Ethyl glucuronide in hair. A sensitive and specific marker of chronic heavy drinking

Aims: This study aims to define a cut-off concentration for ethyl glucuronide in hair to determine if there was a history of heavy drinking. Settings: Pavia, Italy. Participants: We analysed hair samples from 98 volunteers among teetotallers, social drinkers and heavy drinkers, whose ethanol daily intake (EDI) was estimated by means of a written questionnaire. Measurements: Ethyl glucuronide hair concentration (HEtG) was measured by liquid chromatography-tandem mass spectrometry (lower limit of quantification: 3 pg/mg) using a fully validated method. Findings: The HEtG level providing the best compromise between sensitivity (0.92) and specificity (0.96) at detecting an EDI of 60 g or higher during the last 3 months was 27 pg/mg. None of the factors examined among those known to affect ethanol metabolism and/or the diagnostic power of other markers of ethanol use or hair analyses, including age, gender, body mass index, tobacco smoke, prevalent beverage, hair colour, cosmetic treatments and hygienic habits was found to influence marker performance significantly. However, the slight differences in HEtG performance observed for some factors (e.g. body mass index, smoke and hair treatments) require further studies on larger groups of individuals in order to assess their influence more precisely. Conclusions: Our results confirm further that HEtG is a sensitive and specific marker of chronic heavy drinking.