The Australian Alcohol Challenge Twin Study, initiated over 20 years ago, has provided substantial contributions to understanding the genetics of alcohol metabolism in relation to alcohol use disorders, such as heritability of various alcohol-related traits including alcohol consumption habits and pharmacokinetic measures.30,31 Initial studies have demonstrated genetic influences on peak blood alcohol concentrations, rate of decrease in blood alcohol concentration, and alcohol dependence.32 More recently, Whitfield et al analyzed the relationship between blood or breath alcohol values after an alcohol challenge test, a reflection of pharmacokinetics, and risk of alcohol dependence over a 10-year period of follow-up.33 They observed a two- to threefold increased risk in individuals who demonstrated blood or breath alcohol concentrations in the highest quartile of values compared with those in the lowest.
