Chronic and excessive alcohol ingestion is one of the major causes of liver disease. Per capita, alcohol consumption and cirrhosis have risen in the last decade in United Kingdom and Russia but has decreased in many developed countries including the United States. The pathology of alcoholic liver disease consists of three major lesions, with the injury rarely existing in a pure form: (1) fatty liver, (2) alcoholic hepatitis, and (3) cirrhosis. Fatty liver is present in >90% of binge and chronic drinkers. A much smaller percentage of heavy drinkers will progress to alcoholic hepatitis, thought to be a precursor to cirrhosis. The prognosis of severe alcoholic liver disease is dismal; the mortality of patients with alcoholic hepatitis concurrent with cirrhosis is nearly 60% at 4 years. Although alcohol is considered a direct hepatotoxin, only between 10 and 20% of alcoholics will develop alcoholic hepatitis. The explanation for this apparent paradox is unclear but involves the complex interaction of facilitating factors, such as intake frequency, diet, and gender.
Etiology and Pathogenesis
Quantity and duration of alcohol intake are the most important risk factors involved in the development of alcoholic liver disease (Table 307-1). The roles of beverage type(s), i.e. wine, beer, or spirits, and pattern of drinking (daily versus binge drinking) are less clear. Progress of the hepatic injury beyond the fatty liver stage seems to require additional risk factors that remain incompletely defined. Although there are genetic predispositions for alcoholism (Chapter 392), and candidate genes for liver steatosis and fibrosis, gender is a strong determinant for alcoholic liver disease. Women are more susceptible to alcoholic liver injury when compared to men. They develop advanced liver disease with substantially less alcohol intake. In general, the time it takes to develop liver disease is directly related to the amount of alcohol consumed. It is useful in estimating alcohol consumption to understand that one beer, four ounces of wine, or one ounce of 80% spirits all contain ∼12 g of alcohol. The threshold for developing alcoholic liver disease in men is an intake of >60–80 g/d of alcohol for 10 years, while women are at increased risk for developing similar degrees of liver injury by consuming 20–40 g/d. Ingestion of 160 g/d is associated with a 25-fold increased risk of developing alcoholic cirrhosis. Gender-dependent differences result from poorly understood effects of estrogen and the metabolism of alcohol. Diet, particularly an increase in liver injury from high fat or the protective effect of coffee, has been postulated to play a part in the development of the pathogenic process.
Table 307-1 Risk Factors for Alcoholic Liver Disease |Favorite Table|Download (.pdf)
Table 307-1 Risk Factors for Alcoholic Liver Disease
In men, 40–80 g/d of ethanol produces fatty liver; 160 g/d for 10–20 years causes hepatitis or cirrhosis. Only 15% of alcoholics develop ...