My doctor ordered a dexamethasone suppression test last month and this is the test results I am questioning. My 8 am cortisol level is 1.2. And my ACTH plasma is <1.1. My endocrinologist is from major hospital but I have not been able to reach her by phone- her office does not return calls and I don't see her til end of Sept. I am 65 by the way and have been feeling extremely fatigued lately- should I be concerned? ( I have a 2.8 cm adrenal adenoma which has been watched for 4 years and remained stable in appearance. I also have severe osteoporosis and a 2.0 cm mixed cystic and solid thyroid nodule also being followed yearly on ultrasound. It has gotten marginally bigger in last year and appears more solid but ultrasound says "no suspicious sonographic features" )
A dex suppression test is not a good test for Cushing's disease. It is a better test for location, not for exclusion. I know this as I failed all my dex tests yet I had it (as confirmed by pathology) as did hundreds of other of people that I know.
The problem is that a pituitary lesion can cause a adrenal one, so they need to look up, so to speak, and check out other things as well and do a FULL and complete set of testing. The bone issue shows that the cortisol is a big issue (they may say it is age but that is bunk) and you need action NOW and the dex test is pfffft - you need urine, blood and saliva testing.
I would find another doctor. There are guidelines for the testing for Cushing's and they even say three separate tests so your doc failed to meet the minimum. And the one test ordered is the worst. Ugh. ACTH simply takes the pituitary out. You almost had it the cut off is 1.7 so it shows that you did suppress and the pituitary is more likely the suspect, but it is not perfect.
How was your ACTH done - was the tube chilled, was the tube taken and immediately put into the centrifuge or dumped into the bin? An adrenal source ACTH should be high. Pituitary would be lower. However, lab error in this fussy test means that often people are judged on inaccurate testing! With such a low test, I would guess lab error.
Thanks for responding. I have no doubt that there was probably lab error as the lab my insurance uses sends everything out- not done on premises. I never had saliva testing but I have had 24 hr urine tests done. 24 hr calcium was 478 ( normal 100-300). 24 hr creatinie was 2.1 (normal was .8-1.4)). Cortisol free in urine was 80 (normal 4-50). Also, my BUN and BUN/creatinie also very high. BUN 37 and the BUN/ creatinine ratio is 49. I frankly don't know what any of this means except that it's easy to see the values are high. This doctor is supposed to be good but I get no answers and now not even a response. It would seem logical to me that since I have nodules/ cysts or whatever on my adrenal gland, my thyroid gland and my kidneys that I probably have something on my pituitary too?
You have a high urine - (and the doctor used a test that is less sensitive, there is a more sensitive test that has a lower range using a method called HPLC). The high calcium shows that you may have a parathyroid issue - and that should be addressed as well - in fact, if you have that, with a pituitary and adrenal tumor, the doc should be evaluating you for MEN - multiple endocrine neoplasia. Just my thoughts out there.
I really think you ought to take the testing that you have and find a pituitary doc - they also cover adrenal - and get the more advanced testing that you need.
The health pages to the side have some resources. I would head over to a pituitary center and get in line. It may also take a couple of docs to get a good one - there are duds there too.
So sorry to bother you again but I just had to write again. My dr. Finally called me back today. She said my dexamethasone suppression test was normal. I said " but the values were listed as way below normal." and she replied that they are supposed to be- that means it's all working normally. I know I don't understand this- but why would a test ave a normal range and the results be normal when you are NOT in that range? Am I crazy? She said everything looks fine and she will see me end of Sept. By the way, she lets pituitary as one of her specialties too. I don't know what to think.
The ranges listed, in this case, are not valid for the test. For some odd reason, the docs cannot put that this is POST DEX and the proper range be indicated. So the normal range is not valid.
But I do not agree, as a patient who has been there, done that and has the t-shirt - that the test means that! I failed that test and many others and still had the disease. To diagnose Cushing's is a long, really arduous process and no one test can tell you yes, and no one test tells you no. Same with location.
If you do a bit of research, I think you will find the same. Unless she had neuro-endo and is at a pituitary center and even then, I found quite a few duds myself and went off to find better docs. Heck, I went to a professor (ack!) in my quest to figure out my super duper high ACTH and his take on it was that my adrenals should not have come out. Er? Pathology of enlarged and diseased adrenals aside and my ACTH and prolactin staining pituitary, he wanted to go back over 10+ years of old testing and re-diagnose me and then second guess everything, instead of just treating me as I was today, and only wanted to order 2 blood tests (my doc gives me so many I get like 8-10 tubes every time). I walked away.
A lot of docs *say* they do pituitary - but they don't really.
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