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.
Diagnosis based on evidence of fatty liver infiltration on USS/histology, plus 1 of:
- obesity eg high waist circumference, BMI Z score >1 (85th centile)
- high blood pressure,
- insulin resistance eg high fasting blood sugar, abnormal OGTT, high HbA1c (>39)
- high triglycerides or low LDL
Some drugs can cause, including methotrexate, steroids, valproate, anti-psychotics.
On examination, look for acanthosis nigricans (marker of insulin resistance) as well as signs of chronic liver disease. Hepatomegaly suggests an alternative diagnosis.
Red flags (alternative diagnosis):
- Age <= 8yrs
- Developmental delay
- Neurological signs or deteriorating school performance
- Low albumin or prolonged prothrombin time
- Splenomegaly
- Jaundice
- ALT/AST>150
- Panhypopit
Investigations
Essentially to assess co-morbidity and exclude other causes:
- Fasting serum glucose, HbA1c
- Assessment of liver function and screening for other causes of raised transaminases/ steatosis as for viral or autoimmune hepatitis.
Non-invasive measures of fibrosis eg transient elastography (Fibroscan) not shown to be useful for children.
Management
Lifestyle, primarily.
“Inform families that children with MASLD are at risk of progressive liver disease and liver cancer.
Counsel that children with MASLD are also at risk of hypertension, cardiovascular disease, type 2 diabetes and chronic kidney disease.”
GLP-1 antagonists?
Patient information leaflets and guidance are available at the Children’s Liver Disease Foundation https://www.childliverdisease.org
[LSG UK 2025 guideline]