Tarek Abou Hamdan, MD
Gastroenterologist & Interventional Endoscopist
Clemenceau Medical Center
Nonalcoholic steatohepatitis or NASH is a common, often “silent” liver disease. It resembles alcoholic liver disease, but occurs in people who drink little or no alcohol. The etiology is unknown, but the disease is often associated with type 2 diabetes and obesity.
The major feature in NASH is fat in the liver, along with inflammation and damage. In the event of presence of fat in the liver, but no inflammation or damage, this problem is called non-alcoholic fatty liver disease (NAFLD). Both NASH and NAFLD are becoming more common, possibly because of the greater number of people with obesity. In the past 10 years, the rate of obesity has doubled in adults and tripled in children. Obesity also contributes to diabetes and high blood cholesterol, which can further complicate the health of someone with NASH.
NASH is generally suspected in patients with persistent elevation in hepatic transaminase levels. When further evaluation shows no apparent reason for liver disease (such as medications, viral hepatitis, or excessive use of alcohol) and when imaging studies of the liver show fat, NASH is suspected. The only means of proving a diagnosis of NASH and separating it from NAFLD is a liver biopsy.
NASH is usually a silent disease with few or no symptoms. Patients generally feel well in the early stages and only begin to have symptoms —such as fatigue, weight loss, and weakness— once the disease is more advanced or cirrhosis develops. The progression of NASH can take years, even decades. Not every person with NASH develops cirrhosis, but once serious scarring or cirrhosis is present, few treatments can halt the progression. Patients with diabetes, an elevated body mass index, and fibrosis are at higher risk for progression.
Currently, no specific therapies for NASH exist. General recommendations include a balanced and healthy diet, increase physical activity, and avoid alcohol or unnecessary medications. Gradual weight loss (5-10% over 6 months-1 year) and good control of blood glucose levels (HbA1C < 7%) are recommended. NAFLD patients with dyslipidemia should be treated with statins. Experimental approaches in patients with NASH include addition of antioxidants, such as vitamin E or pentoxifylline. Whether these substances actually help treat the disease is not known. Drugs targeting insulin resistance, such as thiazolidinediones and metformin, are approved for diabetes therapy but not for NAFLD/ NASH, and should be considered experimental. They have shown benefit in lowering hepatic transaminase levels and improving ultrasound findings; however, there is no evidence that long-term use of these agents improves clinical outcomes. Because good evidence is lacking, routine use of these drugs simply to normalize hepatic transaminase levels is not recommended.