The Utility of Commonly Used Laboratory Tests to Screen for Excessive Alcohol Use in Clinical Practice.

Background: This current study was undertaken to carefully assess the accuracy of routinely used laboratory tests in detecting excessive/recent alcohol use. We also determined the kinetics of these markers in subjects who underwent an intensive alcohol rehabilitation program.

Methods: The study cohort consisted of 210 nonexcessive drinkers, 272 excessive drinkers, and 76 with alcoholic cirrhosis. To determine the kinetics of these markers during alcohol abstinence, we followed 45 subjects with history of excessive alcohol use for 12 weeks during the intensive alcohol treatment program.

Results: Percentage of carbohydrate deficient transferrin (%CDT) provided the highest diagnostic performance (area under the curve [AUC] 0.77) followed by gamma-glutamyl transferase (GGT) (AUC 0.68) to detect excessive drinkers. The percentage of excessive drinkers with aspartate aminotransferase:alanine aminotransferase (AST:ALT) > 2 was only 2%, whereas 51% of subjects with alcoholic cirrhosis had AST:ALT > 2. In the multivariate analysis, the levels of GGT and %CDT were associated with the level of alcohol consumed during the past 30 days. The levels of GGT, mean corpuscular volume (MCV), and %CDT were significantly lower compared to those at baseline before alcohol rehabilitation, whereas the AST, ALT, and AST:ALT ratio were unchanged. The percent reduction was ~2.7% (for MCV), 19% (for GGT), and 43% (for %CDT) at the end of the 12-week follow-up compared to the baseline.

Conclusions: %CDT are useful markers to screen for excessive alcohol use and for follow-up of abstinence. Most subjects with excessive alcohol use do not have a high AST:ALT ratio. Rather, the AST:ALT > 2 is suggestive of alcoholic cirrhosis. The performance of the %CDT to screen for heavy alcohol use is still not ideal. Further research to identify the noninvasive marker(s) (i.e., using proteomic or metabolomics approach) should be considered.