Bone in trans persons

Body composition and risk for sarcopenia in transgender women

OBJECTIVES

Body composition and strength of cisgender (cis) individuals are well established. However, those for transgender women (trans women) undergoing gender-affirming hormone therapy remain unclear. This study aimed to detect possible body composition and strength variations related to sarcopenia.

METHODS

This was a cross-sectional comparative study of 37 trans women, 34 cis men, and 34 cis women. Body composition was measured in all individuals by bioelectrical impedance analysis; prehensile strength by dynamometry was studied in trans women.

RESULTS

In this study, trans women had higher body mass index values than cis individuals (P < 0.01). Fat mass was 41% higher for trans women than cis men. Muscle mass (MM) was lower in trans women than cis men (-10%), and higher than cis women (24%). Bone mass was lower in trans women than cis men and higher in cis women (P < 0.01). Trans women's prehensile strengths were 25.26 kg for the right hand and 24.8 kg for the left. Appendicular skeletal muscle mass was 23.63 kg, and appendicular skeletal muscle mass index was 8.14 kg.

CONCLUSION

Trans women undergoing gender-affirming hormone therapy show a tendency to adapt body compartments to those of cis women with increased fat mass and reduced muscle mass. Prehensile strength in trans women was close to the cutoff points for sarcopenia risk. Nutrition, physical activity, strength, and body composition are important to avoid the possible risk for sarcopenia. More studies along these lines are necessary, especially in older adults.

Unraveling sex-specific risks of knee osteoarthritis before menopause: Do sex differences start early in life?

OBJECTIVE

Sufficient evidence within the past two decades have shown that osteoarthritis (OA) has a sex-specific component. However, efforts to reveal the biological causes of this disparity have emerged more gradually. In this narrative review, we discuss anatomical differences within the knee, incidence of injuries in youth sports, and metabolic factors that present early in life (childhood and early adulthood) that can contribute to a higher risk of OA in females.

DESIGN

We compiled clinical data from multiple tissues within the knee joint-since OA is a whole joint disorder-aiming to reveal relevant factors behind the sex differences from different perspectives.

RESULTS

The data gathered in this review indicate that sex differences in articular cartilage, meniscus, and anterior cruciate ligament are detected as early as childhood and are not only explained by sex hormones. Aiming to unveil the biological causes of the uneven sex-specific risks for knee OA, we review the current knowledge of sex differences mostly in young, but also including old populations, from the perspective of (i) human anatomy in both healthy and pathological conditions, (ii) physical activity and response to injury, and (iii) metabolic signatures.

CONCLUSIONS

We propose that to close the gap in health disparities, and specifically regarding OA, we should address sex-specific anatomic, biologic, and metabolic factors at early stages in life, as a way to prevent the higher severity and incidence of OA in women later in life.

Hysterectomy and Oophorectomy for Transgender Patients: Preoperative and Intraoperative Considerations

OBJECTIVE

To review the preoperative and intraoperative considerations for gynecologic surgeons when performing hysterectomy with or without oophorectomy for transgender patients.

DESIGN

Stepwise demonstration of techniques with narrated video footage.

SETTING

Approximately 0.3% of hysterectomies performed annually in the United States are for transgender men. While some transgender men choose hysterectomy for the same indications as cisgender women, the most prevalent diagnosis for the performed surgeries is gender dysphoria [1]. Hysterectomy with or without oophorectomy can be offered to patients who meet the World Professional Association for Transgender Health criteria [2].

INTERVENTIONS

Important perioperative counseling points for transgender patients include establishing the terminology for the relevant anatomy as well as the patient's name and pronouns; if applicable, discussing options for fertility preservation if the patient desires biological children [3,4] and discussing the use of hormone therapy post oophorectomy to reduce the loss of bone density [5,6]; and reviewing intraoperative and postoperative expectations. When performing an oophorectomy on a transgender patient for gender affirmation, it is especially important to minimize the risk of ovarian remnant syndrome and the need for additional surgery, as, for example, caused by persistent menstruation. A 2-layer vaginal cuff closure should be considered to reduce the risk of vaginal cuff complications and is preferable for patients whose pelvic organs cause gender dysphoria [7,8].

