Alternative names: Nonalcoholic Steatohepatitis, NASH, Nonalcoholic Fatty Liver Disease
NASH is the abbreviation of nonalcoholic steatohepatitis, which is a common, often silent, disease of the liver.
The hallmark of NASH is fat in the liver, which causes inflammation and damage to the liver cells. If left untreated, NASH can lead to cirrhosis. The damage the fat does to the liver is similar to the damage caused by long-term alcohol abuse, even if the person does not drink alcohol, which explains the name.
NASH currently affects 2 to 5 percent of people in America, usually those who are middle-aged, overweight and who often have hypertension and diabetes. However, thin people without diabetes can also develop NASH.
A related condition called nonalcoholic fatty liver (NAFL) affects a larger percentage of Americans than NASH. People with NAFL have fat in their liver, but no inflammation or damage. It is a little confusing that sometimes the term NAFLD is used, the "D" meaning disease, but excess fat itself is not necessarily a disease.
Many people with NASH have no symptoms. Instead, the disease is diagnosed after they have blood testing done in conjunction with an annual physical, insurance exam, and other tests.
Those with more advanced disease may complain of fatigue, weakness, weight loss and sometimes a dull, aching pain below the right ribcage. This may be caused by the cover (capsule) of the liver stretching as it gets bigger and more inflamed.
The exact cause of NASH is unknown. Studies show that the risk is much higher for people who are overweight or obese. Others at risk are women taking hormones (estrogen) and people who have lost a great deal of weight in a short amount of time.
Genetic factors very likely play a role. These factors may predispose people to develop the disease, as well as making them more sensitive to the damaging effects of alcohol.
To check for NASH, your doctor may do any of these tests:
- Blood tests that check for liver enzymes and other markers of liver disease
- An ultrasound, which uses sound waves to create images of the inside of your body: this may strongly suggest an abundance of fat.
- A computerized axial tomography (CT) scan, which is an X-ray that provides images of the inside of your abdomen, showing your liver, spleen, fluid, etc.
- A magnetic resonance imaging (MRI) scan, which uses magnetic beams to make detailed images of your liver.
- Liver biopsy, a procedure where the doctor uses a special needle to remove a tiny sample of your liver. The sample is then checked at a laboratory for signs of liver damage or disease. The procedure is done through the skin, and only takes about 20 minutes. It may cause some discomfort, and you will need to take it easy for a few days after the surgery. Occasionally complications such as bleeding may occur.
Some people have so many risk factors for NASH that the doctor may decide not to do a liver biopsy, but rather base the diagnosis on the combination of clinical information obtained.
The current treatment for NASH includes the following:
- Weight loss. This is the key. The benefits are numerous and include helping to achieve optimal control of the NASH risk factors mentioned below:
- Lipid abnormalities (high cholesterol etc.)
- High blood pressure
- Recommendations include:
- Changing to a balanced, healthy, low saturated fat and above all, low calorie diet
- Regular exercise - 30 to 60 minutes a day
- Abstaining from alcohol
If recommendations are followed and weight loss occurs, liver tests and imaging studies usually show dramatic improvement.
There are other treatments that may help with NASH, such as anti-oxidants (like vitamin E), ursodeoxycholic acid (Urso) and others. They are, however, not FDA approved or convincingly shown to be beneficial in clinical trials.