Men and women, so different, so similar: observations from cross-sex hormone treatment of transsexual subjects

Exploring Hormone Therapy Effects on Reproduction and Health in Transgender Individuals

Transgender individuals often face elevated mental health challenges due to gender dysphoria, but gender-affirming treatments such as surgery and hormone therapy have been linked to significant improvements in mental well-being. The potential influence of time and circadian rhythms on these treatments is prevalent. The intricate interplay between hormones, clock genes, and fertility is profound, acknowledging the complexity of reproductive health in transgender individuals. Furthermore, risks associated with gender-affirming hormonal therapy and potential complications of puberty suppression emphasize the importance of ongoing surveillance for these patients and the need of fertility preservation and family-building options for transgender individuals. This narrative review delves into the intricate landscape of hormone therapy for transgender individuals, shedding light on its impact on bone, cardiovascular, and overall health. It explores how hormone therapy affects bone maintenance and cardiovascular risk factors, outlining the complex interplay of testosterone and estrogen. It also underscores the necessity for further research, especially regarding the long-term effects of transgender hormones. This project emphasizes the critical role of healthcare providers, particularly obstetricians and gynecologists, in providing affirming care, calling for comprehensive understanding and integration of transgender treatments. This review will contribute to a better understanding of the impact of hormone therapy on reproductive health and overall well-being in transgender individuals. It will provide valuable insights for healthcare providers, policymakers, and transgender individuals themselves, informing decision-making regarding hormone therapy and fertility preservation options. Additionally, by identifying research gaps, this review will guide future studies to address the evolving healthcare needs of transgender individuals. This project represents a critical step toward addressing the complex healthcare needs of this population. By synthesizing existing knowledge and highlighting areas for further investigation, this review aims to improve the quality of care and support provided to transgender individuals, ultimately enhancing their reproductive health and overall well-being.

Cardiovascular disease and feminizing gender-affirming hormone therapy: Implications for the provision of safe and lifesaving care

Sex recorded at birth, gender identity, and feminizing gender-affirming hormone therapy (fGAHT) likely contribute to cardiovascular disease (CVD) risk in transgender women. Understanding the interplay of these factors is necessary for the provision of safe, affirming, and lifesaving care. Among transgender women taking fGAHT, data show increases in CVD mortality and rates of myocardial infarction, stroke, and venous thromboembolism compared to reference populations, depending on study design and comparators. However, most studies are observational with a paucity of contextualizing information (e.g., dosing, route of administration, gonadectomy status), which makes it difficult to parse adverse fGAHT effects from confounders and interaction with known CVD risk factors (e.g., obesity, smoking, psychosocial and gender minority stressors). Increased CVD risk in transgender women points toward a need for greater attention to CVD management in this population including cardiology referral when indicated and additional research on the mechanisms and mediators of CVD risk.

SERUM HORMONE CONCENTRATIONS IN TRANSGENDER INDIVIDUALS RECEIVING GENDER-AFFIRMING HORMONE THERAPY: A LONGITUDINAL RETROSPECTIVE COHORT STUDY

OBJECTIVE

To examine the association of various gender-affirming hormone therapy regimens with blood sex hormone concentrations in transgender individuals.

METHODS

This retrospective study included transgender people receiving gender-affirming hormone therapy between January 2000 and September 2018. Data on patient demographics, laboratory values, and hormone dose and frequency were collected. Nonparametric tests and linear regression analyses were used to identify factors associated with serum hormone concentrations.

RESULTS

Overall, 196 subjects (134 transgender women and 62 transgender men), with a total of 941 clinical visits, were included in this study. Transgender men receiving transdermal testosterone had a significantly lower median concentration of serum total testosterone when compared with those receiving injectable preparations (326.0 ng/dL vs 524.5 ng/dL, respectively, P = .018). Serum total estradiol concentrations in the transgender women were higher in those receiving intramuscular estrogen compared with those receiving oral and transdermal estrogen (366.0 pg/mL vs 102.0 pg/mL vs 70.8 pg/mL, respectively, P < .001). A dose-dependent increase in the hormone levels was observed for oral estradiol (P < .001) and injectable testosterone (P = .018) but not for intramuscular and transdermal estradiol. Older age and a history of gonadectomy in both the transgender men and women were associated with significantly higher concentrations of serum gender-affirming sex hormones.

CONCLUSION

In the transgender men, all routes and formulations of testosterone appeared to be equally effective in achieving concentrations in the male range. The intramuscular injections of estradiol resulted in the highest serum concentrations of estradiol, whereas transdermal estradiol resulted in the lowest concentration. There was positive relationship between both oral estradiol and injectable testosterone dose and serum sex hormone concentrations in transgender people receiving GAHT.

Endocrine treatment of transgender individuals: current guidelines and strategies

INTRODUCTION

This review summarizes gender affirming medical and surgical care available to transgender individuals, along with proposals to improve medically and culturally appropriate care.

