significant alcohol consumption and other causes of liver disease. However, data suggest that significant alcohol consumption is often under-reported in patients classified as having NAFLD and that alcohol and metabolic factors interact to exacerbate the progression of liver disease. In this Review, we analyse existing data on the interaction between alcohol consumption and metabolic syndrome as well as the overlapping features and differences in the pathogenesis of ALD and NAFLD. We also discuss the clinical implications of the coexistence of alcohol consumption, of any degree, in patients with evidence of metabolic derangement as well as the use of alcohol biomarkers to detect alcohol intake. Finally, we summarize the evolving nomenclature of fatty liver disease and describe a recent proposal to classify patients at the intersection of NAFLD and ALD. We propose that, regardless of the presumed aetiology, patients with fatty liver disease should be evaluated for both metabolic syndrome and alcohol consumption to enable better prognostication and a personalized medicine approach.

Hepatocellular carcinoma (HCC) mortality rates are increasing globally, and particularly in the Western world. Cirrhosis remains the predominant risk factor for HCC. However, epidemiological shifts in the incidence of HCC from patients with virus-related liver disease to those with non-viral aetiologies, including alcohol-associated and metabolic dysfunction-associated steatotic liver disease, have important implications for prevention, surveillance and treatment. Hepatitis B vaccination and antiviral therapy for hepatitis B and C are effective for primary prevention of virus-related HCCs, but chemoprevention strategies for non-viral liver disease remain an unmet need. Emerging data suggest associations between aspirin, statins, metformin and coffee and reduced HCC incidence, although none has been proved to be causally related. Secondary prevention of HCC via semi-annual surveillance is associated with improvements in early detection and thus reduced mortality; however, current tools, including abdominal ultrasonography, have suboptimal sensitivity for the detection of early stage HCC, particularly in patients with obesity and/or non-viral liver disease. Promising blood-based or imaging-based surveillance strategies are emerging, although these approaches require further validation before adoption in clinical practice. In the interim, efforts should be focused on maximizing use of the existing surveillance tools given their prevalent underuse globally. Remarkable advances have been made in the treatment of HCC, including expanded eligibility for surgical therapies, improved patient selection for locoregional treatments and increased systemic treatment options, including immune-checkpoint inhibitors. In this Review, we discuss trends in the epidemiology of HCC and their implications for screening, prevention and therapy.

Alcohol use disorder remains a significant public health concern, affecting around 5% of adults worldwide. Novel pathways of damage have been described during the last years, providing insight into the mechanism of injury due to alcohol misuse beyond the direct effect of ethanol byproducts on the liver parenchyma and neurobehavioral mechanisms. Thus, the gut-liver-brain axis and immune system involvement could be therapeutic targets for alcohol use disorder. In particular, changes in gut microbiota composition and function, and bile acid homeostasis, have been shown with alcohol consumption and cessation. Alcohol can also directly disrupt intestinal and blood-brain barriers. Activation of the immune system can be triggered by intestinal barrier dysfunction and translocation of bacteria, pathogen-associated molecular patterns (such as lipopolysaccharide), cytokines, and damage-associated molecular patterns. These factors, in turn, promote liver and brain inflammation and the progression of liver fibrosis. Other involved mechanisms include oxidative stress, apoptosis, autophagy, and the release of extracellular vesicles and miRNA from hepatocytes. Potential therapeutic targets include gut microbiota (probiotics and fecal microbiota transplantation), neuroinflammatory pathways, as well as neuroendocrine pathways, for example, the ghrelin system (ghrelin receptor blockade), incretin mimetics (glucagon-like peptide-1 analogs), and the mineralocorticoid receptor system (spironolactone). In addition, support with psychological and behavioral treatments is essential to address the multiple dimensions of alcohol use disorder. In the future, a personalized approach considering these novel targets can contribute to significantly decreasing the alcohol-associated burden of disease.

Patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism (I148M) is strongly associated with non-alcoholic steatohepatitis and advanced fibrosis; however, the underlying mechanisms remain largely unknown. In this study, we investigated the effect of PNPLA3-I148M on the activation of hepatic stellate cell line LX-2 and the progression of liver fibrosis. Immunofluorescence staining and enzyme-linked immunosorbent assay were used to detect lipid accumulation. The expression levels of fibrosis, cholesterol metabolism, and mitochondria-related markers were measured via real-time PCR or western blotting. Electron microscopy was applied to analyze the ultrastructure of the mitochondria. Mitochondrial respiration was measured by a Seahorse XFe96 analyzer. PNPLA3-I148M significantly promoted intracellular free cholesterol aggregation in LX-2 cells by decreasing cholesterol efflux protein (ABCG1) expression; it subsequently induced mitochondrial dysfunction characterized by attenuated ATP production and mitochondrial membrane potential, elevated ROS levels, caused mitochondrial structural damage, altered the oxygen consumption rate, and decreased the expression of mitochondrial-function-related proteins. Our results demonstrated for the first time that PNPLA3-I148M causes mitochondrial dysfunction of LX-2 cells through the accumulation of free cholesterol, thereby promoting the activation of LX-2 cells and the development of liver fibrosis.

Non-alcoholic fatty liver disease (NAFLD) can progress to cirrhosis and hepatic decompensation, but whether genetic variants influence the rate of progression to cirrhosis or are useful in risk stratification among patients with NAFLD is uncertain.

We included participants from 2 independent cohorts, they Michigan Genomics Initiative (MGI) and UK Biobank (UKBB), who had NAFLD defined by elevated alanine aminotransferase (ALT) levels in the absence of alternative chronic liver disease. The primary predictors were genetic variants and metabolic comorbidities associated with cirrhosis. We conducted time-to-event analyses using Fine-Gray competing risk models.

We included 7893 and 46,880 participants from MGI and UKBB, respectively. In univariable analysis, PNPLA3-rs738409-GG genotype, diabetes, obesity, and ALT of ≥2× upper limit of normal were associated with higher incidence rate of cirrhosis in both MGI and UKBB. PNPLA3-rs738409-GG had additive effects with clinical risk factors including diabetes, obesity, and ALT elevations. Among patients with indeterminate fibrosis-4 (FIB4) scores (1.3-2.67), those with diabetes and PNPLA3-rs738409-GG genotype had an incidence rate of cirrhosis comparable to that of patients with high-risk FIB4 scores (>2.67) and 2.9-4.8 times that of patients with diabetes but CC/CG genotypes. In contrast, FIB4 <1.3 was associated with an incidence rate of cirrhosis significantly lower than that of FIB4 of >2.67, even in the presence of clinical risk factors and high-risk PNPLA3 genotype.

PNPLA3-rs738409 genotype and diabetes identified patients with NAFLD currently considered indeterminate risk (FIB4 1.3-2.67) who had a similar risk of cirrhosis as those considered high-risk (FIB4 >2.67). PNPLA3 genotyping may improve prognostication and allow for prioritization of intensive intervention.