Hailing Chen1,2, Chantal M Wiepjes3, Natasja M van Schoor4, Annemieke C Heijboer5,6, Renate T de Jongh3, Martin den Heijer3, Paul Lips3. 1. Department of Endocrinology, Beijing Jishuitan Hospital, Beijing, China. 2. Department of Endocrinology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. 3. Department of Internal Medicine, Endocrine Section, and Center of Expertise on Gender Dysphoria, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. 4. Department of Epidemiology and Biostatistics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Public Health, Amsterdam, Netherlands. 5. Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. 6. Endocrine Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.
Abstract
CONTEXT: Total 25-hydroxyvitamin D [25(OH)D] is mainly bound to vitamin d-binding protein (DBP). Bioavailable 25(OH)D consists of albumin-bound and free 25(OH)D and is available for metabolic processes. As sex steroids influence DBP, hormonal treatment (HT) in transgender people might affect DBP and consequently the available 25(OH)D. Total 25(OH)D might therefore not well represent bioavailable and free 25(OH)D. OBJECTIVE: To investigate the effects of HT on DBP, and total, bioavailable, and free 25(OH)D, and to assess whether total 25(OH)D well represents bioavailable and free 25(OH)D. DESIGN: A prospective study. SETTING: A university hospital. PARTICIPANTS: Twenty-nine transwomen and 30 transmen. INTERVENTION: Estradiol and cyproterone acetate in transwomen, and testosterone in transmen. MAIN OUTCOME MEASURES: DBP, total 25(OH)D, free 25(OH)D, and albumin were measured at baseline and after 3 months of HT, and deseasonalized total 25(OH)D and bioavailable 25(OH)D were calculated. RESULTS: DBP changed with +5% (95% CI, -0% to 10%; P = 0.06) in transwomen and with -3% (95% CI: -9% to 3%; P = 0.34) in transmen. No significant changes were found in total 25(OH)D, free, and bioavailable 25(OH)D concentrations. Total 25(OH)D was well correlated with bioavailable (R2, 0.75) and free (R2, 0.76) 25(OH)D. CONCLUSIONS: DBP tended to increase in transwomen, but did not change in transmen. HT did not influence free 25(OH)D, total 25(OH)D, and bioavailable 25(OH)D concentrations in transwomen and transmen. As total 25(OH)D represents bioavailable and free 25(OH)D well, HT in transgender people does not interfere with the assessment of vitamin D status.
CONTEXT: Total 25-hydroxyvitamin D [25(OH)D] is mainly bound to vitamin d-binding protein (DBP). Bioavailable 25(OH)D consists of albumin-bound and free 25(OH)D and is available for metabolic processes. As sex steroids influence DBP, hormonal treatment (HT) in transgender people might affect DBP and consequently the available 25(OH)D. Total 25(OH)D might therefore not well represent bioavailable and free 25(OH)D. OBJECTIVE: To investigate the effects of HT on DBP, and total, bioavailable, and free 25(OH)D, and to assess whether total 25(OH)D well represents bioavailable and free 25(OH)D. DESIGN: A prospective study. SETTING: A university hospital. PARTICIPANTS: Twenty-nine transwomen and 30 transmen. INTERVENTION: Estradiol and cyproterone acetate in transwomen, and testosterone in transmen. MAIN OUTCOME MEASURES: DBP, total 25(OH)D, free 25(OH)D, and albumin were measured at baseline and after 3 months of HT, and deseasonalized total 25(OH)D and bioavailable 25(OH)D were calculated. RESULTS:DBP changed with +5% (95% CI, -0% to 10%; P = 0.06) in transwomen and with -3% (95% CI: -9% to 3%; P = 0.34) in transmen. No significant changes were found in total 25(OH)D, free, and bioavailable 25(OH)D concentrations. Total 25(OH)D was well correlated with bioavailable (R2, 0.75) and free (R2, 0.76) 25(OH)D. CONCLUSIONS:DBP tended to increase in transwomen, but did not change in transmen. HT did not influence free 25(OH)D, total 25(OH)D, and bioavailable 25(OH)D concentrations in transwomen and transmen. As total 25(OH)D represents bioavailable and free 25(OH)D well, HT in transgender people does not interfere with the assessment of vitamin D status.
Authors: Konstantinos Makris; Harjit P Bhattoa; Etienne Cavalier; Karen Phinney; Christopher T Sempos; Candice Z Ulmer; Samuel D Vasikaran; Hubert Vesper; Annemieke C Heijboer Journal: Clin Chim Acta Date: 2021-03-10 Impact factor: 6.314
Authors: Carlotta Cocchetti; Alessia Romani; Sarah Collet; Yona Greenman; Thomas Schreiner; Chantal Wiepjes; Martin den Heijer; Guy T'Sjoen; Alessandra Daphne Fisher Journal: J Clin Med Date: 2022-03-24 Impact factor: 4.241