Body composition, bone turnover, and bone mass in trans men during testosterone treatment: 1-year follow-up data from a prospective case-controlled study (ENIGI)

Approach to Interpreting Common Laboratory Pathology Tests in Transgender Individuals

CONTEXT

As the number of transgender (trans) people (including those who are binary and/or nonbinary identified) seeking gender-affirming hormone therapy rises, endocrinologists are increasingly asked to assist with interpretation of laboratory tests. Many common laboratory tests such as hemoglobin, iron studies, cardiac troponin, and creatinine are affected by sex steroids or body size. We seek to provide a summary of the impact of feminizing and masculinizing hormone therapy on common laboratory tests and an approach to interpretation.

CASES

Case scenarios discussed include 1) hemoglobin and hematocrit in a nonbinary person undergoing masculinizing hormone therapy; 2) estimation of glomerular filtration rate in a trans woman at risk of contrast-induced nephropathy; 3) prostate-specific antigen (PSA) in a trans woman; and 4) chest pain in a trans man with a cardiac troponin concentration between the reported male and female reference ranges.

CONCLUSIONS

The influence of exogenous gender-affirming hormone therapy on fat and muscle distribution and other physiological changes determines interpretation of laboratory tests that have sex-specific differences. In addition to affirmative practice to ensure a patient's name, gender, and pronoun are used appropriately, we propose that once individuals have commenced gender-affirming hormone therapy, the reference range of the affirmed gender be reported (and specified by treating clinicians) except for PSA or cardiac troponin, which are dependent on organ size. While suggestions may be challenging to implement, they also represent an opportunity to lead best practice to improve the quality of care and experiences of healthcare for all trans people.

Approach to Interpreting Common Laboratory Pathology Tests in Transgender Individuals

CONTEXT

As the number of transgender (trans) people (including those who are binary and/or nonbinary identified) seeking gender-affirming hormone therapy rises, endocrinologists are increasingly asked to assist with interpretation of laboratory tests. Many common laboratory tests such as hemoglobin, iron studies, cardiac troponin, and creatinine are affected by sex steroids or body size. We seek to provide a summary of the impact of feminizing and masculinizing hormone therapy on common laboratory tests and an approach to interpretation.

CASES

Case scenarios discussed include 1) hemoglobin and hematocrit in a nonbinary person undergoing masculinizing hormone therapy; 2) estimation of glomerular filtration rate in a trans woman at risk of contrast-induced nephropathy; 3) prostate-specific antigen (PSA) in a trans woman; and 4) chest pain in a trans man with a cardiac troponin concentration between the reported male and female reference ranges.

CONCLUSIONS

The influence of exogenous gender-affirming hormone therapy on fat and muscle distribution and other physiological changes determines interpretation of laboratory tests that have sex-specific differences. In addition to affirmative practice to ensure a patient's name, gender, and pronoun are used appropriately, we propose that once individuals have commenced gender-affirming hormone therapy, the reference range of the affirmed gender be reported (and specified by treating clinicians) except for PSA or cardiac troponin, which are dependent on organ size. While suggestions may be challenging to implement, they also represent an opportunity to lead best practice to improve the quality of care and experiences of healthcare for all trans people.

Research gaps in medical treatment of transgender/nonbinary people

With the growing number of transgender and gender-nonbinary individuals who are becoming visible, it is clear that there is a need to develop a rigorous evidence base to inform care practice. Transgender health research is often limited to HIV/AIDS or mental health research and is typically subsumed in larger studies with general LGBTQ focus. Although the number of knowledgeable health care providers remains modest, the model for the medical approach to transgender health is shifting owing to growing social awareness and an appreciation of a biological component. Gender-affirming medicine facilitates aligning the body of the transgender person with the gender identity; typical treatment regimens include hormone therapy and/or surgical interventions. While broadly safe, hormone treatments require some monitoring for safety. Exogenous estrogens are associated with a dose-dependent increase in venous thromboembolic risk, and androgens stimulate erythropoiesis. The degree to which progressing gender-affirming hormone treatment changes cancer risk, cardiac heart disease risk, and/or bone health remains unknown. Guidelines referencing the potential exacerbation of cancer, heart disease, or other disease risk often rely on physiology models, because conclusive clinical data do not exist. Dedicated research infrastructure and funding are needed to address the knowledge gap in the field.

Orthopaedic Care of the Transgender Patient

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A transgender person is defined as one whose gender identity is incongruent with their biological sex assigned at birth. This highly marginalized population numbers over 1.4 million individuals in the U.S.; this prevalence skews more heavily toward younger generations and is expected to increase considerably in the future.

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Gender-affirming hormone therapy (GAHT) has physiologic effects on numerous aspects of the patient's health that are pertinent to the orthopaedic surgeon, including bone health, fracture risk, and perioperative risks such as venous thromboembolism and infection.

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Language and accurate pronoun usage toward transgender patients can have a profound effect on a patient's experience and on both objective and subjective outcomes.

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Gaps in research concerning orthopaedic care of the transgender patient are substantial. Specific areas for further study include the effects of GAHT on fracture risk and healing, outcome disparities and care access across multiple subspecialties, and establishment of perioperative management guidelines.

Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage

Males enjoy physical performance advantages over females within competitive sport. The sex-based segregation into male and female sporting categories does not account for transgender persons who experience incongruence between their biological sex and their experienced gender identity. Accordingly, the International Olympic Committee (IOC) determined criteria by which a transgender woman may be eligible to compete in the female category, requiring total serum testosterone levels to be suppressed below 10 nmol/L for at least 12 months prior to and during competition. Whether this regulation removes the male performance advantage has not been scrutinized. Here, we review how differences in biological characteristics between biological males and females affect sporting performance and assess whether evidence exists to support the assumption that testosterone suppression in transgender women removes the male performance advantage and thus delivers fair and safe competition. We report that the performance gap between males and females becomes significant at puberty and often amounts to 10-50% depending on sport. The performance gap is more pronounced in sporting activities relying on muscle mass and explosive strength, particularly in the upper body. Longitudinal studies examining the effects of testosterone suppression on muscle mass and strength in transgender women consistently show very modest changes, where the loss of lean body mass, muscle area and strength typically amounts to approximately 5% after 12 months of treatment. Thus, the muscular advantage enjoyed by transgender women is only minimally reduced when testosterone is suppressed. Sports organizations should consider this evidence when reassessing current policies regarding participation of transgender women in the female category of sport.

A Randomized Double-Blind Placebo-Controlled Pilot Trial on the Effects of Testosterone Undecanoate Plus Dutasteride or Placebo on Muscle Strength, Body Composition, and Metabolic Profile in Transmen

BACKGROUND

While the effects of androgens on muscle are well described in hypogonadal men, literature is still scarce on muscular strength or size variations in transmen; in this population there are no data regarding the relative effect of testosterone (T) and its metabolite dihydrotestosterone on muscle.

AIM

Our primary objective was to compare the effects on muscle strength of 54-week administration of testosterone undecanoate (TU) combined with the 5α-reductase inhibitor dutasteride (DT) or placebo (PL). Secondary outcomes included evaluation of body composition, bone, cutaneous androgenic effects, and metabolic variations.

METHODS

In this randomized, double-blind PL-controlled pilot trial, 16 ovariectomized transmen were randomized to receive TU 1,000 mg IM at week 0, 6, 18, 30, 42 plus a PL pill orally daily (TU + PL, n = 7) or plus DT 5 mg/d (TU + DT, n = 7).

