Modulation of circulating free testosterone fraction by testosterone, dihydrotestosterone, and estradiol during testosterone replacement therapy.
SHBG
allostery
dihydrotestosterone
estradiol
free testosterone
sex hormones
Journal
Andrology
ISSN: 2047-2927
Titre abrégé: Andrology
Pays: England
ID NLM: 101585129
Informations de publication
Date de publication:
02 Aug 2024
02 Aug 2024
Historique:
revised:
26
06
2024
received:
21
05
2024
accepted:
06
07
2024
medline:
2
8
2024
pubmed:
2
8
2024
entrez:
2
8
2024
Statut:
aheadofprint
Résumé
Testosterone, estradiol, and dihydrotestosterone share common ligand binding sites on sex hormone binding globulin and albumin. It is unknown whether and how changes in testosterone, dihydrotestosterone, and estradiol concentrations during testosterone replacement therapy affect free testosterone fraction. To determine the effect of changes in testosterone, dihydrotestosterone, and estradiol concentrations on free testosterone fraction during testosterone replacement therapy of men with hypogonadism. Using data from the Testosterone Trials, we assessed the association of changes in total testosterone, estradiol, and dihydrotestosterone concentrations over 12 months of testosterone replacement therapy with changes in free testosterone fraction, measured using equilibrium dialysis. We used random forests to evaluate the associations of predicted mean changes in free testosterone fraction with changes in circulating concentrations of each hormone at low, mean, or high change in the other two hormones. Testosterone replacement therapy not only increased total testosterone, dihydrotestosterone, estradiol, and free testosterone concentrations, but also the percent free testosterone, even though sex hormone binding globulin levels did not change. The predicted changes in free testosterone fraction during testosterone replacement therapy exhibited a non-linear relationship with changes in each of total testosterone, dihydrotestosterone, and estradiol concentrations. Greater increases in testosterone, dihydrotestosterone, and estradiol levels during testosterone replacement therapy were each associated with higher model-predicted percent free testosterone. Substantially smaller changes in molar concentrations of estradiol and dihydrotestosterone had a greater effect on percent free testosterone than those in testosterone. During testosterone replacement therapy of men with hypogonadism, changes in testosterone, dihydrotestosterone, and estradiol concentrations each altered percent free testosterone non-linearly. Small changes in estradiol concentrations exerted much larger effect on the free testosterone fraction than testosterone and dihydrotestosterone, suggesting complex interactions of the three hormones with the binding proteins. Assessment of changes in free testosterone during testosterone replacement therapy should include consideration of changes in all three hormones.
Sections du résumé
BACKGROUND
BACKGROUND
Testosterone, estradiol, and dihydrotestosterone share common ligand binding sites on sex hormone binding globulin and albumin. It is unknown whether and how changes in testosterone, dihydrotestosterone, and estradiol concentrations during testosterone replacement therapy affect free testosterone fraction.
OBJECTIVE
OBJECTIVE
To determine the effect of changes in testosterone, dihydrotestosterone, and estradiol concentrations on free testosterone fraction during testosterone replacement therapy of men with hypogonadism.
METHODS
METHODS
Using data from the Testosterone Trials, we assessed the association of changes in total testosterone, estradiol, and dihydrotestosterone concentrations over 12 months of testosterone replacement therapy with changes in free testosterone fraction, measured using equilibrium dialysis. We used random forests to evaluate the associations of predicted mean changes in free testosterone fraction with changes in circulating concentrations of each hormone at low, mean, or high change in the other two hormones.
RESULTS
RESULTS
Testosterone replacement therapy not only increased total testosterone, dihydrotestosterone, estradiol, and free testosterone concentrations, but also the percent free testosterone, even though sex hormone binding globulin levels did not change. The predicted changes in free testosterone fraction during testosterone replacement therapy exhibited a non-linear relationship with changes in each of total testosterone, dihydrotestosterone, and estradiol concentrations. Greater increases in testosterone, dihydrotestosterone, and estradiol levels during testosterone replacement therapy were each associated with higher model-predicted percent free testosterone. Substantially smaller changes in molar concentrations of estradiol and dihydrotestosterone had a greater effect on percent free testosterone than those in testosterone.
CONCLUSION
CONCLUSIONS
During testosterone replacement therapy of men with hypogonadism, changes in testosterone, dihydrotestosterone, and estradiol concentrations each altered percent free testosterone non-linearly. Small changes in estradiol concentrations exerted much larger effect on the free testosterone fraction than testosterone and dihydrotestosterone, suggesting complex interactions of the three hormones with the binding proteins. Assessment of changes in free testosterone during testosterone replacement therapy should include consideration of changes in all three hormones.
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Subventions
Organisme : NIH HHS
ID : 5P30AG031679
Pays : United States
Organisme : NIH HHS
ID : 5 R44 AG045011
Pays : United States
Organisme : NIH HHS
ID : R33 AG068234
Pays : United States
Organisme : NIA NIH HHS
ID : U01 AG030644
Pays : United States
Organisme : National Heart, Lung and Blood Institute
Organisme : National Institute of Neurological Diseases and Stroke
Organisme : National Institute of Child Health and Human Development
Informations de copyright
© 2024 American Society of Andrology and European Academy of Andrology.
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