Impact of GnRH Analogues and Hormonal Therapy on Skeletal Dimensions in Transgender Youth
Overview
This study evaluated the effects of puberty suppression (PS) and gender-affirming hormone therapy (GAHT) on shoulder and pelvic skeletal dimensions in transgender individuals aged 18-28 years. Findings indicate that skeletal dimensions are altered by GAHT only if endogenous puberty has not been completed at the start of PS, with early PS leading to skeletal features more aligned with the affirmed gender.
Background
Transgender individuals often undergo gender-affirming hormone therapy to align physical characteristics with their gender identity. Puberty suppression with GnRH analogues is commonly used in adolescents to delay endogenous puberty before initiating GAHT. While sex hormones influence secondary sex characteristics and body composition, their effects on skeletal dimensions, such as shoulder and pelvic morphology, remain unclear. Understanding these effects is important for clinical management, body image considerations, and surgical planning.
Data Highlights
Group
Shoulder Width Change (cm)
Pelvic Inlet Width Change (cm)
Other Pelvic Dimensions
AMAB Early PS + GAHT
−1.3 (95% CI −2.1; −0.5) vs untreated AMAB
Increased vs untreated AMAB, comparable to untreated AFAB
Greater pubic symphysis width and interischial distance vs untreated AMAB
AMAB Late PS + GAHT
No significant shoulder change
Increased pelvic dimensions vs untreated AMAB, comparable to untreated AFAB
Greater pubic symphysis width and interischial distance vs untreated AMAB
AMAB GAHT-only
No significant changes
No significant changes
—
AFAB Early PS + GAHT
No significant shoulder change
Pelvic inlet width smaller (−1.0 cm; 95% CI −1.5; −0.6) vs untreated AFAB, comparable to untreated AMAB
—
AFAB Late PS + GAHT or GAHT-only
No significant changes
No significant changes
—
Key Findings
Early puberty suppression in AMAB individuals leads to reduced shoulder width compared to untreated AMAB.
Both early and late PS in AMAB individuals increase pelvic dimensions to resemble those of untreated AFAB individuals.
Early PS in AFAB individuals results in decreased pelvic inlet width, aligning with untreated AMAB dimensions.
GAHT without prior PS does not significantly alter skeletal dimensions in either AMAB or AFAB individuals.
Skeletal dimension changes depend on the timing of puberty suppression relative to endogenous puberty completion.
Clinical Implications
These findings suggest that initiating puberty suppression before completion of endogenous puberty allows for skeletal remodeling aligned with affirmed gender, which may influence body image and satisfaction. Clinicians should consider timing of PS when planning hormone therapy, as skeletal changes may impact surgical and obstetrical outcomes. Understanding these effects can aid in counseling transgender patients regarding physical changes and expectations.
Conclusion
Gender-affirming hormone therapy alters skeletal dimensions only when preceded by early puberty suppression, highlighting the critical window during endogenous puberty for skeletal remodeling. This knowledge enhances clinical care and informs future research on functional outcomes in transgender populations.
References
van der Loos et al. 2023 -- Influence of GnRH Analogues and Hormonal Treatments on Bone Structure in Transgender Populations
by Lidewij Sophia Boogers, Boukje Teatske Sikma, Mark-Bram Bouman, Adrianus Sarinus Paulus van Trotsenburg, Martin den Heijer, Chantal Maria Wiepjes, Sabine Elisabeth Hannema
