You can't handle the truth! Comparing serum phosphatidylethanol to self-reported alcohol intake in chronic liver disease patients

MetALD: Genetic Factors and Clinical Outcomes

Metabolic and alcohol-related liver disease (MetALD) is a subcategory of steatotic liver disease (SLD) characterized by the coexistence of cardiometabolic risk factors and elevated alcohol intake. The global prevalence of MetALD is estimated to be 2 to 5%, but this is likely underestimated due to self-reporting biases. In real-world settings, fluctuations in alcohol intake mean that many patients with SLD may be classified as having MetALD at some point during their disease. Although MetALD is relatively common, only a minority of patients with the disorder progress to advanced chronic liver disease. Genetic factors modulate disease initiation and progression, with risk variants in PNPLA3, HSD17B13, and TM6SF2 being particularly relevant. Polygenic risk scores incorporating these and other variants have demonstrated a potential for identifying at-risk individuals. This review comprehensively examines MetALD, covering its natural history, genetic underpinnings, clinical outcomes, the predictive potential of genetic risk scores, and future therapeutic avenues involving gene silencing.

Steatotic Liver Disease Classification is Dynamic, Affecting Clinical Trial Eligibility and Subclass-Specific Treatments

BACKGROUND & AIMS

Steatotic liver disease (SLD) includes the subclasses metabolic-dysfunction-associated steatotic liver disease, metabolic and alcohol-related liver disease, and alcohol-related liver disease. We investigated the robustness of the SLD diagnoses after 2 years.

METHODS

We performed a prospective cohort study among individuals from the general population and individuals at risk of SLD. Participants were classified according to the diagnostic criteria of the SLD nomenclature at baseline and after 2 years.

RESULTS

We included 1042 participants, mean age was 57 ± 10 years, 663 were male (64%) and 379 (36%) female, and 70 (7%) had advanced fibrosis. At baseline, 595 (57%) had SLD, hereof 371 (62%) met the criteria for metabolic-dysfunction-associated steatotic liver disease, 140 (24%) for metabolic and alcohol-related liver disease, and 83 (14%) for alcohol-related liver disease, and 1 (<1%) was classified as cryptogenic SLD. Median time between the baseline and follow-up visit was 25 months (interquartile range, 24-31). Overall, 399 (38%) of the 1042 participants changed SLD classification from baseline to follow-up. In the group without SLD at baseline, 25% had SLD at follow-up. In comparison, 38% with metabolic-dysfunction-associated steatotic liver disease at baseline were classified differently at follow-up, whereas 62% and 69% of participants with baseline metabolic and alcohol-related liver disease and alcohol-related liver disease were classified differently at follow-up. The primary reasons for changing classification were that individuals no longer met the criteria for having SLD or had altered their alcohol intake.

CONCLUSIONS

SLD and the subclassification hereof is highly dynamic, especially driven by changes in alcohol use and hepatic steatosis. This affects eligibility for clinical trials and clinical management of patients with SLD.

The steatotic liver disease burden paradox: unravelling the key role of alcohol

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.

Metabolic dysfunction and alcohol-related liver disease (MetALD): Position statement by an expert panel on alcohol-related liver disease

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.

Diagnosis and Management of Early Stages of ALD

Early forms of alcohol-associated liver disease (ALD) include different stages in the progression of compensated liver disease ranging from steatosis to steatohepatitis and fibrosis. ALD has been classically diagnosed at advanced stages more frequently than other liver diseases. This fact probably contributed to the scarcity of studies on early forms of ALD. Recent studies have investigated the prevalence of early ALD in the general population and have described the natural history of alcohol-induced steatosis and fibrosis, which have been linked to worse prognosis compared with early stages of other chronic liver diseases. In addition, studies on screening and early diagnosis of ALD in at-risk populations have shown that these strategies allow early detection and intervention. Of note, up to 28% of the United States population has concurrent alcohol use and metabolic syndrome, and estimated prevalence of advanced fibrosis among heavy drinkers with metabolic syndrome has increased from 3% in the 1990s to more than 10% in the 2010s. Therefore, new challenges and treatment opportunities will emerge for patients with ALD. In this review, we provide an overview of the state of the art in early ALD, focusing on natural history, diagnosis, and management, and provide insights into future perspectives.

Head-to-Head Comparison Between Phosphatidylethanol Versus Indirect Alcohol Biomarkers for Diagnosis of MetALD Versus MASLD: A Prospective Study

BACKGROUND

The current subclassification of steatotic liver disease (SLD) relies on validated questionnaires, such as Alcohol Use Disorders Identification Test (AUDIT) and Lifetime Drinking History (LDH), which, while useful, are impractical and lack precision for their use in routine clinical practice. Phosphatidylethanol (PEth) is a quantitative, objective alcohol biomarker with high sensitivity and specificity.

AIMS

To assess the diagnostic accuracy of PEth for differentiating metabolic dysfunction and alcohol-associated liver disease (MetALD) from metabolic dysfunction-associated steatotic liver disease (MASLD) in a large, population-based, prospective, multiethnic cohort of individuals with overweight or obesity.