CONCLUSION

Special considerations outlined in this video and the World Professional Association for Transgender Health guidelines should be reviewed by gynecologic surgeons to minimize the transgender patient's experiences of gender dysphoria before, during, and after surgery.

[Beyond NICE: Updated Systematic Review on the Current Evidence of Using Puberty Blocking Pharmacological Agents and Cross-Sex-Hormones in Minors with Gender Dysphoria]

Beyond NICE: Updated Systematic Review on the Current Evidence of Using Puberty Blocking Pharmacological Agents and Cross-Sex-Hormones in Minors with Gender Dysphoria Abstract: Objective: The suppression of physiological puberty using puberty-blocking pharmacological agents (PB) and prescribing cross-sex hormones (CSH) to minors with gender dysphoria (GD) is a current matter of discussion, and in some cases, PB and CSH are used in clinical practice for this particular population. Two systematic reviews (one on PB, one on CSH treatment) by the British National Institute for Clinical Excellence (NICE) from 2020 indicated no clear clinical benefit of such treatments regarding critical outcome variables. In particular, these two systematic NICE reviews on the use of PB and CSH in minors with GD detected no clear improvements of GD symptoms. Moreover, the overall scientific quality of the available evidence, as discussed within the above-mentioned two NICE reviews, was classified as "very low certainty" regarding modified GRADE criteria. Method: The present systematic review presents an updated literature search on this particular topic (use of PB and CSH in minors with GD) following NICE principles and PICO criteria for all relevant new original research studies published since the release of the two above-mentioned NICE reviews (updated literature search period was July 2020-August 2023). Results: The newly conducted literature search revealed no newly published original studies targeting NICE-defined critical and important outcomes and the related use of PB in minors with GD following PICO criteria. For CSH treatment, we found two new studies that met PICO criteria, but these particular two studies had low participant numbers, yielded no significant additional clear evidence for specific and clearly beneficial effects of CSH in minors with GD, and could be classified as "low certainty" tfollowing modified GRADE criteria. Conclusions: The currently available studies on the use of PB and CSH in minors with GD have significant conceptual and methodological flaws. The available evidence on the use of PB and CSH in minors with GD is very limited and based on only a few studies with small numbers, and these studies have problematic methodology and quality. There also is a lack of adequate and meaningful long-term studies. Current evidence doesn't suggest that GD symptoms and mental health significantly improve when PB or CSH are used in minors with GD. Psychotherapeutic interventions to address and reduce the experienced burden can become relevant in children and adolescents with GD. If the decision to use PB and/or CSH is made on an individual case-by-case basis and after a complete and thorough mental health assessment, potential treatment of possibly co-occurring mental health problems as well as after a thoroughly conducted and carefully executed individual risk-benefit evaluation, doing so as part of clinical studies or research projects, as currently done in England, can be of value in terms of generation of new research data. The electronic supplement (ESM) 1 is an adapted and abreviated English version of this work.

Gynecologic Care of Transgender and Gender-Diverse People

The visibility and care of transgender and gender-diverse (TGD) people is an important component of gynecology. Transmasculine individuals require routine gynecologic and preventative care. Guidelines can be extrapolated from the cisgender female population, and using affirming language, acknowledging the challenges patients face with pelvic examination, and discussing individual gynecologic needs are important components of care. Transmasculine patients may seek hysterectomy for gender affirmation from gynecologists. Unique nuances exist in the considerations needed when preparing for hysterectomy, and patients should be thoroughly counseled with regard to concurrent vaginectomy or oophorectomy or both. Transfeminine patients often seek gynecologic care after gender-affirming surgery, and, unlike transmasculine patients, the gynecology visit is often very affirming and welcomed by patients. Becoming familiar with the perioperative and delayed postoperative care needs of transfeminine patients undergoing vaginoplasty can help improve the care provided by gynecologists. In general, prospective data on the outcomes of gender-affirming care in large cohorts of TGD patients are limited, but the body of literature is growing. Gynecologists remain central to the care of TGD patients, the academic advancement of the field of transgender health, and the advocacy needed to support this vulnerable patient population.

