Aim:

Feminising hormone therapy with estradiol is used to align an individual’s physical characteristics with their gender identity. Given considerable variations in doses of estradiol therapy administered as gender-affirming hormone therapy (GAHT), we aimed to assess if body mass index (BMI) correlated with estradiol dose/concentration and assess the correlation between estradiol dose and estradiol concentrations.

Methods:

In a retrospective cross-sectional study, we analysed transgender individuals attending a primary or secondary care clinic in Melbourne, Australia who were prescribed oral estradiol valerate for at least 6 months and had estradiol dose and concentration available. Estradiol concentration was measured by immunoassay. Outcomes were the correlation between estradiol dose and BMI, and estradiol dose and estradiol concentration.

Results:

Data were available for 259 individuals {median age 25.8 [interquartile range (IQR) 21.9, 33.5] years}. Median duration of estradiol therapy was 24 (15, 33) months. Median estradiol concentration was 328 (238, 434) pmol/l [89 (65, 118) pg/ml] on 6 (4, 8) mg estradiol valerate. Median BMI was 24.7 (21.8, 28.6) kg/m². There was a weak positive correlation between estradiol dose and estradiol concentration (r = 0.156, p = 0.012). There was no correlation between BMI and estradiol concentration achieved (r = −0.063, p = 0.413) or BMI and estradiol dose (r = 0.048, p = 0.536). Estradiol concentrations were within the target range recommended in consensus guidelines in 172 (66%) individuals.

Conclusion:

Estradiol dose was only weakly correlated with estradiol concentration, suggesting significant interindividual variability. Prescription of estradiol dose should not be based upon an individual’s BMI, which did not correlate with estradiol concentration achieved. In all, 66% of individuals achieved estradiol concentrations recommended in Australian consensus guidelines with a relatively high oral estradiol dose.

中文翻译：

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接受女性化激素治疗的跨性别成人体重指数与口服雌二醇剂量和血清雌二醇浓度之间的关系。

目标：

使用雌二醇进行女性化激素疗法用于使个人的身体特征与其性别认同保持一致。鉴于作为性别肯定激素疗法 (GAHT) 给药的雌二醇治疗剂量存在相当大的差异，我们旨在评估体重指数 (BMI) 是否与雌二醇剂量/浓度相关，并评估雌二醇剂量与雌二醇浓度之间的相关性。

方法：

在一项回顾性横断面研究中，我们分析了在澳大利亚墨尔本的初级或二级保健诊所就诊的跨性别个体，这些个体被处方口服戊酸雌二醇至少 6 个月，并且有可用的雌二醇剂量和浓度。通过免疫测定法测量雌二醇浓度。结果是雌二醇剂量和BMI之间的相关性，以及雌二醇剂量和雌二醇浓度之间的相关性。

结果：

数据可用于 259 人{中位年龄 25.8 [四分位距 (IQR) 21.9, 33.5] 年}。雌二醇治疗的中位持续时间为 24 (15, 33) 个月。6 (4, 8) mg 戊酸雌二醇的中位雌二醇浓度为 328 (238, 434) pmol/l [89 (65, 118) pg/ml]。中位 BMI 为 24.7 (21.8, 28.6) kg/m ²。雌二醇剂量与雌二醇浓度呈弱正相关（r  = 0.156，p  = 0.012）。BMI 与达到的雌二醇浓度 ( r  = -0.063, p  = 0.413) 或 BMI 与雌二醇剂量 ( r  = 0.048, p = 0.536）。172 名 (66%) 个体的雌二醇浓度在共识指南推荐的目标范围内。

结论：

雌二醇剂量仅与雌二醇浓度微弱相关，表明存在显着的个体差异。雌二醇剂量的处方不应基于个体的 BMI，这与达到的雌二醇浓度无关。总之，66% 的个体在口服雌二醇剂量相对较高的情况下达到了澳大利亚共识指南中推荐的雌二醇浓度。