Abnormal Liver Biochemistry – Clinical Relevance

GP Connect clinical feature by Professor John K. Olynyk, Consultant Gastroenterologist & Hepatologist, Fiona Stanley Fremantle Hospital Group, Murdoch, WA;Theme Lead, Health Research, Edith Cowan University, Joondalup, WA.

Abnormalities of standard liver biochemical tests are common. About 14 per cent of adults have elevated Alanine Aminotransferase (ALT) levels and over 20 per cent have elevated Gamma-Glutamyl Transferase (GGT) levels.

So what is the relevance to health outcomes?

In brief, elevated levels of ALT and GGT are associated with significantly elevated risks of mortality from liver disease (up to 20-fold), whilst elevated GGT levels are also a marker of increased cardiovascular disease mortality. This is largely due to its reflection of the metabolic syndrome and metabolic associated (non-alcoholic) fatty liver disease.

Many serious conditions (ranging from gallstones or malignancy through to hepatic drug reaction) can manifest as jaundice, cholestatic patterns (elevated alkaline phosphatase, GGT and/or bilirubin) or various combinations of abnormal liver biochemistry results.

The most common causes of liver disease are:

  • Metabolic associated fatty liver disease (or nonalcoholic fatty liver disease)
  • Alcohol-related liver disease (still the common cause of emergency department presentation)
  • Chronic viral hepatitis (B and C)
  • Hepatotoxic drug reactions (from prescribed and non-prescribed medications or supplements).

Thereafter, a myriad of less common, but nonetheless important, conditions may cause liver disease. Of these, Hereditary Haemochromatosis is common-enough (1 in every 200 individuals of northern European descent) to warrant consideration and even has its own ‘Hereditary Haemochromatosis’ HealthPathway for assistance.

Mortality from chronic liver disease is largely due to:

  • The development of cirrhosis, portal hypertension and its clinical sequelae (ascites, variceal bleeding, encephalopathy and renal failure) that ultimately results in liver failure.
  • Hepatocellular carcinoma (the second most common cause of cancer related death globally after primary lung cancer).

Significant liver disease can also be completely asymptomatic. Thus, clinicians are required to investigate the cause of abnormal liver biochemistry and evaluate requirements for further investigation and treatment.

The ‘Abnormal Liver Function Tests’ HealthPathway

guides clinicians through common causes of abnormal liver biochemistry, how to investigate, what to do and when to refer. Finally, the pathway also provides links for patients to access information.

If in doubt – refer your patient for clinical review by a Gastroenterologist or Hepatologist.

See also the: ‘Chronic Hepatitis B‘ and ‘Chronic Hepatitis C‘ HealthPathways