Still confused by causes of high free T

[Mprtz]

I was really happy with my last blood test - lipids actually got a bit better, pretty much everything in range.

The one thing that stood out was free T... total T was 1157 (348-1197), but free T was 70 (5-21).
This was high enough for them to repeat the test and note the fact.

E2 came in at 25 sensitive, which feels right on to me.

I've seen it mentioned that taking an AI can cause this T/free T imbalance - can anyone explain exactly how? I'm currenty taking .5mg adex per week.

I'm not concerned about the high level, just want to better understand what it means.

 

[Daniel_IMT_Staff]

Hello,

Having a high free testosterone indicates that your SHBG is low, Sex Hormone Binding Globulin as the name suggests binds to sex hormones testosterone and estrogen. The more Testosterone and Estrogen you have to bind to SHBG will lower the SHBG and with low SHBG you will have higher Free testosterone. To answer your question directly, AI will affect Estrogen, lowering estrogen will usually create a higher reading of SHBG.

I included a couple basic links for you, play around with the calculator as well.


Free testosterone, read this one What Is Free Testosterone? | eHow

Here is a free testosterone calculator.

Free & Bioavailable Testosterone calculator


Hope this helps a little bit. Let me know if you need clarification.

 

[jozifp103]

couldn't have said it better myself...

 

[Mprtz]

It does help a little, but I do already understand the basic relationship between Free, Total T, SHBG and Albumin.
I suppose it is logical to conclude that my SHBG and/or Albumin or both must be low, but what does that signify?

In the calculator above, I can't get to my Free T value of 70 ng/dL even if I set SHBG to 1 (the lowest the calculator will allow), unless I also reduce the Albumin concentration from the nominal value of 4.3g/dL.
3g/dL Albumin and 1nmol/L SHBG gets me close.

If my SHBG is low, does that also mean that my normal E2 level correlates to a high level of free estradiol?

What about the role of Arimidex? I think it might have been you, Daniel, that implied that high free T may simply point to AI use in another post. Can you elaborate on that?

 

[Megatron28]

I can answer one part. Take two people who have the same starting Total Test. One uses an AI and the other doesn't. The person who does not use an AI will have lower TT and lower Free T all things being equal as more of the testosterone will aromatize into estradiol.

The person using the AI will keep more of the TT in the form of TT (less lost to aromatization) and thus also have higher Free T all things being equal.

 

[Mprtz]

I can answer one part. Take two people who have the same starting Total Test. One uses an AI and the other doesn't. The person who does not use an AI will have lower TT and lower Free T all things being equal as more of the testosterone will aromatize into estradiol.

The person using the AI will keep more of the TT in the form of TT (less lost to aromatization) and thus also have higher Free T all things being equal.

Ok, that raises the question: which aromatizes into estrogen? Free T? T bound to SHBG? Both?

If (as I have seen suggested) it is free T that aromatizes, then aromatization should lead to a relatively large drop in Free T but only a small drop in Total T, because the former is only a small percentage of the total.

I found the following thread which contains some good discussion (especially from det-oak), but still seems far from conclusive.

http://www.steroidology.com/forum/t...bad-have-your-free-testosterone-too-high.html

Possibly confounding the issue is that I don't have any of the problems that some have reported i.e. TRT not working for them because of low SHBG. It seems to work fine. I feel great.

 

[Megatron28]

What is your SHBG at?

 

[Mprtz]

I wish I knew... it's not part of the male hormone panel I usually get. I could add it for an extra $50 next time.

Looking at the test results, one thing is clear is that they do not measure free Test directly. They measure the percentage of free to total, then numerically calculate the free test concentration.