Salivary and plasma bound and “free” testosterone in men and women

Khan-Dawood, Firyal S.; Choe, Jonggeun; Dawood, M. Yusoff

doi:10.1016/0002-9378(84)90723-3

Cited by 68 publications

(57 citation statements)

References 19 publications

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“…1, table II). This finding is in accordance with a pre vious report by Kahn-Dawood et al [9], who demon strated that young adults have significantly higher plasma fT levels in the morning than in the evening, by means of an equilibrium dialysis method. The circadian variations of the unbound T fraction are probably a stoi chiometric consequence of the T and binding proteins circadian rhythms [4,16], since the relative distribution of a steroid hormone between the protein bound and the free fraction strongly depends upon the actual plasma concentrations of both steroid and protein [6], In elderly men the frequent loss of T circadian rhythm is an aspect of an age-related impairment of the pituitary-gonadal function, as we [11] and others [3,10] have previously reported.…”

Section: Discussionsupporting

confidence: 92%

“…With regard to the pattern of testosterone (T) secretion we [ 11 ] and others [3,10] have found a frequent loss of circadian rhythm in elderly men, whilst the same finding has not been recorded by other authors [13]. To date a few stud ies have been devoted to circadian changes in plasma sex hormone-binding globulin (SHBG) binding capacity [4] and in unbound testosterone (fT) [9], but only in young men. To our knowledge, there is no report in the litera ture about the circadian pattern of plasma fT in elderly men.…”

Section: Introductionmentioning

confidence: 96%

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Age-Related Changes in Plasma Dehydroepiandrosterone Sulphate, Cortisol, Testosterone and Free Testosterone Circadian Rhythms in Adult Men

Montanini¹,

Simoni²,

Chiossi³

et al. 1988

Horm Res

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The circadian rhythms of serum luteinizing hormone, follicle-stimulating hormone, testosterone (T), free testosterone (fT), sex hormone-binding globulin (SHBG), oestradiol, cortisol and dehydroepiandrosterone sulphate (DHA-s) have been investigated in 5 normal male adults and 6 elderly men. Circadian rhythms were detected statistically significant (p < 0.05) by population mean cosinor analysis, for T, fT, cortisol and DHA-s in the young group. In the elderly population, serum cortisol showed a clear circadian rhythm, although with some phase modification, whereas DHA-s secretion lost its circadian rhythmicity. This demonstrates that ageing differently affects the two major adrenal functions, glucocorticoid and androgenic; further, the data suggest that an independent adrenal androgen-regulating system could be selectively impaired in the older subjects. In the elderly group the loss of T circadian rhythm was confirmed, but a statistically significant circadian rhythm of fT was recorded. It was characterized by a marked phase advance and not related with the SHBG modifications found in elderly men. This finding leads us to reconsider the role of fT, which appears more sensitive than total T, in studying circadian rhythm of gonadal androgen secretion.

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Section: Discussionsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 96%

Age-Related Changes in Plasma Dehydroepiandrosterone Sulphate, Cortisol, Testosterone and Free Testosterone Circadian Rhythms in Adult Men

Montanini¹,

Simoni²,

Chiossi³

et al. 1988

Horm Res

View full text Add to dashboard Cite

show abstract

“…They were also small relative to differences among sub jects, consistent with other reports that individual differ ences can overwhelm menstrual cycle effects [1,9], While investigators examining individual differences should control for time of day, as a practical matter the menstrual cycle can be ignored in most studies of indi vidual differences in testosterone. It is unlikely that highor low-testosterone women would be misclassified be cause of variability introduced by the menstrual cycle.…”

Section: Discussionsupporting

confidence: 83%

Salivary Testosterone Measurements among Women: Relative Magnitude of Circadian and Menstrual Cycles

Dabbs

Rue²

1991

Horm Res

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Measures of testosterone among women are potentially useful in behavioral research, but information is needed on how much error is introduced by variability across the menstrual cycle. Morning and evening salivary testosterone concentrations were measured at weekly intervals across one menstrual cycle in each of 22 women, using the luteinizing hormone surge to mark midcycle. Menstrual cycles were statistically significant but smaller than daily cycles or individual differences. Menstrual cycle effects can be ignored in most research relating psychological and behavioral variables to individual differences in testosterone.

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“…The use of salivary testosterone has been reported to be reliable in comparison to serum for re¯ecting gonadal function and circadian patterns (Dabbs 1990;Johnson et al 1987), particularly when frequent sampling occurs (Leymarie et al 1974;Rose et al 1972;Spratt et al 1988). Khan-Dawood et al (1984) have shown the make-up of salivary testosterone to be 78% free testosterone, while serum free testosterone was reported to be at 4%. This large component of free salivary testosterone is due to the fact that sex hormone-binding globulin is not found in the saliva (Wang et al 1981).…”

Section: Discussionmentioning

confidence: 99%

The effect of heavy resistance exercise on the circadian rhythm of salivary testosterone in men

Kraemer

Loebel

Volek

et al. 2001

European Journal of Applied Physiology

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Circadian rhythms of serum testosterone concentrations in men have been shown, in general, to be highest in the morning and lowest in the evening. Thus, the purpose of this investigation was to determine the effects of acute resistance exercise upon the waking circadian rhythm of salivary testosterone over 2 days (with or without resistance exercise). The subjects included ten resistance-trained men (with at least 1 year of lifting experience) with the following characteristics [mean (SD)]: age 21.6 (1.1) years; height 177.8 (9.5) cm; body mass 80.5 (11.5) kg; percent body fat 7.9 (1.7)%. A matched, randomized, crossover study design was used such that each subject was tested under both the resistance exercise and control (no exercise) conditions. The resistance exercise protocol consisted of ten exercises performed for three sets of ten repetitions maximum with 2 min of rest between sets. Saliva sample 1 was collected at 0615 hours and resistance exercise began immediately afterwards at approximately 0620 hours, and sample 2 was collected at 0700 hours, which corresponded approximately to a mid-exercise (or control) time point. Saliva samples were then obtained every hour on the hour from 0800 hours until 2200 hours. No significant differences were observed between the exercise and resting conditions for salivary testosterone, with the exception of a significant decrease at 0700 hours during the resistance exercise protocol. The results of this investigation indicate that resistance exercise does not affect the circadian pattern of salivary testosterone secretion over a 16-h waking period in resistance-trained men.

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Salivary and plasma bound and “free” testosterone in men and women

Cited by 68 publications

References 19 publications

Age-Related Changes in Plasma Dehydroepiandrosterone Sulphate, Cortisol, Testosterone and Free Testosterone Circadian Rhythms in Adult Men

Age-Related Changes in Plasma Dehydroepiandrosterone Sulphate, Cortisol, Testosterone and Free Testosterone Circadian Rhythms in Adult Men

Salivary Testosterone Measurements among Women: Relative Magnitude of Circadian and Menstrual Cycles

The effect of heavy resistance exercise on the circadian rhythm of salivary testosterone in men

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