Non alcoholic fatty liver disease

Metabolic dysfunction Associated Steatotic Liver Disease (MASLD) formally known as Non-alcoholic fatty liver disease (NAFLD) is the commonest chronic liver disorder in the UK and is increasing in prevalence. MASLD refers to the liver disorder associated with the metabolic syndrome and comprises simple fatty liver (steatosis), metabolic dysfunction associated steatohepatitis (MASH) and MASLD cirrhosis. This disorder is very similar to alcoholic liver disease in its pathology and natural history.

It is usually identified in patients with mildly abnormal LFTs or an ultrasound suggestive of a fatty liver. The commonest LFT abnormalities are modestly elevated ALT and GGT, although some patients will have normal LFTs and in those with cirrhosis sometimes only the GGT is elevated. An ultrasound examination is usually reported as showing a bright or fatty liver. In those with cirrhosis a heterogeneous or coarse echotexture, a nodular outline or splenomegaly may be found, but patients with cirrhosis may have a normal ultrasound.

Most patients will have a BMI over 30 and/or type 2 diabetes mellitus but this is not invariable. A liver screen will be negative and alcohol intake within recommended limits. The combination of alcoholic liver disease and MASLD is common and it is sometime difficult to assign the major component.

Who to refer, who not to refer, how to refer

These guidelines should be used in conjunction with the RefHelp guidelines on the management of asymptomatic abnormal LFTs. Not all patients with NAFLD require to be referred and most can be managed in primary care with lifestyle advice.

The reasons to refer to secondary care are:

Diagnostic uncertainty (remember overweight or diabetic patients can develop other liver diseases)
Suspected more advanced disease than simple steatosis, as indicated by the presence of hepatic fibrosis which can be calculated using non invasive scoring. Fib 4 is a recognised scoring system. Fib4 score >1.3 in those under 65 or >2.0 if aged over 65 indicates suspected advanced fibrosis.

Who to refer:

Patients with MASLD and suspected advanced hepatic fibrosis or diagnostic uncertainty.
Patients referred to hepatology may be allocated a clinic appointment or may have further fibrosis assessment arranged

Who not to refer:

Patients with MASLD without hepatic fibrosis
Patients with MASLD without significant fibrosis will be managed in primary care.

The role of Fibroscan, other imaging such as ARFI, hyaluronic acid, other serum biomarkers such as ELF, the AST:ALT ratio and other indirect ratios such as Fibrosis 4 score and MASLD fibrosis score are being actively evaluated.

Primary care management

Most patients with MASLD will have simple steatosis and can be managed in the community with lifestyle advice about exercise, diet and weight reduction, along with active management of diabetes, hypertension and hyperlipidaemia Metformin is the oral hypoglycaemic agent of choice, ACE inhibitors or ARBs are the preferred antihypertensive agents for their antifibrotic properties, and statins can be safely used on MASLD.

The MASLD should be re-staged, but at what interval and by what method is unclear; at present, we advise repeating LFTs and FBC every 2-3 years, and consider referring patients developing hepatic fibrosis as indicated by Fib4 score >1.3 in those under 65 or >2.0 if aged over 65.

Resources and links

Patient Website – https://patient.info/health/non-alcoholic-fatty-liver-disease
British Liver Trust – https://www.britishlivertrust.org.uk/liver-information/liver-conditions/non-alcohol-related-fatty-liver-disease/
NHS Choices –Non-alcoholic fatty liver disease (NAFLD) - NHS (www.nhs.uk)

Local service contact details

bor.gastroenterology@borders.scot.nhs.uk