Lean MASLD (fatty liver disease in normal-weight people) has distinct mechanisms from obesity-related MASLD, with animal models showing GLP-1 analogues like exendin-4 and liraglutide as promising therapeutic candidates.
Lean ≠ obesity MASLDDistinct mechanisms (bile acid dysregulation, leptin signaling, oxidative stress) drive liver disease in lean patients, requiring tailored therapies
What the researchers found
Lean MASLD is mechanistically distinct from obesity-related MASLD, driven by bile acid dysregulation, leptin signaling abnormalities, and oxidative stress. Animal models testing GLP-1 analogues (exendin-4, liraglutide), kinsenoside, silibinin, and bile acid modulators show therapeutic promise for this patient population.
Why it matters
Lean MASLD is often underdiagnosed because patients lack the obesity typically associated with fatty liver disease. Understanding its unique mechanisms through appropriate animal models is essential for developing targeted therapies, including peptide-based treatments, for this overlooked patient population.
The numbers in context
Literature search: PubMed and Scopus, January 2000 to June 2025. Models reviewed include MCD diet, choline-deficient diet, cholesterol/bile acid diets, Pemt-/- and cGas-/- genetic models. Candidate therapies include exendin-4 (GLP-1 analog).
How the study worked
Systematic literature review of PubMed and Scopus (January 2000-June 2025) covering dietary, genetic, and bile acid-focused animal models of lean MASLD.
Who was studied
Animal models of lean MASLD
What this study cannot tell us
Animal models cannot fully replicate human lean MASLD. Most therapeutic candidates are at preclinical stages. The review acknowledges that no single animal model captures all features of human lean MASLD.
How to read the evidence
Comprehensive literature review of preclinical models. Provides strong mechanistic insights but all therapeutic evidence is from animal studies without clinical validation in lean MASLD patients.
When this study was published
Published in 2025; covers literature through June 2025, representing the most current preclinical evidence.
The bigger picture
This review highlights that not all fatty liver disease is the same—lean patients have distinct biological drivers that require tailored treatments. GLP-1 peptide analogues, already proven in obesity and diabetes, may have a specific role in lean MASLD through mechanisms beyond weight loss, potentially including direct liver-protective effects.
Questions still open
- Can GLP-1 analogues treat lean MASLD through mechanisms independent of weight loss?
- Which animal model best predicts therapeutic response in human lean MASLD?
- Should lean MASLD patients be specifically included in clinical trials for peptide-based liver therapeutics?
Common questions
What is lean MASLD?
Could GLP-1 drugs help lean people with fatty liver disease?
Read the original research
Animal models of lean metabolic dysfunction-associated steatotic liver disease (MASLD): bridging pathogenesis and novel drug discovery.
Expert opinion on drug discovery, 20(12), 1683-1700
Citation
Papadakos, Stavros P; Georgiadou, Chara; Kassi, Eva; Velliou, Rallia-Iliana; Chatzigeorgiou, Antonios. (2025). Animal models of lean metabolic dysfunction-associated steatotic liver disease (MASLD): bridging pathogenesis and novel drug discovery.. Expert opinion on drug discovery, 20(12), 1683-1700. https://doi.org/10.1080/17460441.2025.2579124