Quantification of alcohol intake in patients with steatotic liver disease and excessive alcohol intake

Quantifying alcohol intake is crucial for subclassifying participants with steatotic liver disease (SLD) and interpreting clinical trials of alcohol-related liver disease (ALD) and metabolic and alcohol-related liver disease (MetALD). However, the accuracy of self-reported alcohol intake is considered imprecise. We compared the diagnostic and prognostic utility of self-reported alcohol intake with blood-based biomarkers of alcohol intake: phosphatidylethanol (PEth) and carbohydrate-deficient transferrin (CDT).

We studied 192 participants from two randomized controlled trials on MetALD and ALD, all with current or former excessive alcohol intake (≥24/36 [♀/♂] grams daily for at least 1 year) and biopsy-proven liver disease. We assessed self-reported alcohol intake, PEth, and CDT at four time points. We collected follow-up data on hepatic decompensation and death manually through electronic medical records.

Most participants were male (n = 161, 84%) with a mean age of 59 (SD 9) years and 73 participants reported 1-week abstinence before inclusion; the remaining reported a median alcohol intake of 43 g/day. Median PEth was 0.5 μmol/L (IQR: 0.0-1.3) and %CDT = 1.9 (IQR: 1.6-2.3). Of 32 patients reporting at least 6 months of abstinence; 27 (84%) was confirmed by PEth <0.05 μmol/L. Self-reported alcohol intake correlated well with PEth (r = 0.617) and moderately with CDT (r = 0.316). Self-reported alcohol intake, PEth, and CDT all predicted hepatic decompensation and death. However, PEth showed the highest prediction, surpassing self-reported alcohol intake (Harrel's C, PEth = 0.80 vs. self-reported = 0.68, p = 0.026).

Self-reported abstinence can be considered reliable in clinical trials. However, PEth is superior in predicting hepatic decompensation and death in patients with MetALD and ALD.

An accurate quantification of alcohol intake is crucial in the clinical phenotyping of patients with steatotic liver disease and when designing clinical trials. This study found self-reported abstinence to be reliable but phosphatidylethanol was a more accurate prognostic biomarker of hepatic decompensation and death in a clinical trial setting. Findings may inform the design of future trials in patients with steatotic liver disease.