Carbohydrate-deficient transferrin (CDT) has been described as a more specific and sensitive marker of recent heavy alcohol consumption as compared with the current tests now available, such as gamma-glutamyltransferase (GGT). Most of the data generated from European populations have not compared the utility of CDT and GGT in the detection of heavy alcohol consumption as a function of gender. We examined the ability of both CDT and GGT to discriminate between 42 men and 18 women with heavy alcohol consumption (> 60 g/day) admitted to an alcohol detoxification center and a group of controls matched for age, race, and gender. CDT was higher, but GGT lower, in control females compared with males. Both CDT and GGT were higher in patients of both genders. At specificities > 90%, the sensitivity of CDT for detecting male alcohol abusers was 79% and for female alcohol abusers 44%. For GGT, the sensitivities were 65% and 44%, respectively. When both tests were used simultaneously, the sensitivity for the detection of alcohol abusers increased to 95% for males and 72% for females. Receiver Operator Characteristic analysis tended to confirm the superiority of CDT over GGT in the detection of heavy alcohol consumption in males, but not in females. A positive relationship was found between serum iron levels and CDT in control females but in no other group. The concordant findings of this American study with those in similar French and Finnish clinical populations, utilizing similar assay techniques, suggest that the measurement of CDT is clinically more useful than GGT in detecting recent heavy alcohol consumption in males.(ABSTRACT TRUNCATED AT 250 WORDS)