Fatty liver/MASLD

Gastro, General paediatrics

Not v uncommon in obese children/adults, which is logical. But non-alcoholic fatty liver disease (97% of which is Metabolic dysfunction associated steatotic liver disease (MASLD)) may progress to steatofibrosis, non-alcoholic steatohepatitis (NASH), cirrhosis, liver failure and hepatocellular carcinoma. It is now the most common cause of liver disease in adolescents and amongst the top three indications for liver transplantation in adults.

Data from 2020 in US found prevalence of 20% for obesity and MASLD among 12-17yr olds, with about 70% of obese adolescents affected by MASLD. More common in boys, particularly among Mexican American adolescents. Adolescents with MASLD had significantly higher triglyceride levels and alanine transaminase (ALT) levels, along with lower high-density lipoprotein (HDL) cholesterol. Insufficient physical activity and poor diet quality were key risk factors, not surprisingly. 

And not all cases are obese.

Alcoholic fatty liver disease is a different thing – depends on type of beverage, genetic risk factors, drinking pattern, duration of exposure etc so unpredictable. 

Particularly likely to progress when co-exists with metabolic syndrome (obesity esp high waist circumference, high blood pressure, high insulin resistance, high lipids).  Some polymorphisms also contribute higher risk of progressive disease.  So family history important too.

Some drugs can contribute, including methotrexate, steroids, valproate.

On examination, look for acanthosis nigricans (marker of insulin resistance) as well as signs of chronic liver disease. Hepatomegaly suggests an alternative diagnosis.

Investigations

Essentially to assess co-morbidity and exclude other causes:

  • Fasting serum glucose/ insulin.
  • HOMA-IR (fasting glucose x fasting insulin/ 22.5)
  • HbA1c measurement
  • Renal function tests
  • Vitamin D level
  • Assessment of liver function and screening for other causes of raised transaminases/ steatosis
    • First Line Investigations: ALT, AST, ALP, GGT, Split bilirubin, FBC, Coagulation screen, Albumin, Fasting lipid profile, Immunogloblins and complement levels, Autoimmune profile including ANCA, Anti-transglutaminase antibodies, Thyroid function tests, A1AT level and phenotype, Copper and caeruloplasmin, Plasma free fatty acids, amino acids, organic acids, uric acid, acylcarnitines, and lactate, Hepatitis A, B, C and E serology
    • Second line investigations: If raised triglyceride level consider Lysosomal acid lipase, 24-hour urine copper collection, ophthalmic examination and/ or genetic testing for Wilson’s disease. If organomegaly/ raised uric acid/ raised lactate or a history of hypoglycaemia consider genetic testing for glycogen storage disease

So pretty much as for viral or autoimmune hepatitis.

Non-invasive measures of fibrosis available in some centres.

Reasons to refer to liver unit

  • Age < 10yr
  • Evidence of alternative cause for steatosis detected through screening investigations
  • Presence of metabolic syndrome, type 2 diabetes mellitus, and/ or hyperlipidaemia
  • Increased AST/ALT ratio (>1) and/or a raised AST/ ALT (≥80IU/L)
  • Raised serum level of GGT
  • Child has panhypopituitarism
  • Raised non-invasive marker of fibrosis measurement
  • Presence of hepatomegaly/splenomegaly
  • Thrombocytopenia
  • Jaundice
  • Synthetic dysfunction (raised PT or low albumin level)

  [Caroline says only if double normal)

Patient information leaflets and guidance for NAFLD are available via the Children’s Liver Disease Foundation at https://www.childliverdisease.org

[BSPGHAN 2020 guideline]