Phosphatidylethanol Reliably and Objectively Quantifies Alcohol Consumption in Adolescents and Young Adults

AUDIT C compared to PEth in middle-aged volunteers

AIMS

To compare Alcohol Use Disorders Identification Test (AUDIT C) to phosphatidylethanol (PEth) in middle-aged randomly selected volunteers. Apply previously suggested lower cut-offs for PEth using moderate alcohol intake according to AUDIT C as a reference.

METHODS

Within the Swedish CardioPulmonary BioImage Study, 2255 middle-aged (50-64 years of age) volunteers in northern Sweden participated in comparing AUDIT C to PEth 16:0/18:1.

RESULTS

There was a moderate correlation between PEth 16:0/18:1 and AUDIT C (r = 0.66). None of the participants with the AUDIT C-score 0 had a measurable PEth. Of moderate alcohol consumers, according to AUDIT C (AUDIT C 1-3 women, 1-4 men), 96% had a PEth below 0.3 μmol/L, 91% had a PEth below 0.16 μmol/L, and 84% had a PEth below 0.11 μmol/L. With PEth equivalent to excessive alcohol consumption (≥0.3 μmol/L), 26% had an AUDIT C-score below excessive alcohol consumption (<4 for women and <5 for men). Thirty percent of patients with a PEth ≥0.16 μmol/L had an AUDIT C-score below excessive alcohol consumption, and 37% had a PEth ≥0.11 μmol/L. We found no significant correlation between BMI and PEth or AUDIT C.

CONCLUSIONS

There is a significant correlation between AUDIT C and PEth. Using AUDIT C alone, 26% of high-consumers, according to PEth, are not found in our cohort, but an AUDIT C-score of 0 will exclude high consumption, according to PEth. Our findings support the current cut-off for PEth of 0.3 μmol/L, but a lower cut-off seems reasonable.

Prevalence and change in alcohol consumption in older adults over time, assessed with self-report and Phosphatidylethanol 16:0/18:1 -The HUNT Study

BACKGROUND

Changes in alcohol consumption may affect older adults' health. We examined prevalence and changes in the alcohol consumption of older women and men (≥65 years) in Norway over a 24-year period.

METHODS

Data from three population-based health surveys (The Trøndelag Health Study-HUNT2 1995-97, HUNT3 2006-08, HUNT4 2017-19) were used. Alcohol consumption was measured using self-reported measures and an objective measure of alcohol consumption (Phosphatidylethanol 16:0/18:1, PEth). Self-reported lifetime abstinence, former drinking, current drinking, frequent drinking (≥4 times/week), and risk drinking (≥8 units/week) were measured. The PEth concentrations were stratified: <0.03 μmol/l (abstinence/very low level of alcohol consumption); >0.06 μmol/l (indicating >1 unit/day); >0.10 μmol/l (indicating >3 units/day), and >0.30 μmol/l (heavy alcohol consumption).

RESULTS

In HUNT4, the prevalence of self-reported lifetime abstinence, frequent drinking, and risk drinking was 5.2%, 4.4%, and 5.6%, respectively, while prevalence of PEth <0.03 μmol/l was 68.1% and PEth >0.06 μmol/l was 21.2%. Over the course of the three surveys, the prevalence of self-reported lifetime abstinence decreased, while the prevalence of frequent drinking and risk drinking increased. Men were less often abstainers and more often frequent and risky drinkers than women in all three surveys. Gender differences for abstinence and current drinking reduced with time. From HUNT3 to HUNT4, the prevalence of PEth <0.03 μmol/l decreased, while the prevalence of PEth >0.06 μmol/l increased. Men compared to women, had less often PEth <0.03 μmol/l and more often PEth >0.06 and >0.10 μmol/l in HUNT3 and HUNT4. Women and men ≥75 years were just as likely to have PEth >0.30 μmol/l in HUNT4. The gender differences in PEth concentrations were reduced in HUNT4 among those aged 70-74 years or ≥75 years.