Bone health and body composition in transgender adults before gender-affirming hormonal therapy: data from the COMET study

PURPOSE

Preliminary data suggested that bone mineral density (BMD) in transgender adults before initiating gender-affirming hormone therapy (GAHT) is lower when compared to cisgender controls. In this study, we analyzed bone metabolism in a sample of transgender adults before GAHT, and its possible correlation with biochemical profile, body composition and lifestyle habits (i.e., tobacco smoke and physical activity).

METHODS

Medical data, smoking habits, phospho-calcic and hormonal blood tests and densitometric parameters were collected in a sample of 125 transgender adults, 78 Assigned Females At Birth (AFAB) and 47 Assigned Males At Birth (AMAB) before GAHT initiation and 146 cisgender controls (57 females and 89 males) matched by sex assigned at birth and age. 55 transgender and 46 cisgender controls also underwent a complete body composition evaluation and assessment of physical activity using the International Physical Activity Questionnaire (IPAQ).

RESULTS

14.3% of transgender and 6.2% of cisgender sample, respectively, had z-score values < -2 (p = 0.04). We observed only lower vitamin D values in transgender sample regarding biochemical/hormonal profile. AFAB transgender people had more total fat mass, while AMAB transgender individuals had reduced total lean mass as compared to cisgender people (53.94 ± 7.74 vs 58.38 ± 6.91, p < 0.05). AFAB transgender adults were more likely to be active smokers and tend to spend more time indoor. Fat Mass Index (FMI) was correlated with lumbar and femur BMD both in transgender individuals, while no correlations were found between lean mass parameters and BMD in AMAB transgender people.

CONCLUSIONS

Body composition and lifestyle factors could contribute to low BMD in transgender adults before GAHT.

Bone health in transgender people: a narrative review

Bone health in transmen and transwomen is an important issue that needs to be evaluated by clinicians. Prior to gender-affirming hormone treatment (GAHT), transwomen have lower bone mineral density (BMD) and a higher prevalence of osteopenia than cismen probably related to external factors, such as hypovitaminosis D and less physical activities. Gonadotropin-releasing hormone (GnRH) analogues in transgender youth may cause bone loss; however, the addition of GAHT restores or at least improves BMD in both transboys and transgirls. The maintenance or increase in BMD shown in short-term longitudinal studies emphasizes that GAHT does not have a negative effect on BMD in adult transwomen and transmen. Gonadectomy is not a risk factor if GAHT is taken correctly. The prevalence of fractures in the transgender population seems to be the same as in the general population but more studies are required on this aspect. To evaluate the risk of osteoporosis, it is mandatory to define the most appropriate reference group not only taking into consideration the medical aspects but also in respect of the selected gender identity of each person.

Transgender Medicine and Hormone Therapy: What the Gynecologist Needs to Know

The transgender community comprises individuals with diverse identities in both gender and sexual orientation. Unfortunately, many face discrimination and harassment within our society-including within the medical system. There is an overall lack of provider training in transgender specific health which has led to health disparities and inequities within this population. This chapter aims to elucidate the medical needs unique to transgender and gender nonconforming individuals and thus enable medical providers to meet those needs with competency and compassion.

Gender-Affirming Hormone Therapy and Bone Health: Do Different Regimens Influence Outcomes in Transgender Adults? A Narrative Review and Call for Future Studies

BACKGROUND

Gender-affirming hormone therapy (GAHT) influences bone health in transgender individuals. Several hormone preparations and administration routes are available for GAHT, but no studies have compared clinical and laboratory bone health measures across different GAHT regimens.

CONTENT

We searched PubMed (MEDLINE), Embase, and Google Scholar for studies measuring bone turnover markers and bone mineral density before and during GAHT in transgender adults. We summarized bone health data by hormone type and administration route (estrogen or testosterone; oral, transdermal/percutaneous, intramuscular). Among trans women, we also examined outcomes among regimens containing different adjunctive agents (antiandrogens or gonadotropin-releasing hormone analogs).

SUMMARY

Most hormone preparations maintained or increased areal bone mineral density among trans adults taking GAHT for at least 12 months from baseline. Different bone turnover markers were measured across studies, and we were unable to compare or comment on the direct influence of selected hormone preparations on these clinical laboratory measures. Larger and uniformed studies are needed to measure volumetric bone mineral density and biomarkers of bone metabolism in trans adults taking standardized GAHT regimens.

