Hair ethyl glucuronide as a biomarker of alcohol consumption in alcohol-dependent patients: Role of gender differences

Background: Ethyl glucuronide (EtG) is a minor alcohol metabolite that accumulates in hair and is proposed as a stable marker for the detection of chronic and excessive alcohol consumption above a cut-off level of 30 pg/mg hair. A correlation between drinking behavior and EtG hair concentrations is observed, but large variability exists. Aims: To investigate the correlation between alcohol consumption and hair EtG concentrations in alcohol dependent patients, and the effect of gender differences as a factor for the variability on this correlation. Methods: EtG was measured by gas chromatography coupled to mass spectrometry in the hairs (first 3 cm) of 36 alcohol dependent patients (25 males/11 females) starting and alcohol detoxification program. Factors that possibly influence EtG content in hair (except age and gender) were excluded. Detailed retrospective alcohol consumption was obtained over the last 3 months using the Timeline Follow Back interview. Results: Median total alcohol consumption over 3 months was 13,050 g pure alcohol (range 60-650 g/day). Hair EtG concentrations varied between 32 and 662 pg/mg. There was a statistically significant linear and positive correlation between hair EtG and amounts of alcohol consumed (Pearson r = 0.83; p < 0.001), in both males (Pearson r = 0.83; p < 0.001) and females (Pearson r = 0.76; p = 0.007). Conclusions: There is a linear correlation, with no significant effect of gender, between hair EtG concentrations and amounts of alcohol consumed in alcohol-dependent individuals. Analysis of EtG in hair can be applied to estimate retrospective alcohol consumption in both male and female alcohol dependent subjects using the same cut-off. (C) 2014 Elsevier Ireland Ltd. All rights reserved.