Non-alcoholic steatohepatitis: clinical significance and pathogenesis.

Non-alcoholic steatohepatitis (NASH) is a form of liver disease resembling alcoholic liver disease in a patient who does not consume significant amounts of alcohol. Since its first description in 1980 it has been recognized with increasing frequency. The natural course is relatively benign, but liver cirrhosis. together with all its sequelae, may develop; sometimes liver transplantation is indicated. NASH should probably be regarded as a two-stage acquired metabolic disorder consisting of the development of the insulin resistance syndrome in a patient with pre-existing metabolic abnormalities. The insulin resistance syndrome may well be the most important metabolic abnormality giving rise to hepatic steatosis. The preexisting metabolic abnormalities can be diverse, and may well be multifactorial and/or polymorphogenetic. A steatotic liver may be more susceptible to the deleterious effects of the pre-existing metabolic abnormalities. Pre-existing metabolic abnormalities of particular interest are increased hepatic iron storage and derangements of lipoprotein metabolism. While awaiting the complete resolution of the pathogenesis, current treatment is largely conservative. Every patient should be encouraged to lose weight and to avoid alcohol and other hepatotoxins. In addition, diabetes, lipid abnormalities and increased iron stores should be looked for.