OUTCOMES

At week 0 and 54 the following parameters were evaluated: isokinetic knee extension and flexion peak torque and handgrip strength, body composition, and bone mineral density, biochemical, hematological, and hormonal parameters.

RESULTS

Handgrip and lower limb strength increased significantly in both groups with no differences between the 2 groups. Fat mass decreased and lean mass increased significantly similarly in both groups. Metabolic parameters remained stable in the 2 groups except for high-density lipoprotein cholesterol that was reduced in both groups. Hepatic and renal function remained normal in both groups and no major adverse effects were registered in either group.

CLINICAL IMPLICATIONS

These results may be particularly relevant for transmen experiencing cutaneous androgenic adverse events such as acne and androgenetic alopecia and in light of the development of non-5α-reduced androgens.

STRENGTHS & LIMITATIONS

The strength of this study was the randomized, double-blind PL-controlled design, while the small number of subjects was definitely the biggest limitation.

CONCLUSION

For the first time we demonstrated that the addition of DT does not impair the anabolic effects of T on muscles in transmen previously exposed to T, supporting the hypothesis that the conversion in dihydrotestosterone is not essential for this role. Gava G, Armillotta F, Pillastrini P, et al. A Randomized Double-Blind Placebo-Controlled Pilot Trial on the Effects of Testosterone Undecanoate Plus Dutasteride or Placebo on Muscle Strength, Body Composition, and Metabolic Profile in Transmen. J Sex Med 2021;18:646-655.

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.

Insulin resistance in transgender individuals correlates with android fat mass

BACKGROUND

Transgender individuals receiving gender-affirming hormone therapy (GAHT) are at increased risk of adverse cardiovascular outcomes. This may be related to effects on body composition and insulin resistance.

AIMS

To examine relationships between body fat distribution and insulin resistance in transgender individuals on established GAHT.

METHODS

Comparisons of body composition (dual energy X-ray absorptiometry) and insulin resistance [Homeostasis Model of Insulin Resistance (HOMA2-IR)] were made between transgender individuals (43 trans men and 41 trans women) on established GAHT (>12 months) and age-matched cisgender controls (30 males and 48 females). Multiple linear regressions were used to examine the relationship between HOMA2-IR and fat mass with gender, adjusting for age and total duration of GAHT and Pearson correlation coefficients are reported.

RESULTS

Compared with control cisgender women, trans men had mean difference of +7.8 kg (4.0, 11.5), p < 0.001 in lean mass and higher android:gynoid fat ratio [0.2 (0.1, 0.3), p < 0.001], but no difference in overall fat mass or insulin resistance. Compared with control cisgender men, trans women had median difference in lean mass of -6.9 kg (-10.6, -3.1), p < 0.001, fat mass of +9.8 kg (3.9, 14.5), p = 0.001, lower android:gynoid fat ratio -0.1 (-0.2,-0.0), p < 0.05), and higher insulin resistance 1.6 (1.3-1.9), p < 0.001). Higher HOMA2-IR correlated with higher android (r ² = 0.712, p < 0.001) and gynoid (r ² = 0.572, p < 0.001) fat mass in both trans men and trans women.

CONCLUSION

Android fat more strongly correlates with insulin resistance than gynoid fat in transgender individuals. Higher fat mass and insulin resistance in trans women may predispose to increased cardiovascular risk. Despite adverse fat distribution, insulin resistance was not higher in trans men.

Effect of gender affirming hormones on athletic performance in transwomen and transmen: implications for sporting organisations and legislators

OBJECTIVE

To examine the effect of gender affirming hormones on athletic performance among transwomen and transmen.

METHODS

We reviewed fitness test results and medical records of 29 transmen and 46 transwomen who started gender affirming hormones while in the United States Air Force. We compared pre- and post-hormone fitness test results of the transwomen and transmen with the average performance of all women and men under the age of 30 in the Air Force between 2004 and 2014. We also measured the rate of hormone associated changes in body composition and athletic performance.

RESULTS

Participants were 26.2 years old (SD 5.5). Prior to gender affirming hormones, transwomen performed 31% more push-ups and 15% more sit-ups in 1 min and ran 1.5 miles 21% faster than their female counterparts. After 2 years of taking feminising hormones, the push-up and sit-up differences disappeared but transwomen were still 12% faster. Prior to gender affirming hormones, transmen performed 43% fewer push-ups and ran 1.5 miles 15% slower than their male counterparts. After 1 year of taking masculinising hormones, there was no longer a difference in push-ups or run times, and the number of sit-ups performed in 1 min by transmen exceeded the average performance of their male counterparts.

SUMMARY

The 15-31% athletic advantage that transwomen displayed over their female counterparts prior to starting gender affirming hormones declined with feminising therapy. However, transwomen still had a 9% faster mean run speed after the 1 year period of testosterone suppression that is recommended by World Athletics for inclusion in women's events.

Hormone therapy, health outcomes and the role of nutrition in transgender individuals: A scoping review

OBJECTIVE

The objective of this scoping review is to describe the extent, range, and nature of available literature examining nutrition-related intermediate and long-term health outcomes in individuals who are transgender. Specific sub-topics examined include 1) dietary intake, 2) nutrition-related health disparities, 3) validity and reliability of nutrition assessment methods, 4) the effects of nutrition interventions/exposures, and 5) hormone therapy.

METHODS

A literature search was conducted using MEDLINE, Embase, PsycINFO, CINAHL, Web of Science, and other databases for peer-reviewed articles published from January 1999 until December 5, 2019 to identify studies addressing the research objective and meeting eligibility criteria. Conference abstracts and registered trials published or registered in the five years prior to the search were also included. Findings were reported in a study characteristics table, a bubble chart and heat maps.

RESULTS

The search of the databases identified 5403 studies, including full peer-reviewed studies, systematic reviews, conference abstracts and registered trials. Following title/abstract screening, 189 studies were included in the narrative analysis. Ten studies reported dietary intake in transgender individuals, 64 studies reported nutrition-related health disparities in transgender compared to cisgender individuals, one study examined validity and reliability of nutrition assessment methods, two studies reported nutrition interventions, and 127 studies reported on the intermediate and health effects of hormone therapy.

CONCLUSION

Individuals who are transgender have unique nutrition needs, which may vary according to the stage and type of gender-affirmative therapy that they are undergoing. There is scant research examining effective nutrition therapy methods for nutrition professionals working with transgender individuals. More research is needed in order to inform evidence-based clinical practice guidelines for nutrition practitioners working with transgender individuals.

Effects of androgen excess and glucocorticoid exposure on bone health in adult patients with 21-hydroxylase deficiency

CONTEXT

This study aimed to determine the role of modifiable predictors on bone health in congenital adrenal hyperplasia (CAH).

DESIGN

Cross-sectional, single center study, including 97 patients (N = 42 men) with classic CAH due to 21-hydroxylase deficiency (N = 65 salt wasting, N = 32 simple virilizing).

MAIN OUTCOME MEASURES

Treatment-related predictors of bone health.

