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Testosterone Replacement, Low T, HCG, & Beyond
Testosterone Basics & Questions
What are all possible reasons for a higher total Testosterone number but significantly lower Free T number
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<blockquote data-quote="madman" data-source="post: 150412" data-attributes="member: 13851"><p>Using the newer calculated method <strong><span style="color: rgb(184, 49, 47)">TruT</span> Free Testosterone Calculator </strong>if one had a <span style="color: rgb(0, 0, 0)"><strong>TT level 600 ng/dL </strong></span>or less along with an <span style="color: rgb(184, 49, 47)"><strong>SHBG of 55 nmoL/L </strong></span>than they would definitely have sub-par <strong><span style="color: rgb(184, 49, 47)">FT levels 18.01 ng/dL</span> reference range <span style="color: rgb(184, 49, 47)">16-31 ng/dL</span></strong></p><p>[ATTACH=full]7565[/ATTACH]</p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p>In your case with a TT of 880 ng/dL and an SHBG of 55 nmoL/L than using the newer calculated method (TruT™ provides the most accurate estimates for free testosterone)</p><p><span style="font-size: 18px"><strong><a href="https://tru-t.org/" target="_blank">TruT Free Testosterone Calculator by FPT</a> </strong></span>than your <strong><span style="color: rgb(184, 49, 47)">FT level</span></strong><span style="color: rgb(0, 0, 0)"> is</span><strong><span style="color: rgb(184, 49, 47)"> near the top end of the range 28.94 ng/dL </span>reference range <span style="color: rgb(184, 49, 47)">16-31 ng/dL</span></strong></p><p>[ATTACH=full]7566[/ATTACH]</p><p></p><p></p><p></p><p></p><p>People need start understanding that all of these other equations whether <strong><span style="color: rgb(184, 49, 47)">linear law-of-mass action models or </span><span style="color: rgb(0, 0, 0)">empiric equations</span> </strong><span style="color: rgb(0, 0, 0)">are flawed!</span></p><p></p><p></p><p></p><p></p><p></p><p></p><p><strong><span style="color: rgb(184, 49, 47)">Current problems with accurate free testosterone determination</span></strong></p><p><strong>Current methods for measuring free testosterone (fT) are technically challenging and not accurate.</strong> <span style="color: rgb(26, 188, 156)"><strong>The widely used direct immunoassay and tracer analog techniques for measuring fT have been shown to be inaccurate.</strong></span> <span style="color: rgb(251, 160, 38)"><strong>Equilibrium dialysis, the reference method against which other methods are compared, is labor-intensive and cumbersome, and therefore has had limited clinical adoption.</strong></span> <strong>As an alternative, <span style="color: rgb(184, 49, 47)">free testosterone </span>can be computed from the <em>total</em> testosterone, <span style="color: rgb(184, 49, 47)">SHBG</span>, and <span style="color: rgb(44, 130, 201)">albumin</span> concentrations. </strong>Recently, Endocrine Society’s Expert Panel acknowledged the experimental problems in fT measurements and concluded that "...the calculation of free testosterone is the most useful estimate of free testosterone in plasma..." <strong>However, we have demonstrated that <span style="color: rgb(184, 49, 47)">even the calculated fT values derived from the prevailing equations, based on linear law-of-mass action models or empiric equations</span>, differ systematically from <span style="color: rgb(251, 160, 38)">free testosterone measured by equilibrium dialysis </span><span style="color: rgb(26, 188, 156)">by as much as 40%.</span></strong></p><p></p><p></p><p></p><p><strong>Why <span style="color: rgb(184, 49, 47)">TruT™</span>?</strong></p><p><strong>The <em>only</em> FDA-registered free testosterone calculator</strong></p><ul> <li data-xf-list-type="ul"><strong>Improved <span style="color: rgb(184, 49, 47)">biophysical characterizations</span> have suggested the <span style="color: rgb(184, 49, 47)">importance of models that consider allosteric coupling of testosterone with dimeric SHBG</span>. This model, as implemented by <span style="color: rgb(184, 49, 47)">TruT™ </span>provides the<span style="color: rgb(184, 49, 47)"> most accurate estimates for free testosterone.</span></strong></li> <li data-xf-list-type="ul"><strong>Commonly available <span style="color: rgb(26, 188, 156)">free testosterone calculators </span><span style="color: rgb(184, 49, 47)">(issam.ch, nebido.com, pctag.uk)</span><span style="color: rgb(26, 188, 156)"> use models of testosterone:SHBG binding (proposed by Vermeulen et al. and Sodergard et. al) which were developed before the crystal structure for SHBG:T complexes were available. </span><span style="color: rgb(184, 49, 47)">These models assume that the two SHBG monomers behave identically in binding testosterone. Detailed experimental data show that the "simplified linear model is erroneous."