Nonalcoholic fatty liver disease: current concepts, epidemiology and management strategies

Nonalcoholic fatty liver disease (NAFLD) is now the most prevalent liver disease in the world. It involves a spectrum of conditions from hepatic steatosis to nonalcoholic steatohepatitis and liver fibrosis, and is a major cause of cirrhosis and hepatocellular carcinoma. It is defined by presence of steatosis in 5% of hepatocytes or more in the absence of other causes of fatty liver. The metabolic syndrome is the major known risk factor for NAFLD. Dietary contributors such as high fructose intake and coffee consumption appear to increase and decrease the risk of disease respectively, but these links are unclear. Genetic associations have also been identified. The estimated prevalence of the disease varies according to diagnostic method and population demographics. It appears to be a major issue in Europe with population studies showing up to 50% of the individuals are affected while in the USA one in three adults are estimated to have NAFLD. Laboratory investigations and ultrasound are typically first-line investigations. Fibrosis may be assessed noninvasively through transient elastography and biomarkers but liver biopsy remains the gold standard to quantify hepatic damage. Associated comorbidities include cardiovascular disease and chronic kidney disease. Weight loss, dietary changes and exercise are recommended in management. Medications should be considered to manage underlying risk factors including insulin resistance. Surgical options include bariatric procedures and liver transplantation. The combination of rising prevalence and significant potential complications warrant further research into NAFLD, particularly in areas with research gaps including Eastern Europe.