RESULTS

Average T scores (-0.9 ± 1.4 vs. -0.4 ± 1.4; p = 0.036) as well as Z scores (-1.0 ± 1.3 vs. -0.1 ± 1.4; p = 0.012) at the spine in patients with CAH were significantly lower in men than women. While osteoporosis was rare in women, it was documented in 9.1% of men with CAH. There was a significant positive correlation of Z scores at the spine with advancing age in women with CAH (R² = 0.178; p = 0.003). In multivariate analysis, the intake of conventional hydrocortisone (HC) instead of synthetic glucocorticoids was independently associated with a higher bone mineral density (BMD) at the hip region in both sexes. In women, there was a positive association with vitamin D concentrations. Interestingly, higher sodium levels were associated with a lower BMD independent of renin levels and fludrocortisone dosage. Neither in men nor in women, markers of androgen control were predictive for BMD at any site. Markers of bone turnover indicated low bone turnover. No pathological fractures were documented.

CONCLUSIONS

Men with CAH are particularly prone to low bone density, while women seem to be relatively protected by androgen excess compared to the general female population. The use of HC instead of synthetic GCs for hormone replacement may translate into better bone health.

Bone health of transgender adults: what the radiologist needs to know

Sex steroids are important regulators of bone development before puberty and of bone homeostasis throughout adulthood. Gender-affirming therapies with sex steroids are used in transgender and gender diverse persons for treatment of gender dysphoria, which may have profound impacts on their bone metabolism. Many studies have described variable changes in bone density and geometry in transgender cohorts. In order to provide informed guidance on the effect of gender-affirming therapy, the International Society of Clinical Densitometry issued official position statements in 2019 for the performance and interpretation of dual-energy x-ray absorptiometry in transgender and gender-diverse patients. We review the effects of gender-affirming hormone therapy on bone physiology and the changes in bone modulation that have been reported in the literature in transgender patients who have received gender-affirming therapy. We also summarize the recent guidelines for interpretation of dual energy x-ray absorptiometry as an update for the radiologist.

Effects of gender affirming hormone therapy on body mass index in transgender individuals: A longitudinal cohort study

Introduction

Many transgender people take hormone therapy to affirm their gender identity. One potential long-term consequence of gender affirming hormone therapy is increased body mass index (BMI), which may be associated with metabolic syndrome, cardiovascular disease and higher mortality. Only a few published studies explored changes in BMI in transgender people taking gender affirming hormone therapy (GAHT).

Objective

To examine the changes in BMI longitudinally in response to GAHT in transgender women and men.

Methods

We conducted a retrospective cohort study of transgender individuals who received GAHT from the endocrinology clinic between January 1, 2000 and September 6, 2018. Subjects who sought GAHT were included if they had two separate measurements of BMI and were excluded if they had a BMI greater than 35 kg/m² or were missing demographic data at entry. We used a linear mixed model to analyze the longitudinal change in BMI.

Results

There were a total of 227 subjects included in this cohort. Among subjects already on GAHT, transgender women were receiving GAHT longer than transgender men (6.59 ± 9.35 vs 3.67 ± 3.43 years, p-value = 0.04). Over the period of 7 years, there was a significant increase in BMI in transwomen who newly initiated GAHT (p-value 0.004). There were no changes in BMI in transgender men and women already on GAHT or in transgender men who newly initiated GAHT in the study.

Conclusion

We conclude that BMI significantly increases in transwomen but not in transmen after initiation of GAHT in a single center based in the United States. In transwomen and transmen, BMI appears to be stable following 3 to 6 years of GAHT. Future investigations should examine the causes for increased BMI in transgender women including type of GAHT, diet and lifestyle, and association with risk of metabolic syndrome and cardiovascular disease.

Effects of gender-affirming hormone therapy on insulin resistance and body composition in transgender individuals: A systematic review

BACKGROUND

Transgender individuals receiving masculinising or feminising gender-affirming hormone therapy with testosterone or estradiol respectively, are at increased risk of adverse cardiovascular outcomes, including myocardial infarction and stroke. This may be related to the effects of testosterone or estradiol therapy on body composition, fat distribution, and insulin resistance but the effect of gender-affirming hormone therapy on these cardiovascular risk factors has not been extensively examined.

AIM

To evaluate the impact of gender-affirming hormone therapy on body composition and insulin resistance in transgender individuals, to guide clinicians in minimising cardiovascular risk.

METHODS

We performed a review of the literature based on PRISMA guidelines. MEDLINE, Embase and PsycINFO databases were searched for studies examining body composition, insulin resistance or body fat distribution in transgender individuals aged over 18 years on established gender-affirming hormone therapy. Studies were selected for full-text analysis if they investigated transgender individuals on any type of gender-affirming hormone therapy and reported effects on lean mass, fat mass or insulin resistance.

RESULTS

The search strategy identified 221 studies. After exclusion of studies that did not meet inclusion criteria, 26 were included (2 cross-sectional, 21 prospective-uncontrolled and 3 prospective-controlled). Evidence in transgender men suggests that testosterone therapy increases lean mass, decreases fat mass and has no impact on insulin resistance. Evidence in transgender women suggests that feminising hormone therapy (estradiol, with or without anti-androgen agents) decreases lean mass, increases fat mass, and may worsen insulin resistance. Changes to body composition were consistent across almost all studies: Transgender men on testosterone gained lean mass and lost fat mass, and transgender women on oestrogen experienced the reverse. No study directly contradicted these trends, though several small studies of short duration reported no changes. Results for insulin resistance are less consistent and uncertain. There is a paucity of prospective controlled research, and existing prospective evidence is limited by small sample sizes, short follow up periods, and young cohorts of participants.

CONCLUSION

Further research is required to further characterise the impact of gender-affirming hormone therapy on body composition and insulin resistance in the medium-long term. Until further evidence is available, clinicians should aim to minimise risk by monitoring cardiovascular risk markers regularly in their patients and encouraging healthy lifestyle modifications.

Muscle Strength, Size, and Composition Following 12 Months of Gender-affirming Treatment in Transgender Individuals

CONTEXT

As many sports are divided in male/female categories, governing bodies have formed regulations on the eligibility for transgender individuals to compete in these categories. Yet, the magnitude of change in muscle mass and strength with gender-affirming treatment remains insufficiently explored.

OBJECTIVE

This study explored the effects of gender-affirming treatment on muscle function, size, and composition during 12 months of therapy.

DESIGN, SETTINGS, PARTICIPANTS

In this single-center observational cohort study, untrained transgender women (TW, n = 11) and transgender men (TM, n = 12), approved to start gender-affirming medical interventions, underwent assessments at baseline, 4 weeks after gonadal suppression of endogenous hormones but before hormone replacement, and 4 and 12 months after treatment initiation.

MAIN OUTCOME MEASURES

Knee extensor and flexor strength were assessed at all examination time points, and muscle size and radiological density (using magnetic resonance imaging and computed tomography) at baseline and 12 months after treatment initiation.

RESULTS

Thigh muscle volume increased (15%) in TM, which was paralleled by increased quadriceps cross-sectional area (CSA) (15%) and radiological density (6%). In TW, the corresponding parameters decreased by -5% (muscle volume) and -4% (CSA), while density remained unaltered. The TM increased strength over the assessment period, while the TW generally maintained their strength levels.

CONCLUSIONS

One year of gender-affirming treatment resulted in robust increases in muscle mass and strength in TM, but modest changes in TW. These findings add new knowledge on the magnitude of changes in muscle function, size, and composition with cross-hormone therapy, which could be relevant when evaluating the transgender eligibility rules for athletic competitions.

