Metabolic-Associated Steatohepatitis (MASH) Diagnosis and Management

Disease Definition and Spectrum

Metabolic-associated steatohepatitis (MASH) is a progressive inflammatory liver disease characterized by fat accumulation, hepatocyte injury, inflammation, and fibrosis that occurs in patients with cardiometabolic risk factors and can lead to cirrhosis, hepatocellular carcinoma, and liver-related death, as defined by the Journal of Hepatology 1
The disease spectrum progresses from simple steatosis to MASH, characterized by fat accumulation plus hepatocyte injury, inflammation, and ballooning, and eventually to fibrosis and cirrhosis, according to the Journal of Hepatology 1, 2
MASH represents the severe, progressive form within the broader spectrum of metabolic dysfunction-associated steatotic liver disease (MASLD), which was previously termed non-alcoholic fatty liver disease (NAFLD), as stated in the Journal of Hepatology 1

MASLD (and therefore MASH) is defined by the presence of hepatic steatosis plus at least one cardiometabolic risk factor, including type 2 diabetes or prediabetes, as defined by Metabolism: Clinical and Experimental 3
Critical exclusion criteria include alcohol consumption >20 g/day in women or >30 g/day in men, and absence of other causes of liver disease, as stated in the Journal of Hepatology 1

The most important prognostic factor is the degree of liver fibrosis, not the presence of inflammation alone, according to the Journal of Hepatology 1
Advanced fibrosis (stage ≥2) predicts liver-related outcomes including cirrhosis, hepatic decompensation, and hepatocellular carcinoma, as stated in the Journal of Hepatology 1, 4
The American Association for the Study of Liver Diseases recommends managing MASH as part of the broader cardiometabolic syndrome, not as an isolated liver condition, as stated in Metabolism: Clinical and Experimental 3, 5

Case-finding should be performed in all patients with a risk profile (obesity, type 2 diabetes, dyslipidemia, hypertension) using non-invasive tests rather than routine liver biopsy, as recommended by the Journal of Hepatology 1, 4
The recommended stepwise approach includes calculating the FIB-4 score and performing transient elastography for intermediate or high-risk scores, as stated in the Journal of Hepatology 1, 4