METHODS

This is a cross-sectional analysis of a prospective study including 374 adults with overweight or obesity residing in Southern California who had SLD as defined by MRI-PDFF ≥ 5%. The clinical research visit included medical history, biochemical and PEth testing, standardised validated questionnaires (including AUDIT and LDH), physical examination, and advanced imaging using MRI-PDFF and MRE.

RESULTS

Among 374 adults with SLD, the prevalence of MASLD, MetALD, and ALD was 90.1%, 6.4%, and 3.5%, respectively. PEth had a robust diagnostic accuracy in the detection of MetALD (AUROC 0.81, 95%CI 0.73-0.89) and the Youden cut-off was 25 ng/mL. In head-to-head comparative efficacy analysis, PEth was both statistically and clinically superior to all previously used indirect alcohol biomarkers for diagnosing MetALD, including aspartate aminotransferase/alanine aminotransferase ratio, mean corpuscular volume, gamma glutamyltransferase, and ALD/NAFLD index (p < 0.05).

CONCLUSIONS

PEth outperforms previously used non-invasive tests in differentiating MetALD from MASLD and has the potential to change clinical practice by enhancing the subclassification of SLD.

Long-term outcomes and risk modifiers of metabolic dysfunction-associated steatotic liver disease between lean and non-lean populations

One-third of adults across the globe exhibit metabolic dysfunction-associated steatotic liver disease (MASLD)-formerly known as nonalcoholic fatty liver disease (NAFLD). To date, MASLD is the fastest-growing etiology of chronic liver disease and hepatocellular carcinoma (HCC). Besides the population with obesity, MASLD can also be found in lean populations, accounting for 13% of the global population, especially Asians. Notably, individuals with lean MASLD face equal or higher overall mortality rates compared to their non-lean counterparts. Risk modifiers encompass advanced age, hepatic fibrosis, and type 2 diabetes mellitus (T2DM). Moreover, the population with lean MASLD is associated with an increased risk of HCC, while their non-lean counterparts are more prone to cardiovascular outcomes and T2DM. Existing evidence indicates a similar risk of liver-related events and extrahepatic cancer between the two groups. However, MASLD-related genetic variants, such as PNPLA3 and TM6SF2, did not significantly affect mortality between the two populations. Still, underreporting alcohol consumption and regional representation limits the study's comprehensiveness. Longitudinal studies and mechanistic explorations are needed to understand differences in lean versus non-lean MASLD populations. This review highlights the need for awareness and tailored interventions in managing MASLD, considering lean individuals' unique risks.

Metabolic Dysfunction-Associated Steatotic Liver Disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease in the United States. It is characterized by steatosis in the liver and is potentially reversible. Risk factors include obesity, type 2 mellitus, and other metabolic disorders. Metabolic dysfunction-associated steatohepatitis (MASH), a more severe form of MASLD, puts patients at risk for cirrhosis, liver decompensation, and liver cancer. Diet, exercise, and weight loss are the cornerstones of management. Although only 1 medication has been approved for treatment of MASH, other pharmacotherapies and surgeries that aid weight loss and optimize metabolic risk factors can be used. Early diagnosis and intervention are important to prevent progression to cirrhosis and its complications, including cancer.

Steatotic liver disease

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.

Envisioning how to advance the MASH field

Since 1980, the cumulative effort of scientists and health-care stakeholders has advanced the prerequisites to address metabolic dysfunction-associated steatotic liver disease (MASLD), a prevalent chronic non-communicable liver disease. This effort has led to, among others, the approval of the first drug specific for metabolic dysfunction-associated steatohepatitis (MASH; formerly known as nonalcoholic steatohepatitis). Despite substantial progress, MASLD is still a leading cause of advanced chronic liver disease, including primary liver cancer. This Perspective contextualizes the nomenclature change from nonalcoholic fatty liver disease to MASLD and proposes important considerations to accelerate further progress in the field, optimize patient-centric multidisciplinary care pathways, advance pharmacological, behavioural and diagnostic research, and address health disparities. Key regulatory and other steps necessary to optimize the approval and access to upcoming additional pharmacological therapeutic agents for MASH are also outlined. We conclude by calling for increased education and awareness, enhanced health system preparedness, and concerted action by policy-makers to further the public health and policy agenda to achieve at least parity with other non-communicable diseases and to aid in growing the community of practice to reduce the human and economic burden and end the public health threat of MASLD and MASH by 2030.

Natural history and progression of metabolic dysfunction-associated steatotic liver disease

The natural history of metabolic dysfunction-associated steatotic liver disease (MASLD), previously referred to as non-alcoholic fatty liver disease (NAFLD), is complex and long. A minority of patients develop inflammation and risk progressive fibrosis that can result in cirrhosis. Progression to cirrhosis occurs in 3-5% of patients and often takes more than 20 years. This narrative review presents an update on the natural history of MASLD, discussing studies and risk estimates for progression to severe outcomes, such as decompensated cirrhosis or hepatocellular carcinoma. We highlight the dynamic progression of liver damage, how to identify patients whose disease progresses over time, and how risk factors might be mitigated to reduce the risk for disease progression.