Fracture Risk in Trans Women and Trans Men Using Long-Term Gender-Affirming Hormonal Treatment: A Nationwide Cohort Study

Concerns about bone health in transgender people using gender-affirming hormonal treatment (HT) exist, but the fracture risk is not known. In this nationwide cohort study, we aimed to compare the fracture incidence in transgender people using long-term HT with an age-matched reference population. All adult transgender people who started HT before 2016 at our gender-identity clinic were included and were linked to a random population-based sample of 5 age-matched reference men and 5 age-matched reference women per person. Fracture incidence was determined using diagnoses from visits to hospital emergency rooms nationwide between 2013 and 2015. A total of 1089 trans women aged <50 years (mean 38 ± 9 years) and 934 trans women aged ≥50 years (mean 60 ± 8 years) using HT for median 8 (interquartile range [IQR] 3-16) and 19 (IQR 11-29) years, respectively, were included. A total of 2.4% of the trans women aged <50 years had a fracture, whereas 3.0% of the age-matched reference men (odds ratio [OR] = 0.78, 95% confidence interval [CI] 0.51-1.19) and 1.6% of the age-matched reference women (OR = 1.49, 95% CI 0.96-2.32) experienced a fracture. In trans women aged ≥50 years, 4.4% experienced a fracture compared with 2.4% of the age-matched reference men (OR = 1.90, 95% CI 1.32-2.74) and 4.2% of the age-matched reference women (OR = 1.05, 95% CI 0.75-1.49). A total of 1036 trans men (40 ± 14 years) using HT for median 9 (IQR 2-22) years were included. Fractures occurred in 1.7% of the trans men, 3.0% of the age-matched reference men (OR = 0.57, 95% CI 0.35-0.94), and 2.2% of the age-matched reference women (OR = 0.79, 95% CI 0.48-1.30). In conclusion, fracture risk was higher in older trans women compared with age-matched reference men. In young trans women, fracture risk tended to be increased compared with age-matched reference women. Fracture risk was not increased in young trans men. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

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.

Gender-Affirming Hormone Treatment Decreases Bone Turnover in Transwomen and Older Transmen

Sex steroids play a key role in bone turnover and preserving BMD; hence, gender-affirming hormone treatment (HT) in transgender people affects bone metabolism. Most studies have looked into the effect of HT on changes in BMD; however, they do not provide insights into changes in bone metabolism caused by HT. This study investigated changes in bone turnover markers (BTMs) and sclerostin, as well as their correlations with change in BMD in transwomen and transmen during the first year of HT. Transwomen received estradiol and antiandrogens; transmen received testosterone. Sclerostin; P1NP; alkaline phosphatase (ALP); CTx; and BMD of the total hip, the femoral neck, and the lumbar spine were evaluated at baseline and after 1 year of HT. There were 121 transwomen (median age 30 years, interquartile range [IQR] 24 to 41 years) and 132 transmen (median age 24 years, IQR 21 to 33 years) included in the study. In transwomen, ALP decreased in 19% (95% CI, -21 to-16), CTx in 11% (95% CI, -18 to-4), and sclerostin in 8% (95%CI, -13 to-4) of study participants after 1 year of HT. In contrast, in transmen P1NP, ALP, and sclerostin increased in 33% (95% CI, 24 to 42), 16% (95% CI, 12 to 20), and 15% (95% CI, 10 to 20) of study participants, respectively, after 1 year of HT. No age differences were seen in transwomen, whereas in transmen aged ≥50 years a decrease in all BTMs was found in contrast with the other age groups. These transmen had low estrogen concentration at the start of HT based on their postmenopausal state before the start of HT; their estradiol concentrations increased during testosterone treatment. Changes in BTMs and BMD were weakly correlated (correlation coefficient all <0.30). To conclude, 1 year of HT resulted in decreased bone turnover in transwomen and older transmen, whereas it increased in younger transmen. The decrease in bone resorption in older transmen shows the importance of estrogen as a key regulator of bone turnover. © 2019 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc.

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.

Bone geometry and trabecular bone score in transgender people before and after short- and long-term hormonal treatment

BACKGROUND

Gender-affirming hormonal treatment (HT) in adult transgender people influences bone mineral density (BMD). Besides BMD, bone geometry and trabecular bone score are associated with fracture risk. However, it is not known whether bone geometry and TBS changes during HT.

PURPOSE

To investigate the bone geometry and TBS in adult transgender people at different time points, up to 25 years, of HT.

METHODS

A total of 535 trans women and 473 trans men were included, who were divided into three groups at time of their DXA: 20-29 years, 30-39 years, and 40-59 years. Subsequently, each group was divided into different HT durations: baseline, or after 5, 15, or 25 years of HT. Hip structure analysis was performed to measure subperiosteal width, endocortical diameter, average cortical thickness, and section modulus. TBS was calculated based on lumbar spine DXA images.

RESULTS

In trans women in all age groups and in young trans men, no differences were observed in periosteal width, endocortical diameter, average cortical thickness, and section modulus for different durations of HT. In trans men aged 40-59 years, subperiosteal width, endocortical diameter, and section modulus were slightly higher in the groups who were using HT compared to the (peri- or postmenopausal) baseline group. In younger trans women, TBS tended to be higher in those using HT compared to the baseline groups, and in older trans women TBS was higher in those using HT for 25 years versus baseline (+0.04, 95%CI +0.00; +0.08). In younger trans men, TBS tended to be lower in those who used HT compared to the baseline groups, and in older trans men TBS was lower in those using 5 years HT versus baseline (-0.05, 95%CI -0.08; -0.01).

CONCLUSION

No differences in cortical bone geometry parameters were found during different HT-durations. TBS increased in trans women and decreased in trans men, indicating that estrogens have positive effects on TBS. These data may be helpful in determining what sex reference values for calculating T-scores and Z-scores in adult transgender people should be used.

Physiological and Biochemical Effects of Intrinsically High and Low Exercise Capacities Through Multiomics Approaches

Regular exercise prevents lipid abnormalities and conditions such as diabetes mellitus, hypertension, and obesity; it considerably benefits sedentary individuals. However, individuals exhibit highly variable responses to exercise, probably due to genetic variations. Animal models are typically used to investigate the relationship of intrinsic exercise capacity with physiological, pathological, psychological, behavioral, and metabolic disorders. In the present study, we investigated differential physiological adaptations caused by intrinsic exercise capacity and explored the regulatory molecules or mechanisms through multiomics approaches. Outbred ICR mice (n = 100) performed an exhaustive swimming test and were ranked based on the exhaustive swimming time to distinguish intrinsically high- and low-capacity groups. Exercise performance, exercise fatigue indexes, glucose tolerance, and body compositions were assessed during the experimental processes. Furthermore, the gut microbiota, transcriptome, and proteome of soleus muscle with intrinsically high exercise capacity (HEC) and low exercise capacity (LEC) were further analyzed to reveal the most influential factors associated with differential exercise capacities. HEC mice outperformed LEC mice in physical activities (exhaustive swimming and forelimb grip strength tests) and exhibited higher glucose tolerance than LEC mice. Exercise-induced peripheral fatigue and the level of injury biomarkers (lactate, ammonia, creatine kinase, and aspartate aminotransferase) were also significantly lower in HEC mice than in LEC mice. Furthermore, the gut of the HEC mice contained significantly more Butyricicoccus than that of the LEC mice. In addition, transcriptome data of the soleus muscle revealed that the expression of microRNAs that are strongly associated with exercise performance-related physiological and metabolic functions (i.e., miR-383, miR-107, miR-30b, miR-669m, miR-191, miR-218, and miR-224) was higher in HEC mice than in LEC mice. The functional proteome data of soleus muscle indicated that the levels of key proteins related to muscle function and carbohydrate metabolism were also significantly higher in HEC mice than in LEC mice. Our study demonstrated that the mice with various intrinsic exercise capacities have different gut microbiome as well as transcriptome and proteome of soleus muscle by using multiomics approaches. The specific bacteria and regulatory factors, including miRNA and functional proteins, may be highly correlated with the adaptation of physiological functions and exercise capacity.