CONCLUSION

Alcohol consumption has increased among Norwegian older adults over a 24-year period, but at a slower pace during the last decade.

In Vivo Administration of Phosphatidic Acid, a Direct Alcohol Target Rescues Fetal Growth Restriction and Maternal Uterine Artery Dysfunction in Rat FASD Model

Fetal growth restriction is a hallmark of Fetal Alcohol Syndrome (FAS) and is accompanied by maternal uterine circulatory maladaptation. FAS is the most severe form of Fetal Alcohol Spectrum Disorder (FASD), a term for the range of conditions that can develop in a fetus when their pregnant mother consumes alcohol. Alcohol exerts specific direct effects on lipids that control fundamental developmental processes. We previously demonstrated that direct in vitro application of phosphatidic acid (PA, the simplest phospholipid and a direct target of alcohol exposure) to excised uterine arteries from alcohol-exposed rats improved vascular function, but it is unknown if PA can rescue end organ phenotypes in our FASD animal model. Pregnant Sprague-Dawley rats (n = 40 total dams) were gavaged daily from gestational day (GD) 5 to GD 19 with alcohol or maltose dextrin, with and without PA supplementation, for a total of four unique groups. To translate and assess the beneficial effects of PA, we hypothesized that in vivo administration of PA concomitant with chronic binge alcohol would reverse uterine artery dysfunction and fetal growth deficits in our FASD model. Mean fetal weights and placental efficiency were significantly lower in the binge alcohol group compared with those in the control (p < 0.05). However, these differences between the alcohol and the control groups were completely abolished by auxiliary in vivo PA administration with alcohol, indicating a reversal of the classic FAS growth restriction phenotype. Acetylcholine (ACh)-induced uterine artery relaxation was significantly impaired in the uterine arteries of chronic in vivo binge alcohol-administered rats compared to the controls (p < 0.05). Supplementation of PA in vivo throughout pregnancy reversed the alcohol-induced vasodilatory deficit; no differences were detected following in vivo PA administration between the pair-fed control and PA alcohol groups. Maximal ACh-induced vasodilation was significantly lower in the alcohol group compared to all the other treatments, including control, control PA, and alcohol PA groups (p < 0.05). When analyzing excitatory vasodilatory p1177-eNOS, alcohol-induced downregulation of p1177-eNOS was completely reversed following in vivo PA supplementation. In summary, these novel data utilize a specific alcohol target pathway (PA) to demonstrate a lipid-based preventive strategy and provide critical insights important for the development of translatable interventions.

Scoping review of assessment tools for, magnitudes of and factors associated with problem drinking in population-based studies

BACKGROUND

The term "problem drinking" includes a spectrum of alcohol problems ranging from excessive or heavy drinking to alcohol use disorder. Problem drinking is a leading risk factor for death and disability globally. It has been measured and conceptualised in different ways, which has made it difficult to identify common risk factors for problem alcohol use. This scoping review aims to synthesise what is known about the assessment of problem drinking, its magnitude and associated factors.

METHODS

Four databases (PubMed, Embase, PsycINFO, Global Index Medicus) and Google Scholar were searched from inception to 25 November 2023. Studies were eligible if they focused on people aged 15 and above, were population-based studies reporting problem alcohol use and published in the English language. This review was reported based on guidelines from the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews Checklist'. Critical appraisal was done using the Newcastle-Ottawa Scale.

