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Testosterone Replacement, Low T, HCG, & Beyond
Testosterone Basics & Questions
troughs of natural T?
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<blockquote data-quote="madman" data-source="post: 264943" data-attributes="member: 13851"><p>You are not going to see a huge difference in natty peak--->trough.</p><p></p><p></p><p><em><strong>*Fluctuations from peak--->trough would be around 20-25%</strong></em></p><p><em><strong></strong></em></p><p><em><strong>*Total and free blood testosterone (TT, FT) concentrations are circadian rhythmic in young healthy males; concentrations are <u>highest during nighttime sleep</u>, <u>elevated following awakening</u>, and <u>lowest midmorning to late evening</u></strong></em></p><p><em><strong></strong></em></p><p><em><strong>*In elderly and hypogonadal men, mean T and FT blood levels are <u>significantly dampened and their circadian variation is markedly depressed or absent</u></strong></em></p><p></p><p></p><p></p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/androderm%C2%AE-tds.23888/#post-235726[/URL]</p><p></p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/day-of-injection-feel-like-a-million-bucks-but.27536/#post-252134[/URL]</p><p></p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/does-patient-applied-trt-pose-risk-for-blood-pressure-elevation.26423/[/URL]</p><p></p><p><em><strong> *in most instances, the goal of TRT is the normalization of the T level, <u>without the complementary goal of normalization of T circadian patterning</u>, which in both<u> primary and secondary hypogonadism is blunted or absent</u>.</strong></em></p><p></p><p></p><p></p><p></p><p><strong>Normal Adult Male Testosterone Circadian Rhythm</strong></p><p></p><p><em>T synthesis takes place in the Leydig cells of the testes through LH stimulation. LH is secreted by the pituitary gland into the peripheral circulation in pulses in response to pulses of gonadotropin-releasing hormone (GnRH) emanating from the hypothalamus.<strong> LH pulses exhibit 24 h temporal patterning; they occur in greater number and higher amplitude during the sleep than wake span, suggesting the involvement of sleep-facilitating or sleep-dependent processes (10, 17, 57, 164, 175–177). <u>Consequently, T production occurs in the greatest amount during sleep as recurring pulses at approximately 90 min intervals in healthy young males and approximately 140 min in healthy middle-aged males</u> (91). </strong>T and its aromatized product estradiol, through negative feedback to the hypothalamus-pituitary axis, induce acute LH suppression and thus reduced T production. In response to the subsequently attenuated serum T concentration, GnRH and LH are again expressed in a pulsatile manner to induce pulsatile androgen hormone synthesis (28, 41, 123, 144).</em></p><p><em></em></p><p><em></em></p><p><em></em></p><p><em></em></p><p><em><strong><u>Figures 2A-2F</u> depict the TT 24 h pattern achieved by the 6 different solution and gel PA-TRTs, and Figures 3A-3D depict the TT 24 h pattern achieved by the buccal tablet, oral capsule, transdermal patch, and subcutaneously injected PATRTs</strong>. <strong><u>There are substantial differences between the therapies in the derived TT 24 h pattern; moreover, all but one of them differs either somewhat or greatly from the normative one of diurnally active young adult males, which is defined by</u>:</strong> </em></p><p><em></em></p><p><em><strong>(i) elevated and near peak TT level during nighttime sleep, (ii) peak TT level around the time of morning awakening, (iii) moderately elevated TT level during the initial hours of wakefulness, (iv) reduced TT level in the late afternoon, and (v) lowest TT level in the evening. <u>Based upon these criteria, only the Androderm® transdermal patch (Figure 3D), when applied in the evening (∼22:00 h) as recommended, closely mimics the TT circadian rhythm of normal young adult males</u>.