Sex differences of carbohydrate-deficient transferrin, γ-glutamyltransferase, and mean corpuscular volume in alcohol-dependent patients

Background: Biological markers like carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and mean corpuscular volume (MCV) are used widely to screen for alcoholism. Most research has focused on male alcoholics, and there are few studies on female patients. The results are inconsistent; in general, they show lower sensitivities for all markers for women. Methods: We compared the diagnostic value of CDT, GGT, and MCV in 126 alcohol-dependent patients (91 men, 35 women) who entered an inpatient treatment program. For the receiver operating characteristic (ROC) analyses, we investigated a control group of 112 patients (64 men, 38 women) from the Department of Psychiatry at the University of Tubingen with no diagnosis of substance abuse or substance dependency. Results: Mean levels of CDT and MCV were significantly different in male and female patients. CDT showed higher test results in men (4.4% vs. 2.8%,p < 0.05), whereas mean levels of MCV were higher in women (99.7 fl vs. 96.4 fl,p < 0.01). The sensitivities of CDT and GGT were higher in men than in women (CDT: 76% vs. 54%,p < 0.1; GGT: 68% vs. 43%,p < 0.05), and the sensitivity of MCV was significantly higher in women (71% vs. 41%,p < 0.01). The superiority of MCV in women also was supported by ROC analyses (p < 0.01). The combined use of markers showed satisfactory sensitivity rates of greater than or equal to 80% not only in men but also in women. Yet, the specificity rates were partly below the recommended 90% for identifying alcohol abuse; therefore, these markers must be combined with caution. Conclusions: If combined, the biological markers CDT and GGT are useful diagnostic instruments for both alcohol-dependent men and women. According to our results, the "forgotten" marker MCV is superior in women and is a marker of second choice in men. The combination GGT and MCV is the most cost-effective choice for men and women.