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.

Change in grip strength in trans people and its association with lean body mass and bone density

OBJECTIVE

Gender-affirming hormonal treatment (HT) in trans people changes physical appearance. Muscle mass and strength are important aspects of physical appearance, but few data exist on the effect of HT on grip strength and muscle mass. This study aimed to investigate the change in grip strength in trans people during the first year of HT and to study the possible determinants of this change and the associations between changes in grip strength, lean body mass and bone mineral density (BMD).

DESIGN AND METHODS

A multicenter, prospective study was performed, including 249 transwomen and 278 transmen. Grip strength, lean body mass and BMD were measured at baseline and after 1 year.

RESULTS

After 1 year of HT, grip strength decreased with -1.8 kg (95% CI -2.6; -1.0) in transwomen and increased with +6.1 kg (95% CI +5.5; +6.7) in transmen. No differences in grip strength change was found between age groups, BMI groups, hormonal administration routes or hormone concentrations. In transmen, increase in grip strength was associated with increase in lean body mass (per kg increase in grip strength: +0.010 kg, 95% CI +0.003; +0.017), while this was not found in transwomen (per kg increase in grip strength: +0.004 kg, 95% CI -0.000; +0.009). Change in grip strength was not associated with change in BMD in transwomen and transmen.

CONCLUSIONS

After 1 year of HT, grip strength decreased in transwomen, and increased in transmen. In transmen only, change in grip strength was associated with change in lean body mass.

Cancer Risk in Transgender People

Gender-affirming hormonal treatment (HT) in transgender people is considered safe in general, but the question regarding (long-term) risk on sex hormone-related cancer remains. Because the risk on certain types of cancer differs between men and women, and some of these differences are attributed to exposure to sex hormones, the cancer risk may be altered in transgender people receiving HT. Although reliable epidemiologic data are sparse, the available data will be discussed in this article. Furthermore, recommendations for cancer screening and prevention will be discussed as well as whether to withdraw HT at time of a cancer diagnosis.

Transmasculine Hormone Therapy

Prescribing gender-affirming hormonal therapy in transgender men (TM) not only induces desirable physical effects but also benefits mental health. In TM, testosterone therapy is aimed at achieving cisgender male serum testosterone to induce virilization. Testosterone therapy is safe on the short term and middle term if adequate endocrinological follow-up is provided. Transgender medicine is not a strong part of the medical curriculum, although a large number of transgender persons will search for some kind of gender-affirming care. Because hormonal therapy has beneficial effects, all endocrinologists or hormone-prescribing physicians should be able to provide gender-affirming hormonal care.

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.

Bone Safety During the First Ten Years of Gender-Affirming Hormonal Treatment in Transwomen and Transmen

Concerns about the effects of gender-affirming hormonal treatment (HT) on bone mineral density (BMD) in transgender people exist, particularly regarding the decrease in estrogen concentrations in transmen. Although it is known that HT is safe for BMD in the short term, long-term follow-up studies are lacking. Therefore this study aimed to investigate the change in BMD during the first 10 years of HT, to determine whether HT is safe and if assessing BMD during HT is necessary. A follow-up study was performed in adult transgender people receiving HT at the VU University Medical Center Amsterdam between 1998 and 2016. People were included if they were HT naive and had a dual-energy X-ray absorptiometry (DXA) scan at the start of HT. Follow-up DXA scans performed after 2, 5, and/or 10 years of HT were used for analyses. The course of BMD of the lumbar spine during the first 10 years of HT was analyzed using multilevel analyses. A total of 711 transwomen (median age 35 years; IQR, 26 to 46 years) and 543 transmen (median age 25 years; IQR, 21 to 34 years) were included. Prior to the start of HT, 21.9% of transwomen and 4.3% of transmen had low BMD for age (Z-score < -2.0). In transwomen lumbar spine BMD did not change (+0.006; 95% CI, -0.005 to +0.017), but lumbar spine Z-score increased by +0.22 (95% CI, +0.12 to +0.32) after 10 years of HT. Also in transmen lumbar spine BMD did not change (+0.008; 95% CI, -0.004 to +0.019), but lumbar spine Z-score increased by +0.34 (95% CI, +0.23 to +0.45) after 10 years of HT. This study showed that HT does not have negative effects on BMD, indicating that regularly assessing BMD during HT is not necessary. However, a high percentage of low BMD was found prior to HT, especially in transwomen. Therefore, evaluation of BMD before start of HT may be considered. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Assessment of Gender-Affirming Hormone Therapy Requirements

PURPOSE

There are currently no recommendations regarding the starting doses of hormone therapy for individuals with gender dysphoria. The purpose of this study was to assess the hormone dose needed to achieve target hormone levels in transgender men and transgender women, and whether body mass index (BMI) affects these doses.

METHODS

A retrospective chart review of subjects seeking gender-affirming hormone therapy was performed. Height, weight, hormone doses, and serum hormone levels were collected from charts. Data were analyzed for a correlation between BMI and effective hormone dosing (dose that achieved hormone levels in the target range).

RESULTS

Charts from 319 subjects were reviewed; however, only 84 transgender women and 71 transgender men had serum hormone levels available and only 40 transgender women and 54 transgender men had plasma hormone levels in the target range (normal range for affirmed gender). For transgender women, there was a significant negative correlation between BMI and effective estradiol dose (r = -0.337, p = 0.04). For transgender men, there was a positive correlation between BMI and effective testosterone dose (r = 0.409, p = 0.002).

CONCLUSION

Increased BMI was associated with lower estrogen dose requirements in transgender women. In transgender men, an increase in BMI was associated with increased testosterone dose requirements. These results suggest that BMI may influence effective gender-affirming hormone dosing; however, further studies are needed to examine its utility in determining the initial hormone dose.

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.

Addressing the Needs of Transgender Patients: How Gynecologists Can Partner in Their Care

Importance

With the increase in patients who identify as transgender, it is crucial that gynecologists are culturally and clinically competent in understanding their unique needs.

Objective

The aim of this study was to identify the key gynecologic issues facing transgender patients and develop an overarching framework of tools needed to address these issues.

Evidence Acquisition

A review of the existing literature was undertaken to address the key clinical aspects of care.

Results

Various aspects of the gynecologic care of transgender patients, including health maintenance and cancer screening examinations, hormone replacement therapy, hysterectomy and salpingo-oophorectomy, and referral and collaboration with the patient's care team, are outlined.

