Adams Leon A, Talwalkar Jayant A
Division of Gastroenterology and Hepatology, Mayo Clinic and College of Medicine, Rochester, MN 55905, USA.
J Clin Gastroenterol. 2006 Mar;40 Suppl 1:S34-8. doi: 10.1097/01.mcg.0000168642.38945.f1.
Nonalcoholic fatty liver disease (NAFLD) is a diagnostic consideration among patients with asymptomatic elevated aminotransaminases, patients with radiologic findings of hepatic fatty infiltration, or occasionally in the patient with "cryptogenic" cirrhosis. The diagnosis of NAFLD requires evidence of fatty infiltration of the liver in the absence of excessive alcohol ingestion. Clinical evaluation should examine for metabolic risk factors (central obesity, glucose intolerance, hypertension, hypertriglyceridemia, and low HDL cholesterol), which are suggestive but not specific for the diagnosis of NAFLD. Secondary causes of NAFLD, such as medications and intestinal bypass surgery, should be excluded as management of these conditions may differ. Confirmation of hepatic steatosis can usually be done by imaging studies, although occasionally liver biopsy is required. Among suspected NAFLD patients with chronically elevated aminotransaminases, clinical evaluation and serological testing should be performed to exclude other causes of chronic liver disease. Liver biopsy is required to stage fibrosis and distinguish between nonalcoholic steatohepatitis and steatosis. This is valuable for providing prognosis, excluding other liver disease, monitoring response to therapy or evaluating disease progression over time. Clinical features, particularly diabetes, obesity, and older age, can aid in stratifying patients at risk for advanced fibrosis but are not sufficiently accurate to replace liver biopsy.
非酒精性脂肪性肝病（NAFLD）是无症状性转氨酶升高患者、肝脏脂肪浸润有影像学表现的患者，或偶尔在“隐源性”肝硬化患者中的诊断考虑因素。NAFLD的诊断需要在无过量饮酒的情况下有肝脏脂肪浸润的证据。临床评估应检查代谢风险因素（中心性肥胖、葡萄糖耐量异常、高血压、高甘油三酯血症和低高密度脂蛋白胆固醇），这些因素对NAFLD的诊断有提示作用但不具有特异性。应排除NAFLD的继发性病因，如药物和肠道旁路手术，因为这些情况的处理可能不同。肝脂肪变性的确认通常可通过影像学检查完成，不过偶尔需要进行肝活检。在疑似NAFLD且转氨酶长期升高的患者中，应进行临床评估和血清学检测以排除慢性肝病的其他病因。需要肝活检来对纤维化进行分期，并区分非酒精性脂肪性肝炎和单纯性脂肪变性。这对于提供预后、排除其他肝病、监测治疗反应或评估疾病随时间的进展很有价值。临床特征，特别是糖尿病、肥胖和老年，有助于对有进展性纤维化风险的患者进行分层，但不够准确，不能替代肝活检。
