Carbohydrate deficient transferrin (CDT) predicts heavy drinking in adolescents with alcohol dependence

A biomarker that could indicate problematic drinking in adolescents and/or reflect changes in heavy drinking would be a valuable addition to prevention, treatment, and research efforts. Carbohydrate deficient transferrin (CDT) is a valid biomarker of heavy drinking in adults; however, it is not well examined in adolescents. Adolescents with alcohol dependence (AD) (n = 21; 9 females) and non-dependent controls (ND) (n = 6; 3 females), ages 14-20, were interviewed to determine drinks per drinking day, peak number of drinks, and percent days heavy drinking (≥4 standard drinks/day). Blood samples from participants were assayed for percent of transferrin that was carbohydrate deficient (%CDT). Analyses compared groups on drinking and %CDT, examined the relationship between %CDT and indices of drinking, and provided preliminary estimates of the test validity of %CDT for heavy drinking in adolescents. Among adolescents with AD, %CDT was significantly and strongly correlated (r = .54) with percent heavy drinking days, and this relationship was consistent for both males and females. AD adolescents did not differ from ND on mean %CDT levels, despite significantly greater alcohol use. Indicators of test validity showed that %CDT had low sensitivity (33%) but adequate specificity (83%) for heavy drinking. Results provide proof of concept that %CDT is a potentially valuable tool to use in alcohol treatment and research in adolescents. Even if %CDT does not discriminate between adolescents with and without alcohol dependence, it could be an effective monitoring tool to indicate changes over time in binge drinking. Improved %CDT measurement methods might enhance its utility.