Levels and types of alcohol biomarkers in DUI and clinic samples for estimating workplace alcohol problems

Brief history of the alcohol biomarkers CDT, EtG, EtS, 5-HTOL, and PEth

This article traces the historical development of various biomarkers of acute and/or chronic alcohol consumption. Much of the research in this domain of clinical and laboratory medicine arose from clinics and laboratories in Sweden, as exemplified by carbohydrate deficient transferrin (CDT) and phosphatidylethanol (PEth). Extensive studies of other alcohol biomarkers, such as ethyl glucuronide (EtG), ethyl sulfate (EtS), and 5-hydroxytryptophol (5-HTOL), also derive from Sweden. The most obvious test of recent drinking is identification of ethanol in a sample of the person's blood, breath, or urine. However, because of continuous metabolism in the liver, ethanol is eliminated from the blood at a rate of 0.15 g/L/h (range 0.1-0.3 g/L/h), so obtaining positive results is not always possible. The widow of detection is increased by analysis of ethanol's non-oxidative metabolites (EtG and EtS), which are more slowly eliminated from the bloodstream. Likewise, an elevated ratio of serotonin metabolites in urine (5-HTOL/5-HIAA) can help to disclose recent drinking after ethanol is no longer measurable in body fluids. A highly specific biomarker of hazardous drinking is CDT, a serum glycoprotein (transferrin), with a deficiency in its N-linked glycosylation. Another widely acclaimed biomarker is PEth, an abnormal phospholipid synthesized in cell membranes when people drink excessively, having a long elimination half-life (median ~6 days) during abstinence. Research on the subject of alcohol biomarkers has increased appreciably and is now an important area of drug testing and analysis.

Relation between age at first alcohol drink & adult life drinking patterns in alcohol-dependent patients

Background & objectives:

Age at first drink has its influence on later life drinking patterns. The association between age at first drink and adult alcohol consumption has not been studied in clinical population. This study was aimed to determine the age at first drink and its correlation with adult life drinking patterns in alcohol-dependent patients.

Methods:

Adult participants with alcohol dependence were included from the inpatient and outpatient wards of a tertiary care de-addiction facility in India. Questionnaires administered were National Institute on Alcohol Abuse and Alcoholism-Quantity Frequency for alcohol and the Fagerstrom Test for Nicotine Dependence for tobacco.

Results:

Of the 99 participants (92% males) with mean age 37±8.36 yr, mean age at first drink was 21.14±5.33 yr. After controlling for age, satisfaction with life scores and smoking, age at first drink showed a significant negative correlation with drinking days per week (r=-0.259, P=0.012), typical drink per day (r=-0.218, P=0.035) and maximum drinks in the previous month/year (r=-0.233, -0.223 and P=0.024, 0.031, respectively).

Interpretation & conclusions:

Our study suggested that earlier age of first drink correlated with chronic heavy drinking patterns in later adult life in alcohol-dependent patients. This may have implications for alcohol control policies determining the age for legal consumption.

A utilitarian comparison of two alcohol use biomarkers with self-reported drinking history collected in antenatal clinics

BACKGROUND

Alcohol use is reported accurately among pregnant women in some populations.

METHODS

Self-reported alcohol use via the AUDIT and 90-day recall for 193 women from antenatal clinics was compared to biomarker results: phosphatidylethanol (PEth) from bloodspots and ethyl glucuronide (EtG) in fingernails.

RESULTS

AUDIT was positive for 67.9% of respondents, and 65.3% directly reported drinking. Individual biomarkers detected less drinking (PEth = 57.0%, EtG = 38.9%) than self-report. But 64.8% had drinking-positive values (>8 ng) on one or both biomarkers, which was not significantly different from self-report. Biomarkers indicated that 3.1% -6.8% of drinkers denied drinking. Combined biomarker sensitivity was 95% -80% and specificity 49% -76% for drinking in the previous 7-90 days. Combined biomarker results have their best yield (89.6%) and accuracy (78.8%) when measuring 90 day drinking.

CONCLUSIONS

Women reported their alcohol use accurately, and the combined use of PEth and EtG is supported.

