Myth: UFC’s are the Gold Standard for Cushing’s testing
Fact: UFC stands for Urinary Free Cortisol. In layman’s terms this test assesses cortisol by collecting urine for 24 hours. It was once thought that this was the gold standard and the end all and be all in terms of assessing Cushing’s in a patient. What we now know is that this is not necessarily true. Though this test is helpful in assessing for Cushing’s in some patients, not all patients have positive labs with this test, even if they DO, in fact, have Cushing’s.
There are various theories as to why. Cyclical Cushing’s patients also tend to report having a lower prevalence of positive UFCs in their test batteries.
Cushing’s experts understand that the most effective way to test for Cushing’s, especially in cases where it is suspected that the patient is cycling, is to administer multiple test measures across an extended period of time.
The following links may be helpful:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2978784/
Click to access LimitationsSC_UFC_dex_mildCS.pdf
http://survivethejourney.blogspot.com/2008/08/when-gold-standard-becomes-tarnished.html
Dr. Karen Thames has been sharing these on her Facebook Page, Empowering People with Invisible Chronic Illness – The EPIC Foundation
She has graciously given me permission to share them here and in the CushieWiki and on the Cushing’s Help message boards.
I was diagnosed with ACTH independent cyclical cushings. It took 5 years to get a diagnosis.
I was diagnosed from ACTH whichwas consistently undetectable and 24hr UFC’s (half were normal)
All other tests were normal including dex suppression tests.