RESULTS

From the 14 296 records identified, 10 749 underwent title/abstract screening, of which 352 full-text articles were assessed, and 81 articles were included for data extraction. Included studies assessed alcohol use with self-report quantity/frequency questionnaires, criteria to determine risky single occasion drinking, validated screening tools, or structured clinical and diagnostic interviews. The most widely used screening tool was the Alcohol Use Disorder Identification Test. Studies defined problem drinking in various ways, including excessive/heavy drinking, binge drinking, alcohol use disorder, alcohol abuse and alcohol dependence. Across studies, the prevalence of heavy drinking ranged from <1.0% to 53.0%, binge drinking from 2.7% to 48.2%, alcohol abuse from 4.0% to 19.0%, alcohol dependence from 0.1% to 39.0% and alcohol use disorder from 2.0% to 66.6%. Factors associated with problem drinking varied across studies. These included sociodemographic and economic factors (age, sex, relationship status, education, employment, income level, religion, race, location and alcohol outlet density) and clinical factors (like medical problems, mental disorders, other substance use and quality of life).

CONCLUSIONS

Due to differences in measurement, study designs and assessed risk factors, the prevalence of and factors associated with problem drinking varied widely across studies and settings. The alcohol field would benefit from harmonised measurements of alcohol use and problem drinking as this would allow for comparisons to be made across countries and for meta-analyses to be conducted.

TRIAL REGISTRATION NUMBER

Open Science Framework ID: https://osf.io/2anj3.

Hematocrit Correction of Whole Blood Phosphatidylethanol Concentrations to Estimate Erythrocyte PEth Concentrations: Sensitivity, Specificity and Influence on Test Utility

Phosphatidylethanol (PEth) forms in erythrocyte membranes after alcohol consumption, offering a persisting biomarker, that is measurable in whole blood, washed erythrocytes and dried blood spots. For a predominantly erythrocyte-restricted analyte, erythrocyte concentrations seem to have most validity in patients who are anemic through alcoholism or other pathologies, despite preparation increasing assay complexity. Differences in specimen preparation alter PEth concentrations for the same patient, meaning that criteria for interpreting PEth results should relate to specimen type, presenting a barrier to achieving harmonization. We therefore tested whether erythrocyte PEth might be validly calculated by hematocrit correction of a whole blood PEth measurement. PEth testing primarily serves to distinguish drinkers from non-drinkers. In choosing between specimen types, it is important to compare their utility in separating those two groups. We therefore processed 281 blood samples from 17 non-drinkers and 61 drinkers, to prepare matched whole blood and washed erythrocyte specimens. These were assayed by liquid chromatography-tandem mass spectrometry and compared in identifying alcohol consumption. The erythrocyte PEth concentration in the whole blood specimens was also calculated by correcting whole blood concentration by the specimen's hematocrit, as an alternative to prepare washed erythrocytes. The hematocrit-corrected erythrocyte concentrations were included in these comparisons. Predictably, this work found that sensitivity was consistently better at the lower cut-off of 8 µg/L than at 20 µg/L. Sensitivities were also higher for washed erythrocytes than whole blood, explained by the lower erythrocyte mass in the same volume of whole blood. Hematocrit-corrected whole blood PEth concentrations correlated with erythrocyte concentrations, except for the four highest values, which did not influence comparative sensitivity. Specificity was 100% for washed erythrocytes, whole blood and hematocrit-corrected whole blood at either cut-off because non-drinkers had undetectable PEth. We conclude that hematocrit correction of whole blood PEth concentrations theoretically provides an alternative to the preparation of washed erythrocytes.

Can PEth be Detected with a Cutoff of 20 ng/mL after Single Alcohol Consumption?

