Roeb Elke
Gastroenterology, Justus Liebig University and University Hospital Gießen, Gießen, Germany.
Visc Med. 2021 Aug;37(4):273-280. doi: 10.1159/000515445. Epub 2021 Apr 13.
Nonalcoholic fatty liver disease (NAFLD) describes a continuum of liver abnormalities from simple nonalcoholic fatty liver (NAFL) to nonalcoholic fatty liver hepatitis or steatohepatitis (NASH) to NASH fibrosis. It has a variable course, but just like alcoholic fatty liver disease, it can lead to liver cirrhosis and cancer (hepatocellular carcinoma).
NAFLD is a clinical entity characterized by the presence of liver steatosis, which affects at least 5% of hepatocytes. Affected are people who consume little or no alcohol and who have no secondary cause of liver steatosis such as viral hepatitis, drug intake (e.g., tamoxifen, amiodarone, methotrexate, etc.), or lipodystrophy. NAFLD is, nowadays, the most common liver disease in Europe, with an estimated prevalence of 25%. The currently widely recognized recommendation for the therapy of NAFLD is a lifestyle modification with the goal of weight loss. Although no drugs are currently approved for the treatment of NAFLD, several candidates are in clinical trials. Besides weight loss and physical activity, corresponding single active ingredients or combination therapies are intended to stop the progression of the disease and, in the best case, reverse it. The newly propagated name MAFLD (metabolic-associated fatty liver disease) should indicate that the disease is associated with metabolic disorders. The term MAFLD also implies multiple overlapping causes and drivers of this soaring disease.
The prevalence of NAFLD continues to rise worldwide. NAFLD, NASH, and fibrosis in NAFLD occur predominantly in patients with obesity and type 2 diabetes (T2DM) or else precede these conditions. The progression of NAFLD is highly dependent on changes in glucose, lipid metabolism, and fibrogenesis. A new definition and nomenclature of fatty liver disease, "metabolic associated fatty liver disease" (MAFLD), should be discussed carefully, since around 40% of the global population with NAFLD are classified as non-obese and almost 1/5 as lean. Since the pathogenesis of fatty liver disease, obesity, and glucose and lipid metabolism diseases are very closely related, it is important to continue to look for mechanisms that these diseases have in common and develop new therapeutic approaches.
非酒精性脂肪性肝病（NAFLD）描述了从单纯性非酒精性脂肪肝（NAFL）到非酒精性脂肪性肝炎或脂肪性肝炎（NASH）再到NASH纤维化的一系列肝脏异常情况。其病程多变，但与酒精性脂肪性肝病一样，可导致肝硬化和癌症（肝细胞癌）。
NAFLD是一种以肝脏脂肪变性为特征的临床实体，脂肪变性影响至少5%的肝细胞。受影响的是很少饮酒或不饮酒且没有肝脏脂肪变性的继发原因（如病毒性肝炎、药物摄入（如他莫昔芬、胺碘酮、甲氨蝶呤等）或脂肪营养不良）的人群。如今，NAFLD是欧洲最常见的肝脏疾病，估计患病率为25%。目前广泛认可的NAFLD治疗建议是通过改变生活方式来实现体重减轻。虽然目前尚无药物被批准用于治疗NAFLD，但有几种候选药物正在进行临床试验。除了体重减轻和体育活动外，相应的单一活性成分或联合疗法旨在阻止疾病进展，最好的情况是逆转疾病。新提出的名称MAFLD（代谢相关脂肪性肝病）应表明该疾病与代谢紊乱有关。MAFLD这个术语还意味着这种日益普遍的疾病有多种重叠的病因和驱动因素。
NAFLD在全球的患病率持续上升。NAFLD、NASH以及NAFLD中的纤维化主要发生在肥胖和2型糖尿病（T2DM）患者中，或者在这些疾病之前出现。NAFLD的进展高度依赖于葡萄糖、脂质代谢和纤维化的变化。应仔细讨论脂肪性肝病的新定义和命名法“代谢相关脂肪性肝病”（MAFLD），因为全球约40%的NAFLD患者被归类为非肥胖，近五分之一为瘦人。由于脂肪性肝病、肥胖以及葡萄糖和脂质代谢疾病的发病机制密切相关，继续寻找这些疾病的共同机制并开发新的治疗方法很重要。