Medical transition for gender diverse patients

Purpose of review

The purpose of this review is to provide an up-to-date overview of gender-affirming hormone therapy, including the various hormone regimens available, the efficacy and potential risks of these treatments, and considerations for surveillance and long-term care.

Recent findings

Recent studies reaffirm that hormone therapy has positive physical and psychological effects for many transgender individuals. The overall risks of treatment are low. Transgender women may have an increased risk of venous thromboembolism and breast cancer based on recent cohort studies, but these findings have yet to be confirmed with randomized controlled trials. Important long-term considerations include metabolic, cardiovascular, and skeletal health.

Summary

High-quality, long-term studies on the effectiveness and safety of various gender-affirming hormone treatment regimens are lacking, but the currently available evidence suggests that it is overall safe and effective with appropriate oversight.

Sexual orientation-based disparities in bone health: Evidence of reduced bone mineral density and mineral content among sexual minority men but not women in multiple NHANES waves

INTRODUCTION

Sexual minority (SM) people experience significant stress associated with stigma, contributing to a higher rate of adverse health outcomes. Several known factors (eg, smoking) elevate risk of poor bone health, but to date little research has examined disparities in bone health among SM people. To address this, we analyzed sexual orientation differences in an available bone mineral density (BMD) cross-sectional dataset assessed via dual X-ray absorptiometry.

METHODS

We combined the 2007 to 2008, 2009 to 2010, and 2013 to 2014 cycles of US National Health and Nutrition Examination Survey to examine sexual orientation-based differences in z-scored BMD in the proximal femur (greater trochanter and intertrochanter locations), bone mineral content (BMC) in the femur and spine, and osteoporosis risk among Lesbian/Gay (n = 53), Bisexual (n = 97), Same-Sex Experienced (n = 103), and Heterosexual (n = 2990) adults.

RESULTS

Sexual orientation-based disparities in bone mass were observed across all anatomical sites. This effect was due to differences between heterosexual and gay men and persisted in linear regressions after adjusting for risk factors. We found differences in femoral and femoral neck BMC in heterosexual and gay men (P = .02) and in femoral, femoral neck and spinal BMC between heterosexual and bisexual women (P = .05). Sexual orientation remained significant in BMC regressions.

CONCLUSION

Our findings suggest that SM men but not women are at greater risk for poor bone health relative to heterosexuals and this disparity is independent of the lifestyle and psychosocial risks included in our models.

Fracture risk assessment in an Italian group of transgender women after gender-confirming surgery

INTRODUCTION

Bone health is a critical issue in transgender women (TW) health care. Conflicting results have been reported on bone status after gender-confirming surgery (GCS). No recent data in Italian TW are available.

MATERIALS AND METHODS

The aim of this cross-sectional study was to evaluate fracture risk, lumbar spine BMD and 25OH vitamin D (25OHD) levels in a population of TW on estrogen replacement therapy (ERT) after GCS. We retrospectively analyzed a group of 57 TW, aged 45.3 ± 11.3 years, referred to our Gender Dysphoria Clinic, at least 2 years after GCS. Anthropometric parameters, patient compliance to ERT, biochemical and hormonal assessment, lumbar spine BMD and fracture risk were evaluated.

RESULTS

Prevalence of low bone mass (Z-score ≤ -2) was 40% according to the natal gender. In this group, 17β-estradiol levels were significantly lower (median 21 pg/ml [25th-75th percentile 10.6-48.5] vs 63 pg/ml [38.5-99.5]; p < 0.001) and a higher prevalence of low compliance to ERT was recorded (83% vs 29%; p < 0.0001) compared to those with higher bone mass. An intermediate-high fracture risk was found in 14% of the sample. A high percentage (93%) of hypovitaminosis D was present.

CONCLUSIONS

TW on ERT have a high prevalence of low bone mass, significantly associated with low estradiol levels and low compliance to ERT. A high prevalence of hypovitaminosis D was highlighted. Considering that one out of seven TW showed an intermediate-high 10-year fracture risk, such risk assessment may be considered to prevent and manage osteoporosis in this clinical setting.

