Purpose: An estimation of ethanol intake is frequently of importance in the frame work of studies, but not trivial to achieve. Problems are "underreporting", a very short time frame for the detection of ethanol as direct marker and interference of many in- and outside body factors with strain parameters. The aim of this study was to explore the suitability of the direct urinary biomarkers ethyl glucuronide (EtG) and ethyl sulphate (EtS) to assess moderate but regular alcohol consumption.
Materials and methods: A total of 175 male workers without any known occupational contact to substances influencing liver functions or metabolism of ethanol were examined. Strain parameters of alcohol consumption, i.e. the liver function tests (LFTs: aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase), carbohydrate-deficient transferrin (CDT), mean corpuscular erythrocyte volume (MCV) and the markers of alcohol consumption (EtG and EtS) have been analysed and compared.
Results: Up to 14 % of workers had been outside reference range for strain parameters. 62.3 % of the workers had at least traceable amounts of EtG and 84.6 % of EtS. Values above cut-off (indicating voluntary ethanol intake) were found in 34.9 and 51.4 % of the workers for EtG and EtS, respectively. In multiple linear regression analyses, CDT and MCV but not the LFTs showed a dependency from the non-oxidative ethanol metabolites. The LFTs were influenced by BMI.
Conclusion: Determination of EtG and EtS in urine is an adequate tool to assess moderate but regular alcohol consumption.
Keywords: Ethyl glucuronide; Ethyl sulphate; Hepatotoxicity; Non-oxidative ethanol metabolites.