Lower serum estradiol levels in assigned female at birth transgender people with initiation of testosterone therapy : results from the European Network for the Investigation of Gender Incongruence

Purpose: Concerns have been raised about undesired estrogenic effects in assigned female at birth (AFAB) transgender people on testosterone therapy. How serum estradiol levels change after initiation of testosterone therapy and if these levels should be monitored remain unclear. Methods: This prospective cohort study was part of the European Network for the Investigation of Gender Incongruence. Serum levels of sex steroids were assessed in 746 AFAB transgender people during a 3-year follow-up period, starting at the initiation of hormone treatment. Results: Estradiol levels decreased from median [P25-P75] 45.6 [24.0-102.2] pg/mL to 36.5 [25.0-46.2] pg/mL over 3 years (p < 0.001); a change was already noticeable during the first 3 months (mean -17.1 pg/mL, 95% confidence interval -23.8 to -10.6, p < 0.001). Serum estradiol levels were lower in people without endogenous estradiol production from ovarian source (contraceptive users or post hystero-oophorectomy) at baseline and after 3 months, compared with people with endogenous estradiol production. Using long-acting testosterone undecanoate injections resulted in a more prominent decrease in serum estradiol values over 12 months, compared with short-acting mixed testosterone esters (p < 0.001) or testosterone gel (p = 0.001). Changes in serum estradiol were positively correlated to changes in luteinizing hormone (rho = 0.107, p < 0.001) and negatively correlated to changes in follicle-stimulating hormone levels (rho = -0.167, p < 0.001) and body mass index (rho = -0.082, p < 0.001). Conclusion: Testosterone administration in AFAB transgender people resulted in decreasing serum estradiol levels. Our results suggest that testosterone therapy leads to central suppression of estradiol production, with partial restitution due to aromatization

Breast development in transwomen after 1 year of cross-sex hormone therapy : results of a prospective multicenter study

Context: Breast development is a key feature of feminization and therefore important to transwomen (male-to-female transgender persons). It is not exactly known when breast development starts after initiating cross-sex hormone therapy (CHT) and how much growth may be expected. Objective: To investigate breast development in transwomen during their first year of CHT and whether clinical or laboratory parameters predict breast development. Design: This study was performed as part of the European Network for the Investigation of Gender Incongruence, which is a prospective multicenter cohort study. Setting: Gender clinics in Amsterdam, Ghent, and Florence. Participants: Transwomen who completed the first year of CHT (n = 229). Intervention: CHT. Main Outcome Measures: Breast development in centimeter and cup size. Results: The median age of the included transwomen was 28 years (range, 18 to 69). Mean breast-chest difference increased to 7.9 +/- 3.1 cm after 1 year of CHT, mainly resulting in less than an AAA cup size (48.7%). Main breast development occurred in the first 6 months of therapy. Serum estradiol levels did not predict breast development after 1 year of CHT (first quartile, 3.6 cm [95% confidence interval (CI), 2.7 to 4.5], second quartile, 3.2 cm [95% CI, 2.3 to 4.2], third quartile, 4.4 cm [95% CI, 3.5 to 5.3], and fourth quartile, 3.6 cm [95% CI, 2.7 to 4.5]). Conclusion: This study shows that, after 1 year of CHT, breast development is modest and occurs primarily in the first 6 months. No clinical or laboratory parameters were found that predict breast development

A comparative study of 3D measuring methods for monitoring breast volume changes

Three-dimensional (3D) imaging techniques are promising new tools for measuring breast volume, for example in gender-affirming therapy. Transgender individuals can be treated with gender-affirming hormone therapy (GAHT). A robust method for monitoring breast volume changes is critical to be able to study the effects of feminizing GAHT. The primary aim of this study was to compare the accuracy of three 3D devices (Vectra XT, Artec LEO and iPhone XR) for measuring modest breast volume differences using a mannequin. The secondary aim of this study was to evaluate these methods in several performance domains. We used reference prostheses of increasing volumes and compared the volumes using GOM-inspect software. For Vectra XT 3D images, manufacturer-provided software was used to calculate volumes as well. The scanning methods were ranked based on their performance in a total of five categories: volume estimations, costs, user-friendliness, test subject- friendliness and technical aspects. The 3D models analyzed with GOM-inspect showed relative mean estimate differences from the actual volumes of 9.1% for the Vectra XT, 7.3% for the Artec LEO and 14% for the iPhone XR. For the Vectra XT models analyzed with the built-in software this was 6.2%. Root mean squared errors (RMSE) calculated based on the GOM-inspect volume analyses showed mean RMSEs of 2.27, 2.54 and 8.93 for the Vectra XT, Artec LEO and iPhone XR, respectively. The Vectra software had a mean RMSE of 3.00. In the combined performance ranking, the Vectra XT had the most favorable ranking, followed by the Artec LEO and the iPhone XR. The Vectra XT and Artec LEO are the preferred scanners to monitor breast development due to the combination of higher accuracy and overall performance. The current study shows that 3D techniques can be used to adequately measure modest breast volume differences and therefore will be useful to study for example breast changes in transgender individuals using feminizing GAHT. These observations may also be relevant in other fields of 3D imaging research.</p

Bone mineral density increases in trans persons after 1 year of hormonal treatment : a multicenter prospective observational study

