I have recently been diagnosed with a "fatty" liver by ultrasound and an elevated ALT. Will the problem resolve itself if I lose weight?

B.J.

In the last several years, we have gained a much better understanding of the condition commonly known as "fatty" liver. The medical term for this disorder is nonalcoholic steatohepatitis (NASH), which refers to the fact that there is accumulation of fat (steato) and inflammation (hepatitis) in the liver even though the patient does not drink alcohol. The absence of alcohol is very important because drinking can produce similar damage in the liver.

The cause of NASH is not known, but several factors appear to play a role. Patients with NASH are often obese, tend to have diabetes and frequently have elevated levels of fat in their bloodstream. Also, certain metabolic abnormalities and medications (for example, tetracycline and estrogen compounds) have been associated with NASH. Many other rarer associations have been written about in the medical literature. As research into this disease has increased, doctors have realized that it is much more common than previously thought.

Patients are usually diagnosed with NASH when they are found to have elevated liver-enzyme levels when blood is drawn for another reason. An ultrasound or CT scan of the abdomen will often show the fatty appearance of the liver. The only way to confirm the diagnosis is through a liver biopsy. Many patients thought to have NASH do not get the biopsy because it is invasive and other diseases have already been ruled out. Again, it is important to stress that a history of alcohol use must be ruled out before even considering the diagnosis of NASH.

Various medications have been tried for treating NASH, most with no success. Since NASH is associated with obesity, doctors often recommend weight loss, along with tight control of the levels of sugar and fat in the bloodstream. However, only a minority of patients actually show improvement with this treatment. Many doctors also encourage patients to change their lifestyles to eliminate other potential contributing factors -- for example, by lowering cholesterol levels, controlling diabetes and discontinuing problem medications.

The long-term outlook for patients with NASH is not yet known. It does appear that the inflammation associated with NASH can lead to scarring and cirrhosis over the years. However, this complication seems to occur in a small minority of patients. Currently, the best advice for a patient with NASH is to visit your doctor regularly for close follow-up.