Clain D J, Lefkowitch J H
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York.
Gastroenterol Clin North Am. 1987 Jun;16(2):239-52.
About 90 per cent of morbidly obese patients show histological abnormalities of the liver. One third of patients have fatty change involving more than 50 per cent of hepatocytes. Fatty liver disease can be divided into four histological groups: Fatty liver, fatty hepatitis, fatty liver with portal fibrosis, and cirrhosis. Most patients show only fatty change. Alcohol, drugs, diabetes, poor nutrition, and weight-reducing surgery contribute to progressive liver damage, but morbid obesity alone may lead to severe disease showing all the features of alcoholic hepatitis and may end in cirrhosis and liver failure. The accumulation of fat alone is unlikely to be the stimulus to inflammation and fibrosis. Only one fifth of patients have complaints that arise from the liver. The development of severe fatty liver disease may also be asymptomatic and rarely shows the florid picture associated with alcoholic hepatitis. There is poor correlation of liver function test results with morphology in obesity. ALT levels exceeding twice the normal limit have some predictive value for histological grades of severity, but they are present in few patients. Pericentral and pericellular fibrosis in prebypass liver biopsies may be an important prognostic lesion for the development of fatty hepatitis and cirrhosis. In contrast with the frequent progression to massive fatty change, inflammation and fibrosis after bypass surgery, weight loss by low-calorie dieting, or starvation is accompanied by improvement in fatty change and return of liver function tests to normal.
约90%的病态肥胖患者存在肝脏组织学异常。三分之一的患者出现脂肪变性，累及超过50%的肝细胞。脂肪性肝病可分为四个组织学类型：脂肪肝、脂肪性肝炎、伴有门脉纤维化的脂肪肝和肝硬化。大多数患者仅表现为脂肪变性。酒精、药物、糖尿病、营养不良和减肥手术会导致肝脏进行性损害，但单纯病态肥胖也可能导致严重疾病，呈现出酒精性肝炎的所有特征，并可能最终发展为肝硬化和肝衰竭。单纯脂肪堆积不太可能是炎症和纤维化的刺激因素。只有五分之一的患者有肝脏相关的不适主诉。严重脂肪性肝病的发展也可能没有症状，很少呈现出与酒精性肝炎相关的典型表现。肥胖患者的肝功能检查结果与形态学之间的相关性较差。谷丙转氨酶（ALT）水平超过正常上限两倍对组织学严重程度分级有一定预测价值，但只有少数患者出现这种情况。旁路手术前肝脏活检中的中央周围和细胞周围纤维化可能是脂肪性肝炎和肝硬化发展的重要预后性病变。与经常进展为重度脂肪变性不同，旁路手术、低热量节食或饥饿导致体重减轻后，炎症和纤维化会伴随脂肪变性改善以及肝功能检查恢复正常。
