INVESTIGATOR-OBSERVED ALCOHOL-INDUCED FLUSHING BUT NOT SELF-REPORT OFFLUSHING IS A VALID PREDICTOR OF ALDH2 GENOTYPE

Objective: This article presents data on the validity of using self-re port of alcohol-induced flushing and actual investigator-observed flus hing following alcohol challenge to predict ALDH2 genotype in Asian-Am erican men. Method: Men between the ages of 21 and 25 years who were o f Chinese, Japanese or Korean descent completed questionnaires about t heir drinking history and their alcohol-induced flushing history and a ssociated symptoms. Fifty men selected for participation in the study were genotyped for alleles of ALDH2 and individually tested on two sep arate occasions following oral administration of placebo and 0.75 ml/k g (0.56 g/kg) alcohol. Facial flushing Was assessed at baseline and at intervals over a 150-minute period after drinking using observational ratings. Results: By comparing the results of ALDH2 genotype with inv estigator-observed flushing and with previous self-report of facial fl ushing, it was found that investigator-observed flushing is both a sen sitive (100%) and specific (96%) predictor of ALDH2 genotype, whereas self-report of facial flushing is a sensitive (100%) but not a specifi c (68%) predictor of ALDH2 genotype. Conclusions: The results suggest that investigator-observed flushing provides a valid estimate of ALDH2 genotype, but that self-report of facial flushing is biased, giving a substantial overestimate. Due to an increase in error variance, studi es that rely solely on self-report of flushing will more often lead to the conclusion that no association exists. This study suppeas the imp ortance of using ALDH2 genotype, rather than self-report of flushing o r ALDH2 phenotype, when examining factors associated with differences in drinking behavior, response to alcohol and risk for alcoholism or a lcohol-related disease among Asians.