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. 2025 Aug 4.
doi: 10.1007/s40618-025-02675-5. Online ahead of print.

Age-dependent bone mineral density responses to gender-affirming hormone therapy in transgender individuals: a one-year prospective study

Chiara Ceolin #  1   2 , Martina Dall'Agnol #  3 , Giulia Termini  3 , Mario Virgilio Papa  3 , Giulia Casali  4 , Anna Bertocco  3 , Alberto Scala  4 , Sandro Giannini  5 , Alberto Ferlin  4 , Giuseppe Sergi  3 , Andrea Garolla #  4 , Marina De Rui #  3 ; GIIG group
Affiliations

Age-dependent bone mineral density responses to gender-affirming hormone therapy in transgender individuals: a one-year prospective study

Chiara Ceolin et al. J Endocrinol Invest. .

Abstract

Purpose: Evidence on the skeletal effects of gender-affirming hormone therapy (GAHT) in transgender individuals remains limited, especially across age groups. Individuals assigned male at birth (AMAB) often show reduced bone mineral density (BMD) even before GAHT, whereas findings in those assigned female at birth (AFAB) are more variable. Given the key role of adolescence and early adulthood in peak bone mass, timely skeletal assessment is essential. This study compared BMD before and after one year (1-y) of GAHT to age-matched cisgender controls.

Methods: Prospective observational study involving 269 adults (162 transgender and 107 cisgender controls) conducted at the University Hospital of Padua (January 2020-November 2024). Dual-energy X-ray absorptiometry (DXA) was performed at baseline and after 1-y of GAHT.

Results: After 1-y of GAHT, in AMAB individuals, lumbar spine BMD significantly increased (from 0.97 ± 0.16 to 1.02 ± 0.14 g/cm², p < 0.001), particularly in those under 20 years. AFAB individuals experienced a modest but significant reduction in femoral neck BMD (from 0.81 ± 0.12 to 0.79 ± 0.13, p < 0.05), especially in the 20-30-year age group. Age-stratified analyses revealed that younger participants showed greater BMD improvements, while those over 20 exhibited stable or declining values. Linear regression confirmed age as an independent predictor of BMD change, with older age associated with reduced skeletal responsiveness to GAHT at key femoral sites.

Conclusions: GAHT has variable effects on bone health, influenced by age and sex assigned at birth. Early initiation may favor bone accrual, especially in AMAB individuals, while AFAB individuals may require closer monitoring for site-specific bone loss during testosterone therapy.

Keywords: BMD; Bone; Gender incongruence; Gender-Affirming hormone therapy; Transgender.

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Conflict of interest statement

Declarations. Competing interests: nothing to declare. Ethical approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study protocol was approved by the Ethics Committee for Clinical Research of the Province of Padua (approval no. 0025087). Informed consent: Written informed consent was obtained from all participants prior to enrollment. Consent to publish: not applicable. Clinical trail registration: not applicable.

References

    1. Atkinson SR, Russell D (2015) Gender dysphoria. Aust Fam Physician 44(11):792–796
    1. Beek TF, Cohen-Kettenis PT, Kreukels BPC (2016) Gender incongruence/gender dysphoria and its classification history. Int Rev Psychiatry 28(1):5–12. https://doi.org/10.3109/09540261.2015.1091293 - DOI
    1. Salas-Humara C, Sequeira GM, Rossi W, Dhar CP (2019) Gender affirming medical care of transgender youth. Curr Probl Pediatr Adolesc Health Care 49(9):100683. https://doi.org/10.1016/j.cppeds.2019.100683 - DOI
    1. Centro Risorse LGBTI, Certi Diritti F, Arcobaleno, Intersexioni (2014) and ILGA-Europe, Italy: the status of the human rights of lesbian, gay, bisexual, transgender and intersex people. Univers Period Rev Italy, pp. 1–12
    1. Zucker KJ (2017) Epidemiology of gender dysphoria and transgender identity. Sex Health 14(5):404–411. https://doi.org/10.1071/SH17067 - DOI

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