Nonalcoholic fatty liver disease and cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is among the most common causes of chronic liver disease in the westernized world and now represents a worldwide public health problem. NAFLD encompasses a broad spectrum of conditions, ranging from simple steatosis (nonalcoholic fatty liver) to nonalcoholic steatohepatitis (NASH). The latter is recognized as a potentially progressive disease that could lead to cirrhosis, liver failure, and hepatocellular carcinoma. The recent rise in obesity likely explains the NAFLD epidemic worldwide. Recognition of the importance of NAFLD and its strong association with metabolic syndrome has stimulated interest in its putative role in the development of cardiovascular disease (CVD). Recently, accumulating evidence suggests that NAFLD is associated with a significant greater overall mortality, as well as with increased prevalence of CVD, both of which are independent of classical atherosclerotic risk factors. Furthermore, observation studies of natural history of NAFLD have shown that increased age-related mortality of NAFLD patients is attributable to CVD and liver-related diseases such as liver failure and hepatocellular carcinoma. In this paper, we review clinical data to support a strong association between NAFLD and CVD, and discuss possible underlying mechanisms for accelerated atherosclerosis in NAFLD.