CPD: Key questions on metabolic dysfunction-associated steatotic liver disease (MASLD)
Hepatologists Dr Ahmed Elsharkawy and Dr Laurence Hopkins discuss changes to the name, diagnosis and management of the condition MASLD, formerly known as non-alcoholic fatty liver disease (NAFLD). Read the full module on Pulse 365 today.
Learning objectives
This module will support your knowledge of MASLD diagnosis and management, in particular:
- Recent changes to the name and definition of the condition.
- How these changes affect diagnosis, prognosis and management.
- Identification of patients at highest risk of liver disease.
- Interpretation of FIB-4 scores and when to refer to specialist services.
- Use and interpretation of fibroscan testing.
1. What does MASLD mean and why has this replaced the previous name of NAFLD?
MASLD stands for metabolic dysfunction-associated steatotic liver disease. MASLD was previously called non-alcoholic fatty liver disease (NAFLD). It is part of a broader group of conditions termed steatotic liver disease (SLD). SLD includes alcohol-related liver disease and other causes of steatosis such as genetic conditions and drug-induced liver injury.
All major international liver associations, notably the American Association for the Study of Liver Disease (AASLD), the European Association for the Study of the Liver (EASL) and the Asian Pacific Association for the Study of the Liver (APASL), along with patient advocacy groups, recently agreed on the name change, which puts more emphasis on metabolic dysfunction as the underlying driver of the disease and replaces the negative definition (non-alcoholic). The change addressed patient concerns about ‘alcoholic’ and ‘fatty’, words patients may see as stigmatising.1
2. How is the diagnosis of MASLD made?
MASLD represents a spectrum of disease from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH) to cirrhosis and its associated complications including hepatocellular carcinoma (HCC). MASLD is an asymptomatic disease until end-stage disease where patients may present with complications of cirrhosis such as jaundice, ascites, encephalopathy or bleeding. Accordingly, many patients with MASLD remain undiagnosed.
MASLD should be suspected in patients with cardiometabolic risk factors (Table 1) and mildly elevated serum ALT or AST levels. Patients suspected to have MASLD should undergo a full non-invasive liver screen and liver ultrasound to exclude other liver diseases. The presence of steatosis on ultrasound in patients with type 2 diabetes alone, or obesity and a cardiometabolic risk factor, in the absence of other liver diseases (particularly alcohol-related liver disease), is sufficient to diagnose MASLD. An incidental finding of steatosis on liver ultrasound should prompt a thorough alcohol history and a non-invasive liver screen, with MASLD diagnosed where other causes of steatosis have been excluded. It is important to note that patients with MASLD can have normal serum ALT and AST levels.
Cardiometabolic risk factor Definition in terms of MASLD risk Body weight Body mass index (BMI) >25kg/m2 (≥23kg/m2 in people of Asian ethnicity) Waist circumference ≥94cm in men and ≥80cm in women (Europeans) ≥90cm in men and ≥80cm in women (South Asians and Chinese) ≥85cm in men and ≥90cm in women (Japanese) Pre-diabetes HbA1c 39-47mmol/mol Type 2 diabetes HbA1c ≥48mmol/mol Hypertriglyceridaemia Plasma triglycerides ≥1.7mmol/L or statin use Dyslipidaemia HDL ≤1.0mmol/L in men and ≤1.3mmol/L in women or statin use Hypertension ≥130/85mmHg or antihypertensive use
Table 1: Cardiometabolic risk factors for MASLD.1,2 (Note the threshold for pre-diabetes differs from that in NICE guidance.)
Once patients are diagnosed with MASLD, the likelihood of significant fibrosis can be assessed using non-invasive scores such as the FIB-4 score or NAFLD fibrosis score (NFS). The FIB-4 score is easy to perform in general practice and is widely validated for estimating fibrosis risk across many liver aetiologies. The NFS is a slightly more complex score which can be used to more accurately determine the risk of fibrosis specifically in patients with MASLD. Fibroscan can be used to further stratify patients’ risk and is useful in predicting the degree of fibrosis in patients with MASLD and other liver diseases. Liver biopsy remains the gold standard method of determining fibrosis stage; however, it is increasingly reserved for cases with diagnostic uncertainty, given the widespread availability of fibroscan.
3. Does the name change imply a change in management or clinical emphasis?
NICE guidelines were last updated in 2016 and use the term NAFLD. The EASL, European Association for the Study of Diabetes (EASD) and European Association for the Study of Obesity (EASO) jointly published a specific guideline for MASLD in 2024.2 The change to MASLD emphasises a more holistic approach, which aims to address cardiometabolic risk factors including diabetes, obesity, hypertension and dyslipidaemia, as well as accumulation of fat in the liver.
4. What is the prevalence and epidemiology of MASLD?
The prevalence of MASLD is increasing and estimated to be 30% worldwide and 25% in Western Europe.3 A high prevalence of MASLD has been reported in adolescents and children in the UK.4 The true prevalence in the UK and globally is unknown as many patients are undiagnosed. The British Liver Trust quotes The UK prevalence of MASLD as 20%.
The prevalence of MASLD increases with age and BMI. It is more common in men than women, although the gender gap is reportedly decreasing. Patients from lower socioeconomic groups have a higher prevalence of MASLD. The accumulation of cardiometabolic risk factors, particularly type 2 diabetes and obesity, is linked to an increasing risk of MASLD. Patients from all ethnic backgrounds develop MASLD, but populations which experience metabolic dysfunction at comparatively lower BMIs (eg, those from South Eastern Asia) have disproportionately higher rates.
Click here to complete the full module on Pulse 365 and log 2 CPD hours towards revalidation
Dr Ahmed Elsharkawy is consultant hepatologist and Dr Laurence Hopkins is clinical fellow in hepatology at University Hospitals Birmingham NHS Foundation Trust
References
- Rinella M et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. J Hepatology 2023;79:1542-1556
- Tacke F et al. EASL–EASD–EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD). J Hepatology 2024;81:492-542
- Younossi Z et al. The global epidemiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH): a systematic review. Hepatology 2023;77(4):1335-1347
- Abeysekera K et al. Prevalence of steatosis and fibrosis in young adults in the UK: a population-based study. Lancet Gastroenterol Hepatol 2020;5(3):295-305
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