Sex steroids are important determinants of bone acquisition and bone homeostasis. Cross-sex hormonal treatment (CHT) in transgender persons can affect bone mineral density (BMD). The aim of this study was to investigate in a prospective observational multicenter study the first-year effects of CHT on BMD in transgender persons. A total of 231 transwomen and 199 transmen were included who completed the first year of CHT. Transwomen were treated with cyproterone acetate and oral or transdermal estradiol; transmen received transdermal or intramuscular testosterone. A dual-energy X-ray absorptiometry (DXA) was performed to measure lumbar spine (LS), total hip (TH), and femoral neck (FN) BMD before and after 1 year of CHT. In transwomen, an increase in LS (+3.67%, 95% confidence interval [CI] 3.20 to 4.13%, p < 0.001), TH (+0.97%, 95% CI 0.62 to 1.31%, p < 0.001), and FN (+1.86%, 95% CI 1.41 to 2.31%, p < 0.001) BMD was found. In transmen, TH BMD increased after 1 year of CHT (+1.04%, 95% CI 0.64 to 1.44%, p < 0.001). No changes were observed in FN BMD (–0.46%, 95% CI –1.07 to 0.16%, p = 0.144). The increase in LS BMD was larger in transmen aged ≥50 years (+4.32%, 95% CI 2.28 to 6.36%, p = 0.001) compared with transmen aged <50 years (+0.68%, 95% CI 0.19 to 1.17%, p = 0.007). In conclusion, BMD increased in transgender persons after 1 year of CHT. In transmen of postmenopausal age, the LS BMD increased more than in younger transmen, which may lead to the hypothesis that the increase in BMD in transmen is the result of the aromatization of testosterone to estradiol

Change in visceral fat and total body fat and the effect on cardiometabolic risk factors during transgender hormone therapy

Introduction: Excess visceral fat increases the risk of type 2 diabetes and cardiovascular disease and is influenced by sex hormones. Our aim was to investigate changes in visceral fat and the ratio of visceral fat to total body fat (VAT/TBF) and their associations with changes in lipids and insulin resistance after 1 year of hormone therapy in trans persons. Methods: In 179 trans women and 162 trans men, changes in total body and visceral fat estimated with dual-energy X-ray absorptiometry before and after 1 year of hormone therapy were related to lipids and insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR)] with linear regression analysis. Results: In trans women, total body fat increased by 4.0 kg (95% CI 3.4, 4.7), while the amount of visceral fat did not change (-2 grams; 95% CI -15, 11), albeit with a large range from -318 to 281, resulting in a decrease in the VAT/TBF ratio of 17% (95% CI 15, 19). In trans men, total body fat decreased with 2.8 kg (95% CI 2.2, 3.5), while the amount of visceral fat did not change (3 g; 95% CI -10, 16; range -372, 311), increasing the VAT/TBF ratio by 14% (95% CI 10, 17). In both groups, VAT/TBF was not associated with changes in blood lipids or HOMA-IR. Conclusions: Hormone therapy in trans women and trans men resulted in changes in VAT/TBF, mainly due to changes in total body fat and were unrelated to changes in cardiometabolic risk factors, which suggests that any unfavorable cardiometabolic effects of hormone therapy are not mediated by changes in visceral fat or VAT/TBF.Clinical epidemiolog

Changes in regional body fat, lean body mass and body shape in trans persons using cross-sex hormonal therapy: results from a multicenter prospective study

Objective Cross-sex hormonal therapy (CHT) in trans persons affects their total body fat and total lean body mass. However, it is unknown how separate body regions are affected and whether these changes alter body shape. Therefore, the aim of this study was to determine the effects on body fat and lean body mass in separate body regions and on body shape after one year of CHT. Design and methods In a multicenter prospective study at university hospitals, 179 male-to-female gender dysphoric persons, referred to as transwomen, and 162 female-to-male gender dysphoric persons, referred to as transmen, were included. All underwent whole-body dual-energy X-ray absorptiometry and anthropometric measurements before and after one year of CHT. Results In transwomen, increases in body fat ranged from +18% (95% CI: 13%;23%) in the android region to +42% (95% CI: 37%;46%) in the leg region and +34% (95% CI: 29%;38%) in the gynoid region. In transmen, changes in body fat ranged from −16% (95% CI: −19;−14%) in the leg region and −14% in the gynoid region (95% CI: −16%;−12) to no change in the android region (+1%, 95% CI: −3%;5%). Waist-to-hip ratio (WHR) decreased in transwomen (−0.03, 95% CI: −0.04;−0.02) mainly due to an increase in hip circumference (+3.2 cm, 95% CI: 2.3;4.0). Transmen have a decrease in hip circumference (−1.9 cm, 95% CI: −3.1;−0.7) resulting in an increase in WHR (+0.01, 95% CI: 0.00;0.02). Conclusions CHT causes a more feminine body fat distribution and a lower WHR in transwomen and a more masculine body fat distribution with a lower hip circumference in transmen

Bone health in adult trans persons: An update of the literature

Purpose of review Hormonal treatment in trans persons can affect bone health. In this review, recent studies published on this topic in adults are discussed. Recent findings Before starting hormonal treatment, trans women were found to have lower bone mineral density than cis men, which seems to be related to lower vitamin D concentrations and lower lean body mass, whereas this was not found in trans men. Short-term and long-term studies show that hormonal treatment does not have detrimental effects on bone mineral density in trans women and trans men. Low estradiol concentrations were associated with a decrease in bone mineral density in trans women. Summary Based on the reassuring findings in these studies, regularly assessing bone mineral density during hormonal treatment does not seem necessary. This confirms the Endocrine Society Guideline stating that bone mineral density should be measured only when risk factors for osteoporosis exist, especially in people who stop hormonal treatment after gonadectomy. The relationship with estradiol concentrations indicate that hormone supplementation should be adequate and therapy compliance should be stimulated. As vitamin D deficiency frequently occurs, vitamin D supplementation should be considered. Future research should focus on fracture risk and long-term changes in bone geometry