</strong></em></p><p><em><strong></strong></em></p><p><em><strong></strong></em></p><p><em><strong></strong></em></p><p><em><strong></strong></em></p><p><em><strong>*Total and free blood testosterone (TT, FT) concentrations are circadian rhythmic in young healthy males; concentrations are highest during nighttime sleep, elevated following awakening, and lowest midmorning to late evening</strong></em></p><p><em><strong></strong></em></p><p><em><strong>*In elderly and hypogonadal men, mean T and FT blood levels are significantly dampened and their circadian variation is markedly depressed or absent</strong></em></p><p></p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/testosterone-assays.27661/[/URL]</p><p></p><p><strong>OTHER FACTORS AFFECTING ACCURACY OF TOTAL TESTOSTERONE MEASUREMENT</strong></p><p><strong></strong></p><p><strong>Timing of Laboratory Testing</strong></p><p></p><p><em><strong>Circadian variation in testosterone levels is a well-documented phenomenon, with the highest levels of testosterone released in the morning and relatively lower levels of testosterone released in the afternoon and evening,43 while <u>trough levels of testosterone are observed approximately 12 hours after the peak</u>.44</strong> <strong><u>This diurnal variation in testosterone levels has been reported to be blunted in older populations of men</u>.</strong> A 2009 study reported a 20–25% difference in testosterone levels in younger men (aged 30–40 years) between the hours of 08:00 and 16:00 compared to a 10% difference in testosterone levels between the same hours for older men (aged 70 years).44</em></p><p><em></em></p><p><em>Notably, this study of 66 men included many subjects with normal morning (before 12:00) testosterone levels (>300 ng/dL) and low testosterone levels (<300 ng/dL) in the afternoon. <strong>For these reasons, testosterone measurements should ideally be performed as close to waking as possible. </strong><u><strong>In clinical practice, this may translate to sample procurement between 07:00 and 09:00</strong></u><strong>.</strong></em></p><p></p><p></p><p></p><p></p><p><strong>Repeat Laboratory Testing</strong></p><p></p><p><em><strong>Testosterone laboratory values should be confirmed with at least one duplicate measurement for the diagnosis of low testosterone. </strong>In one community-based study, 30% of men with initial testosterone values considered to be in the hypogonadal range were found to have normal testosterone values on repeat measurements.45 <strong>There has been evidence reported that week-to-week variability can account for some of this variation.46 </strong>Another study, which employed frequent testing of testosterone levels at 20-minute intervals, found that 3 of 10 healthy subjects intermittently registered testosterone concentrations below the normal range.47</em></p><p><em></em></p><p><em><strong><u>Repeat measurements have been noted to vary widely (65–153%) depending on the assay utilized</u>. Conducting two or more repeat measurements can mitigate some of this variability.4</strong></em></p></blockquote><p></p>
[QUOTE="madman, post: 264943, member: 13851"] You are not going to see a huge difference in natty peak--->trough. [I][B]*Fluctuations from peak--->trough would be around 20-25% *Total and free blood testosterone (TT, FT) concentrations are circadian rhythmic in young healthy males; concentrations are [U]highest during nighttime sleep[/U], [U]elevated following awakening[/U], and [U]lowest midmorning to late evening[/U] *In elderly and hypogonadal men, mean T and FT blood levels are [U]significantly dampened and their circadian variation is markedly depressed or absent[/U][/B][/I] [URL unfurl="true"]https://www.excelmale.com/forum/threads/androderm%C2%AE-tds.23888/#post-235726[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/day-of-injection-feel-like-a-million-bucks-but.27536/#post-252134[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/does-patient-applied-trt-pose-risk-for-blood-pressure-elevation.26423/[/URL] [I][B] *in most instances, the goal of TRT is the normalization of the T level, [U]without the complementary goal of normalization of T circadian patterning[/U], which in both[U] primary and secondary hypogonadism is blunted or absent[/U].[/B][/I] [B]Normal Adult Male Testosterone Circadian Rhythm[/B] [I]T synthesis takes place in the Leydig cells of the testes through LH stimulation. LH is secreted by the pituitary gland into the peripheral circulation in pulses in response to pulses of gonadotropin-releasing hormone (GnRH) emanating from the hypothalamus.