Analytical and diagnostic aspects of carbohydrate deficient transferrin (CDT): A critical review over years 2007-2017

The need for investigating alcohol abuse by means of objective tools is worldwide accepted. Among the currently available biomarkers of chronic alcohol abuse, carbohydrate-deficient transferrin (CDT) is one of the most used indicator, mainly because of its high specificity. However, some CDT analytical and interpretation aspects are still under discussion, as witnessed by numerous research papers and reviews. The present article presents a critical review of the literature on CDT appeared in the period from 2007 to 2017 (included). The article is organized in the following sections: (1) introduction, (2) pre-analytical aspects (3) analytical aspects (4) diagnostic aspects (5) concluding remarks. As many as 139 papers appeared in the international literature and retrieved by the search engines PubMed, Web of Science and Scopus are quoted.

Mandating Treatment Based on Interlock Performance: Evidence for Effectiveness

BACKGROUND

Vehicle alcohol ignition interlocks reduce alcohol-impaired driving recidivism while installed, but recidivism reduction does not continue after removal. It has been suggested that integrating alcohol use disorder (AUD) treatment with interlock programs might extend the effectiveness of interlocks in reducing recidivism beyond their removal. This study evaluated the first implementation of a Florida policy mandating AUD treatment for driving under the influence (DUI) offenders on interlocks. Treatment was required when the offender accumulated 3 violations (defined as 2 "lockouts" within 4 hours; a lockout occurs when the device prevents a drinking driver from starting the vehicle).

METHODS

Cox regression was used to compare alcohol-impaired driving recidivism during the 48 months following the interlock removal between 2 groups: (i) 640 multiple DUI offenders who received AUD treatment while interlocks were installed; and (ii) 806 matched offenders not mandated to treatment while interlocks were installed.

RESULTS

The ignition interlock plus treatment group experienced 32% lower recidivism, 95% confidence interval [9, 49], following the removal of the interlock during the 12 to 48 months in which they were compared with the nontreatment group. We estimated that this decline in recidivism would have prevented 41 rearrests, 13 crashes, and almost 9 injuries in crashes involving the 640 treated offenders over the period following interlock removal.

CONCLUSIONS

This study provides strong support for the inclusion of AUD treatment for offenders in interlock programs based on the number of times they are "locked out." The offenders required to attend treatment demonstrated a one-third lower DUI recidivism following their time on the interlock compared to similar untreated offenders.

Quantitation of Ethyl Glucuronide and Ethyl Sulfate in Urine Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Ethyl glucuronide and ethyl sulfate are minor conjugated metabolites of ethanol that can be detected in urine for several days after last ingestion of ethanol. The monitoring of ethanol use has both clinical and forensic applications and a longer detection window afforded by monitoring these metabolites is obvious. LC-MS/MS is used to analyze diluted urine with deuterated analogs of each analyte as internal standards to ensure accurate quantitation and control for any potential matrix effects. High aqueous HPLC is used to chromatograph the metabolites. Negative ion electrospray is used to introduce the metabolites into the mass spectrometer. Selected reaction monitoring of two product ions for each analyte allows for the calculation of ion ratios which ensures correct identification of each metabolite, while a matrix-matched calibration curve is used for quantitation.

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions

BACKGROUND

The quantitative, measurable detection of drinking is important for the successful treatment of alcohol misuse in transplantation of patients with alcohol disorders, people living with human immunodeficiency virus that need to adhere to medication, and special occupational hazard offenders, many of whom continually deny drinking. Their initial misconduct usually leads to medical problems associated with drinking, impulsive social behavior, and drunk driving. The accurate identification of alcohol consumption via biochemical tests contributes significantly to the monitoring of drinking behavior.

METHODS

A systematic review of the current methods used to measure biomarkers of alcohol consumption was conducted using PubMed and Google Scholar databases (2010-2015). The names of the tests have been identified. The methods and publications that correlate between the social instruments and the biochemical tests were further investigated. There is a clear need for assays standardization to ensure the use of these biochemical tests as routine biomarkers.

FINDINGS

Alcohol ingestion can be measured using a breath test. Because alcohol is rapidly eliminated from the circulation, the time for detection by this analysis is in the range of hours. Alcohol consumption can alternatively be detected by direct measurement of ethanol concentration in blood or urine. Several markers have been proposed to extend the interval and sensitivities of detection, including ethyl glucuronide and ethyl sulfate in urine, phosphatidylethanol in blood, and ethyl glucuronide and fatty acid ethyl esters in hair, among others. Moreover, there is a need to correlate the indirect biomarker carbohydrate deficient transferrin, which reflects longer lasting consumption of higher amounts of alcohol, with serum γ-glutamyl transpeptidase, another long term indirect biomarker that is routinely used and standardized in laboratory medicine.

