Some individuals can develop fatty liver. Most people who do not abuse alcohol and have fatty liver are obese. Fatty liver is called steatosis, and fatty liver with liver inflammation is called or steatohepatitis. Steatosis and steatohepatitis can be caused by alcohol and other drugs and can also sometimes occur in patients with diabetes mellitus. Steatohepatitis notcaused by alcohol is sometimes referred to as non-alcoholic steatohepatitis or "NASH." The factors that determine who will develop fatty liver are not known. Some mildly obese and occasional non-obese patients will develop fatty liver while some who are severely obese will not.
Patients with fatty liver or steatohepatitis usually present to a physician with unexplained elevations in the serum aminotransferase activities. Serum alkaline phosphatase and gamma-glutamyltranspeptidase activities can also be elevated. The patient is usually 10% or more above his/her ideal body weight.
The diagnosis is usually suspected after other causes of hepatitis are excluded. A careful drug and alcohol history should be taken and serological testing for HBsAg and antibodies against the hepatitis C virus should be performed. Metabolic diseases should be excluded by a careful family history and appropriate testing if they are suspected. Serum protein electrophoresis and testing for autoantibodies should be performed if autoimmune hepatitis is suspected. Sometimes, patients with fatty liver or steatohepatitis will have elevated serum trigyceride concentrations, however, this is not always the case.
If a patient has elevations in serum aminotransferase activities for longer than six months, he/she should have a liver biopsy to make the diagnosis the fatty liver or steatohepatitis. Click to see a microscopic section of a NORMAL LIVER LOBULE and an example of FATTY LIVER (STEATOSIS). (Images are part of WebPath and are copyrighted by the Pathology Department of the University of Utah Health Sciences Center. Link with permission of Edward C. Klatt, M. D.)
Steatohepatitis can progress to cirrhosis. Treatment (diet and exercise) may stop this progression. Steatosis and steatohepatitis will often improve with weight loss, preferably to near the patient's ideal body weight. Avoidance of alcohol and potentially hepatotoxic drugs may also be beneficial.
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