[Adipocitokines and nonalcoholic steatohepatitis]

Nonalcoholic steatohepatitis is one of the most common liver diseases. It is part of the nonalcoholic fatty liver disease, which ranges from simple hepatic steatosis to necroinflammation and fibrosis of various degrees, so that many patients can evolve towards advanced liver disfunction and even cirrhosis. Insulin resistance is the main factor involved in the development of fatty liver. As the adipose tissue is the source of many metabolically active peptides (the adipocitokines), their involvement in the pathogenesis of the hepatic steatosis and steatohepatitis has begun to be intensively studied during the last years. The most substantial information collected until now concerns the tumor necrosis factor alpha (a proinflammatory cytokine that induces insulin resistance, fat accumulation in the liver and even fibrosis and necrosis), adiponectin (an anti-inflammatory adipokine that acts as an insulin sensitizer and a hepatic protector) and leptin (a signal of the adipose tissue mass with effects on the appetite and food intake, but also acting upon insulin secretion and action and perhaps upon the liver fat accumulation).