What is CDT (carbohydrate deficient transferrin)?
The CDT test is a sensitive biomarker that tracks heavy alcohol consumption over the longer term. The results of this test will give an indication of the extent of recent alcohol consumption.
If you drink steadily and heavily (4-6 units of alcohol per day) over several weeks, the percentage of CDT increases. You will continues as long as you continuously drink heavily. Occasional or binge drinking also raises CDT levels, though this depends on the frequency and the quantity consumed.
If you reduce your alcohol consumption, your CDT levels will fall after a few weeks. CDT is a specific test, meaning other substances do not affect the test result. CDT is used as an official test to evaluate harmful alcohol use.
Why Test CDT?
Job Requirement
Some employers require you to take this test before starting a new job.
Official Requirement
You may need this alongside a GGT test to satisfy an authority, for example the Swedish Transport Authority.
What do the results mean?
CDT test results indicate the extent of recent alcohol consumption when combined with other tests, such as GGT.
Low/Normal
A low test result indicates that you have not been drinking excessively over the last few weeks.
High
An elevated CDT indicates excess drinking for the last few weeks or months.
Preparations for this test
Avoid drinking alcohol the night before taking this test.
The day of the test
Always take your ID with you when going for a test. Arrive early, and sit down quietly for 15 minutes before the test is taken.