Hi,
I have asked this question in the USMLE forum, but did not get a reply, so thought it was worth asking it here. (NB I can't delete the old thread, apologies).
Anyhow I am studying cushing's at the moment and I'm a little confused about measuring cortisol levels.
From my understanding, correct me if I am wrong, you need to measure urine cortisols, either at a specific time during the day in all patients (eg 9am or midnight) or after collecting the urine for 24 hours. This is due to the circadian rhythm of cortisol release, which will mean different values at different times of the day.
However surely just measuring cortisol at one point during the day is quicker & easier? So why do we need to do a 24 hour urine test?
Thanks in advance for your help.
I have asked this question in the USMLE forum, but did not get a reply, so thought it was worth asking it here. (NB I can't delete the old thread, apologies).
Anyhow I am studying cushing's at the moment and I'm a little confused about measuring cortisol levels.
From my understanding, correct me if I am wrong, you need to measure urine cortisols, either at a specific time during the day in all patients (eg 9am or midnight) or after collecting the urine for 24 hours. This is due to the circadian rhythm of cortisol release, which will mean different values at different times of the day.
However surely just measuring cortisol at one point during the day is quicker & easier? So why do we need to do a 24 hour urine test?
Thanks in advance for your help.