Fatty liver disease (MASLD)

What is MASLD, and why was the name changed?

In 2023 a multi-society Delphi consensus renamed non-alcoholic fatty liver disease (NAFLD) as MASLD — metabolic dysfunction-associated steatotic liver disease.^[1] The change was not cosmetic. The old name defined the condition by what it was not, which was both stigmatising and diagnostically unhelpful. The new name requires the presence of at least one cardiometabolic criterion — raised BMI or waist circumference, raised glucose or established diabetes, raised blood pressure, raised triglycerides, or low HDL — so it identifies the condition by its actual driver.

How is fatty liver diagnosed and staged?

Ultrasound detects the fat readily and grades it, conventionally from I to III by how bright the liver appears against the kidney and how well the deep structures and vessel walls can be seen. But grade of fat is a poor guide to prognosis. The question that actually matters is whether scarring has begun, and that is answered without a biopsy in most patients.

The FIB-4 score is calculated from age, AST, ALT and platelet count — four values usually already available — and stratifies patients into low, indeterminate and high risk of advanced fibrosis. A FIB-4 below 1.3 in a patient under 65 has a high negative predictive value and effectively rules out advanced fibrosis, which means most patients need nothing further. Those above the threshold go on to transient elastography (FibroScan), which measures liver stiffness in kilopascals. Liver biopsy is now reserved for cases where non-invasive tests are discordant, where another diagnosis is possible, or where a specific answer will change management.

How is fatty liver treated?

There is no substitute for treating the cause, and the cause is metabolic. Gradual, sustained weight loss remains the most powerful available therapy, and the relationship is dose-dependent: around 5% of body weight clears hepatic fat, 7 to 10% reduces inflammation and can improve early fibrosis, and above 10% the histological benefit is greater still. Alongside this, tight control of diabetes, blood pressure and lipids protects the liver, and alcohol should be avoided because it compounds the injury.

Where obesity or type 2 diabetes coexists, GLP-1 receptor agonist therapy addresses both the weight and the liver fat, and this overlap is one reason the weight programme and the liver clinic at Uttarbanga Clinic run together. Liver-specific drugs have begun to reach the market for biopsy-confirmed MASH with significant fibrosis and are used selectively under specialist supervision. Vitamin E has a limited evidence base in specific non-diabetic patients and is not a general treatment.

Does fatty liver need lifelong monitoring?

It needs periodic reassessment rather than continuous surveillance. For a patient with a low FIB-4 and no diabetes, repeating the risk assessment every two to three years is reasonable while the metabolic causes are managed. Where there is type 2 diabetes, where FIB-4 is indeterminate or high, or where elastography shows meaningful stiffness, review is more frequent and referral to hepatology may be appropriate. Patients who have reached cirrhosis need six-monthly ultrasound surveillance for liver cancer, which is a different and more intensive pathway.