Conclusions and Relevance

Transgender patients are more likely to be engaged and seek care if their identity and their needs are understood. While many aspects of transgender health care follow standard practices, there are significant and important differences, including gender-affirming therapies. This article aims to give gynecologists the necessary tools to partner in the care of transgender patients.

Effects of Gender-Affirming Hormones on Lipid, Metabolic, and Cardiac Surrogate Blood Markers in Transgender Persons

BACKGROUND

Gender-affirming hormonal therapy consists of testosterone in transgender men and estrogens and antiandrogens in transgender women. Research has concluded that gender-affirming therapy generally leads to high satisfaction rates, increased quality of life, and higher psychological well-being. However, given the higher incidence of cardiometabolic morbidity and mortality in cisgender men compared with cisgender women, concerns about the cardiometabolic risk of androgen therapy have been raised.

CONTENT

A literature research was conducted on PubMed, Embase, and Scopus, searching for relevant articles on the effects of gender-affirming hormone therapy on cardiometabolic risk and thrombosis. After screening 734 abstracts, 77 full text articles were retained, of which 11 were review articles.

SUMMARY

Studies describing a higher risk for cardiometabolic and thromboembolic morbidity and/or mortality in transgender women (but not transgender men) mainly covered data on transgender women using the now obsolete ethinyl estradiol and, therefore, are no longer valid. Currently, most of the available literature on transgender people adhering to standard treatment regimens consists of retrospective cohort studies of insufficient follow-up duration. When assessing markers of cardiometabolic disease, the available literature is inconclusive, which may be ascribed to relatively short follow-up duration and small sample size. The importance of ongoing large-scale prospective studies/registries and of optimal management of conventional risk factors cannot be overemphasized.

Alterations in Body Uneasiness, Eating Attitudes, and Psychopathology Before and After Cross-Sex Hormonal Treatment in Patients with Female-to-Male Gender Dysphoria

Body dissatisfaction plays an important role in the development of psychiatric problems such as eating disorders as well as gender dysphoria (GD). Cross-sex hormonal treatment (CHT) alleviates the dissatisfaction by making various changes in the body. We examined the alteration of body uneasiness, eating attitudes and behaviors, and psychological symptoms longitudinally in Turkish participants with female-to-male gender dysphoria (FtM GD) after CHT. Thirty-seven participants with FtM GD and 40 female controls were asked to complete the Body Uneasiness Test to explore different areas of body-related psychopathology, the Eating Attitudes Test to assess eating disturbances, and the Symptom Checklist-90 Revised to measure psychological state, both before CHT and after 6 months of CHT administration. The baseline mean body weight, BMI scores, body uneasiness scores, and general psychopathological symptoms of participants with FtM GD were significantly higher than female controls, whereas baseline eating attitudes and behaviors were not significantly different. Over time, FtM GD participants' mean body weight and BMI scores increased, body uneasiness and general psychopathological symptoms decreased, and eating attitudes and behaviors had not changed at 24th weeks following CHT administration compared to baseline. CHT may have a positive impact on body uneasiness and general psychopathological symptoms in participants with FtM GD. However, CHT does not have an impact on eating attitudes and behaviors.

Circulating Testosterone as the Hormonal Basis of Sex Differences in Athletic Performance

Elite athletic competitions have separate male and female events due to men's physical advantages in strength, speed, and endurance so that a protected female category with objective entry criteria is required. Prior to puberty, there is no sex difference in circulating testosterone concentrations or athletic performance, but from puberty onward a clear sex difference in athletic performance emerges as circulating testosterone concentrations rise in men because testes produce 30 times more testosterone than before puberty with circulating testosterone exceeding 15-fold that of women at any age. There is a wide sex difference in circulating testosterone concentrations and a reproducible dose-response relationship between circulating testosterone and muscle mass and strength as well as circulating hemoglobin in both men and women. These dichotomies largely account for the sex differences in muscle mass and strength and circulating hemoglobin levels that result in at least an 8% to 12% ergogenic advantage in men. Suppression of elevated circulating testosterone of hyperandrogenic athletes results in negative effects on performance, which are reversed when suppression ceases. Based on the nonoverlapping, bimodal distribution of circulating testosterone concentration (measured by liquid chromatography-mass spectrometry)-and making an allowance for women with mild hyperandrogenism, notably women with polycystic ovary syndrome (who are overrepresented in elite athletics)-the appropriate eligibility criterion for female athletic events should be a circulating testosterone of <5.0 nmol/L. This would include all women other than those with untreated hyperandrogenic disorders of sexual development and noncompliant male-to-female transgender as well as testosterone-treated female-to-male transgender or androgen dopers.

Proandrogenic and Antiandrogenic Progestins in Transgender Youth: Differential Effects on Body Composition and Bone Metabolism

CONTEXT

Progestins can be used to attenuate endogenous hormonal effects in late-pubertal transgender (trans) adolescents (Tanner stage B4/5 and G4/5). Currently, no data are available on the effects of progestins on the development of bone mass or body composition in trans youth.

OBJECTIVE

To study prospectively the evolution of body composition and bone mass in late-pubertal trans adolescents using the proandrogenic or antiandrogenic progestins lynestrenol (L) and cyproterone acetate (CA), respectively.

DESIGN AND OUTCOME MEASUREMENTS

Forty-four trans boys (Tanner B4/5) and 21 trans girls (Tanner G4/5) were treated with L or CA for 11.6 (4 to 40) and 10.6 (5 to 31) months, respectively. Anthropometry, grip strength, body composition, and bone mass, size, and density were determined by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography before the start of progestin and before addition of cross-sex hormones.

RESULTS

Using L, lean mass [+3.2 kg (8.6%)] and grip strength [+3 kg (10.6%)] significantly increased, which coincided with a more masculine body shape in trans boys. Trans girls showed loss of lean mass [-2.2 kg (4.7%)], gain of fat mass [+1.5 kg (9.4%)], and decreased grip strength Z scores. CA limited normal bone expansion and impeded pubertal bone mass accrual, mostly at the lumbar spine [Z score: -0.765 to -1.145 (P = 0.002)]. L did not affect physiological bone development.

CONCLUSION

Proandrogenic and antiandrogenic progestins induce body composition changes in line with the desired appearance within 1 year of treatment. Bone health, especially at the lumbar spine, is of concern in trans girls, as bone mass accrual is severely affected by androgen suppressive therapy.

Metabolic and functional changes in transgender individuals following cross-sex hormone treatment: Design and methods of the GEnder Dysphoria Treatment in Sweden (GETS) study

Background

Although the divergent male and female differentiation depends on key genes, many biological differences seen in men and women are driven by relative differences in estrogen and testosterone levels. Gender dysphoria denotes the distress that gender incongruence with the assigned sex at birth may cause. Gender-affirming treatment includes medical intervention such as inhibition of endogenous sex hormones and subsequent replacement with cross-sex hormones. The aim of this study is to investigate consequences of an altered sex hormone profile on different tissues and metabolic risk factors. By studying subjects undergoing gender-affirming medical intervention with sex hormones, we have the unique opportunity to distinguish between genetic and hormonal effects.

Methods

The study is a single center observational cohort study conducted in Stockholm, Sweden. The subjects are examined at four time points; before initiation of treatment, after endogenous sex hormone inhibition, and three and eleven months following sex hormone treatment. Examinations include blood samples, skeletal muscle-, adipose- and skin tissue biopsies, arteriography, echocardiography, carotid Doppler examination, whole body MRI, CT of muscle and measurements of muscle strength.

