Gastrointestinal cancers in lean individuals with non-alcoholic fatty liver disease: A systematic review and meta-analysis

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.

MASLD: a systemic metabolic disorder with cardiovascular and malignant complications

Non-alcoholic fatty liver disease (NAFLD) has rapidly become the most common chronic liver disease globally and is currently estimated to affect up to 38% of the global adult population. NAFLD is a multisystem disease where systemic insulin resistance and related metabolic dysfunction play a pathogenic role in the development of NAFLD and its most relevant liver-related morbidities (cirrhosis, liver failure and hepatocellular carcinoma) and extrahepatic complications, such as cardiovascular disease (CVD), type 2 diabetes mellitus, chronic kidney disease, and certain types of extrahepatic cancers. In 2023, three large multinational liver associations proposed that metabolic dysfunction-associated steatotic liver disease (MASLD) should replace the term NAFLD; the name chosen to replace non-alcoholic steatohepatitis was metabolic dysfunction-associated steatohepatitis (MASH). Emerging epidemiological evidence suggests an excellent concordance rate between NAFLD and MASLD definitions-that is, ~99% of individuals with NAFLD meet MASLD criteria. In this narrative review, we provide an overview of the literature on (a) the recent epidemiological data on MASLD and the risk of developing CVD and malignant complications, (b) the underlying mechanisms by which MASLD (and factors strongly linked with MASLD) may increase the risk of these extrahepatic complications and (c) the diagnosis and assessment of CVD risk and potential treatments to reduce CVD risk in people with MASLD or MASH.

What Is New in Metabolic Dysfunction-Associated Steatotic Liver Disease in Lean Individuals: From Bench to Bedside

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects more than 30% of the world's adult population. While it is associated with obesity and metabolic syndrome, emerging evidence has shown that a substantial number of MASLD patients have a normal body mass index ("lean individuals with MASLD"). In this article, we provide an overview of the definition, epidemiology, pathogenesis, and clinical outcomes associated with lean individuals with MASLD and updates on current management.