[Steatosis during chronic hepatitis C: the role of insulin resistance and viral factors].
Liver steatosis is frequent in patients with chronic hepatitis C. Two main types are described: (1) "viral steatosis" induced by the virus, especially genotype 3, which probably inhibits the "Microsomal Triglyceride Transfer Protein", thus decreasing "Very Low Density Lipoprotein" secretion and leading to triglyceride accumulation within hepatocytes; (2) "metabolic steatosis" which is a feature of the metabolic syndrome and insulin resistance, a systemic disorder associated with a high risk of cardiovascular disease and diabetes mellitus. Insulin resistance induces intrahepatic triglyceride accumulation due to excess free fatty acid flux from increased adipose tissue lipolysis as well as increased intrahepatic lipogenesis through activation of the "Sterol Response Element Binding Protein". Hepatitis C Virus itself can also be responsible for insulin resistance, possibly through impairment of the insulin signalling pathway because of increased"Tumor Necrosis Factor Alpha" levels and/or upregulated "Cytokine Signalling Suppressor" expression. Insulin resistance and steatosis, appear to be associated with fibrosis progression and impairment of sustained response to antiviral treatment.
Moucari
Rami
R
Pôle des maladies de l'appareil digestif, Service d'hépatologie et INSERM U773 CRB3, Université Paris VII, Hôpital Beaujon, Clichy.
Marcellin
Patrick
P
Asselah
Tarik
T
D005234:Fatty Liver / Q000209:etiology*; D016174:Hepacivirus / Q000502:physiology; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000378:metabolism* / Q000821:virology; D007333:Insulin Resistance