Non-alcoholic fatty liver disease occurs in people who don’t drink significant amounts of alcohol. Alcohol consumption of over 20g/day (approximately one standard drink) makes pure NAFLD less likely.
An accumulation of fat droplets in the liver cells can produce inflammation, followed by progressive scarring of the liver – a large, important organ that performs 1000s of intricate tasks to keep the rest of the body healthy. Progressive inflammation and scarring can make it difficult for the liver to function as it should.
NAFLD represents a spectrum of disorders ranging from simple steatosis or fatty change (retention of fat in the liver cells) to non-alcoholic steatohepatitis (NASH) – a more serious condition characterised by inflammation. NASH can result in progressive fibrosis (initial scarring), cirrhosis (irreversible scarring of the liver), and an increased risk of hepatocellular carcinoma (primary liver cancer).
The risk of progression to cirrhosis, liver cancer and/or liver failure doesn’t occur in all people and many factors influence this risk.
In order to be diagnosed with NAFLD, there must be:
- Evidence of fat or steatosis in the liver (as suggested by lab tests).
- No evidence of secondary causes of fat build-up in the liver (e.g. no significant alcohol consumption or a hereditary disorder).
NAFLD is linked to overweight and obesity, insulin resistance, diabetes, dyslipidaemia (high levels of cholesterol or fat in the blood), and other metabolic diseases. As such, NAFLD forms part of the so-called “metabolic syndrome” – a collection of risk factors that increase one’s chances of developing cardiovascular disease and diabetes. Features of the metabolic syndrome are not only highly prevalent in people with NAFLD, but components of the metabolic syndrome also increase the risk of NAFLD.
NAFLD may also complicate cardiovascular and kidney disease, and can be a marker of increased cancer risk (e.g. colon cancer).
Reviewed by Dr Mark Sonderup, B Pharm, MB ChB, FCP (SA). Senior Specialist, Division of Hepatology, Department of Medicine, University of Cape Town and Groote Schuur Hospital. July 2018.