Carbohydrate-deficient transferrin (CDT) has previously been reported to be an excellent marker of male alcoholics. Less is known of its efficiency among women and especially of early-phase alcohol abuse in nonselected populations. The present population-based study examined the diagnostic value of CDT among consecutive women, including 13 teetotallers, 135 social drinkers (mean alcohol consumption 45 +/- 34 g/week), and 57 nonalcoholic heavy drinkers (197 +/- 97 g/week). Sixty-two women with a well-documented history of chronic alcoholism (942 +/- 191 g/week) were also studied, as well as 36 pregnant women used as a reference group. Two weeks of abstinence among 11 alcoholics was followed. The CDT (containing part of isotransferrin with pI = 5.7, 5.8, and 5.9) was separated by anion exchange chromatography and assayed by radioimmunoassay. In the whole material, CDT correlated significantly with alcohol consumption (r = 0.43, p < 0.001) but not with conventional markers (gamma-glutamyltransferase, AST, ALT, and mean corpuscular volume). The CDT values of alcoholics (34 +/- 20 units/liter) were significantly (p < 0.001) higher than those of teetotallers (19 +/- 6 units/liter), social drinkers (20 +/- 6 units/liter), or pregnant women (16 +/- 3 units/liter). Heavy drinkers also had higher values (25 +/- 13 units/liter), but the difference did not reach statistic significance. The specificity of CDT was on the level of conventional markers when the cut-off value was increased from 26 to 29 units/liter. At a specificity of 95%, CDT found 19% of the heavy drinkers and 52% of the alcoholics; the best traditional marker, AST, with a specificity of 97%, found 7% and 56%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)