Surgical correction of rigid cervicothoracic deformity in a transgender patient: case report

A number of spinal pathologies result in fusion of the spine, including ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis (DISH), as well as severe degenerative arthropathies. This fusion of spinal elements may result in spinal deformity affecting any region of the spine. Cervicothoracic deformity resulting in chin on chest deformity is poorly tolerated due to inability to maintain a horizontal gaze. Surgical treatment options for this condition are complex and require extensive discussion between the patient and surgical team. Here we present a case report of a 26-year-old transgender female (male to female) patient with severe chin on chest deformity and a unique pattern of spinal fusion involving only the posterior elements. She underwent C2-T8 posterior spinal fusion with thoracic pedicle subtraction osteotomy and multiple cervical facet osteotomies with good functional result. She did have severe dysphagia and required feeding tube for several weeks but did very well by 1 year postoperatively. While posterior elements of the spine are normally affected first in spondyloarthropathies such as ankylosing spondylitis, the lack of anterior spinal involvement is unique and could be attributed to hormonal therapy in this patient. This case describes a unique pattern of spondyloarthropathy and highlights the importance of a having a multi-disciplinary team for the treatment of patients with complex spinal pathologies.

Contraception across the transmasculine spectrum

The field of transgender health continues to expand rapidly, including research in the area of family planning. While much attention has been given to fertility preservation and the parenting intentions of transgender individuals, far less has been paid to pregnancy prevention and contraceptive needs of people along the transmasculine gender spectrum (transgender men and gender-nonbinary persons who were assigned female at birth). Existing research illustrates that many clinicians and transmasculine individuals falsely believe that there is no risk of pregnancy while amenorrheic. These studies also show inconsistent counseling practices provided to transmasculine persons surrounding contraception and pregnancy while falling short of providing robust clinical guidance for improvement. Clinicians report a lack of adequate training in transgender reproductive health, and consequently, many do not feel comfortable treating transgender patients. The aim of this publication is to consolidate the findings of these prior studies and build upon them to offer comprehensive clinical guidance for managing contraception in transmasculine patients. To do so, it reviews the physiologic effects of testosterone on the sex steroid axis and current understanding of why ovulation and pregnancy may still occur while amenorrheic. Gender-inclusive terminology and a suggested script for eliciting a gender-affirming sexual history are offered. Common concerns (such as the effects on gender dysphoria and gender affirmation) and side effects of available contraceptive methods are subsequently addressed and how these may have a unique impact on transmasculine persons as compared with cisgender women. Lastly, a model is provided for approaching contraceptive counseling in the transmasculine population to assist clinicians and patients in determining the need for and selection of the type of contraception. To center transmasculine voices, the development of this publication's guidelines have been led by reproductive care clinicians of transgender experience.

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.

Bone Densitometry in Transgender and Gender Non-Conforming (TGNC) Individuals: 2019 ISCD Official Position

The indications for initial and follow-up bone mineral density (BMD) in transgender and gender nonconforming (TGNC) individuals are poorly defined, and the choice of which gender database to use to calculate Z-scores is unclear. Herein, the findings of the Task Force are presented after a detailed review of the literature. As long as a TGNC individual is on standard gender-affirming hormone treatment, BMD should remain stable to increasing, so there is no indication to monitor for bone loss or osteoporosis strictly on the basis of TGNC status. TGNC individuals who experience substantial periods of hypogonadism (>1 yr) might experience bone loss or failure of bone accrual during that time, and should be considered for baseline measurement of BMD. To the extent that this hypogonadism continues over time, follow-up measurements can be appropriate. TGNC individuals who have adequate levels of endogenous or exogenous sex steroids can, of course, suffer from other illnesses that can cause osteoporosis and bone loss, such as hyperparathyroidism and steroid use; they should have measurement of BMD as would be done in the cisgender population. There are no data that TGNC individuals have a fracture risk different from that of cisgender individuals, nor any data to suggest that BMD predicts their fracture risk less well than in the cisgender population. The Z-score in transgender individuals should be calculated using the reference data (mean and standard deviation) of the gender conforming with the individual's gender identity. In gender nonconforming individuals, the reference data for the sex recorded at birth should be used. If the referring provider or the individual requests, a set of "male" and "female" Z-scores can be provided, calculating the Z-score against male and female reference data, respectively.

