Sialic acid: New potential marker of alcohol abuse

Background: A number of laboratory markers are suggested for the detection and monitoring of alcohol abuse. However, there is still a need to find bet ter indicators of alcohol abuse. Sialic acid (SA) is the name for a series of acyl-derivatives of neuraminic acids that occur as nonreducing terminal residues of glycoproteins or glycolipids in biological fluids and cell memb ranes. In this study, we investigated the diagnostic value of SA as a marke r of alcohol abuse. Methods: Sera from social drinkers (n = 38) and alcoholics (n = 77) were an alyzed for sialic acid by a colorimetric assay and for carbohydrate-deficie nt transferrin (CDT) by a radioimmunoassay method. Mean corpuscular volume (MCV), gamma-glutamyltransferase (GGT), aspartate aminotransferase (ASAT), and alanine aminotransferase (ALAT) were determined by using routine method s. Results: The sialic acid levels of both female and male subjects were signi ficantly (p < 0.001) increased among alcoholic subjects when compared with social drinkers. SA levels were decreased after 3 weeks of treatment. The s ensitivity and specificity for SA, respectively, were 57.7 and 95.5 for wom en and 47.8 and 81.3 for men. The respective values for CDT were 57.7 and 9 5.5 for women and 78.3 and 100.0 for men; for GGT, 60.0 and 95.5 for women and 60.9 and 87.5 for men; for MCV, 52.4 and 95.5 for women and 47.8 and 10 0.0 for men; for ASAT, 53.8 and 95.5 for women and 43.5 and 100.0 for men; and for ALAT, 38.5 and 90.9 for women and 39.1 and 87.5 for men. Among wome n, SA and GGT, and among men CDT, showed the largest area under receiver op eration curve. Conclusion: This study indicated that sialic acid levels were elevated by h igh alcohol consumption and reduced during abstinence, especially among wom en. Thus, sialic acid seems to be an interesting marker that needs further evaluation as a diagnostic tool for alcohol abuse.