Non-Alcoholic Fatty Liver Disease

Abstract

The term “nonalcoholic fatty liver disease” (NAFLD) was coined by gastroenterologists almost 20 years ago to define a spectrum of progressive liver disease that encompasses simple steatosis, nonalcoholic steatohepatitis (NASH, which is characterized by the presence of steatosis, necroinflammation, with/without fibrosis), and ultimately cirrhosis. The same entity was also well known to diabetologists and regarded as an epiphenomenon of the metabolic syndrome. Dramatic changes in the lifestyle of the global population have been fueling a worldwide increase of obesity and its comorbidities, including NAFLD. It is estimated that the burden of end-stage liver disease will increase two- to threefold in both Western nations as well as several Asian countries by 2030, and NAFLD is set to replace viral hepatitis as the primary cause of end-stage liver disease and liver transplantation over the next decade or so, with the disease affecting both adults and children. It is clear that NAFLD is a complex disease, with considerable variation in severity among individuals as a result of the interplay between host genetics, the environment (diet in particular) and other factors, such as the gut microbiota. Accurate diagnosis and staging of NAFLD are of utmost importance, with histological examination the gold standard in diagnosis so far. However, novel noninvasive methods to diagnose liver disease are rapidly evolving. Upon diagnosis of NAFLD or NASH, appropriate management must be started. Importantly, NAFLD can be managed successfully with diet and lifestyle changes, but pharmacological intervention is warranted when these methods fail. Many challenges lie ahead in the NAFLD field. NAFLD is a global problem, and, ultimately, from a societal perspective, it will be essential to attack the root cause of NAFLD to reduce the burden of diseases related to caloric excess and disordered metabolism. This goal will require a broad effort of all stakeholders to address the social, economic, cultural, and medical underpinning of obesity and its related conditions, including NAFLD. The aim of this book is to provide a comprehensive review of the present standing of NAFLD. I wish to thank the Authors, whose brilliant work has been of utmost importance for the current understanding of this disease, for sharing their knowledge in this book.