Non alcoholic fatty liver disease (NAFLD) is an increasingly prevalent form of liver disease characterized by hepatic fatty infiltration associated with obesity and the metabolic syndrome. Non alcoholic steatohepatitis (NASH) is the condition resulting when NAFLD is complicated by hepatocellular inflammation and necrosis. This spectrum of liver disease may have replaced hepatitis C as the most common form of chronic liver disease. Like other forms of liver disease NASH can progress to cirrhosis and hepatocellular carcinoma.
NAFLD and NASH are reviewed in the April 2006 issue of Current Opinion in Endocrinology and Diabetes. Key points:
Sensitivity and specificity tend to be poor with readily available blood and imaging tests.
However, NAFLD is likely in obese patients with the metabolic syndrome.
Magnetic resonance spectroscopy has identified NAFLD in 33% of the general population in the Dallas Heart Study.
The prevalence of NASH in morbid obesity may warrant routine liver biopsy in patients undergoing bariatric surgery.
Weight loss can reverse the histologic changes and is the best treatment.
Thiazoladinediones such as pioglitazone show promise in treatment but definitive recommendations await higher level studies.
Statin drugs, often indicated in the dyslipidemias associated with NAFLD, appear to be safe.