[Metabolic syndrome and the liver (NAFLD/NASH)]

Metabolic syndrome (MS) is one of the most prevalent disease states in the so-called developed countries and is closely associated with the incidence of cardiovascular as well as other diseases. Predominant sign is the abdominal type of obesity with increased visceral fat mass and the associated insulin resistance. Glucose metabolism disorder, dyslipidemia and arterial hypertension are other important attributes. Metabolic syndrome is also closely associated with the liver steatosis, mostly benign and reversible liver disease. Nevertheless, uncomplicated steatosis may, under certain conditions, progress to inflammation and the disease may, through the stage of NASH (nonalcoholic steatohepatitis) and liver fibrosis, result in liver cirrhosis and hepatocellular carcinoma. Anglo-Saxon literature uses the term NAFLD (non-alcoholic fatty liver disease) to refer to these various stages ofthe liver disease (uncomplicated liver steatosis, steatohepatitis, fibrosis and cirrhosis). While simple steatosis is not dangerous for the patient, NASH is the sign of developing cirrhosis. Etiopathogenesis of NASH features identical characteristics as etiopathogenesis of insulin resistance and metabolic syndrome. Even though liver biopsy remains the gold standard in the diagnosis, new diagnostic approaches are emerging that could be useful in distinguishing simple steatosis from NASH. Therapy includes lifestyle changes, insulin resistance-reducing medication (also useful in the treatment of type 2 diabetes) with a range of other agents under development. In the meantime, randomized double-blind placebo-controlled studies with histological proof of the results are still lacking. A range of unresolved issues remains with regards to etiopathogenesis as well as diagnosis and treatment of NAFLD and NASH.