Department of Endocrinology and Metabolism, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Center of Expertise on Gender Dysphoria, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Eur J Endocrinol. 2024 Sep 30;191(4):426-432. doi: 10.1093/ejendo/lvae126.
Bone mineral density (BMD) Z-scores decrease during puberty suppression in transgender youth. Assessment of treatment impact has been based on the assumption that without intervention, BMD Z-scores remain stable. However, the natural course of BMD in this population is unknown.
Retrospective cross-sectional study.
Dual-energy X-ray absorptiometry scans prior to medical intervention were included from 333 individuals assigned male at birth (AMAB) and 556 individuals assigned female at birth (AFAB) aged 12-25 years. The relationship between age and BMD Z-scores of sex assigned at birth was analysed for the lumbar spine (LS), total hip (TH), femoral neck (FN), and total-body-less-head (TBLH), adjusted for height SDS, height-adjusted lean mass Z-score, and whole body percentage fat Z-score.
In individuals AMAB, the BMD Z-score was negatively associated with age between 12 and 22 years: LS -0.13/year (95% confidence interval, CI -0.17; -0.10); TH -0.05/year (95% CI -0.08; -0.02); FN -0.06/year (95% CI -0.10; -0.03); and TBLH -0.12/year (95% CI -0.15; -0.09). Adjusting for height-adjusted lean mass Z-score attenuated the association at the LS and TBLH and eliminated the association at the TH and FN. BMD Z-scores and age were not associated between 22 and 25 years. In individuals AFAB, BMD Z-scores were only associated with age at the TBLH (-0.08/year, 95% CI -0.12; -0.04) between age 12 and 20 years.
In individuals AMAB aged 12-22 years prior to any treatment, BMD Z-scores were inversely correlated with age. This could imply that BMD increases less in individuals AMAB than in the general population, and that changes in Z-score during puberty suppression and subsequent hormone supplementation are not necessarily due to treatment, but possibly related to lifestyle factors.
在跨性别青年的青春期抑制过程中，骨密度（BMD）Z 分数会降低。治疗效果的评估一直基于这样的假设，即如果不进行干预，BMD Z 分数将保持稳定。然而，该人群的 BMD 自然病程尚不清楚。
回顾性横断面研究。
纳入了 333 名出生时被指定为男性（AMAB）和 556 名出生时被指定为女性（AFAB）的 12-25 岁个体在接受医学干预之前的双能 X 射线吸收法（DXA）扫描。分析了出生时性别分配的腰椎（LS）、全髋（TH）、股骨颈（FN）和全身非头部（TBLH）的 BMD Z 分数与年龄的关系，对身高 SDS、身高调整后瘦体重 Z 分数和全身脂肪百分比 Z 分数进行了调整。
在 AMAB 个体中，BMD Z 分数与 12 至 22 岁之间的年龄呈负相关：LS -0.13/年（95%置信区间，CI -0.17；-0.10）；TH -0.05/年（95%CI -0.08；-0.02）；FN -0.06/年（95%CI -0.10；-0.03）；TBLH -0.12/年（95%CI -0.15；-0.09）。调整身高调整后瘦体重 Z 分数后，LS 和 TBLH 的相关性减弱，TH 和 FN 的相关性消失。22 至 25 岁之间，BMD Z 分数与年龄无相关性。在 AFAB 个体中，BMD Z 分数仅与 12 至 20 岁之间的 TBLH 年龄相关（-0.08/年，95%CI -0.12；-0.04）。
在任何治疗前年龄为 12-22 岁的 AMAB 个体中，BMD Z 分数与年龄呈负相关。这可能意味着 AMAB 个体的 BMD 增加幅度低于一般人群，青春期抑制和随后的激素补充治疗期间 Z 分数的变化不一定是由于治疗引起的，而可能与生活方式因素有关。
