Epidemiology and risk factors for alcoholic liver disease

Development of liver damage and cirrhosis (ALD) related to alcohol consumption is complex. Studies have reported a threshold of drinking 20-30 g daily for women compared to 40-50 g daily for men. However, the absolute risk of ALD related to heavy drinking is relatively low, ranging from 6 to 15 %, so the majority of drinkers do not develop significant damage. Consuming more than 50 g of alcohol daily can accelerate progression of chronic hepatitis C and genetic hemochromatosis. Prior studies eliminated generalized malnutrition, chronic hepatitis B infection, and the type of alcoholic beverage consumed as risk factors. Obesity is an important risk factor for ALD in heavy drinkers and substantial evidence suggests genetic risks for liver damage in heavy drinkers as well as a genetic risk for drinking heavily (alcohol use disorders). A single-nucleotide polymorphism in PNPLA3 (G allele) is the most important genetic factor associated with an increase in the risk of alcoholic cirrhosis. Risk factors for obesity are also genetically determined, leading to a complex model for understanding the risk of developing ALD. Individual risk factors for ALD are potentially quantifiable within a population and will identify those populations at higher or lower risk for disease related to alcohol consumption. Careful studies of the patterns and levels of consumption of alcoholic beverages in genetically well-characterized populations are needed to understand the complex interaction between genes and the environment in the development of liver injury due to alcohol. Once these results are obtained, sound advice about the risk associated with consumption of alcoholic beverages can be provided to individuals.