Phosphatidylethanol (PEth) can be determined in capillary blood collected as dried blood spots (DBS) and is a promising direct alcohol biomarker for the determination of drinking habits. Its use for abstinence monitoring needs to be evaluated. Studies with patients undergoing alcohol withdrawal have shown that the elimination of PEth can take up to 2 months. For the determination of PEth 16:0/18:1, a cutoff of 20 ng/mL has been agreed upon in the major US laboratories. However, it is not yet clear what minimum blood alcohol concentrations (BACs) have to be achieved by a single drinking episode to result in PEth concentrations above this cutoff after previous long-term abstinence. To determine whether low drinking amounts can result in a positive PEth concentration above 20 ng/mL, we recruited 12 participants ('social' drinkers). After 4 weeks of abstinence, alcohol was consumed at two separate drinking events with target BACs of 0.5 and 0.3 g/kg, resulting in maximum BACs in the ranges of 0.30-0.63 g/kg and 0.10-0.28 g/kg, respectively. Capillary blood was collected at different time points of the drinking experiment, and PEth was extracted from DBS and analyzed by liquid chromatography-tandem mass spectrometry. Despite drinking doses up to 0.58 g ethanol per kg body weight and reaching BACs of up to 0.63 g/kg, PEth 16:0/18:1 and PEth 16:0/18:2 could not be detected at or above the 20 ng/mL cutoff in any participant at any time after the drinking events. We conclude that after long-term abstinence the cutoff of 20 ng/mL for single alcohol consumption leading to BACs up to 0.63 g/kg is not exceeded.

Assessing the sensitivity and specificity of phosphatidylethanol (PEth) cutoffs to identify alcohol exposed pregnancies

In the literature on alcohol use biomarkers, there has been debate as to what a valid and/or utilitarian cut off level should be for various research applications. In this manuscript, we assessed the sensitivity and specificity of multiple cutoff values for phosphatidylethanol (PEth) from bloodspots relative to self-report, the Alcohol Use Disorder Identification Test (AUDIT) scores, and another alcohol use biomarker ethyl glucuronide (EtG) from fingernails in a sample of 222 pregnant women in the Western Cape Province of South Africa. Receiver operating characteristic (ROC) curves were used to assess the area under the curve (AUC) and assess PEth cutoff values of ≥2, ≥4, ≥8, ≥14, and ≥20 nanograms per milliliter (ng/ml). The highest AUC value was attained when PEth was compared to an AUDIT score of 1 or more. Depending on the cutoff used to determine alcohol consumption, PEth identified 47%-70% of the individuals as alcohol-consuming while 62.6%-75.2% were identified by self-reported measures, and 35.6% were identified by EtG. In this sample, sensitivity and accuracy were highest at less stringent PEth cutoffs when compared to self-report, AUDIT score of 1 or more, 5 or more, 8 or more, and EtG ≥ 8 picograms per milligram (pg/mg). For research purposes, less stringent cutoffs, such as PEth ≥ 8 ng/ml, may be considered a valid, positive cutoff for identifying women who consume alcohol during pregnancy in this population. A cutoff of PEth ≥ 20 ng/ml may miss individuals who reported consuming alcohol (false negatives).

Screening for hazardous alcohol use in the Emergency Department: Comparison of phosphatidylethanol with the Alcohol Use Disorders Identification Test and the Timeline Follow-back

BACKGROUND

Up to 15% of all visits to the Emergency Department (ED) are alcohol related. Identification of problematic alcohol use is important in this setting because it allows for intervention and prevention efforts. This study investigated the correlation between the objective phosphatidylethanol (PEth) marker and the subjective Alcohol Use Disorders Identification Test (AUDIT) and Timeline Followback Questionnaire (TLFB) as screening methods for hazardous alcohol use in the general ED population.

METHODS

This prospective cohort study included 301 ED patients (57% male) who were seen in the ED and required to give a blood sample. The correlation between the values of PEth (PEth 16:0/18:1 and PEth 16:0/18:2) and the scores on the AUDIT and TLFB were analyzed using Spearman's rank correlation coefficient. Differences between risk categories of PEth and AUDIT were also examined.

RESULTS

The Spearman correlation coefficients between PEth 16:0/18:1|PEth 16:0/18:2 values and the AUDIT scores were moderate (PEth 16:0/18:1: 0.67, p < 0.001; PEth 16:0/18:2: 0.67, p < 0.001). Of the patients who scored 'low risk drinking/abstinence' according to the AUDIT questionnaire, respectively 1% and 4% had PEth 16:0/18:1|PEth 16:0/18:2 values indicating excessive alcohol use, and another 10% and 12% had PEth 16:0/18:1|PEth 16:0/18:2 values indicating moderate alcohol consumption. Of the 12 (PEth 16:0/18:1) and 25 (PEth 16:0/18:2) patients with high-risk values, respectively 25% and 40% scored in the lowest risk category on the AUDIT questionnaire. Spearman correlation coefficients between PEth 16:0/18:1|PEth 16:0/18:2 values and TLFB two-week scores were high (PEth 16:0/18:1: 0.74, p < 0.001; PEth 16:0/18:2: 0.82, p < 0.001).

