Fatty liver is the build up of fats within the cells of the liver to the point that more than 5-10% of the liver is fat. There are 2 types of fatty liver disease: alcoholic liver disease and non-alcoholic fatty liver disease (NAFLD). Fatty liver disease can progress to serious complications, such as cirrhosis of the liver.
Fatty liver symptoms
Fatty liver disease usually does not cause any symptoms. Occasionally, people with the condition will complain of feeling tired or generally unwell, but this varies between individuals, and the degree of symptoms does not usually equate to the severity of the disease. Sometimes, a person may feel pain in the upper right abdomen and have weight loss.
Diagnosis of fatty liver disease
Fatty liver disease is often diagnosed by chance, after finding an abnormality on liver function tests, which are often done as part of standard blood tests, or when a person is having an abdominal ultrasound. The changes noticed in liver function tests are often raised concentrations of ALT (alanine aminotransferase) and AST (aspartate aminotransferase). Alternatively, your doctor may detect an enlarged liver while examining your abdomen.
A biopsy of your liver is the only test that can definitively diagnose fatty liver disease, but this is not usually necessary, as other tests such as ultrasound can be sufficiently suggestive to warrant treatment.
Who gets fatty liver disease?
About one in 10 Australians are affected by this condition – it's the most common reason for abnormal liver test results. Fatty liver disease is often caused by an excessive alcohol intake, but it is increasingly being found in people who do not drink to excess, but who are overweight or obese, or have diabetes. In fact, non-alcoholic fatty liver disease (NAFLD) affects one in 3 adults and is the most common cause of chronic liver disease. It's even being diagnosed in Australian teenagers.
Causes of fatty liver disease
Doctors don't really know what causes non-alcoholic fatty liver disease, but it's not necessarily as simple as eating too much fat.
The major factor in the development of non-alcoholic fatty liver disease is insulin resistance, a condition usually associated with obesity and overweight.
Normally, the hormone insulin enables the body’s cells to take up glucose (a type of sugar) from the bloodstream to use as fuel. In insulin resistance, however, the cells don’t respond properly to insulin. They cannot take up sufficient glucose and are therefore deprived of fuel. The blood does not have much glucose removed from it by the cells, so blood glucose levels rise.
Doctors have not yet discovered exactly how insulin resistance causes fat to be deposited within liver cells.
Fatty liver disease can also occur, although far less commonly, with malnutrition, certain medicines and occasionally as a complication of pregnancy.
Alcoholic fatty liver disease is caused by heavy use of alcohol.
Risk factors for non-alcoholic fatty liver disease include:
- High cholesterol.
- High triglycerides (another type of fat in the bloodstream).
- Type 2 diabetes.
- Metabolic syndrome.
- High blood pressure.
- Polycystic ovary syndrome.
Risk factors for alcoholic liver disease
- Not surprisingly, the risk factor for this type of fatty liver disease is drinking too much alcohol.
Complications of fatty liver disease
Fatty liver disease results in fat infiltrating the liver and it may cause no damage, but it can result in serious complications. The excess fat can lead to inflammation of the liver (steatohepatitis), which over time can lead to the scarring and fibrosis of the liver known as liver cirrhosis. Cirrhosis is the most severe complication, with the damage to the liver being permanent and resulting in loss of function. Cirrhosis occurs over years and can lead to liver cancer.
Treatment of fatty liver disease
There is no specific treatment for fatty liver disease, but lifestyle changes can significantly improve the condition and perhaps even reverse it in the early stages. These changes include:
- Avoiding alcohol. If you have alcoholic liver disease, then giving up alcohol is the most important thing you can do. Continuing to drink may result in you getting cirrhosis or alcoholic hepatitis. Giving up alcohol is also good for people with NAFLD.
- Losing weight. This is not easy for many people with fatty liver disease, so having a well-designed management plan designed by a doctor or dietitian can be beneficial. Gradual weight loss is the key, as sudden, severe weight loss can actually make the condition worse. Weight loss surgery may be recommended for some people.
- Exercising. Even if this does not directly result in weight loss, it is very worthwhile as exercise has been shown to reduce insulin resistance, a key factor in fatty liver disease. Both aerobic exercise and resistance training, such as low impact weight training, will help.
- Controlling your blood sugar levels.
- Reducing or avoiding soft drinks and juices and processed foods rich in sugar.
- Treating high cholesterol. Your doctor may suggest medicines to lower your cholesterol levels, in addition to dietary and lifestyle changes.
- Avoiding medicines that may affect your liver, such as some steroids. Do not take medicines that have not been prescribed by your doctor.
- Quit smoking. You will also be advised to quit smoking, to reduce your risk of heart disease.
There are a number of medicines that have been suggested for the treatment of fatty liver disease, although research into these is continuing. These are sometimes prescribed by doctors in particular cases.
By focusing on factors associated with fatty liver disease that can be modified, it may be possible to prevent progression of the disease.
Originally, fatty liver disease was thought to be a harmless condition, but it is now known that it has the potential to progress to more serious liver conditions, such as liver cirrhosis and liver cancer. That's why it's important to make changes early in the condition when it can be improved and even reversed.
What kind of specialist doctor treats fatty liver disease?
In Australia, GPs are at the forefront of diagnosing fatty liver disease, however, the specialists who look after this condition are called gastroenterologists or hepatologists. Accredited Practising Dietitians (APD) may also be involved in designing weight loss and healthy eating plans.
How to prevent fatty liver disease?
Fatty liver disease can usually be prevented by following the same lifestyle advice that is given to people with the disease.
Last Reviewed: 09/02/2016
1. Nonalcoholic fatty liver disease [revised Feb 2011]. In: eTG complete [Internet]. Melbourne: Therapeutic Guidelines Limited; (accessed Feb 2016). http://www.tg.org.au/ 2. Gastroenterological Society of Australia (GESA). Fatty liver disease (updated Aug 2010). Available at: http://www.gesa.org.au/leaflets/fatty-liver.cfm (accessed Feb 2016). 3. NHS Choices. Non-alcoholic fatty liver disease (NAFLD). Updated Apr 2014. http://www.nhs.uk/conditions/fatty-liver-disease/Pages/Introduction.aspx (accessed Feb 2016). 4. Mayo Clinic. Nonalcoholic fatty liver disease. Updated Apr 2014. http://www.mayoclinic.org/diseases-conditions/nonalcoholic-fatty-liver-disease/basics/causes/con-20027761 (accessed Feb 2016). 5. Iser D, Ryan M. Fatty liver disease. A practical guide for GPs. Australian Family Physician July 2013. http://www.racgp.org.au/afp/2013/july/fatty-liver-disease/ (accessed Feb 2016).
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