[B] LH pulses exhibit 24 h temporal patterning; they occur in greater number and higher amplitude during the sleep than wake span, suggesting the involvement of sleep-facilitating or sleep-dependent processes (10, 17, 57, 164, 175–177). [U]Consequently, T production occurs in the greatest amount during sleep as recurring pulses at approximately 90 min intervals in healthy young males and approximately 140 min in healthy middle-aged males[/U] (91). [/B]T and its aromatized product estradiol, through negative feedback to the hypothalamus-pituitary axis, induce acute LH suppression and thus reduced T production. In response to the subsequently attenuated serum T concentration, GnRH and LH are again expressed in a pulsatile manner to induce pulsatile androgen hormone synthesis (28, 41, 123, 144). [B][U]Figures 2A-2F[/U] depict the TT 24 h pattern achieved by the 6 different solution and gel PA-TRTs, and Figures 3A-3D depict the TT 24 h pattern achieved by the buccal tablet, oral capsule, transdermal patch, and subcutaneously injected PATRTs[/B]. [B][U]There are substantial differences between the therapies in the derived TT 24 h pattern; moreover, all but one of them differs either somewhat or greatly from the normative one of diurnally active young adult males, which is defined by[/U]:[/B] [B](i) elevated and near peak TT level during nighttime sleep, (ii) peak TT level around the time of morning awakening, (iii) moderately elevated TT level during the initial hours of wakefulness, (iv) reduced TT level in the late afternoon, and (v) lowest TT level in the evening. [U]Based upon these criteria, only the Androderm® transdermal patch (Figure 3D), when applied in the evening (∼22:00 h) as recommended, closely mimics the TT circadian rhythm of normal young adult males[/U]. *Total and free blood testosterone (TT, FT) concentrations are circadian rhythmic in young healthy males; concentrations are highest during nighttime sleep, elevated following awakening, and lowest midmorning to late evening *In elderly and hypogonadal men, mean T and FT blood levels are significantly dampened and their circadian variation is markedly depressed or absent[/B][/I] [URL unfurl="true"]https://www.excelmale.com/forum/threads/testosterone-assays.27661/[/URL] [B]OTHER FACTORS AFFECTING ACCURACY OF TOTAL TESTOSTERONE MEASUREMENT Timing of Laboratory Testing[/B] [I][B]Circadian variation in testosterone levels is a well-documented phenomenon, with the highest levels of testosterone released in the morning and relatively lower levels of testosterone released in the afternoon and evening,43 while [U]trough levels of testosterone are observed approximately 12 hours after the peak[/U].44[/B] [B][U]This diurnal variation in testosterone levels has been reported to be blunted in older populations of men[/U].[/B] A 2009 study reported a 20–25% difference in testosterone levels in younger men (aged 30–40 years) between the hours of 08:00 and 16:00 compared to a 10% difference in testosterone levels between the same hours for older men (aged 70 years).44 Notably, this study of 66 men included many subjects with normal morning (before 12:00) testosterone levels (>300 ng/dL) and low testosterone levels (<300 ng/dL) in the afternoon. [B]For these reasons, testosterone measurements should ideally be performed as close to waking as possible. [/B][U][B]In clinical practice, this may translate to sample procurement between 07:00 and 09:00[/B][/U][B].[/B][/I] [B]Repeat Laboratory Testing[/B] [I][B]Testosterone laboratory values should be confirmed with at least one duplicate measurement for the diagnosis of low testosterone. [/B]In one community-based study, 30% of men with initial testosterone values considered to be in the hypogonadal range were found to have normal testosterone values on repeat measurements.45 [B]There has been evidence reported that week-to-week variability can account for some of this variation.46 [/B]Another study, which employed frequent testing of testosterone levels at 20-minute intervals, found that 3 of 10 healthy subjects intermittently registered testosterone concentrations below the normal range.47 [B][U]Repeat measurements have been noted to vary widely (65–153%) depending on the assay utilized[/U]. Conducting two or more repeat measurements can mitigate some of this variability.4[/B][/I] [/QUOTE]
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Testosterone Replacement, Low T, HCG, & Beyond
Testosterone Basics & Questions
troughs of natural T?
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