Role of adipokines in the pathogenesis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome. The increased prevalence of obesity, diabetes, hypertension, hypertriglyceridaemia and hypercholesterolemia are considered to be the potential causative factors for NAFLD. NAFLD is emerging as a major clinical problem worldwide. Recently much attention has been focused in India as the prevalence of obesity and diabetes is rising. NAFLD is responsible for unexplained raise in transaminases, and an important cause of cryptogenic cirrhosis and cryptogenic hepatocellular carcinoma in India. NAFLD is a spectrum of disease ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), potentially leading to fibrosis and cirrhosis. Studies have suggested that the adipokines are involved in the pathogenesis of NAFLD and its progression to NASH, through their metabolic and proor anti-inflammatory activity. Adipokines in particular tumor necrosis factor-α and interleukin-6 are believed to mediate the shift in pathology from steatosis to steatohepatitis. In addition, other adipokines such as adiponectin, leptin and resistin also play a crucial role in the development and progression of NAFLD through their metabolic and pro–or anti-inflammatory activity. This suggests that imbalance between pro-inflammatory and anti-inflammatory cytokines may have a role in the development of liver damage in NAFLD. Understanding the relationship between adipokines and NAFLD may play an important role in the early identification/diagnosis, treatment and also help in preventing disease progression.