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World J Gastroenterol. Jun 21, 2011; 17(23): 2801-2811
Published online Jun 21, 2011. doi: 10.3748/wjg.v17.i23.2801
Adiponectin, a key adipokine in obesity related liver diseases
Christa Buechler, Josef Wanninger, Markus Neumeier
Christa Buechler, Josef Wanninger, Markus Neumeier, Department of Internal Medicine I, University Hospital of Regensburg, D-93042 Regensburg, Germany
Author contributions: Buechler C wrote the review article and Neumeier M and Wanninger J revised the manuscript and participated in the design of the figures.
Supported by The Faculty of Medicine of the University of Regensburg (ReForM C); The Deutsche Forschungsgemeinschaft
Correspondence to: Christa Buechler, PhD, Department of Internal Medicine I, University Hospital of Regensburg, D-93042 Regensburg, Germany.
Telephone: +49-941-9447147 Fax: +49-941-9447019
Received: August 17, 2010
Revised: November 17, 2010
Accepted: November 24, 2010
Published online: June 21, 2011

Non-alcoholic fatty liver disease (NAFLD) comprising hepatic steatosis, non-alcoholic steatohepatitis (NASH), and progressive liver fibrosis is considered the most common liver disease in western countries. Fatty liver is more prevalent in overweight than normal-weight people and liver fat positively correlates with hepatic insulin resistance. Hepatic steatosis is regarded as a benign stage of NAFLD but may progress to NASH in a subgroup of patients. Besides liver biopsy no diagnostic tools to identify patients with NASH are available, and no effective treatment has been established. Visceral obesity is a main risk factor for NAFLD and inappropriate storage of triglycerides in adipocytes and higher concentrations of free fatty acids may add to increased hepatic lipid storage, insulin resistance, and progressive liver damage. Most of the adipose tissue-derived proteins are elevated in obesity and may contribute to systemic inflammation and liver damage. Adiponectin is highly abundant in human serum but its levels are reduced in obesity and are even lower in patients with hepatic steatosis or NASH. Adiponectin antagonizes excess lipid storage in the liver and protects from inflammation and fibrosis. This review aims to give a short survey on NAFLD and the hepatoprotective effects of adiponectin.

Keywords: Hepatic steatosis, Non-alcoholic steatohepatitis, Adiponectin, Obesity, Adipose tissue