CONCLUSIONS

AUDIT scores were moderately correlated with PEth values in the general ED population. In almost all cases where there was not a good correlation, patients had high PEth values with low AUDIT scores. We conclude that PEth identifies patients with problematic alcohol use who are missed by the AUDIT questionnaire and therefore PEth could be used as an additional screening method for hazardous alcohol use in this population.

Validity of fatty liver disease indices in the presence of alcohol consumption

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) and alcohol-related liver disease frequently coexist. While several blood-based indices exist for the detection of NAFLD, few studies have examined how alcohol use possibly impacts their diagnostic performance. We analysed the effects of alcohol use on the performance of indices for detecting fatty liver disease (FLD).

METHODS

We included participants from the Cardiovascular Risk in Young Finns Study (Finnish sample) and KORA study (German sample) who underwent abdominal ultrasound or magnetic resonance imaging, respectively, for detection of FLD and had serum analyses available for calculation of Fatty Liver Index (FLI), Hepatic Steatosis Index (HSI), Lipid Accumulation Product (LAP), and Dallas Steatosis Index (DSI). Alcohol use was estimated by questionnaires as mean daily consumption and binge drinking (Finnish sample only). Predictive performance for FLD was assessed according to alcohol consumption.

RESULTS

The study included 1426 (Finnish sample) and 385 (German sample) individuals, of which 234 (16%) and 168 (44%) had FLD by imaging. When alcohol consumption was <50 g/day, all indices discriminated FLD with area under the receiver operating characteristics (AUROC) of 0.82-0.88. AUROCs were 0.61-0.66 among heavy drinkers (>50 g/day). AUROCs decreased to 0.74-0.80 in the highest binge-drinking category (>2 times/week). Alcohol use correlated with FLI and LAP (r-range 0.09-0.16, p-range <.001-.02) in both samples and with DSI (r = 0.13, p < .001) in the Finnish sample.

CONCLUSIONS

Indices perform well and comparably for detection of FLD with alcohol consumption <50 g/day and with different binge-drinking behaviour.

Set-up of a population-based model to verify alcohol abstinence via monitoring of the direct alcohol marker phosphatidylethanol 16:0/18:1

BACKGROUND AND AIMS

Phosphatidylethanol 16:0/18:1 (PEth) is a biomarker for alcohol intake. It has a half-life of 7.9 days. Chronic alcohol consumption causes high PEth values. It can take weeks before PEth values fall below the decision limit for 'alcohol abstinence'. Our aim was to validate whether alcohol abstinence can be determined based on two consecutive PEth results above the decision limit.

DESIGN

Observational study.

SETTING

Belgium, February 2019. The study was linked to a social initiative in Belgium, 'Tournée Minérale'.

PARTICIPANTS

Adults (aged > 18 years, n = 796) with varying drinking habits who self-reportedly refrained from alcohol consumption during the study.

MEASUREMENTS

A validated liquid chromatography-tandem mass spectrometry method was used to quantify PEth in participants' dried blood samples, collected at three time-points via remote fingerprick-based self-sampling.

FINDINGS

A population-based algorithm to evaluate abstinence based on 95% prediction limits was developed by fitting a linear mixed-effect model to discern patterns in PEth elimination over time. It took intra- and inter-individual variability into consideration. The algorithm was included in a two-step decision tree, assessing whether (i) PEth values fell within the prediction interval and (ii) the slope between two PEth values was consistent with no alcohol consumption. Data for 74 participants reporting no alcohol intake during the study were used for validation. With a detection limit of 'four units spread over 14 days', the sensitivity and specificity of the decision tree was 89%.

