Blood Test indications

[Leila50]

Can anyone tell me what is the purpose of the Cortisol Bind Glob (CBG) blood test?  What exactly is it measuring?  I took the test and although my cortisol levels are below normal (2.5), the CBG was high normal (ref range: 19 - 45 mg/L -- mine 45).  Vitamin D below normal too ( was 19 but has come up to 29).  My ACTH was a low normal (I recall 17 - doctor said he expected it to be high) and my DHEA was below normal (< 15).  I'm so weak, falling at least 2x's /week and dropping things a lot.  All over joint pain and stiffness, blurry eyes, weakness in muscles and extreme fatigue.  Dr put me on 5mg of prednisone and I felt better for about 4 days and then the pain returned.  He didn't refill the prednisone script (wanted to see all test results to be sure - thinks I might have adrenal insufficiency) but now I've gone completely back down hill.  

[PlateletGal]

Just wanted to say hi ! Have you been diagnosed yet ? Your symptoms and lab results were almost identical to mine two years ago.

Keep in touch if you can !

((( HUGS )))

~PlateletGal

[rumpled]

In layman's terms, if you have a high CBG, you generally will not have high UFCs (urinary free cortsol) or saliva tests as you will not *spill* free cortisol as you are binding cortisol it instead of *spilling* it. So standard tests for Cushing's may look normal, but you are really sick. Serum tests may still be high as those are not effected.
Agree, the doctor is good as not many know to run this test.

[estrelinha]

CBG is the protein that binds to 75% of the cortisol (and other steroid hormones) and carries it to circulation , it is also called transcortin, it varies significantly between individuals,.It is produced in liver. The use of the Cort/CBG ratio, rather than serum total cortisol levels alone is sometimes more appropriate in the interpretation of  dynamic tests of the HPA (hypothalamic--pituitary--adrenal ) axis. Low cortisol (free) gives those symptoms, looks like your doctor knows what he is doing.

[stella5349]

I sent them a Personal Message with your question

You should hear something soon.

[Leila50]

Can anyone tell me what is the purpose of the Cortisol Bind Glob (CBG) blood test?  What exactly is it measuring?  I took the test and although my cortisol levels are below normal (2.5), the CBG was high normal (ref range: 19 - 45 mg/L -- mine 45).  Vitamin D below normal too ( was 19 but has come up to 29).  My ACTH was a low normal (I recall 17 - doctor said he expected it to be high) and my DHEA was below normal (< 15).  I'm so weak, falling at least 2x's /week and dropping things a lot.  All over joint pain and stiffness, blurry eyes, weakness in muscles and extreme fatigue.  Dr put me on 5mg of prednisone and I felt better for about 4 days and then the pain returned.  He didn't refill the prednisone script (wanted to see all test results to be sure - thinks I might have adrenal insufficiency) but now I've gone completely back down hill.  

[stella5349]

I am not really good at these tests at this time - Some one may chime in here - but a member estralinha or Kitty9309 is very knowledgable on this sort of testing.

PM them and they will reply too.