Determinants of alcohol use and abuse: Impact of quantity and frequency patterns on liver disease

More than 70% of alcohol is consumed by 10% of the population in the United States. Implicit in this statistic is that tremendous variation in the pattern of drinking (quantity, frequency, and duration) exists among alcohol consumers. Individuals who are binge or chronic drinkers will have different health outcomes than social drinkers. Therefore, knowing the pattern of drinking will shed light on how severely individuals are alcohol-dependent and on the extent of liver damage. Thus, these parameters assume particular relevance for the treatment-providing physician. Genetic factors contribute substantially to differences in alcohol metabolism. Variations in the activities of the alcohol-metabolizing enzymes, cytosolic alcohol dehydrogenase and mitochondrial aldehyde dehydrogenase, in part determine blood alcohol concentration, thereby contributing to the predisposition to becoming alcohol-dependent and to susceptibility to alcohol-induced liver damage. Chronic alcohol consumption induces cytochrome P450 2E1, a microsomal enzyme that metabolizes alcohol at high concentrations and also metabolizes medications such as acetaminophen and protease inhibitors. Alcohol metabolism changes the redox state of the liver, which leads to alterations in hepatic lipid, carbohydrate, protein, lactate, and uric acid metabolism. The quantity and frequency of alcohol consumption severely impact the liver in the presence of comorbid conditions such as infection with hepatitis B or C and/or human immunodeficiency virus, type 2 diabetes, hemochromatosis, or obesity and thus have implications with respect to the extent of injury and response to medications. Conclusion: Knowledge of the relationships between the quantity, frequency, and patterns of drinking and alcoholic liver disease is limited. A better understanding of these relationships will guide hepatologists in managing alcoholic liver disease.