RBC Count Increasing

@Lugnut, where’s your SHBG from last blood work? Then we can trace back and see if the free T you are showing here is Vermeulen or Tru-T method (both calculated values).

Quest had some issues with correctly updating their reference ranges and methods in the past. @youthful55guy, you can look through this previous thread attached (up above).

Between direct method, calculated Vermeulen and TruT methods, guys must be totally confused with the free T numbers they get back!

Good example here:

Tru-T vs Vermeulen calculation comparison:

Couldn’t agree more! It also reinforces that comparing results from laboratory to another is unwise, not only can the normal ranges be different, but the test method with similar sounding names can be very different.

This is why I prefer to stick with one laboratory and one test method to monitor and compare my hormone levels from year to year and/or if I make changes to the protocol. As for me, I’ve used LabCorp for my personal labs and Pacific Diagnostic for the labs my Dr. orders (her preference). Interestingly, she prefers bioavailable T over Free T, so it gives me an opportunity to compare the test results with LabCopr’s Free T (Direct Method) and, within my physiological normal hormone levels, they parallel each other quite well.

Unfortunately, Discounted Labs has switch affiliations from LabCorp to QUEST, so I am forced to go to QUEST for my future labs. I will probably change test methods for Free T too from the Direct Method to the LC/MS method. It costs a bit more, but does return more reliable results. I’ll probably order my first set of labs from QUEST in a month or so.

I heard about that too, kind of annoying they don’t at least give people the option of both. I wonder if there are other sites that will still offer testing through labcorp.

Ok, let me see if I can spit this out correctly. The way the lab info is given to me doesn’t allow me to screen shot the info.

First attachment should be initial blood testing during fast back in sept 2019

Next two attachments are also sept 2019 with no fasting


This last one is from Jan 2020

I think this is what you are referring to, LC/MS for Total T and equilbrium dialysis for free T.

https://testdirectory.questdiagnostics.com/test/test-detail/36170/testosterone-free-dialysis-and-total-ms?cc=SJC

For someone trying to make sense of all this, Quest website very different than Labcorp where they share example reports and provide ranges and reference info.

I feel for you @lugnut. Quest is all over the place. Here’s what I think you had done (first photo you attached):

https://testdirectory.questdiagnostics.com/test/test-detail/14966/testosterone-free-bioavailable-and-total-ms?cc=MASTER

Total T by LC/MS but then look at the methods they list for the other components:

Test Details

Includes

  • Testosterone, Total, MS
  • Testosterone, Free
  • Testosterone, Bioavailable
  • Sex Hormone Binding Globulin (SHBG)
  • Albumin

Methodology

Chromatography/Mass Spectrometry • Calculation (CALC) • Spectrophotometry (SP) • Immunochemiluminescent Assay

Now go to their testosterone testing FAQ and see question 12-13:

Question 12. How are free, bioavailable, and total testosterone measured?

The reference method for measuring total testosterone is liquid chromatography–tandem mass spectrometry (LC/MS/MS).13 Though immunoassays are widely used, they cannot reliably quantify low concentrations (ie, those below the lower limit of the reference interval for men). They are therefore inappropriate for quantifying testosterone in children, women, and hypogonadal men but may be used to screen men with suspected hypogonadism.

Direct measurement of free and bioavailable testosterone is not available, so concentrations are estimated from calculations. Free testosterone is best calculated based on the LC/MS/MS-derived total testosterone and

equilibrium dialysis-derived percent free levels. Alternatively, free testosterone can be calculated based on total testosterone, SHBG, and albumin measurements. Bioavailable testosterone is calculated similarly. This method, however, does not account for estrogens or other compounds that displace testosterone from SHBG.

Question 13. How are free and bioavailable testosterone calculated?

Using the LC/MS/MS and equilibrium-based dialysis methods, free testosterone is calculated as follows:

Free testosterone = (total testosterone) (% free)

The concentration of free (and bioavailable) testosterone can also be calculated by use of one of several published equations. The two most widely used equations for calculating free and bioavailable testosterone are those described by Vermeulen et al20 and Sodergard et al.21 Both equations are based on the law of mass action. These equations assume that when the concentrations of total testosterone, SHBG, and albumin are known, free and bioavailable testosterone can be calculated using known constants for the binding of testosterone to SHBG and albumin. Accordingly, these equations are accurate as long as competition for SHBG and albumin binding sites is limited. Quest Diagnostics employs a modified Vermeulen equation which takes into account the dimeric SHBG measured by our assay:

Free testosterone = total T – (SHBG bound T) – (albumin bound T)

Bioavailable testosterone = total testosterone – (SHBG bound T)

Where…

T = testosterone

SHBG = sex hormone binding globulin

So here’s my estimates using the Vermeulen and Tru-T calculators:


So I can’t line up Quest’s results with their purported calculation method:

Note 36.5 pg/mL is 3.65 ng/dL

If I use SHBG of 22 nmol/L (you didn’t include for this set) and albumin of 4.7 g/dL and calculate free T:

Vermeulen: 8.31 ng/dL
Tru-T: 11.07 ng/dL

It seems to me that Quest is using a cut corners approach to testing for T levels. Most likely at a cost savings as well. I have noticed that in the beginning I was getting more information from the tests. Now I am just getting their versions of Total and Free T.

I will see if I can request another lab for the next workup. I thought Labcorp was the other in my area, but they may be gone just as another poster mentioned.

We use Quest and have not seen any change in their reporting over several years.

Assuming whatever method utilized is consistent, I think it is more important to focus on the changes, rather than the number itself.

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I agree. Although readalot is stating that Quests own results aren’t syncing up with their own reporting methods.

Bare in mind, I don’t know a whole lot about this. I know enough to get myself in big trouble. I read these numbers and I see almost a year on TRT and my numbers aren’t getting much better. Doesn’t help that the Dr keeps cutting the dosage in half. Hence why I am looking for solutions to the RBC issue. I have another blood work test this week to check after being on 60mg every other week for the last three months. I suspect that my levels are.going to come back lower. In the last month or so I have noticed symptoms that I originally had last year coming back

The doctor ordered different tests.