CONCLUSIONS

Claims of alcohol abstinence can be verified using a two-step decision tree for phosphatidylethanol 16:0/18:1 values, even when those values are above the limit for 'alcohol abstinence'.

Identification of unhealthy alcohol use by self-report and phosphatidylethanol (PEth) blood concentrations in an acute psychiatric department

BACKGROUND

The use of standard screening methods could improve the detection rate of unhealthy alcohol use in patients admitted to psychiatric acute and emergency departments. The aim of the present study was to investigate the ability of the alcohol biomarker phosphatidylethanol (PEth) to identify patients with high levels of alcohol consumption prior to admission.

METHODS

The data were prospectively collected at admittance to an acute psychiatric department in the period January 2016 to June 2017. A blood sample for the analysis of PEth was available from 177 patients. We compared the PEth concentrations with the Alcohol Use Disorders Identification Test (AUDIT) scores during the hospital stay, and psychiatric diagnoses at discharge.

RESULTS

A total of 45.8% of the patients had a PEth concentration ≥ 0.03 μmol/L, indicating significant alcohol consumption. AUDIT scores consistent with unhealthy alcohol use were present in 51.7%. There was a significant positive correlation between PEth concentrations and AUDIT scores (r = 0.631, p < 0.001). PEth was above the detection limit of 0.03 μmol/L in 19% of those reporting an average daily intake of zero alcohol units per day during the last week before admission. PEth concentrations were significantly higher among those with an alcohol diagnosis than among those without such a diagnosis (0.82 μmol/L vs. 0.09 μmol/L, p = 0.001).

CONCLUSION

PEth provides supplementary information on recent alcohol consumption in a psychiatric population and would be particularly helpful in patients unable or unwilling to give such information at admission.

Factors associated with phosphatidylethanol (PEth) sensitivity for detecting unhealthy alcohol use: An individual patient data meta-analysis

BACKGROUND

Objective measurement of alcohol consumption is important for clinical care and research. Adjusting for self-reported alcohol use, we conducted an individual participant data (IPD) meta-analysis to examine factors associated with the sensitivity of phosphatidylethanol (PEth), an alcohol metabolite, among persons self-reporting unhealthy alcohol consumption.

METHODS

We identified 21 eligible studies and obtained 4073 observations from 3085 participants with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) positive scores (≥3 for women and ≥4 for men) and PEth measurements. We conducted 1-step IPD meta-analysis using mixed effects models with random intercepts for study site. We examined the associations between demographic (sex, race/ethnicity, and age) and biologic (body mass index-BMI, hemoglobin, HIV status, liver fibrosis, and venous versus finger-prick blood collection) variables with PEth sensitivity (PEth≥8 ng/ml), adjusting for the level of self-reported alcohol use using the AUDIT-C score.

RESULTS

One third (31%) of participants were women, 32% were African, 28% African American, 28% White, and 12% other race/ethnicity. PEth sensitivity (i.e., ≥8 ng/ml) was 81.8%. After adjusting for AUDIT-C, we found no associations of sex, age, race/ethnicity, or method of blood collection with PEth sensitivity. In models that additionally included biologic variables, those with higher hemoglobin and indeterminate and advanced liver fibrosis had significantly higher odds of PEth sensitivity; those with higher BMI and those living with HIV had significantly lower odds of PEth sensitivity. African Americans and Africans had higher odds of PEth sensitivity than whites in models that included biologic variables.

CONCLUSIONS

Among people reporting unhealthy alcohol use, several biological factors (hemoglobin, BMI, liver fibrosis, and HIV status) were associated with PEth sensitivity. Race/ethnicity was associated with PEth sensitivity in some models but age, sex, and method of blood collection were not. Clinicians should be aware of these factors, and researchers should consider adjusting analyses for these characteristics where possible.