Health considerations for transgender women and remaining unknowns: a narrative review

Transgender (trans) women (TW) were assigned male at birth but have a female gender identity or gender expression. The literature on management and health outcomes of TW has grown recently with more publication of research. This has coincided with increasing awareness of gender diversity as communities around the world identify and address health disparities among trans people. In this narrative review, we aim to comprehensively summarize health considerations for TW and identify TW-related research areas that will provide answers to remaining unknowns surrounding TW's health. We cover up-to-date information on: (1) feminizing gender-affirming hormone therapy (GAHT); (2) benefits associated with GAHT, particularly quality of life, mental health, breast development and bone health; (3) potential risks associated with GAHT, including cardiovascular disease and infertility; and (4) other health considerations like HIV/AIDS, breast cancer, other tumours, voice therapy, dermatology, the brain and cognition, and aging. Although equally deserving of mention, feminizing gender-affirming surgery, paediatric and adolescent populations, and gender nonbinary individuals are beyond the scope of this review. While much of the data we discuss come from Europe, the creation of a United States transgender cohort has already contributed important retrospective data that are also summarized here. Much remains to be determined regarding health considerations for TW. Patients and providers will benefit from larger and longer prospective studies involving TW, particularly regarding the effects of aging, race and ethnicity, type of hormonal treatment (e.g. different oestrogens, anti-androgens) and routes of administration (e.g. oral, parenteral, transdermal) on all the topics we address.

Transgender bone health

Gonadal sex steroids play a pivotal role in bone health. Medical and surgical therapies for gender dysphoria in both adolescents and adults can lead to skeletal changes. This review evaluates the literature on transgender bone health, and how the data can be translated into clinical practice.

Bone Health in the Transgender Population

It is well known that sex steroids, particularly estrogen, play a crucial role in the attainment and maintenance of peak bone density in all people. Transgender (trans) women have been frequently observed to have low bone density prior to initiation of gender-affirming hormone therapy, while trans men generally do not. With pharmacologic estrogen, many studies show improving bone density in trans women. With pharmacologic testosterone, bone density in trans men remains largely unchanged although androgens have indirect effects on bone health via changes in fat and lean mass. Much remains unknown about best practices to optimize bone health, interpret DXA scans and assess fracture risk in trans adults.

Bone Mass Effects of Cross-Sex Hormone Therapy in Transgender People: Updated Systematic Review and Meta-Analysis

Context

The impact of long-term cross-sex hormone therapy (CSHT) in transgender men and women is still uncertain.

Objective

To perform a systematic review and meta-analysis and update the evidence regarding the effects of CSHT on bone mineral density (BMD) in transgender men and women.

Data Sources

Medline, Cochrane Central Register of Controlled Trials, and Embase were searched for studies published until August 2018.

Study Selection

Of 10,849 studies, 19 were selected for systematic review. All included patients were aged >16 years and received CSHT with BMD assessment by dual-energy X-ray absorptiometry (DXA).

Data Extraction

Data on BMD, CSHT, and clinical factors affecting bone mass were collected. A National Institutes of Health scale was used to assess the quality of studies.

Data Synthesis

Nineteen studies were meta-analyzed (487 trans men and 812 trans women). In trans men, mean BMD difference compared with natal women was not significant in any site in either cross-sectional or before-after studies. In trans women, mean BMD difference was not significant compared with natal men at the femoral neck, total femur, and lumbar spine in cross-sectional studies; before-after studies reported a slight but significant increase in lumbar spine BMD after 12 and ≥24 months of treatment.

Conclusions

Long-term CSHT had a neutral effect on BMD in transgender men. In transgender women, only lumbar spine BMD seemed to be affected after CSHT. This evidence is of low to moderate quality as a result of the observational design of studies, small sample sizes, and variations in hormone therapy protocols.