Results

The primary outcome measure is transcriptomic and epigenomic changes in skeletal muscle. Secondary outcome measures include transcriptomic and epigenomic changes associated with metabolism in adipose and skin, muscle strength, fat cell size and ability to release fatty acids from adipose tissue, cardiovascular function, and body composition.

Conclusions

This study will provide novel information on the role of sex hormone treatment in skeletal muscle, adipose and skin, and its relation to cardiovascular and metabolic disease.

ESTROGEN LEVELS DO NOT RISE WITH TESTOSTERONE TREATMENT FOR TRANSGENDER MEN

OBJECTIVE

Existing transgender treatment guidelines suggest that for transmasculine treatment, there is a possible need for estrogen-lowering strategies adjunct to testosterone therapy. Further, guidelines advocate consideration of prophylactic female reproductive tissue surgeries for transgender men to avoid the possibility of estrogen-related health risks. Despite the paucity of objective data, some transgender men seek conversion inhibitors. We sought to determine estradiol levels in transgender men treated with testosterone therapy and the change in those levels with treatment, if any.

METHODS

Estradiol levels were extracted from the electronic medical records of 34 anonymized transgender men treated with testosterone therapy at the Endocrinology Clinic at Boston Medical Center. Data were sufficient to observe 6 years of follow-up.

RESULTS

With increased testosterone levels in trans-gender men, a significant decrease in estradiol levels was noted. There was a significant negative correlation between testosterone levels and body mass index, which may serve to explain part of the mechanism for the fall in estradiol levels. Even though the fall in estradiol levels was significant statistically, the actual levels remained within the normal male range, even with 6 years of follow-up.

CONCLUSION

These data suggest that when exogenous testosterone is used to achieve normal serum male testosterone levels for transgender men, it is converted to normal male levels of estradiol, with some decline in those estradiol levels that might be attributable to a fall in fat mass. There appears to be no role for aromatase conversion inhibitors or other estrogen-reducing strategies in trans-gender men. Abbreviation: BMI = body mass index.

The androgen receptor in bone marrow progenitor cells negatively regulates fat mass

It is well established that testosterone negatively regulates fat mass in humans and mice; however, the mechanism by which testosterone exerts these effects is poorly understood. We and others have shown that deletion of the androgen receptor (AR) in male mice results in a phenotype that mimics the three key clinical aspects of hypogonadism in human males; increased fat mass and decreased bone and muscle mass. We now show that replacement of the Ar gene specifically in mesenchymal progenitor cells (PCs) residing in the bone marrow of Global-ARKO mice, in the absence of the AR in all other tissues (PC-AR Gene Replacements), completely attenuates their increased fat accumulation. Inguinal subcutaneous white adipose tissue and intra-abdominal retroperitoneal visceral adipose tissue depots in PC-AR Gene Replacement mice were 50-80% lower than wild-type (WT) and 75-90% lower than Global-ARKO controls at 12 weeks of age. The marked decrease in subcutaneous and visceral fat mass in PC-AR Gene Replacements was associated with an increase in the number of small adipocytes and a healthier metabolic profile compared to WT controls, characterised by normal serum leptin and elevated serum adiponectin levels. Euglycaemic/hyperinsulinaemic clamp studies reveal that the PC-AR Gene Replacement mice have improved whole-body insulin sensitivity with higher glucose infusion rates compared to WT mice and increased glucose uptake into subcutaneous and intra-abdominal fat. In conclusion, these data provide the first evidence for an action of androgens via the AR in mesenchymal bone marrow PCs to negatively regulate fat mass and improve metabolic function.

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.

Effect of Sex Steroids on the Bone Health of Transgender Individuals: A Systematic Review and Meta-Analysis

BACKGROUND

The impact of sex steroids on bone health in transgender individuals is unclear.

METHODS

A comprehensive search of several databases to 7 April 2015 was conducted for studies evaluating bone health in transgender individuals receiving sex steroids. Pairs of reviewers selected and appraised studies. A random effects model was used to pool weighted mean differences and 95% confidence intervals (CIs).

RESULTS

Thirteen studies evaluating 639 transgender individuals were identified [392 male-to-female (MTF), 247 female-to-male (FTM)]. In FTM individuals and compared with baseline values before initiation of masculinizing hormone therapy, there was no statistically significant difference in the lumbar spine, femoral neck, or total hip bone mineral density (BMD) when assessed at 12 and 24 months. In MTF individuals and compared with baseline values before initiation of feminizing hormone therapy, there was a statistically significant increase in lumbar spine BMD at 12 months (0.04 g/cm2; 95% CI, 0.03 to 0.06 g/cm2) and 24 months (0.06 g/cm2; 95% CI, 0.04 to 0.08 g/cm2). Fracture rates were evaluated in a single cohort of 53 MTF and 53 FTM individuals, with no events at 12 months. The body of evidence is derived mostly from observational studies at moderate risk of bias.

CONCLUSION

In FTM individuals, masculinizing hormone therapy was not associated with significant changes in BMD, whereas in MTF individuals feminizing hormone therapy was associated with an increase in BMD at the lumbar spine. The impact of these BMD changes on patient-important outcomes such as fracture risk is uncertain.

Ten Most Important Things to Know About Caring for Transgender Patients

Transgender people have a gender that is not in agreement with their birth sex. Previous barriers, including lack of provider knowledge, have created significant healthcare disparities for this population. Recent societal changes are increasing the numbers of transgender people seen by primary care practitioners. Ten key principles are provided to help primary care practitioners create more welcoming environments and provide quality care to transgender patients. Overall, all members of the healthcare team (primary and specialty) need to become aware of the transition process and maintain communication regarding risks, benefits, and goals. Transwomen (aka male to female) can be treated with estrogens, antiandrogens, or a combination. Benefits include change in fat distribution, skin softening, and breast development. Significant risks for thrombosis from estrogens have been linked to genetic mutations, smoking, prolonged inactivity, and hormone formulation. Oral administration may provide increased risk over peripheral administration. Transmen (aka female to male) can be treated with peripheral testosterone preparations. Benefits include deepening of voice and development of facial and body hair with variable changes in muscle mass. Risks from testosterone appear to be less common than from estrogen. Laboratory monitoring can guide treatment decisions and provide early detection of some complications. Monitoring of "existing" anatomy (either hormonally or surgically created or removed) is an important component of healthcare for transgender patients. Primary care providers also should be aware of resources in their community and online, which can help patients optimize their transition.

Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To update the "Endocrine Treatment of Transsexual Persons: An Endocrine Society Clinical Practice Guideline," published by the Endocrine Society in 2009.

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of nine experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

Group meetings, conference calls, and e-mail communications enabled consensus. Endocrine Society committees, members and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines.

