Experts reframe steatotic liver disease as a dynamic continuum
Researchers argue that steatotic liver disease should be viewed as an evolving trajectory rather than rigid categories, citing significant patient migration between subclasses.
Experts reframe steatotic liver disease as a dynamic continuum
The medical understanding of steatotic liver disease (SLD) is shifting from a set of rigid categories toward a model of evolving disease trajectories. In an article published in eGastroenterology, researchers from Charité - Universitätsmedizin Berlin argue that the three primary classifications—metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol-associated liver disease (MetALD), and alcohol-associated liver disease (ALD)—should be viewed as an interconnected continuum rather than isolated conditions.
Dr. Chen, Dr. Horn, and Prof. Tacke suggest that current diagnostic frameworks rely too heavily on snapshot assessments. Because metabolic status and alcohol intake fluctuate, patients frequently transition between these categories. Prospective cohort data cited by the authors reveals significant migration across SLD subclasses in only six months.
- Approximately 36% of people first classified as MetALD shifted to either MASLD or ALD.
- 32% of patients with ALD transitioned toward MetALD or MASLD.
- Around 11% of cases initially labeled as MASLD, the most stable subtype, underwent reclassification.
The biological basis for this fluidity lies in shared pathogenic pathways. Alcohol exposure and metabolic dysfunction both converge on inflammation, oxidative stress, lipotoxicity, and the progression of fibrosis. According to the authors, metabolic dysfunction can increase a patient's susceptibility to liver injury caused by alcohol, while alcohol consumption can worsen hypertension, hypertriglyceridemia, and obesity.
This reciprocal interaction creates the high-risk phenotype associated with MetALD.
The Challenge of Alcohol Assessment
Accurately identifying a patient's place on this continuum is complicated by the unreliability of self-reporting. The authors note that self-reported alcohol consumption may underestimate actual intake by up to 57.7%, which introduces uncertainty into risk assessment and subclassification.
To improve accuracy, the researchers highlight the use of objective biomarkers. Phosphatidylethanol (PEth), a blood-based marker, can reflect alcohol consumption from the preceding 1–3 weeks and is less affected by body mass index or sex than questionnaires. Other tools mentioned include EtG in hair and validated tests like AUDIT and AUDIT-C.
Expert review suggests specific PEth cut-off values for classification:
| Classification | PEth Level |
|---|---|
| MASLD | <20 ng/mL |
| MetALD | 20–200 ng/mL |
| ALD | >200 ng/mL |
Risk Stratification and Management
The proposed framework prioritizes non-invasive fibrosis assessment as a primary determinant of long-term outcomes. Clinicians use the fibrosis-4 (FIB-4) index and vibration-controlled transient elastography (VCTE) to categorize patient risk.
Low risk is defined as FIB-4 <1.3. Moderate risk is identified by a FIB-4 of 1.3–2.67 combined with VCTE <8 kPa. High risk is designated for those with FIB-4 >2.67, or a FIB-4 of 1.3–2.67 paired with VCTE ≥8 kPa. For individuals older than 65 years, the FIB-4 threshold for risk is >2.0.
Management strategies are based on these risk levels and combine metabolic optimization with alcohol abstinence or reduction. While early stages focus on these adjustments, advanced disease may necessitate liver transplantation, bariatric surgery, or pharmacotherapy. Left unchecked, disease progression can lead to hepatocellular carcinoma and cirrhosis.
Metabolic dysfunction within this framework includes arterial hypertension, dyslipidaemia (characterized by low high-density lipoprotein cholesterol and/or high triglycerides), obesity, and hyperglycaemia or type 2 diabetes.
Implications for Future Treatment
This shift toward longitudinal monitoring may change how clinical trials are designed. Because patients can shift between SLD subclasses, future trials may require repeated monitoring of metabolic status and alcohol exposure to ensure accurate interpretation of how patients respond to treatment.
Such precision may become critical as new therapies, such as thyroid hormone receptor-β agonists and GLP-1 receptor agonists, are introduced into clinical practice for steatotic liver disease.
