Labs Indicating Pituitary Problems?

[MarijoR]

Dr. Mark,

I have a question about diagnosing pituitary disorders.  I suspect that I might have one.  First, here are my labs:

            02/21            02/28            Norms

TSH         0.453             0.746          .4-4.2

T4-Free     0.5                0.6           .8-1.9
Direct

T3SerPlQn    N/A                145           82-179

My MD started me on Levoxyl 75 mcg, stating I was hypothyroid.  However, when I questioned this, he had me stop the Levoxyl, wait 4 weeks and have labs redrawn by a different method to see if my T4-Free was really low.  The labs were:

T-Uptake 40 (right in the middle of normal)
FTI  5.8 (low) the normal I believe starts at 6.0
T4 SerPlQn 5.8 (the lowest it can be still in normal range)
He also took a Prolactin level (normal), but did not order a TSH -he thought he had, but one was not drawn.

He is not questioning my pituitary status stating this would be "very rare".  However, why else would my TSH be low normal and my Free T-4 low?  He is a good doctor, but I don't think he understands this - he says that the TSH is the main indicator of thyroid status.  Which is true, if there is no issue with the pituitary or hypothalamus!

Would you recommend that I pursue this?  I'm in a mananaged plan, so I can not see a Specialist without my GP's approva1. My GP was fine with me starting back on the Levoxyl (which is helping), but I know the dosage should be measured by the T4 and not the TSH if it is a pituitary problem!

Thank you for your help.  Is there something I am not seeing in all of this?

Thanks,
Marijo  

  

[Mark Lupo, M.D.]

This may be a pituitary problem, would consider measuring TRH (high in pituitary prob, low in primary hyperthyroidism).  The free T4 may be normal for you -- can be measure by equilibrium dialysis to be certain.  The T3 is in the mid normal range -- usually this would be low as well if definitely pituitary.  So, I doubt this is pituitary, but further studies are needed to be certain.  Would ask for an endo referral.

[MarijoR]

Oops!  I just read my posting, and the labs are hard to read.  Let me try again:


02/21    TSH 0.453                     T4Free-Direct  0.5

02/28    TSH 0.746                     T4Free-Direct  0.6

Norms   TSH 0.4-4.2                   T4Free-Direct 0.8-1.9

So, my TSH has been low normal, and my T4Free low in each testing.  I had a T3SerPL Qn drawn once (2-28) and it was 145 (norm 82-179).

Thank you!

[MarijoR]

Thank you very much for sharing your expertise; I will pursue finding an Endo MD.  

[trixielynn42]

A related discussion, thyroid gland was started.