title: Influence of repeated permanent coloring and bleaching on ethyl glucuronide concentrations in hair from alcohol-dependent patients.
abstract: BACKGROUND
  Ethyl glucuronide (EtG), a minor metabolite of alcohol, is used as a sensitive marker in hair to detect the retrospective consumption of alcohol. The proximal 0-3 cm hair segment is often used for analysis, providing information on alcohol consumption over the past 3 months. Using more distal segments would allow the detection of alcohol consumption over longer time periods, thereby addressing the chronicity of the consumption. In view of this, permanent coloring and bleaching were shown in vitro to alter EtG concentrations in hair, but no in vivo studies are available to prove or disprove this.
  
  
  OBJECTIVE
  To investigate the influence of repeated bleaching and permanent coloring on EtG concentrations in vivo and to assess the stability of EtG concentrations in distal compared to proximal hair segments.
  
  
  METHODS
  Hair samples from alcohol-dependent patients with uncolored/unbleached (N=4), permanent coloration (N=5) and bleached hair (N=5) were analyzed in two to six 3 cm long segments for EtG concentrations, and alcohol consumption and hair cosmetic treatments were assessed.
  
  
  RESULTS
  We observed that hair bleaching and permanent coloring reduces EtG concentrations by 82±11% and 65±24%, respectively, with correlations between the number of cosmetic treatments and the decrease in EtG concentrations. EtG remained stable in untreated hair samples up to 18 cm.
  
  
  CONCLUSIONS
  EtG is a sensitive marker to assess chronic alcohol consumption up to 18 months in alcohol-dependent patients with no cosmetic hair treatments. However, in alcohol-dependent patients who color or bleach their hair, care should be taken when interpreting EtG measurements.
authors.affiliation: Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium. Electronic address: cleo.crunelle@gmail.com.
authors.forename: Cleo L
authors.initials: CL
authors.lastname: Crunelle
authors.affiliation: Laboratoire National de Santé, Service de Toxicologie, Dudelange, Luxembourg.
authors.forename: Michel
authors.initials: M
authors.lastname: Yegles
authors.affiliation: Toxicology Laboratory, ZNA Stuivenberg, Antwerp, Belgium.
authors.forename: Mireille
authors.initials: M
authors.lastname: De Doncker
authors.affiliation: Collaborative Antwerp Psychiatric Research Institute, University of Antwerp, Antwerp, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Dom
authors.affiliation: Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Delphine
authors.initials: D
authors.lastname: Cappelle
authors.affiliation: Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Kristof E
authors.initials: KE
authors.lastname: Maudens
authors.affiliation: Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Alexander L N
authors.initials: AL
authors.lastname: van Nuijs
authors.affiliation: Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
authors.affiliation: Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium; Toxicology Laboratory, ZNA Stuivenberg, Antwerp, Belgium.
authors.forename: Hugo
authors.initials: H
authors.lastname: Neels
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000175:diagnosis; D015415:Biomarkers / Q000032:analysis; D005260:Female; D053593:Forensic Toxicology; D008401:Gas Chromatography-Mass Spectrometry; D005965:Glucuronates / Q000032:analysis*; D006197:Hair / Q000737:chemistry*; D006202:Hair Dyes / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012973:Sodium Hypochlorite / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D005965:Glucuronates; D006202:Hair Dyes; C093924:ethyl glucuronide; D012973:Sodium Hypochlorite
keywords: Alcohol marker; Alcoholism; Bleaching; Coloring; EtG; Ethyl glucuronide