Dr John - Free Testosterone reference ranges

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    Dr John - Free Testosterone reference ranges


    A guy on another forum pointed out to me that my labs were showing the wrong Free Testosterone ranges. For instance, the reference ranges on my blood tests for free T are 60 - 130 pmol/L. Yet guys who are getting their reference ranges in pg/mL, have reference ranges of 47 - 244 pg/mL.

    When you convert the pg/mL to pmol/L, you get a reference range of 163 - 846 pmol/L. That is a huge difference and would mean that even though my labs say I am OVER my range, I could be in fact under the correct reference range.

    Is this correct?

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    Quote Originally Posted by jaydee View Post
    A guy on another forum pointed out to me that my labs were showing the wrong Free Testosterone ranges. For instance, the reference ranges on my blood tests for free T are 60 - 130 pmol/L. Yet guys who are getting their reference ranges in pg/mL, have reference ranges of 47 - 244 pg/mL.

    When you convert the pg/mL to pmol/L, you get a reference range of 163 - 846 pmol/L. That is a huge difference and would mean that even though my labs say I am OVER my range, I could be in fact under the correct reference range.

    Is this correct?
    Thre are many useless Free Testosterone tests.
    Read more here:
    http://jcem.endojournals.org/cgi/reprint/86/6/2903.pdf
    Quote "I know of no other that has been demonstrated
    to be so egregiously incorrect."

    I am trying to spread the news since I found obout it few moths ago.

    There is workaroud, get TotalT, SHBG and Albumin in the same blood draw and calculate your self using:
    Free & Bioavailable Testosterone calculator
    and
    http://www.get-back-on-track.com/en/tools/umrechner.php

    Only Quest Diagnostic have correct FreeT, but it also makes it hard to get. On standard ordering form they list the bad one. To get correct one you have to order
    Free, Bioavailable, and Total Testosterone.
    Testosterone, LC/MS/MS from Quest Diagnostics

    When Dr Shippen is adjusting its patients and try a range 100-250 that is for the correct FreeT.

    There is 2006 work that discusses better method of calculating to account for new knowledge about SHBG.
    -----http://www.atypon-link.com/WDG/doi/pdf/10.1515/JLM.2006.050

    It does not help me much, but it have information of FreeT and BAT levels in healthy men,
    Table2
    10 healthy young men BAT=5.5(nmol/L)
    Table 4
    10 male control subjects FreeT=199(pmol/L)
    =======================
    Please add to this topic.
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    Quote Originally Posted by JanSz View Post
    Thre are many useless Free Testosterone tests.
    Read more here:
    http://jcem.endojournals.org/cgi/reprint/86/6/2903.pdf
    Quote "I know of no other that has been demonstrated
    to be so egregiously incorrect."

    I am trying to spread the news since I found obout it few moths ago.

    There is workaroud, get TotalT, SHBG and Albumin in the same blood draw and calculate your self using:
    Free & Bioavailable Testosterone calculator
    and
    http://www.get-back-on-track.com/en/tools/umrechner.php

    Only Quest Diagnostic have correct FreeT, but it also makes it hard to get. On standard ordering form they list the bad one. To get correct one you have to order
    Free, Bioavailable, and Total Testosterone.
    Testosterone, LC/MS/MS from Quest Diagnostics

    When Dr Shippen is adjusting its patients and try a range 100-250 that is for the correct FreeT.

    There is 2006 work that discusses better method of calculating to account for new knowledge about SHBG.
    -----http://www.atypon-link.com/WDG/doi/pdf/10.1515/JLM.2006.050

    It does not help me much, but it have information of FreeT and BAT levels in healthy men,
    Table2
    10 healthy young men BAT=5.5(nmol/L)
    Table 4
    10 male control subjects FreeT=199(pmol/L)
    =======================
    Please add to this topic.
    No wonder it gets confusing. One of the websites have 3 tables and I can't decypher exactly what the normal values are!
    •   
       

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    Quote Originally Posted by SoMdHunter View Post
    No wonder it gets confusing. One of the websites have 3 tables and I can't decypher exactly what the normal values are!
    Quest Diagnostics shows ranges for their tests here:
    http://www.questdiagnostics.com/hcp/.../Table%201.pdf

    The Total T column and the two right columns are to be used.

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