The complementarity of phosphatidylethanol in whole blood and ethyl glucuronide in hair as biomarkers for the monitoring of alcohol use.

ABSTRACT

Monitoring long-term alcohol use and/or abstinence is essential in clinical and medico-legal cases. Analysis of ethyl glucuronide (EtG) in hair provides information on alcohol consumption over several months. However, there is a lag time between ethanol consumption, incorporation of EtG in the hair bulb and hair growing out of the scalp. Phosphatidylethanol (PEth) 160/181 analysis in whole blood has a detection window of 2-4 weeks, allowing for the detection of recent alcohol consumption. In this study, 2340 paired samples (of hair and venous whole blood from 1170 individuals) were analysed for EtG in hair (hEtG) and PEth 160/181 in venous whole blood. PEth 160/181 and hEtG results were subdivided into three categories according to the consensus of SoHT (hEtG) and PEth-NET (PEth) abstinence/low, moderate or excessive alcohol consumption. For hEtG analysis, 446 individuals presented abstinence/low alcohol consumption, of which 2% were classified as excessive alcohol users through PEth 160/181 analysis. This suggests excessive alcohol consumption in the weeks before sample collection. Out of 483 individuals classified as heavy alcohol users based on hEtG analysis, 14% showed abstinence/low alcohol consumption for PEth 160/181 analysis, implying that these subjects stopped drinking 2-4 weeks before sample collection. Our results show that the analysis of the two different biomarkers can lead to a more accurate categorisation of individuals. Therefore, we emphasize that for the retrospective investigation of alcohol use, it is necessary to include two alcohol use biomarkers with different detection windows.