Carbohydrate-deficient transferrin is a sensitive marker of alcohol consumption in fatty liver disease.

Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) and alcohol-associated/related liver disease (ALD) with metabolic syndrome is increasing globally. Metabolic syndrome and excessive alcohol consumption synergically exacerbate liver pathologies; therefore, drinking-specific serum markers unaffected by liver injury or metabolic syndrome are essential for assessing alcohol consumption. We evaluated the ratio of carbohydrate-deficient transferrin to total transferrin (%CDT) in patients with fatty liver disease, particularly focusing on its correlation with metabolic factors (UMIN000033550).

Methods: A total of 120 patients with fatty liver disease, including ALD and NAFLD, were screened for alcohol misuse using the Alcohol Use Disorders Identification Test. Associations of metabolic syndrome-related factors and hepatic steatosis/liver stiffness with drinking markers, such as %CDT, gamma-glutamyl transferase (GGT), and mean corpuscular volume (MCV), were assessed using multiple linear regression analyses.

Results: %CDT significantly increased with 3-4 drinks/day. The optimal cutoff value for identifying non- to light drinkers was 1.78% (sensitivity, 71.8%; specificity, 83.7%; and area under the receiver operating characteristic curve [AUROC], 0.851), which was significantly higher than that for GGT. The cutoff value for identifying heavy drinkers was 2.08% (sensitivity, 65.5%; specificity, 86.8%; and AUROC, 0.815). Multiple regression analysis revealed that this proportion was negatively correlated with body mass index, whereas GGT and MCV were influenced by multiple factors involved in liver injury and dyslipidemia.

Conclusions: %CDT showed a strong correlation with alcohol consumption, independent of liver damage, steatosis/stiffness, or metabolic syndrome-related factors, indicating that it is a useful drinking marker for the accurate diagnosis of NAFLD and ALD.