MASLD (metabolic dysfunction-associated steatotic liver disease)

MASLD (metabolic dysfunction-associated steatotic liver disease) is the 2023 reclassification of what was previously called non-alcoholic fatty liver disease (NAFLD), agreed by major hepatology societies including EASL, AASLD, and ALEH. The new nomenclature shifts from exclusion-based (excluding alcohol) to inclusion-based criteria: steatosis on imaging or biopsy must co-occur with at least one of five cardiometabolic risk factors (overweight/obesity, prediabetes or T2D, elevated blood pressure, elevated triglycerides, or low HDL), reflecting the metabolic substrate of the disease. Patients who drink above defined alcohol thresholds but also meet cardiometabolic criteria are classified as MetALD. The histological spectrum progresses from simple steatosis through metabolic dysfunction-associated steatohepatitis (MASH, formerly NASH) to fibrosis, cirrhosis, and hepatocellular carcinoma. MASLD affects an estimated 25–32% of adults globally and is a leading cause of liver-transplant waitlisting in the United States and several other high-income countries.