Complications, morbidity and mortality of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized public health problem, affecting up to a quarter of the world's adult population. The burden of NAFLD is influenced by the epidemics of obesity and type 2 diabetes mellitus (T2DM) and the prevalence of these conditions is not expected to decrease in the forthcoming decades. Consequently, the burden of NAFLD-related liver complications (non-alcoholic steatohepatitis [NASH], cirrhosis and hepatocellular carcinoma) and the need for life-saving liver transplantation are also expected to increase further in the near future. A large body of clinical evidence indicates that NAFLD is associated not only with increased liver-related morbidity and mortality, but also with an increased risk of developing other important extra-hepatic diseases, such as cardiovascular disease (that is the predominant cause of death in patients with NAFLD), extra-hepatic cancers (mainly colorectal cancers), T2DM and chronic kidney disease. Thus, NAFLD creates a considerable health and economic burden worldwide and often results in poor quality of life. This narrative review provides an overview of the current literature on main complications, morbidity and mortality of this common and burdensome liver disease.