AKT · Gastroenterology/Liver

Metabolic dysfunction-associated steatotic liver disease (MASLD)

Hepatic steatosis associated with metabolic dysfunction (formerly NAFLD)

Overview

Fat accumulation in the liver associated with metabolic dysfunction (obesity, type 2 diabetes, dyslipidaemia, metabolic syndrome) — formerly NAFLD. A spectrum from simple steatosis to steatohepatitis (MASH/NASH — inflammation) to fibrosis/cirrhosis. Usually asymptomatic with incidental fatty liver/mildly raised ALT. The key task is risk-stratifying fibrosis (the prognostic driver) and managing metabolic risk; now the commonest chronic liver disease.

Recognise

Asymptomatic; incidental fatty liver on ultrasound or mildly raised ALT; metabolic syndrome features (central obesity, T2DM, dyslipidaemia, hypertension)
Most have simple steatosis; a minority progress to steatohepatitis → fibrosis → cirrhosis/HCC
Cardiovascular disease is the leading cause of death

Red flags

Advanced fibrosis/cirrhosis (the prognostic driver) → HCC/varices surveillance
Exclude other/contributing liver disease (alcohol, viral, autoimmune)

Differentials & how to tell them apart

Alcohol-related liver diseasealcohol history, AST:ALT >2 — MASLD is metabolic with ALT often > AST

Viral/autoimmune hepatitisserology/autoantibodies

Drug-induced steatosisamiodarone, methotrexate, steroids

Investigations

USS (steatosis); exclude other causes (alcohol history, viral serology, autoantibodies, ferritin). Fibrosis risk: FIB-4/NAFLD fibrosis score → ELF test/fibroscan (transient elastography); manage cardiometabolic risk (HbA1c, lipids, BP).

Management

Weight loss + cardiometabolic risk management; fibrosis risk-stratification

1Confirm steatosis and exclude other liver disease. RISK-STRATIFY FIBROSIS (FIB-4 → ELF/fibroscan) — fibrosis stage drives prognosis. Weight loss and aggressive cardiometabolic risk management.Gate: It is the FIBROSIS stage (not the fat itself) that determines outcome — risk-stratify and refer advanced fibrosis; and cardiovascular disease, not the liver, is the commonest cause of death, so manage cardiometabolic risk hard
2Advanced fibrosis → hepatology, HCC/varices surveillance; pharmacotherapy for MASH (e.g. resmetirom), bariatric options; optimise diabetes/lipids.

Weight loss + treat metabolic risk factors — the foundation — diet/exercise (≥7–10% weight loss improves histology); manage diabetes/lipids/BP

SGLT2 inhibitor/GLP-1/pioglitazone; resmetirom — diabetes drugs with hepatic benefit; specialist pharmacotherapy for MASH

Key points

Fatty liver + metabolic syndrome (and ALT often > AST) = MASLD. Fibrosis stage is what matters — FIB-4/fibroscan to risk-stratify. Weight loss is the treatment; cardiovascular disease is the main killer. (Alcohol gives AST:ALT >2 instead.)

Monitor & prognosis

Fibrosis (FIB-4/fibroscan); cardiometabolic risk.

Mostly benign; advanced fibrosis drives liver outcomes.

Source: NICE NG49; EASL/AASLD