Non-alcoholic fatty liver disease: Definition and subtypes

Abstract

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide, with a global prevalence of approximately 30%. However, the prevalence of NAFLD has been variously reported depending on the comorbidities. The rising prevalence of obesity in both the adult and pediatric populations is projected to consequently continue increasing NAFLD prevalence. It is a major cause of chronic liver disease worldwide, including cirrhosis and hepatocellular carcinoma (HCC). NAFLD has a variety of clinical phenotypes and heterogeneity due to the complexity of pathogenesis and clinical conditions of its occurrence, resulting in various clinical prognoses. In this article, we briefly described the basic definition of NAFLD and classified the subtypes based on current knowledge in this field.

Editorial: Will MRI‐PDFF become the new standard for steatosis assessment in NAFLD?

“…By measuring the proton density fat fraction with proton magnetic resonance spectroscopy or quantitative fat/water selective magnetic resonance imaging (MRI), the grade of steatosis can be quantitatively defined. 2 Herein, Kim et al 6 In the multivariable models, this was also proven in terms of higher histology-defined steatosis.…”

“…In its progression, it is a major cause of chronic liver disease worldwide. 2 Paediatric NAFLD should be suspected for any child 9 years or older with obesity/overweight and additional risk factors. 3 Screening in persons with obesity or metabolic syndrome is recommended by the European Association for the Study of Liver, the European Association for the Study of Diabetes and the European Association for the Study of Obesity.…”

“…The excessive hepatic fat accumulation is related to insulin resistance and is defined as steatosis in >5% hepatocytes. By measuring the proton density fat fraction with proton magnetic resonance spectroscopy or quantitative fat/water selective magnetic resonance imaging (MRI), the grade of steatosis can be quantitatively defined 2 …”

“…In adults, but also in the paediatric population, the rising prevalence of obesity is reflected in increasing NAFLD prevalence. In its progression, it is a major cause of chronic liver disease worldwide 2 …”

Lean vs. obese phenotypes of nonalcoholic fatty liver disease: similar or different?

“…In addition, the etiology of NAFLD in lean individuals may be based on central obesity and visceral fat. 10 Accordingly, the body weightbased BMI-driven approach for the classification of NAFLD may need to be reappraised.…”