Carbohydrate-deficient transferrin--a valid marker of alcoholism in population studies? Results from the Copenhagen City Heart Study.

Carbohydrate-deficient transferrin (CDT) was analyzed by a modified radioimmunoassay test in a random population sample of 400 individuals, and results were compared with reported alcohol intake derived from a structured questionnaire. Among the 180 men, the test was found to be acceptable with respect to detecting harmful alcohol intake (> 35 beverages/week) and alcohol intake above the recommended level (21 beverages/week), although the positive predictive values were low. Among the 220 women, the test was invalid with low predictive values. CDT was compared with other known markers of high alcohol intake, and it was observed that CDT had higher sensitivity and specificity than AST and short Michigan Alcoholism Screening Test (sMAST) in men, whereas the positive and negative predictive values were low in all tests. A combination of CDT and AST proved to be a better marker of both harmful alcohol intake and alcohol intake above the recommended level than the other markers. Neither CDT, AST, CDT/AST, nor sMAST proved to be useful as markers of alcohol intake in women. There were no differences between the values for pre- and postmenopausal women. These results from a population survey indicate that CDT is a marker of alcohol intake among men, although not ideal, but CDT cannot be used in the screening of harmful alcohol intake in women.