CONCLUSION

Gender affirmation is multidisciplinary treatment in which endocrinologists play an important role. Gender-dysphoric/gender-incongruent persons seek and/or are referred to endocrinologists to develop the physical characteristics of the affirmed gender. They require a safe and effective hormone regimen that will (1) suppress endogenous sex hormone secretion determined by the person's genetic/gonadal sex and (2) maintain sex hormone levels within the normal range for the person's affirmed gender. Hormone treatment is not recommended for prepubertal gender-dysphoric/gender-incongruent persons. Those clinicians who recommend gender-affirming endocrine treatments-appropriately trained diagnosing clinicians (required), a mental health provider for adolescents (required) and mental health professional for adults (recommended)-should be knowledgeable about the diagnostic criteria and criteria for gender-affirming treatment, have sufficient training and experience in assessing psychopathology, and be willing to participate in the ongoing care throughout the endocrine transition. We recommend treating gender-dysphoric/gender-incongruent adolescents who have entered puberty at Tanner Stage G2/B2 by suppression with gonadotropin-releasing hormone agonists. Clinicians may add gender-affirming hormones after a multidisciplinary team has confirmed the persistence of gender dysphoria/gender incongruence and sufficient mental capacity to give informed consent to this partially irreversible treatment. Most adolescents have this capacity by age 16 years old. We recognize that there may be compelling reasons to initiate sex hormone treatment prior to age 16 years, although there is minimal published experience treating prior to 13.5 to 14 years of age. For the care of peripubertal youths and older adolescents, we recommend that an expert multidisciplinary team comprised of medical professionals and mental health professionals manage this treatment. The treating physician must confirm the criteria for treatment used by the referring mental health practitioner and collaborate with them in decisions about gender-affirming surgery in older adolescents. For adult gender-dysphoric/gender-incongruent persons, the treating clinicians (collectively) should have expertise in transgender-specific diagnostic criteria, mental health, primary care, hormone treatment, and surgery, as needed by the patient. We suggest maintaining physiologic levels of gender-appropriate hormones and monitoring for known risks and complications. When high doses of sex steroids are required to suppress endogenous sex steroids and/or in advanced age, clinicians may consider surgically removing natal gonads along with reducing sex steroid treatment. Clinicians should monitor both transgender males (female to male) and transgender females (male to female) for reproductive organ cancer risk when surgical removal is incomplete. Additionally, clinicians should persistently monitor adverse effects of sex steroids. For gender-affirming surgeries in adults, the treating physician must collaborate with and confirm the criteria for treatment used by the referring physician. Clinicians should avoid harming individuals (via hormone treatment) who have conditions other than gender dysphoria/gender incongruence and who may not benefit from the physical changes associated with this treatment.

Effects of testosterone therapy on BMI, blood pressure, and laboratory profile of transgender men: a systematic review

Testosterone is the main hormonal agent used for cross-sex hormone therapy in female-to-male transgender persons. Our aim was to systematically review the literature concerning the effects of testosterone on body mass index (BMI), blood pressure, hematocrit, hemoglobin, lipid profile, and liver enzymes in transgender men. PUBMED and EMBASE were searched for studies published until March 2017. Studies were included if they reported interventions with any dose of testosterone and comparison of variables before and during treatment. Of 455 potentially eligible articles, 13 were reviewed. Study duration ranged from 6 to 60 months, sample size ranged from 12 to 97 patients, and the most common treatment was parenteral testosterone undecanoate 1000 mg/12 weeks. Slight but significant increases in BMI were reported (from 1.3 to 11.4%). Three out of seven studies assessing the impact of different testosterone formulations on blood pressure detected modest increases or clinically irrelevant changes in this variable. In another study, however, two patients developed hypertension, which was resolved after cessation of testosterone therapy. Decreases in HDL-cholesterol and increases in LDL-cholesterol were consistently observed. Eight studies observed a relationship between testosterone and increased hemoglobin (range: 4.9-12.5%) and hematocrit (range: 4.4-17.6%), but discontinuation of androgen therapy was not necessary. In one study, two patients developed erythrocytosis (hematocrit >52%) after 9 and 12 months of treatment. One study analyzing testosterone formulations observed smaller increases in hemoglobin and hematocrit with testosterone gel. Six studies assessing liver function showed slight or no changes. Overall, the quality of evidence was low, given the lack of randomized clinical/controlled trials and the small sample sizes. In conclusion, exogenous testosterone administration to transgender men was associated with modest increases in BMI, hemoglobin/hematocrit, and LDL-cholesterol, and with decreases in HDL-cholesterol. Long-term studies are needed to assess the long-term risks of testosterone therapy, particularly as they relate to cardiometabolic risks such as diabetes, dyslipidemia and the metabolic syndrome.

When Gender Identity Doesn't Equal Sex Recorded at Birth: The Role of the Laboratory in Providing Effective Healthcare to the Transgender Community

BACKGROUND

Transgender is an umbrella term used to describe individuals who identify with a gender incongruent to or variant from their sex recorded at birth. Affirming gender identity through a variety of social, medical, and surgical interventions is critical to the mental health of transgender individuals. In recent years, awareness surrounding transgender identities has increased, which has highlighted the health disparities that parallel this demographic. These disparities are reflected in the experience of transgender patients and their providers when seeking clinical laboratory services.

CONTENT

Little is known about the effect of gender-affirming hormone therapy and surgery on optimal laboratory test interpretation. Efforts to diminish health disparities encountered by transgender individuals and their providers can be accomplished by increasing social and clinical awareness regarding sex/gender incongruence and gaining insight into the physiological manifestations and laboratory interpretations of gender-affirming strategies. This review summarizes knowledge required to understand transgender healthcare including current clinical interventions for gender dysphoria. Particular attention is paid to the subsequent impact of these interventions on laboratory test utilization and interpretation. Common nomenclature and system barriers are also discussed.

SUMMARY

Understanding gender incongruence, the clinical changes associated with gender transition, and systemic barriers that maintain a gender/sex binary are key to providing adequate healthcare to transgender community. Transgender appropriate reference interval studies are virtually absent within the medical literature and should be explored. The laboratory has an important role in improving the physiological understanding, electronic medical system recognition, and overall social awareness of the transgender community.

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. © 2017 American Society for Bone and Mineral Research.

Testosterone therapy for transgender men

Testosterone therapy is a cornerstone of medical treatment for transgender men who choose to undergo it. The goal of testosterone therapy is usually to achieve serum testosterone concentrations in the male reference range. Testosterone has several desired effects as well as undesired and unknown effects. The desired effects include increased facial and body hair, increased lean mass and strength, decreased fat mass, deepening of the voice, increased sexual desire, cessation of menstruation, clitoral enlargement, and reductions in gender dysphoria, perceived stress, anxiety, and depression. Achievement of these goals comes with potential undesired effects and risks including acne, alopecia, reduced HDL cholesterol, increased triglycerides, and a possible increase in systolic blood pressure. An additional benefit of testosterone therapy (with or without mastectomy) is a reduced risk of breast cancer. Most of the effects of testosterone start to develop within several months of starting therapy, although facial hair and alopecia continue to develop after 1 year. A major limitation in the study of testosterone therapy for transgender men is a paucity of high-quality data due to a shortage of randomised controlled trials (partly because of ethical issues), few prospective and long-term studies, the use of suboptimum control groups, loss to follow-up, and difficulties in recruitment of representative samples of transgender populations.

Hormonal and Surgical Treatment Options for Transgender Men (Female-to-Male)

Untreated transgender men face serious negative health care outcomes. Effective medical, surgical, and mental health treatment ameliorates these risks. Although the research is not as robust as would be ideal, hormone treatment is effective and generally well tolerated with few serious medical risks. Surgeries carry serious risks; but for most transgender men, the benefits outweigh the risks. This review describes current evidence-based medical treatments for transgender men and provides an overview of surgical therapy to enable practitioners to discuss these options with their transgender male patients.