Current solutions for obesity-related liver disorders: non-alcoholic fatty liver disease and non-alcoholic steatohepatitis.

o besity is a worldwide epidemic with more than 1 billion overweight adults and at least 300 million obese patients [1]. According to recent statistics from the United States, 16.9% of children and adolescents aged 2–19 years were obese in 2009–2010 and 31.8% were either overweight or obese [2]. The rise in childhood obesity has been accompanied by an increase in pediatric liver diseases: 70%–80% of obese children and adolescents have liver diseases [3]. A review of the epidemiology of non-alcoholic fatty liver disease (NAFLD) found that in studies of bariatric surgery patients, 76% had NAFLD, 37% had nonalcoholic steatohepatitis (NASH), 23% had fibrosis, and 5.8% had cirrhosis [4]. NAFLD is defined by hepatic fat infiltration of > 5% hepatocytes, as detected by liver biopsy, with no evidence of excessive alcohol intake, or viral, autoimmune or drug-induced liver disease. It constitutes a spectra of liver disease ranging from intrahepatic fat accumulation (steatosis) to various degrees of necrotic inflammation and fibrosis (NASH) [5]. In predisposed individuals, NAFLD can evolve to cirrhosis and hepatocellular carcinoma, with the consequent need for liver transplantation [6]. NAFLD is associated with abdominal obesity and severe metabolic impairments such as insulin resistance, type 2 diabetes, dyslipidemia and hypertension. It is a risk factor for metabolic syndrome and cardiovascular disease [7]. In view of the obesity and liver disease epidemic, the diagnosis and treatment of this population should become a priority for health care systems.