Bone Mineral Density in Transgender Adolescents Treated With Puberty Suppression and Subsequent Gender-Affirming Hormones.

Importance: Bone mineral density (BMD) z scores in transgender adolescents decrease during puberty suppression with a gonadotropin-releasing hormone (GnRH) agonist. Previous research found that after short-term use of gender-affirming hormones (GAH), pretreatment z scores were not restored. Long-term follow-up studies are lacking. Objective: To assess BMD after long-term GAH treatment in transgender adults who used puberty suppression in adolescence. Design, Setting, and Participants: This single-center cohort study with follow-up duration of 15 years selected participants from a database containing all people visiting a gender identity clinic at an academic hospital in the Netherlands between 1972 and December 31, 2018. Recruitment occurred from March 1, 2020, to August 31, 2021. A total of 75 participants diagnosed with gender dysphoria who had used puberty suppression before age 18 years prior to receiving at least 9 years of long-term GAH were included. Exposures: Puberty suppression with a GnRH agonist followed by GAH treatment. Main Outcomes and Measures: Lumbar spine, total hip, and femoral neck BMD and z scores before the start of puberty suppression, at start of GAH, and at short- and long-term follow-up. Results: Among 75 participants, 25 were assigned male at birth, and 50 were assigned female at birth. At long-term follow-up, the median (IQR) age was 28.2 (27.0-30.8) years in participants assigned male at birth and 28.2 (26.6-30.6) years in participants assigned female at birth. The median (IQR) duration of GAH treatment was 11.6 (10.1-14.7) years among those assigned male at birth and 11.9 (10.2-13.8) years among those assigned female at birth. The z scores decreased during puberty suppression. In individuals assigned male at birth, the mean (SD) z score after long-term GAH use was -1.34 (1.16; change from start of GnRH agonist: -0.87; 95% CI, -1.15 to -0.59) at the lumbar spine, -0.66 (0.75; change from start of GnRH agonist: -0.12; 95% CI, -0.31 to 0.07) at the total hip, and -0.54 (0.84; change from start of GnRH agonist: 0.01; 95% CI, -0.20 to 0.22) at the femoral neck. In individuals assigned female at birth, after long-term GAH use, the mean (SD) z score was 0.20 (1.05; change from start of GnRH agonist: 0.09; 95% CI, -0.09 to 0.27) at the lumbar spine, 0.07 (0.91; change from start of GnRH agonist: 0.10; 95% CI, -0.06 to 0.26) at the total hip, and -0.19 (0.94; change from start of GnRH agonist: -0.20; 95% CI, -0.26 to 0.06) at the femoral neck. Conclusions and Relevance: In this cohort study, after long-term use of GAH, z scores in individuals treated with puberty suppression caught up with pretreatment levels, except for the lumbar spine in participants assigned male at birth, which might have been due to low estradiol concentrations. These findings suggest that treatment with GnRH agonists followed by long-term GAH is safe with regard to bone health in transgender persons receiving testosterone, but bone health in transgender persons receiving estrogen requires extra attention and further study. Estrogen treatment should be optimized and lifestyle counseling provided to maximize bone development in individuals assigned male at birth.

The dose-dependent effect of estrogen on bone mineral density in trans girls.

OBJECTIVE: Treatment in transgender girls can consist of puberty suppression (PS) with a gonadotropin-releasing hormone agonist (GnRHa) followed by gender-affirming hormonal treatment (GAHT) with estrogen. Bone mineral density (BMD) Z-scores decrease during PS and remain relatively low during GAHT, possibly due to insufficient estradiol dosage. Some adolescents receive high-dose estradiol or ethinyl estradiol (EE) to limit growth allowing comparison of BMD outcomes with different dosages. DESIGN: Retrospective study. METHODS: Adolescents treated with GnRHa for ≥1 year prior to GAHT followed by treatment with a regular estradiol dose (gradually increased to 2 mg), 6 mg estradiol or 100-200 µg EE were included to evaluate height-adjusted BMD Z-scores (HAZ scores) on DXA. RESULTS: Eighty-seven adolescents were included. During 2.3 ± 0.7 years PS, lumbar spine HAZ scores decreased by 0.69 [95% confidence interval (CI) -0.82 to -0.56)]. During 2 years HT, lumbar spine HAZ scores hardly increased in the regular group (0.14, 95% CI -0.01 to 0.28, n = 59) vs 0.42 (95% CI 0.13 to 0.72) in the 6 mg group (n = 13), and 0.68 (95% CI 0.20 to 1.15) in the EE group (n = 15). Compared with the regular group, the increase with EE treatment was higher (0.54, 95% CI 0.05 to 1.04). After 2 years HT, HAZ scores approached baseline levels at start of PS in individuals treated with 6 mg or EE (difference in 6 mg group -0.20, 95% CI -0.50 to 0.09; in EE 0.17, 95% CI -0.16 to 0.50) but not in the regular group (-0.64, 95% CI -0.79 to -0.49). CONCLUSION: Higher estrogen dosage is associated with a greater increase in lumbar spine BMD Z-scores. Increasing dosage up to 2 mg estradiol is insufficient to optimize BMD and approximately 4 mg may be required for adequate serum concentrations.

Continuation of gender-affirming hormones in transgender people starting puberty suppression in adolescence: a cohort study in the Netherlands.

BACKGROUND: In the Netherlands, treatment with puberty suppression is available to transgender adolescents younger than age 18 years. When gender dysphoria persists testosterone or oestradiol can be added as gender-affirming hormones in young people who go on to transition. We investigated the proportion of people who continued gender-affirming hormone treatment at follow-up after having started puberty suppression and gender-affirming hormone treatment in adolescence. METHODS: In this cohort study, we used data from the Amsterdam Cohort of Gender dysphoria (ACOG), which included people who visited the gender identity clinic of the Amsterdam UMC, location Vrije Universiteit Medisch Centrum, Netherlands, for gender dysphoria. People with disorders of sex development were not included in the ACOG. We included people who started medical treatment in adolescence with a gonadotropin-releasing hormone agonist (GnRHa) to suppress puberty before the age of 18 years and used GnRHa for a minimum duration of 3 months before addition of gender-affirming hormones. We linked this data to a nationwide prescription registry supplied by Statistics Netherlands (Centraal Bureau voor de Statistiek) to check for a prescription for gender-affirming hormones at follow-up. The main outcome of this study was a prescription for gender-affirming hormones at the end of data collection (Dec 31, 2018). Data were analysed using Cox regression to identify possible determinants associated with a higher risk of stopping gender-affirming hormone treatment. FINDINGS: 720 people were included, of whom 220 (31%) were assigned male at birth and 500 (69%) were assigned female at birth. At the start of GnRHa treatment, the median age was 14·1 (IQR 13·0-16·3) years for people assigned male at birth and 16·0 (14·1-16·9) years for people assigned female at birth. Median age at end of data collection was 20·2 (17·9-24·8) years for people assigned male at birth and 19·2 (17·8-22·0) years for those assigned female at birth. 704 (98%) people who had started gender-affirming medical treatment in adolescence continued to use gender-affirming hormones at follow-up. Age at first visit, year of first visit, age and puberty stage at start of GnRHa treatment, age at start of gender-affirming hormone treatment, year of start of gender-affirming hormone treatment, and gonadectomy were not associated with discontinuing gender-affirming hormones. INTERPRETATION: Most participants who started gender-affirming hormones in adolescence continued this treatment into adulthood. The continuation of treatment is reassuring considering the worries that people who started treatment in adolescence might discontinue gender-affirming treatment. FUNDING: None.