</span></strong> <a href="https://tru-t.org/evidence/#existing-calculators-are-inaccurate" target="_blank">References</a>.</li> <li data-xf-list-type="ul">The Endocrine Society has issued position statements which highlights the laboratory- and operator-dependent variability inherent in direct free testosterone measurements. For this reason they advocate for indirect "calculator" based methods <a href="https://tru-t.org/evidence#endocrine-society-position" target="_blank">References</a>.</li> <li data-xf-list-type="ul"><strong>The<span style="color: rgb(184, 49, 47)"> TruT™ calculator </span>provides the ideal solution by using <span style="color: rgb(184, 49, 47)">measurements of </span><span style="color: rgb(44, 130, 201)">total testosterone, SHBG, and albumin </span>to <span style="color: rgb(184, 49, 47)">calculate free testosterone </span>while taking into account <span style="color: rgb(44, 130, 201)">the complex, non-linear allostery in SHBG's association with testosterone. </span><span style="color: rgb(184, 49, 47)">TruT™</span> i<span style="color: rgb(184, 49, 47)">s the only calculator available</span> that uses <span style="color: rgb(184, 49, 47)">this more complex formulation. </span></strong><a href="https://tru-t.org/evidence#trut-improvements" target="_blank">References</a></li> </ul><p></p><p></p><p></p><p>Forget relying on the older <span style="color: rgb(184, 49, 47)"><strong>calculated methods</strong></span> let alone <span style="color: rgb(26, 188, 156)"><strong>direct immunoassay and tracer analog techniques.....</strong></span><span style="color: rgb(0, 0, 0)">either pay to have the </span><span style="color: rgb(251, 160, 38)"><strong>gold standard equilibrium dialysis</strong></span><span style="color: rgb(0, 0, 0)"> or</span><span style="color: rgb(250, 197, 28)"> <strong>ultrafiltration</strong></span><span style="color: rgb(0, 0, 0)"> or better yet do not spend the money and simply use the newer calculated method <span style="font-size: 18px"><strong><a href="https://tru-t.org/" target="_blank">TruT Free Testosterone Calculator by FPT</a></strong></span></span></p><p></p><p></p><p>People tend to go on and on and on about high SHBG resulting in low FT.....sure when TT levels are sub-par or low but when TT levels are high enough even with a higher SHBG one can still have healthy FT levels.</p><p></p><p>Even with an SHBG of 70,80.90 as long as TT is high enough one can have a healthy FT.</p><p></p><p>In your case although most would consider an SHBG of 55 nmol/L high seeing as your TT (trough) is fairly high 880 ng/dL than your FT of 28.49 ng/dL is right near the top end of the reference range of 16-31 ng/dL and keep in mind this is using the newer calculated method <strong> <span style="color: rgb(184, 49, 47)">TruT™ which provides the most accurate estimates for free testosterone.</span></strong></p></blockquote><p></p>
[QUOTE="madman, post: 150412, member: 13851"] Using the newer calculated method [B][COLOR=rgb(184, 49, 47)]TruT[/COLOR] Free Testosterone Calculator [/B]if one had a [COLOR=rgb(0, 0, 0)][B]TT level 600 ng/dL [/B][/COLOR]or less along with an [COLOR=rgb(184, 49, 47)][B]SHBG of 55 nmoL/L [/B][/COLOR]than they would definitely have sub-par [B][COLOR=rgb(184, 49, 47)]FT levels 18.01 ng/dL[/COLOR] reference range [COLOR=rgb(184, 49, 47)]16-31 ng/dL[/COLOR][/B] [ATTACH=full]7565[/ATTACH] In your case with a TT of 880 ng/dL and an SHBG of 55 nmoL/L than using the newer calculated method (TruT™ provides the most accurate estimates for free testosterone) [SIZE=18px][B][URL='https://tru-t.org/']TruT Free Testosterone Calculator by FPT[/URL] [/B][/SIZE]than your [B][COLOR=rgb(184, 49, 47)]FT level[/COLOR][/B][COLOR=rgb(0, 0, 0)] is[/COLOR][B][COLOR=rgb(184, 49, 47)] near the top end of the range 28.94 ng/dL [/COLOR]reference range [COLOR=rgb(184, 49, 47)]16-31 ng/dL[/COLOR][/B] [ATTACH=full]7566[/ATTACH] People need start understanding that all of these other equations whether [B][COLOR=rgb(184, 49, 47)]linear law-of-mass action models or [/COLOR][COLOR=rgb(0, 0, 0)]empiric equations[/COLOR][COLOR=rgb(184, 49, 47)] [/COLOR][/B][COLOR=rgb(0, 0, 0)]are flawed![/COLOR] [B][COLOR=rgb(184, 49, 47)]Current problems with accurate free testosterone determination[/COLOR] Current methods for measuring free testosterone (fT) are technically challenging and not accurate.[/B] [COLOR=rgb(26, 188, 156)][B]The widely used direct immunoassay and tracer analog techniques for measuring fT have been shown to be inaccurate.