A twin study of ethanol metabolism

Blood alcohol measurements were obtained for 206 pairs of twins who had ingested a standard dose of alcohol (0.75 g/kg body weight) and repeat measurements were obtained for 40 of these pairs on a second occasion. The repeatability of the peak blood alcohol concentration (BAC) was 0.66, that of the rate elimination was 0.39, and that of the time to peak BAC was 0.27. It is concluded that short-term environmental factors exercise considerable influence on alcohol metabolism, particularly in the absorption phase. All of the repeatable variance in peak BAC and rate of elimination was due to genetic factors. ONly a small proportion of any of the genetic variance could be explained by individual differences in weight, adiposity, or lung function. Likewise, these three factors were unable to account for the fact that females had higher BACs than males during both absorption and elimination.