Hair EtG: Alterations in segment levels accompanying hair growth

Driving license regranting: Hair EtG, serum CDT, and the role of sociodemographic and medicolegal variables

Driving under the influence (DUI) of alcohol is a road safety problem. Driving license regranting is based on the evaluation of medicolegal and toxicological variables that may include serum carbohydrate-deficient transferrin (CDT) and hair ethyl glucuronide (hEtG). The aim of the study was to compare the diagnostic performance of CDT and hEtG in a population of DUI offenders. Other factors potentially associated with heavy alcohol use were explored. The population included DUI offenders examined during the period of January 1, 2019, through June 30, 2022. Sociodemographic, medicolegal, and toxicological variables were collected. CDT in serum and EtG in head hair were determined in all subjects. Excessive alcohol intake (hEtG ≥30 pg/mg) was considered cause for unfitness to drive. Cohen's kappa coefficient was calculated. Descriptive analyses were performed using chi-square and Mann-Whitney tests. Variables significantly different between the groups were included in a multivariate binary logistic regression model. The sample encompassed 838 subjects (case group: 179, comparison group: 689). CDT exhibited poor agreement (κ = 0.053) with hEtG as the reference test. Lower education, age at DUI, heavy smoking, and GGT levels associated with heavy alcohol consumption differentiated the two groups. For DUI offenders, the use of CDT to assess heavy alcohol consumption is limited, possibly due to the time-window assessed, the time required for normalization, and the different amount of ethanol needed to reach higher CDT levels, in comparison to hEtG; thus, hEtG assessment is strongly recommended for this population. Heavy smoking, GGT, education, and age could be related to heavy alcohol consumption and higher risk of DUI.

Ethyl glucuronide in hair: a 5-years retrospective cohort study in subjects sanctioned for driving under the influence of alcohol and psychoactive substances

BACKGROUND

The evaluation of drinking behaviours can help in limiting high-risk situation, such as driving under the influence (DUI). We investigate ethyl glucuronide in hair (hEtG) levels to evaluate alcohol consumption behaviour in subjects followed up after having been charged for DUI of psychoactive substances and/or alcohol.

METHODS

We performed a retrospective observational cohort study on 4328 subjects over 18 years old who underwent hEtG analysis in the period 2015-2019 in the Italian Province of Pavia. hEtG level was used as a proxy for the alcohol consumption behaviour. Effects of age, sex and district on alcohol drinking behaviour were investigated with an ordinal logit model. A state sequence analysis was used to study people's alcohol consumption behaviour over time.

RESULTS

hEtG was found ≥7.0 pg/mg in 22.2% of the drivers (of which 7% has an hEtG ≥30.0 pg/mg). Among positive cases, a prevalence of males (96.3%) aged 35-44 (32.6%), coming from main city and hinterland (38.2%) was observed. The propensity to drink was higher for males (OR≈2.28, p<0.001) and for subject coming from the district devoted to the cultivation of vineyards. Young age classes have a reduced drinking risk if compared to the drivers over 55 years old (p<0.001). A general decreasing trend over time in hEtG values was observed.

CONCLUSION

Being male, age ≥ 55 years, and coming from rural areas are potential risk factors related to alcohol drinking habits among drivers. Ethyl glucuronide in hair test in the driving license reissuing protocol contributed to decrease alcohol misuse behaviours.