[/B][/COLOR] [COLOR=rgb(251, 160, 38)][B]Equilibrium dialysis, the reference method against which other methods are compared, is labor-intensive and cumbersome, and therefore has had limited clinical adoption.[/B][/COLOR] [B]As an alternative, [COLOR=rgb(184, 49, 47)]free testosterone [/COLOR]can be computed from the [I]total[/I] testosterone, [COLOR=rgb(184, 49, 47)]SHBG[/COLOR], and [COLOR=rgb(44, 130, 201)]albumin[/COLOR] concentrations. [/B]Recently, Endocrine Society’s Expert Panel acknowledged the experimental problems in fT measurements and concluded that "...the calculation of free testosterone is the most useful estimate of free testosterone in plasma..." [B]However, we have demonstrated that [COLOR=rgb(184, 49, 47)]even the calculated fT values derived from the prevailing equations, based on linear law-of-mass action models or empiric equations[/COLOR], differ systematically from [COLOR=rgb(251, 160, 38)]free testosterone measured by equilibrium dialysis [/COLOR][COLOR=rgb(26, 188, 156)]by as much as 40%.[/COLOR][/B] [B]Why [COLOR=rgb(184, 49, 47)]TruT™[/COLOR]? The [I]only[/I] FDA-registered free testosterone calculator[/B] [LIST] [*][B]Improved [COLOR=rgb(184, 49, 47)]biophysical characterizations[/COLOR] have suggested the [COLOR=rgb(184, 49, 47)]importance of models that consider allosteric coupling of testosterone with dimeric SHBG[/COLOR]. This model, as implemented by [COLOR=rgb(184, 49, 47)]TruT™ [/COLOR]provides the[COLOR=rgb(184, 49, 47)] most accurate estimates for free testosterone.[/COLOR][/B] [*][B]Commonly available [COLOR=rgb(26, 188, 156)]free testosterone calculators [/COLOR][COLOR=rgb(184, 49, 47)](issam.ch, nebido.com, pctag.uk)[/COLOR][COLOR=rgb(26, 188, 156)] use models of testosterone:SHBG binding (proposed by Vermeulen et al. and Sodergard et. al) which were developed before the crystal structure for SHBG:T complexes were available. [/COLOR][COLOR=rgb(184, 49, 47)]These models assume that the two SHBG monomers behave identically in binding testosterone. Detailed experimental data show that the "simplified linear model is erroneous."[/COLOR][/B] [URL='https://tru-t.org/evidence/#existing-calculators-are-inaccurate']References[/URL]. [*]The Endocrine Society has issued position statements which highlights the laboratory- and operator-dependent variability inherent in direct free testosterone measurements. For this reason they advocate for indirect "calculator" based methods [URL='https://tru-t.org/evidence#endocrine-society-position']References[/URL]. [*][B]The[COLOR=rgb(184, 49, 47)] TruT™ calculator [/COLOR]provides the ideal solution by using [COLOR=rgb(184, 49, 47)]measurements of [/COLOR][COLOR=rgb(44, 130, 201)]total testosterone, SHBG, and albumin [/COLOR]to [COLOR=rgb(184, 49, 47)]calculate free testosterone [/COLOR]while taking into account [COLOR=rgb(44, 130, 201)]the complex, non-linear allostery in SHBG's association with testosterone. [/COLOR][COLOR=rgb(184, 49, 47)]TruT™[/COLOR] i[COLOR=rgb(184, 49, 47)]s the only calculator available[/COLOR] that uses [COLOR=rgb(184, 49, 47)]this more complex formulation. [/COLOR][/B][URL='https://tru-t.org/evidence#trut-improvements']References[/URL] [/LIST] Forget relying on the older [COLOR=rgb(184, 49, 47)][B]calculated methods[/B][/COLOR] let alone [COLOR=rgb(26, 188, 156)][B]direct immunoassay and tracer analog techniques.....[/B][/COLOR][COLOR=rgb(0, 0, 0)]either pay to have the [/COLOR][COLOR=rgb(251, 160, 38)][B]gold standard equilibrium dialysis[/B][/COLOR][COLOR=rgb(0, 0, 0)] or[/COLOR][COLOR=rgb(250, 197, 28)] [B]ultrafiltration[/B][/COLOR][COLOR=rgb(0, 0, 0)] or better yet do not spend the money and simply use the newer calculated method [SIZE=18px][B][URL='https://tru-t.org/']TruT Free Testosterone Calculator by FPT[/URL][/B][/SIZE][/COLOR] People tend to go on and on and on about high SHBG resulting in low FT.....sure when TT levels are sub-par or low but when TT levels are high enough even with a higher SHBG one can still have healthy FT levels. Even with an SHBG of 70,80.90 as long as TT is high enough one can have a healthy FT. In your case although most would consider an SHBG of 55 nmol/L high seeing as your TT (trough) is fairly high 880 ng/dL than your FT of 28.49 ng/dL is right near the top end of the reference range of 16-31 ng/dL and keep in mind this is using the newer calculated method [B] [COLOR=rgb(184, 49, 47)]TruT™ which provides the most accurate estimates for free testosterone.[/COLOR][/B] [/QUOTE]
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Testosterone Replacement, Low T, HCG, & Beyond
Testosterone Basics & Questions
What are all possible reasons for a higher total Testosterone number but significantly lower Free T number
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