low testosterone vs low thyroid

[Rhino 2.0]

I am assuming it must be my thyroid then. I have not had my rt3 or antibodies tested yet for my thyroid. I have heard from a couple people on here that stated if my shbg is high then there is no way my free test can be high. My blood work shows that they can co exist though? You can have high free test even if you have high shbg?

 

[madman]

I am assuming it must be my thyroid then. I have not had my rt3 or antibodies tested yet for my thyroid. I have heard from a couple people on here that stated if my shbg is high then there is no way my free test can be high. My blood work shows that they can co exist though? You can have high free test even if you have high shbg?

What assay was used for your free t?

EQUILIBRIUM DIALYSIS is the gold standard and the assay you would want (which you may have had on previous labs), you need to look over those labs.

 

[madman]

Scroll to page 13-14 and look over Table 4: Assays For The Diagnosis Of Teststerone Deficiency and look under assay for Free TESTOSTERONE and you will see the difference in co-efficient of variation, adavantages/disadvantages between equilibrium dialysis, calculated method and direct (ultracentrifugation, analog)

As you will see the EQUILIBRIUM DIALYSIS- co-efficent of variation for intra assay is 10% and inter assay is 6.8%

-advantages of equilibrium dialysis - considered gold standard and has excellent sensitivity/specifity
-disadvantages- labor intensive, low throughput



As you will see CALCULATED METHOD- co-efficient of variation is 18-30%

-advantages of calculated method - rapid, simple, has correlated in some series (BUT NOT ALL) well with equilibrium dialysis
-disadvantages- relies on TT and SHBG assay accuracy, accuracy relies on equilibrium dissociation constants for binding of SHBG and albumin to testosterone, higher inter-assay variability

 

[Rhino 2.0]

The assays used for my last two blood test with Defy were Direct. The ones used before that was the calculated method. I have noticed my free t is always on the higher end of the range whenever the direct assay is used. When the calculated method is used my free t is always on the lower end of normal. I checked and have not had the equilibrium dialysis assay yet on any of my blood test.

 

[madman]

The assays used for my last two blood test with Defy were Direct. The ones used before that was the calculated method. I have noticed my free t is always on the higher end of the range whenever the direct assay is used. When the calculated method is used my free t is always on the lower end of normal. I checked and have not had the equilibrium dialysis assay yet on any of my blood test.

The direct analog is still reliable and as far as the equilibrium dialysis it is not used by most commercial labs as it is expensive/time consuming so if you were interested in getting it find out if it is offered through Labcorp.

I live in Canada so not sure what labs in US offer the testing method.