metabolic dysfunction–associated steatotic liver disease
metabolic dysfunction–associated steatotic liver disease
Overview
Metabolic dysfunction–associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is currently the most prevalent chronic liver disease worldwide, affecting approximately one-third of the global population. The condition is defined by hepatic fat accumulation (steatosis) occurring in the context of metabolic dysfunction—encompassing obesity, insulin resistance, type 2 diabetes, arterial hypertension, and dyslipidemia—in the absence of significant alcohol consumption or other competing causes of liver injury. MASLD represents a histological spectrum ranging from simple steatosis to the more aggressive inflammatory subtype, metabolic dysfunction–associated steatohepatitis (MASH), which can drive progressive hepatic fibrosis, cirrhosis, hepatocellular carcinoma (HCC), and liver-related mortality. The disease is the hepatic manifestation of systemic metabolic derangement, closely linked to cardiovascular disease, type 2 diabetes, and cardiovascular-kidney-metabolic (CKM) syndrome, and is now the second leading indication for liver transplantation in the United States.
The pathogenesis of MASLD is multifactorial, involving dysregulated lipid metabolism, oxidative stress, chronic low-grade inflammation, gut microbiome perturbation, and immune-mediated hepatocellular injury. Key molecular mediators include proinflammatory cytokines (such as interleukin-1 beta), nuclear factor kappa B (NF-κB) signaling, TLR4 pathway activation, transforming growth factor-beta–driven fibrogenesis, and disruption of fatty acid oxidation via pathways involving PPARA (peroxisome proliferator-activated receptor alpha) and PRKAA1 (AMP-activated protein kinase). Lipid droplet dynamics, ferroptosis, and dysregulation of the PI3K/AKT/mTOR pathway further contribute to disease progression. The condition exhibits marked racial and sex-specific heterogeneity in incidence, progression, and clinical outcomes, reflecting the interplay of genetic polymorphisms, epigenetic factors, and environmental exposures.
Focus of Latest Publications
Recent publications on metabolic dysfunction–associated steatotic liver disease (MASLD) have focused heavily on noninvasive detection, risk stratification, and real-world disease burden. One study examined the progression of metabolic dysfunction-associated steatohepatitis (MASH) to cirrhosis, decompensation, and mortality, with particular attention to the utility of non-invasive testing (NIT) for identifying MASH and estimating incidence rates and time to progression. In a population-based Greek adult cohort, MASLD prevalence was assessed using validated NITs, including the Liver Fat Score and the index of nonalcoholic steatohepatitis, and higher Mediterranean diet adherence was associated with lower odds of MASLD without steatohepatitis. Another survey study in people with type 2 diabetes highlighted marked racial and ethnic differences among those at risk of MASLD and related complications, underscoring the importance of social determinants of health in this population.
Several publications investigated clinical and biochemical markers linked to MASLD severity. In women with obesity-associated MASLD, the platelet-activating factor pathway was studied by evaluating hepatic expression of the platelet-activating factor receptor and circulating lipoprotein-associated phospholipase A2 across disease stages. Another study focused on fibroblast activation protein (Fap), a serine protease upregulated in chronic liver disease, to assess its involvement in MASLD and its downstream effects on circulating substrates such as fibroblast growth factor 21 and α2-antiplasmin. In children and adolescents with obesity, a parsimonious prediction model incorporating age, sex, BMI SDS, and waist circumference SDS showed robust performance for early identification of MASLD and outperformed HOMA-IR and adult-derived indices, while metabolic markers such as insulin, AST, ALT, and HOMA-IR increased with steatosis severity.
Intervention and mechanistic studies also featured prominently. Lactoferrin was tested in obese children and adolescents with MASLD in a randomized controlled study. Herbal and natural product investigations included Pueraria montana var. lobata root extract, which reduced lipid accumulation, inflammation, liver injury, and fibrosis in mice and was linked to increased mitochondrial β-oxidation and mitochondrial-peroxisome contact through direct activation of CPT1A signaling. The active components of the Danshen-Shanzha herb-pair were reported to protect against MASLD by synergistically promoting fatty acid oxidation via activation of PPARα, Plin-5, and Plin-2. Swertia mussotii was also studied in NAFLD models, where it reduced body weight, serum lipids, hepatic lipid accumulation, inflammation, and oxidative stress, while restoring dysregulated metabolic pathways and activating the SIRT1/AMPK axis, with downstream effects on ACC, SREBP-1c, FASN, and PPAR-γ.
Lifestyle and epidemiologic studies further reinforced the metabolic context of MASLD. In older adults in longevity regions of China, higher physical activity was inversely associated with NAFLD prevalence, although household-only or leisure-only activity was not significantly associated. A clinical dialogue podcast emphasized that obesity is strongly linked to MASLD and that the condition is often underdiagnosed because it is frequently asymptomatic. Across these publications, MASLD was consistently framed as a metabolically driven liver disease in which obesity, insulin resistance, oxidative stress, and related cardiometabolic factors shape risk, detection, and progression.