Accelerated Extraction and Analysis of Ethyl Glucuronide in Hair by Means of Pressurized Liquid Extraction Followed by Liquid Chromatography-Tandem Mass Spectrometry Determination

The measurement of ethyl glucuronide (EtG) in hair is an established practice to evaluate alcohol consumption habits of the donors; nevertheless, analytical variability has shown to be an important factor to be considered: measured EtG values can vary significantly as a consequence of analyte washout during decontamination, pulverization of samples, extraction solvent and incubation temperature. In the present study, we described a new method for automated hair decontamination and EtG extraction from the inner core of the hair by using pressurized liquid extraction (PLE), followed by solid-phase extraction (SPE) cleanup; validation was performed according to SWGTOX guidelines. The extraction efficiency of the new method was evaluated by comparing the results with those obtained by a validated and ISO/IEC 17025:2005 accredited method; an average positive difference of + 32% was observed when the extraction was performed by PLE. The effect of hair pulverization was also studied, and a good correlation between cut and milled hair was observed, implying that PLE allowed a highly efficient extraction of EtG from the inner keratin core of the hair, no matter if it has been cut or pulverized. Finally, to verify the results, paired aliquots of 27 real hair samples were analyzed with both PLE and a protocol optimized by design-of-experiment strategies planned to maximize the extraction yield; in this case, a comparable efficiency was observed, suggesting that exhaustive EtG extraction was obtained with both approaches. This finding opens new perspectives in the eligible protocols devoted to hair EtG analysis, in terms of speed, automation and reproducibility.

The Effect of Prolonged Storage Time on the Stability of Fatty Acid Ethyl Esters in Hair Samples

The advantages of analysis of drugs in hair samples are recognized for the long window of detection, alongside easy sampling and long stability after sample collection. Alcohol markers, ethyl glucuronide (EtG) and total fatty acid ethyl esters (FAEEs) in hair, are widely used for monitoring alcohol consumption for clinical and forensic purposes. Although stability of drugs and EtG in hair samples is documented to a certain extent, stability of FAEEs in hair samples after collection has not been reported. This study covered hair samples that had been tested for FAEEs on the day of arrival at the laboratory and retested between 4 and 80 months later. The statistical analysis of the data set reveals significant lower FAEEs levels including ethyl palmitate (EtPa) ester levels when samples were retested for the second time after 6 days of storage under ideal conditions. Specifically, the results suggest that when measuring total FAEEs or solely EtPa in hair samples, the elapsed time between sample collection and analysis of the sample needs to be considered when interpreting the results. The recommendation is that whenever hair samples need to be tested for total FAEEs or EtPa, the analytical procedure needs to be performed within 1 week after collection in order to obtain meaningful results. The study results substantiate the case for the use of hair samples solely for the analysis of EtG, in conjunction with other measurements such as full blood count, carbohydrate-deficient transferrin test, liver function test or phosphatidylethanol alongside clinical assessment for a more effective evaluation of alcohol consumption.

Determination of ethyl glucuronide in human hair samples: Decontamination vs extraction

Decontamination of samples prior to analysis is common practice and recommended for ethyl glucuronide (EtG) hair testing. The aim of this study was to evaluate the applied decontamination procedure during routine hair EtG analysis by monitoring the ethyl glucuronide concentrations in the washing solutions from a representative cohort of individual hair samples. Hair samples from 150 individuals were tested for hair EtG by a validated routine procedure (liquid chromatography/tandem mass spectrometry). A four-step decontamination procedure (ethanol, water, acetone, dichloromethane) was applied to all samples prior to analysis. Hair samples from 20 individuals were analyzed along with the complete set of individual washing solutions. Hair samples from an additional 130 individuals were analyzed along with the corresponding aqueous wash fraction only. No EtG was detected in the washing solutions from hair samples that tested negative for EtG (n = 42). Hair samples positive for ethyl glucuronide (n = 108) were found to liberate different amounts of EtG during decontamination: whereas no, or low portions of, EtG (< 10% of extracted hair EtG) were found in the corresponding washing solutions of the majority (n = 91) of individual samples, there was a minority of samples (n = 6) with more than half of the extracted hair EtG present in the decontamination solvent. No correlation of the decontaminated amount of EtG and the extracted hair EtG was observed. Further experimental studies are necessary to investigate if the observed easily removable fraction of EtG is associated with external contamination and if analysis of wash solutions could be helpful for identifying external contamination in hair testing for ethyl glucuronide.