Endocrinology of Transgender Medicine

Gender-affirming treatment of transgender people requires a multidisciplinary approach in which endocrinologists play a crucial role. The aim of this paper is to review recent data on hormonal treatment of this population and its effect on physical, psychological, and mental health. The Endocrine Society guidelines for transgender women include estrogens in combination with androgen-lowering medications. Feminizing treatment with estrogens and antiandrogens has desired physical changes, such as enhanced breast growth, reduction of facial and body hair growth, and fat redistribution in a female pattern. Possible side effects should be discussed with patients, particularly those at risk for venous thromboembolism. The Endocrine Society guidelines for transgender men include testosterone therapy for virilization with deepening of the voice, cessation of menses, and increases of muscle mass and facial and body hair. Owing to the lack of evidence, treatment of gender nonbinary people should be individualized. Young people may receive pubertal suspension, consisting of GnRH analogs, later followed by sex steroids. Options for fertility preservation should be discussed before any hormonal intervention. Morbidity and cardiovascular risk with cross-sex hormones is unchanged among transgender men and unclear among transgender women. Sex steroid-related malignancies can occur but are rare. Mental health problems such as depression and anxiety have been found to reduce considerably following hormonal treatment. Future studies should aim to explore the long-term outcome of hormonal treatment in transgender people and provide evidence as to the effect of gender-affirming treatment in the nonbinary population.

Impact of cross-sex hormone therapy on bone mineral density and body composition in transwomen

OBJECTIVE

Cross-sex hormone therapy (CSHT) has been associated with changes in bone and lean/fat mass. This study assessed bone mineral density (BMD), appendicular lean mass (ALM), and total fat mass in transwomen undergoing CSHT.

PATIENTS AND DESIGN

We evaluated 142 transwomen (mean age: 33.7 ± 10.3 years; BMI: 25.4 ± 4.6; 86.6% with previous CSHT) during the first 3 months of regular oestrogen treatment (with or without anti-androgens). A reference group including 22 men and 17 cis women was also studied.

MEASUREMENTS

Clinical and hormonal evaluation and dual-energy X-ray absorptiometry (DXA).

RESULTS

Bone mineral density was similar in trans and reference women, and lower at all sites in transwomen vs men. Low bone mass for age was observed in 18% of transwomen at baseline vs none of the reference women or men. Appendicular lean mass and total fat mass were positively correlated with L1-L4 BMD, explaining 14.9% of the observed variation in lumbar spine BMD and 20.6% of the variation in total femur BMD. Appendicular lean mass was similar in trans and reference women, and lower in transwomen vs men. Total fat mass was lower in trans vs reference women. Densitometry was repeated after a mean of 31.3 ± 6.5 months in 46 transwomen. There was a significant increase in total fat mass and a significant decrease in ALM. Bone mineral density remained stable over time.

CONCLUSIONS

The fairly high prevalence of low bone mass in this sample of transwomen from southern Brazil seems to be related to lower ALM. Non-pharmacological lifestyle-related strategies for preventing bone loss could be beneficial for transgender women receiving long-term CSHT.

Cross-sex testosterone therapy in ovariectomized mice: addition of low-dose estrogen preserves bone architecture

Cross-sex hormone therapy (XHT) is widely used by transgender people to alter secondary sex characteristics to match their desired gender presentation. Here, we investigate the long-term effects of XHT on bone health using a murine model. Female mice underwent ovariectomy at either 6 or 10 wk and began weekly testosterone or vehicle injections. Dual-energy X-ray absorptiometry (DXA) was performed (20 wk) to measure bone mineral density (BMD), and microcomputed tomography was performed to compare femoral cortical and trabecular bone architecture. The 6-wk testosterone group had comparable BMD with controls by DXA but reduced bone volume fraction, trabecular number, and cortical area fraction and increased trabecular separation by microcomputed tomography. Ten-week ovariectomy/XHT maintained microarchitecture, suggesting that estrogen is critical for bone acquisition during adolescence and that late, but not early, estrogen loss can be sufficiently replaced by testosterone alone. Given these findings, we then compared effects of testosterone with effects of weekly estrogen or combined testosterone/low-dose estrogen treatment after a 6-wk ovariectomy. Estrogen treatment increased spine BMD and microarchitecture, including bone volume fraction, trabecular number, trabecular thickness, and connectivity density, and decreased trabecular separation. Combined testosterone-estrogen therapy caused similar increases in femur and spine BMD and improved architecture (increased bone volume fraction, trabecular number, trabecular thickness, and connectivity density) to estrogen therapy and were superior compared with mice treated with testosterone only. These results demonstrate estradiol is critical for bone acquisition and suggest a new cross-sex hormone therapy adding estrogens to testosterone treatments with potential future clinical implications for treating transgender youth or men with estrogen deficiency.