Effects of puberty suppression on bone, body composition, handgrip strength and glucolipid profile in early-pubertal transgender adolescents

Abstract

Introduction

The effects of puberty suppression for more than 2 years before the start of gender-affirming hormones (GAH) on bone mass acquisition and body composition are understudied.

Materials and methods

Retrospective study on 46 transgender adolescents (20 trans boys and 26 trans girls) receiving a gonadotropin-releasing hormone analogue (GnRHa) from Tanner stage 2-3, followed by GAH around the age of 16 years. At start of GnRHa and at start of GAH, dual-energy X-ray absorptiometry (DXA) at lumbar spine (LS), femoral neck (FN) and total body (TB), handgrip strength test and fasting blood sampling were performed. Z-scores were calculated using reference values for both cis girls and cis boys.

Results

GnRHa were administered for a median of 3.2 years (± 0.69) in trans boys and 2.7 years (± 1.05) in trans girls. Bone mineral apparent density (BMAD)-LS Z-scores decreased significantly in both trans boys and trans girls, while BMAD-FN Z-scores decreased only in trans boys. Fat% and Fat Mass Index Z-scores significantly increased in both groups, while Lean Mass Index Z-scores significantly decreased. Handgrip strength Z-scores for the sex registered at birth (SRAB) remained stable in trans boys while they decreased in trans girls. There was no significant influence of the treatment on either insulin sensitivity or lipid profile.

Discussion

GnRHa administration for more than two years during the physiological time of puberty decreases bone mass acquisition, mainly at the lumbar spine and induces a general increase in fat mass. Although lean mass acquisition is undermined in both groups, handgrip strength is affected mainly in trans girls compared with age-matched peers for the SRAB.

Keywords:

• Body composition
• bone
• GnRHa
• muscle strength
• puberty
• transgender

Acknowledgments

The authors thank all the participants who allowed use of their data in the study and Roel Vandecappelle for excellent technical assistance. The authors also thank Thiberiu Banica and Lloyd Tack for helpful discussions.

Ethical approval and statement of human rights

The ethics committee of Ghent University Hospital approved the study (2016/0107). 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.

Authors’ contributions

Study conceptualization: SC, MC. Funding acquisition: MC. Data acquisition: SC, MC, MC, DK. Writing of the first draft: SC, MC. Revision of the manuscript: VD, CV, DV. All authors approved the final version of the manuscript.

Disclosure statement

The authors have nothing to disclose.

Data availability statement

All data generated or analyzed during this study are included in this published article or are available from the corresponding author upon reasonable request.

Additional information

Funding

This work is supported by a project grant from the Research Foundation - Flanders (FWO; G065819N). MC is supported by a FWO senior clinical investigator grant (FWO; 1801018 N) and by a Ghent University Fund for Innovation and Clinical Research (FIKO IV) grant.