Accounting for sex-related differences in the estimation of breath alcohol concentrations using transdermal alcohol monitoring

RATIONALE

Previously, we reported methods to estimate peak breath alcohol concentrations (BrAC) from transdermal alcohol concentrations (TAC) under conditions where alcohol consumption was controlled to produce similar BrAC levels in both sexes.

OBJECTIVE

This study characterized differences in the relationship between BrAC and TAC as a function of sex and developed a model to predict peak BrAC that accounts for known sex differences in peak BrAC.

METHODS

TAC and BrAC were monitored during the consumption of a varying number of beers on different days. Both men (n=11) and women (n=10) consumed one, two, three, four, and five beers at the same rate in a 2-h period. Sex and sex-related variables were considered for inclusion in a multilevel model to develop an equation to estimate peak BrAC levels from TAC.

RESULTS

While peak BrAC levels were significantly higher in women than men, sex differences were not significant in observed TAC levels. This lack of correspondence was evidenced by significant sex differences in the relationship between peak TAC and peak BrAC. The best model to estimate peak BrAC accounted for sex-related differences by including peak TAC, time-to-peak TAC, and sex. This model was further validated using previously collected data.

CONCLUSIONS

The relationship between peak TAC and actual peak BrAC differs between men and women, and these differences can be accounted for in a statistical model to better estimate peak BrAC. Further studies are required to extend these estimates of peak BrAC to the outpatient environment where naturalistic drinking occurs.

Do variable rates of alcohol drinking alter the ability to use transdermal alcohol monitors to estimate peak breath alcohol and total number of drinks?

BACKGROUND

Transdermal alcohol monitoring is a noninvasive method that continuously gathers transdermal alcohol concentrations (TAC) in real time; thus, its use is becoming increasingly more common in alcohol research. In previous studies, we developed models that use TAC data to estimate peak breath alcohol concentration (BrAC) and standard units consumed when the rate of consumption was tightly controlled.

METHODS

Twenty-two healthy participants aged 21 to 52 who reported consuming alcohol on 1 to 4 days per week were recruited from the community. The final study sample included 11 men and 8 women. Both TAC and BrAC were monitored while each participant drank 1, 2, 3, 4, and 5 beers in the laboratory on 5 separate days. In contrast to previous studies, a self-paced alcohol administration procedure was used.

RESULTS

While there was considerable variation in the times it took to consume each beer, key TAC parameters were not affected by pace of drinking. TAC data were then used in combination with the previously derived equations and estimated peak BrAC and standard units of alcohol consumed.

CONCLUSIONS

Transdermal alcohol monitoring can be used to reliably estimate peak BrAC and standard number of units consumed regardless of the rate of consumption, further demonstrating its usefulness in clinical research.

Use of continuous transdermal alcohol monitoring during a contingency management procedure to reduce excessive alcohol use

BACKGROUND

Research on contingency management to treat excessive alcohol use is limited due to feasibility issues with monitoring adherence. This study examined the effectiveness of using transdermal alcohol monitoring as a continuous measure of alcohol use to implement financial contingencies to reduce heavy drinking.

METHODS

Twenty-six male and female drinkers (from 21 to 39 years old) were recruited from the community. Participants were randomly assigned to one of the two treatment sequences. Sequence 1 received 4 weeks of no financial contingency (i.e., $0) drinking followed by 4 weeks each of $25 and then $50 contingency management; Sequence 2 received 4 weeks of $25 contingency management followed by 4 weeks each of no contingency (i.e., $0) and then $50 contingency management. During the $25 and $50 contingency management conditions, participants were paid each week when the Secure Continuous Remote Alcohol Monitor (SCRAM-II™) identified no heavy drinking days.

RESULTS

Participants in both contingency management conditions had fewer drinking episodes and reduced frequencies of heavy drinking compared to the $0 condition. Participants randomized to Sequence 2 (receiving $25 contingency before the $0 condition) exhibited less frequent drinking and less heavy drinking in the $0 condition compared to participants from Sequence 1.

