Phosphatidylethanol (PEth) as a marker of alcohol consumption with particular focus on women: Could there be a future for increased use?

Abstract

English summary Alcohol is the most commonly abused substance and it carries significant harm to the fetus. It not only leads to psychological, physical, and familial issues for the individual, but also imposes a substantial economic burden on society. Despite its legality, widespread availability, and social acceptance, early identification of harmful alcohol usage remains a challenge. Nonetheless, early detection improves the prognosis. In these studies, we explored the relationship between the alcohol biomarker, PEth, and self-reported alcohol consumption in healthy individuals using a daily digital alcohol registration, comparing it to retrospective alcohol use reporting. Additionally, we employed PEth to examine alcohol consumption in two specific groups: mentally ill patients and pregnant women. PEth is a specific alcohol marker that only forms in the presence of ethanol. With a half-life of approximately 6 days, it can detect alcohol consumption within a 4-week window. A concentration less than 0.03 μmol/l indicates abstinence or low-level alcohol consumption. In contrast, a rate equal to or above 0.03 μmol/l suggests moderate use and a concentration equal to or above 0.3 μmol/l indicates excessive consumption. In study 1, we enlisted healthy individuals who did not have alcohol use disorder (AUD) or any history of alcohol abstinence. Over 2 weeks, these participants recorded their daily alcohol consumption on their smartphones. Both at the start and end of this period, we measured their phosphatidylethanol (PEth) levels. We then compared the results of the daily digital records with those acquired through a Timeline Followback (TLFB), a method where alcohol consumption over the past fortnight is recorded on a calendar. Our focus was the correlation between PEth levels and daily alcohol units consumed. We found a strong correlation between alcohol intake and PEth levels, which remained consistent regardless of the reporting method used and was not influenced by factors such as sex or body mass index (BMI). Based on this study, in order to identify persons with a daily alcohol consumption of more than 2 or 3 units of alcohol with a sensitivity of 80% or 90%, we suggest a cut-off of around 0.1 μmol/l. In our second study, we examined alcohol consumption among acutely hospitalized psychiatric patients. We utilised the Alcohol Use Disorder Identification Test (AUDIT) and compared its results with the diagnosis of an alcohol use disorder and PEth concentration. Notably, roughly 50% of these patients had significant or harmful alcohol use, and about 20% showed signs of excessive use or alcohol dependence. There was a noteworthy correlation not only between PEth concentrations and AUDIT scores, but also between PEth concentrations and self-reported alcohol consumption. Patients diagnosed with an AUD during their stay demonstrated significantly higher PEth concentrations compared to those without such a diagnoses. Moreover, the study uncovered PEth concentrations indicative of significant or excessive alcohol use unreported by the psychiatric patients in their questionnaire responses. In our third study, we gathered over 4,000 blood samples from expectant mothers in the Trøndelag region. The blood samples collected were sent to St. Olav’s Hospital, Trondheim University Hospital, for Rhesus typing from September 2017 to October 2018. Due to our interest in any alcohol use, we lowered the quantification limit for PEth to 0.003 μmol/l, aligning with national and international guidelines that recommend zero alcohol intake during pregnancy. In total, 1.4% of women showed a detectable PEth around gestational week 12. Most positive PEth samples surfaced in the summer and fall seasons. Nonetheless, the proportion of PEth-positive cases revealed no significant difference concerning the age or living environments (urban vs. rural) of the participants. Our findings suggest that measuring PEth is a practical method that is feasible for implementation alongside screenings for other conditions in healthcare settings. PEth can detect alcohol consumption in recent weeks, albeit with individual variations. It can identify individuals at risk of harmful alcohol use, capturing valuable information that might otherwise be overlooked. Additionally, the potential application of PEth in prenatal care warrants further investigation, specifically its potential role in preventing and diagnosing conditions like fetal alcohol syndrome and fetal alcohol spectrum disorder.