Recent guidelines on MASLD from the European Association of the Study of the liver came in 2024. For non liver experts, non alcoholic fatty disease nomenclature if no longer referred as NAFLD or NASH, but MASLD (metabolic dysfunction associated steatotic liver disease) and MASH (Metabolic associated- Steato Hepatitis)
MASLD in the general population has risen from 25% in 201612 to currently more than 30%, with a trend that seems to increase in the next following years unless we manage to slow down the obesity incidence as global pandemic.
What to know?
Definitions: The presence of excess fatty tissue in liver indicates Steatotic liver disease (SLD) This can be metabolic associated steatosis (MASLD) , alcohol related (ALD) dual etiology (MetALD) or other causes such as drug induced, genetic, viral , etc. If after thorough investigations no obvious metabolic risk factor is seen, then ‘possible MASLD’ is acceptable definition –requiring further tests of insulin-resistance– or cryptogenic SLD.
We know that classically liver has excess of fat when its parenchyma is seen as hyperecogenic on sonography (when fat exceeds 20% of total), or in liver biopsy when presence of > 5% steatotic hepatocytes in a liver tissue section.
Note that the presence of fat per se does not associate liver-related outcomes, however one fith progresses to steatohepatitis (MASH) which can ultimately lead to liver cirrhosis in a further fifth of MASH patients and therefore higher risk of liver failure and hepatocellular carcinoma (HCC)
In this guidelines they highlight the importance of clear alcohol history, as if patient drinks
- More than 50-60g a day (about 4 cans or 3.5 pints of beer or 2 200ml glasses of wine or 4 shots of liquor)= alcohol related etiology
- More than 20-30g a day ( 500ml beer a day, around 1 big can or standard bottle) one 200ml glass of wine= could be dual etiology – they stablish the interface of MASLD and Alcohol-related liver disease as a dual etiology condition named MetALD
- Less than this : No alcohol related. (However, any alcohol would be discouraged as it acts as a synergistic in liver injury, and no studies have shown a ´safe´ amonunt)
The cardiometabolic risk factors in the definition of MASLD are the following:
| Metabolic risk factor | Adult criteria |
|---|---|
| Overweight or Obesity | Body mass index ≥25 kg/m2 (≥23 kg/m2 in people of Asian ethnicity) |
| Waist circumference•≥94 cm in men and ≥80 cm in women (Europeans)•≥90 cm in men and ≥80 cm in women (South Asians and Chinese)•≥85 cm in men and ≥90 cm in women (Japanese) | |
| Dysglycaemia or type 2 diabetes | Prediabetes: HbA1c 39-47 mmol/mol (5.7-6.4%) or fasting plasma glucose 5.6-6.9 mmol/L (100-125 mg/dl) or 2-h plasma glucose during OGTT 7.8-11 mmol/L (140-199 mg/dl) or Type 2 diabetes: HbA1c ≥48 mmol/mol (≥6.5%) or fasting plasma glucose ≥7.0 mmol/L (≥126 mg/dl) or 2-h plasma glucose during OGTT ≥11.1 mmol/L (≥200 mg/dl) or Treatment for type 2 diabetes |
| Plasma triglycerides | ≥1.7 mmol/L (≥150 mg/dl) or lipid-lowering treatment |
| HDL-cholesterol | ≤1.0 mmol/L (≤39 mg/dl) in men and ≤1.3 mmol/L (≤50 mg/dl) in women or lipid-lowering treatment |
| Blood pressure | ≥130/85 mmHg or treatment for hypertension |
HbA1c, glycated haemoglobin; HDL, high-density lipoprotein; OGTT, oral glucose tolerance test.
In terms of screening, they recommmend to screen any T2DM or obesity+Metabolic risk factors. Obviously those with abnormal liver blood test, should also have some degree of screening with FIB-4 or NAFLD score
Once we diagnose MASLD, it is fundamental to build a multidisciplinar approach to diagnose all the other potential metabolic comorbidities. Remember than many MALSD patients will die not of cirrhosis, but of cardiovascular complications.
Also, based on their close link, comorbiidities such as Obesity, HTN, T2-DM, dyslipidaemia, Atherosclerosis Obstructive sleep apnoea , Hypothyroidism or PCOS have a higher prevalence in MASLD and they can be independent factors linked to progression of the hepatopathy. This guidelines recommend to screen for all these pathologies, both at initial diagnosis and at regular follow up intervals.
If no clear diagnosis of T2DM, consider HOMA-IR or oral glucose tolerance test, as some of the DIabetes or prediabetic conditions may be incipient or underdiagnosed.
Also, those patients with comorbidities should be screened for extrahepatic cancer when approppriate (Cardiovascular factors, such as obesity or diabetes are in themselves independent risks for many cancers)
Fibrosis screening
To assess the risk of fibrosis in MASLD individuals , initial screening should be done with non invasive tools such as FIB 4, NAFLD scores, and keep repeting scores every 1-3 years. If ever some of the scores are indetermintate, another test should be made to rule out or in significant fibrosis (Transient elastrography, US-elastography, or another blood biomarker such as ELF)
blood biomarkers and elastography should be used to exclude advanced fibrosis, while elastogaphy is better suited to predict advanced fibrosis
Non-invasive tests have been linked with histologically assessed treatment response, but the most appropriate non-invasive test may depend on the type of intervention and patient-related factors. In general, they recommend
Treatment
Weight loss and behavioural therapy are the cornerstone of the treatment for MASLD: depending on the percetnage of total body weight loss, > −5% to reduce liver fat, 7-10 % to improve liver inflammation, and >10 % to improve fibrosis
Pharmacological treatment
GLP1RAs are safe to use in MASH (including compensated cirrhosis) and should be used for their respective indications, namely type 2 diabetes and obesity, as their use improves cardiometabolic outcomes. Resmetiron, on the oher hand, can be used in F2(>8kpa) or F3 (>10Kpa) But not cirrhosis (>15kpa)