CONCLUSIONS

Transdermal alcohol monitoring can be used to implement contingency management programs to reduce excessive alcohol consumption.

Ethylglucuronide in hair is a top predictor of impaired driving recidivism, alcohol dependence, and a key marker of the highest BAC interlock tests

OBJECTIVES

This study focuses on the predictive and comparative significance of ethyl glucuronide measured in head hair (hEtG) for estimating risks associated with alcohol-impaired driving offenders. Earlier work compared different alcohol biomarkers for estimating rates of failed blood alcohol concentration (BAC) tests logged during 8 months of interlock participation. These analyses evaluate the comparative performance of several alcohol markers including hEtG and other markers, past driver records, and psychometric assessment predictors for the detection of 4 criteria: new driving under the influence (DUI) recidivism, alcohol dependence, and interlock record variables including fail rates and maximal interlock BACs logged.

METHODS

Drivers charged with alcohol impairment (DUI) in Alberta, Canada (n = 534; 64% first offenders, 36% multiple offenders) installed ignition interlock devices and consented to participate in research to evaluate blood-, hair-, and urine-derived alcohol biomarkers; sit for interviews; take psychometric assessments; and permit analyses of driving records and interlock log files. Subject variables included demographics, alcohol dependence at program entry, preprogram prior DUI convictions, postenrollment new DUI convictions, self-reported drinking assessments, morning and overall rates of failed interlock BAC tests, and maximal interlock BAC readings. Recidivism, dependence, high BAC, and combined fail rates were set as criteria; other variables were set as predictors. Area under the receiver operating characteristics (ROC) curve (A') estimates of sensitivity and specificity were calculated. Additional analyses were conducted on baseline hEtG levels. Driver performance and drinking indicators were evaluated against the standard hEtG cutoff for excessive drinking at (30 pg/mg) and a higher criterion of 50 pg/mg. HEtG splits were evaluated with the Mann-Whitney rank statistic.

RESULTS

HEtG emerged as a top overall predictor for discriminating new recidivism events that occur after interlock installation, for entry alcohol dependence, and for the highest interlock BACs recorded. Together, hEtG and phosphatidylethanol (PEth) were the top predictors of all criterion measures. By contrast, the hair-derived alcohol biomarkers hEtG and hFAEE (fatty acid ethyl esters) were poorer than other alcohol biomarkers as detectors of interlock BAC test fail rates.

CONCLUSIONS

This study showed that hEtG, an objective alternative to often unreliable self-reported past representation of drinking levels, yields crucial insight into driver alcohol-related risks early in an interlock program and is a top predictor of new recidivist events. Together with PEth, these markers would be excellent anchors in a panel for detecting alcohol consumption.

Multivariate strategies for screening evaluation of harmful drinking

Background: A chemometric class modeling strategy (unequal dispersed classes [UNEQ]) is applied for the first time to evaluate harmful alcohol drinking within large population screening programs, in comparison with traditional strategies of data interpretation. Five inexpensive indirect biomarkers (aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, mean corpuscular volume and carbohydrate-deficient transferrin) were determined in blood samples from 423 patients, classified as low-risk or harmful drinkers, according to their ethanol consumption. Results: The multivariate UNEQ approach remarkably improves the diagnostic performances of indirect biomarkers in harmful drinking evaluation, leading to reliable decision rules, with few doubtful classifications to be reviewed through complex confirmation procedures. Conclusion: This UNEQ model represents an innovative general approach for clinical evaluation that efficiently extracts the information content present in each biomarker to provide a new synthetic multivariate parameter, to be directly used in diagnostic protocols.

Carbohydrate deficient transferrin and alcoholism

Alcohol abuse is an important public health problem, with major implications in patients with a pre-existing liver pathology of viral origin. Hepatitis C, for example, is one of the diseases in which alcohol consumption can lead to the transition from a fairly benign outline to a potentially life-threatening liver disease. Alcohol abuse is usually identified on the basis of clinical judgment, alcoholism related questionnaires, laboratory tests and, more recently, biomarkers. Also on this list of tests, carbohydrate deficient transferrin (CDT) is widely available and useful for determining recent alcohol consumption, particularly when corroborated with elevation of other liver-associated enzymes. Clinicians should be aware of the indications and limitations of this test in order to better evaluate alcohol consumption in their patients.