Lab Results

The endocrinology  doc question is full so I figured this was the next best forum.

Hx. 34yo woman, obstructive non-communicating hydrocephalus (diagnosed at age 29); chronic persistent daily headache (non-stop for six years) ; hyperpigmentation; abnormal menses, othrwise healthy.

My NEW endocrinologist ran some labs after years of having a very low cortisol and DHEA; and high prolactin.

Recent Results:

Prolactin 20.7
ACTH basline:<5.0
ACTH (60min.) <5.0
Cortisol baseline: 2.9
Cortisol (60min) 25.2
DHEA: 17 (previous lab)
Thyroid panel normal (Free T3 slightly high).  FSH, LH, Estradiol all normal.

It seems to me that these labs look fine and any pituitary or adrenal problems can be ruled out.  The one value that is confusing is the "baseline ACTH', shouldn't be higher if my pituitary is functioning normally?  Any thoughts would be helpful! Also, MRI of pituitary is unremarkable.  Thank you for your time.

[Anita Ramsetty, MD]

Hi,
Without seeing all the normal ranges on your lab sheet(labs do vary in their normal ranges), I am a little bit limited. I am also assuming that the post 60 minute ACTH and Cortisol are from a standard ACTH stimulation test(is that right?). If so, then your post-results are normal. You are right that the baseline ACTH would be expected to be higher in general, but it does not necessarily mean something is wrong with your pituitary. It may be a function of the sensitivity of the lab  i.e it could be at 4.9 and not abnormal, or down at 1.9, but because your lab cannot  detect differences in that range everything is reported as '<5.0'.  It could also be low if you were recently on steroids.
Hope this helps.

[Andren]

Also being treated for high BP.

[Andren]

Thank you for your comments.  My neurologist and internist are grasping for an answer to my intractable headaches--as nothing has worked (in terms if medication, accupuncture, surgery, pain clinic, etc.)

I understand linearity in terms of the ACTH (i.e.<5), the ranges for the ACTH dection are not available.  So I understand that a basline ACTH of <5 coul be, in fact, normal.  

I have another question, what causes low ACTH production (other than high cortisol)? whithout the stimulation test, my ACTH and cortisol do not interchange as expected (Could it be that there is a problem in the "adrenal-pituitary-hypothalmic axis? i.e..could it be that the hypothalamus is producing too little CRH?)

I really respect endocrinologists!

I have listed the nomal ranges (based on the lab) for the previously mentioned test (I have also included the labs drawn in July of this year.) ACTH and Cortisol are from a standard ACTH stimulation test.  Have not been on steroids.

[LABS FROM 9/26/07]

Prolactin 20.7  (3.8-23.2)
ACTH basline:<5.0 (lab did not report normal range)
ACTH (60min.) <5.0 (lab did not report normal range)
Cortisol baseline: 2.9 (2.5-25.0)
Cortisol (60min) 25.2 (2.5-25.0)
Thyroid panel normal (Free T3 slightly high).  FSH, LH, Estradiol all normal.
DHEA not done

[LABS FROM 7/11/07]

Prolactin 59.8 (3.3-26.7)
Cortisol AM 2.3 (4.0-22.0)
DHEA 17 (130-980)
Testosterone <12 (6-82)
FSH, LH, and Seritonin all normal)

THANK YOU FOR YOUR HELP!