What is CDT?
The biomarker S-CDT, or (carbohydrate-poor transferrin) is a biomarker used to detect long-term and/or high alcohol consumption. CDT is a specific type of transferrin, a protein that transports iron in the body, and its levels in the blood can change with alcohol consumption.
When a person consumes alcohol regularly and in large quantities, certain biochemical processes in the body are affected. One of these changes is glycosylation, where carbohydrates are attached to proteins. In the case of transferrin, if a person has a high and prolonged alcohol consumption, the transferrin molecules can be glycosylated in a way that differs from people who do not consume alcohol to a greater extent.
During a CDT analysis, changes in transferrin are identified and the test result can therefore give an indication of whether a person has a high risk of alcohol-related problems or a higher alcohol consumption.
What is a high CDT value?
Usually, CDT constitutes a small proportion (< 2.0%) of the total transferrin in blood serum. However, when a person has been drinking a lot of alcohol for a long time, it is common for CDT values to be higher than 2.0%.
How much alcohol consumption is required for a high CDT value?
It is important to understand that there is not an exact and linear correlation between alcohol consumption and CDT levels above 2%. Alcohol metabolism and its effect on CDT levels can vary between individuals depending on genetic factors, metabolism and other health conditions.
Generally speaking, long-term and "high" alcohol consumption (460 grams of alcohol per week) gives a CDT value above 2%. However, it is difficult to determine a specific amount of alcohol in terms of number of drinks or amount of consumption, as it varies from person to person. In conclusion, prolonged and heavy alcohol consumption is usually required. This can be in the form of daily high alcohol consumption over a longer period, often several months.