Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the term for a build-up of fat in the liver, in the absence of excessive alcohol consumption. It is usually seen in people who are overweight or obese.

A healthy liver should contain little or no fat. It's estimated that up to 1 in every 3 people in the UK has early stages of NAFLD with evidence of varying amounts of fat in their liver.

Early-stage NAFLD doesn't usually cause any harm, but the variant of non-alcoholic steatohepatitis (NASH) can lead to serious liver damage, including cirrhosis, if it gets worse.

Having high levels of fat in the liver is also associated with an increased risk of problems associated with metabolic syndrome such as type 2 diabetes, heart attacks, and strokes.

If detected and managed at an early stage, it's possible to stop NAFLD getting worse and reduce the amount of fat, inflammation and scarring in the liver.

Scope

This guideline covers how to identify the adults, young people and children with non-alcoholic fatty liver disease (NAFLD), and identify those at increased risk of NASH who have advanced liver fibrosis and are most at risk of further complications. It outlines the lifestyle changes and pharmacological treatments that can manage NAFLD and advanced liver fibrosis.

Out of Scope

NAFLD may co-exist with other causes of abnormal liver function tests such as viral or auto immune hepatitis, which should be excluded, particularly if alanine aminotransferase (ALT) is more than 60.

For investigation and exclusion of other causes of abnormal liver function tests (LFTs) see Assessment of Abnormal Liver Function Tests Clinical Referral Guideline before performing non-invasive fibrosis staging tests including Fib4 and Fibroscan.

Assessment

Diagnosis

NAFLD is suspected by one or more of the following:

  • steatosis on ultrasound scan (USS)
  • +/- raised ALT
  • +/- metabolic risk factors:
    • obesity
    • type 2 diabetes
    • hypertension
    • high lipids

NAFLD diagnosis requires exclusion of excess alcohol consumption for over 3 months (i.e. under 14 units per week for women; under 21 units for men)

And / Or

  • Imaging evidence of an ultrasound bright fatty liver, and / or abnormal liver function tests.

Differential Diagnosis

  • Alcohol related steatohepatitis
  • Drug induced liver injury

Red Flags

  • Jaundice
  • Signs of liver failure (ascites, encephalopathy)
  • ALT more than 5x ULN

Investigations

Imaging evidence of an ultrasound showing bright fatty liver, and / or abnormal liver function tests.

Management

Once the diagnosis of suspected NAFLD is confirmed, the risk of having NASH with significant fibrosis / cirrhosis can be assessed non-invasively using this algorithm



Score
Age <40 0

≥40

1
Type 2 diabetes?
No
0

Yes – good control (HbA1c48-75 mmol/mol] 1
Yes – poor control HbA1c>76 mmol/mol] 2


BMI kg / M2
<29.9 0
≥30 1
FIB-4 score*

<1.3

(*<2.0 for those aged ≥65)
0
1.3 – 2.67 2
≥2.67 3

*Fibrosis-4 (FIB-4) Index for Liver Fibrosis

Please also see this flowchart which shows the complete NAFLD pathway

NAFLD risk assessment score 0-2 = low
  • Intervention: Stay in primary care
  • Lifestyle advice: Weight loss, diet and exercise
  • Provide patient information sheet
  • Reassess and repeat NAFLD risk assessment score in 3 years
NAFLD risk assessment score 3 and over or 2 and over if aged over 40 = intermediate or high risk
  • Refer to hepatology via DRSS
  • Straight to test fibroscan via hepatology

Fibroscan is performed by a Fibroscan Technician as second tier of non-invasive risk stratification:

  • A Fibroscan Patient information sheet will be provided with the booking
  • The Fibroscan Technician will inform the patient of the result at the time of the scan, however the Fibroscan technician is not a clinician with professional registration with a regulatory body, and therefore unable to give clinical onward advice. Interpretation of the Fibroscan result along with further recommendations and tests must be undertaken by the referring clinician.

Following fibroscan:

If Fibroscan KPa less than or equal to 7.8 KPa = low risk of advanced fibrosis

  • Intervention: Refer back to primary care
  • Lifestyle advice: Weight loss, diet and exercise
  • Provide patient information sheet
  • Optimise treatment of metabolic syndrome:
    • Diabetes control
    • Blood pressure
    • Lipid profile
  • GP to re-assess NAFLD risk assessment score in 3 years

If KPa 7.9 – 9.6 = Intermediate risk of advanced fibrosis

  • Intervention: Hepatology to arrange follow up fibroscan for 1 year (no primary care intervention required)
  • Lifestyle advice: Weight loss, diet and exercise
  • Provide patient information sheet
  • Letter to GP to advise of result. GP to optimise treatment of metabolic syndrome:
    • Diabetes control
    • Blood pressure
    • Lipid profile
  • Repeat fibroscan arranged by hepatology in 1 year

If KPa over 9.6

or

more than or equal to 7.9 with increased fibroscan score from test carried out previous year or earlier = High risk of advanced fibrosis

  • Intervention: to be seen in specialist Hepatology outpatients for further assessment of the liver disease, consideration of liver biopsy, treatment, screening of portal hypertension and hepatocellular carcinoma (HCC) surveillance.
  • Lifestyle advice: Weight loss, diet and exercise
  • Provide patient information sheet
  • Optimise treatment of metabolic syndrome:
    • Diabetes control
    • Blood pressure
    • Lipid profile

Referral

Referral Criteria

NAFLD diagnosis requires:
  • Exclusion of excess alcohol consumption for over 3 months (i.e. under 14 units per week women; under 21 units men)
  • NAFLD may be suspected because of metabolic risk factors:
    • obesity
    • type 2 diabetes
    • hypertension
    • high lipids
  • Imaging evidence of an echo with bright fatty liver, and / or abnormal liver function tests
  • Exclusion of other causes of abnormal LFTs if ALT more than or equal to 60
Low risk patients (calculated risk score 0-2) do not require a referral
  • Intervention: Stay in primary care, patient does not need to be referred
  • Lifestyle advice: Weight loss, diet and exercise
  • Provide patient information sheet
  • Re-assess NAFLD risk score in 3 years
Intermediate or high risk patients (calculated risk score of 3 and over, or 2 and over if aged over 40) require a direct to test Fibroscan for further assessment.
  • Refer to Hepatology via DRSS for straight to test fibroscan

Referral to include:

Referral Instructions

e-Referral Service Selection

  • Specialty: GI & Liver
  • Clinic Type: Hepatology
  • Service: DRSS-Western-Hepatology-CCG-99p

Referral Forms

DRSS referral form

​Supporting Information

 

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