AREAS COVERED

Transgender individuals are those whose gender identity differs from that recorded at birth (usually based on visualization of external sexual anatomy). In order to align the body with the patient's gender identity, clinicians can provide hormone therapy (HT) to bring sex hormone levels to the range associated with the patient's gender identity. At steady state, monitoring for maintenance of levels, as well as for known risks and complications, is required. Treating clinicians should have knowledge of trans assessment criteria, hormone therapy, surgical options, primary care, and mental health needs of transgender patients. A narrative literature review was conducted using Pubmed and EMBASE with articles then selected for relevance. The initial search terms were: androgen suppression, antiandrogen, breast development, chest reconstruction, cisgender, estrogen, fertility preservation, gender-affirming surgery, gender identity, gender incongruence, genital reconstruction, hormone replacement, hyperlipidemia, orchiectomy, prolactin, prostate atrophy, spermatogenesis, spironolactone, testosterone, thrombogenesis, transgender, and virilization.

EXPERT OPINION

Although guidelines exist and examples of training are available, systematic formal training must be implemented to truly mainstream high-quality gender-affirming health care .

Cardiovascular disease in transgendered people: A review of the literature and discussion of risk

This review examines the impact of gender affirming hormone therapy used in the transgendered and non-binary populations on cardiovascular outcomes and surrogate markers of cardiovascular health. Current evidence suggests that hormonal therapy for transgendered women decreases or is neutral regarding myocardial infarction risk. There is an increased incidence of venous thromboembolism (VTE), but newer studies suggest that the risk is significantly lower than previously described. For transgendered men, there appears to be an adverse effect on lipid parameters but this does not translate into an increased risk of cardiovascular disease above that of general male population. In all transgendered people, risk factor interventions such as smoking cessation, weight management and treatment of co-morbid conditions are important in optimising cardiovascular health. The effect of gender affirming hormonal therapy in transgendered people is difficult to interpret due to the variety of hormone regimens used, the relative brevity of the periods of observation and the influence of confounding factors such as the historical use of less physiological, oestrogens such as conjugated equine oestrogen and ethinylestradiol which are more pro-thrombotic than the 17β oestradiol that is used in modern practice.

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.

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.

Testosterone undecanoate and testosterone enanthate injections are both effective and safe in transmen over 5 years of administration

OBJECTIVE

To retrospectively evaluate and compare safety and efficacy of short and long-acting testosterone (T) parenteral formulations over 5 years in transmen.

DESIGN AND METHODS

Fifty transmen between 21 and 42 years of age were enrolled. Twenty-five received T undecanoate 1000 mg IM (weeks 0 and 6 then every 12-16 weeks), and 25 received T enanthate 250 mg IM (every 3-4 weeks). Hormonal and biochemical parameters, anthropometric characteristics and blood pressure were assessed at baseline and then every 12 months. Body composition was evaluated at baseline and then after 1, 3 and 5 years of T treatment. Global satisfaction was assessed at baseline and after 1 and 5 years.

RESULTS

Both T formulations led to amenorrhoea in all subjects within 1 year of T administration. Both T treatments led to a similar increase in haemoglobin and haematocrit which always remained within the physiological range. T administration was associated with an increase in total cholesterol, low-density lipoprotein cholesterol and triglycerides and a slight reduction in high-density lipoprotein cholesterol. Coagulative and glucidic profiles and blood pressure did not change significantly in either group. Body weight and BMI showed a slight but not significant increase in both groups, while lean mass rose significantly in both groups. Global satisfaction was increased at years 1 and 5 in both groups.

CONCLUSIONS

Preliminary results from this pilot study suggest that administration of either TU or TE for 5 years in young transmen is both effective and safe. Our study presents the longest follow-up published so far reporting no adverse events and these data are consistent with previous reports with a shorter follow-up.

Endocrine treatment of aging transgender people

High quality empirical data assessing morbidity and mortality and cancer incidence among transgender people are almost non-existent. Sex hormone treatment of conditions in older non-transgender people might as yet be taken as the best available analogy to hormone administration to aging transgender persons. Testosterone administration to transgender men carries little risk with regard to cardiovascular disease and cancer. A dose adaptation may be needed in men with a high hematocrit or cardiac insufficiency. In transgender men, even after breast ablation, breast cancer may occur in residual mammary tissue. Treatment with estrogens (specifically oral ethinylestradiol) of transgender women, particularly in combination with progestins, carries a significant relative risk of developing cardiovascular disease (almost a twofold incidence compared to the general population). The dose of estrogens may have to be reduced with aging. A change from oral to probably safer transdermal estrogens must be considered. Though rare, tumors of the breasts, prostate, meninges and pituitary have been encountered. Based upon the available expertise, initiation of cross-sex hormone treatment in elderly subjects is without disproportionate risks.

MECHANISMS IN ENDOCRINOLOGY: The sexually dimorphic role of androgens in human metabolic disease

Female androgen excess and male androgen deficiency manifest with an overlapping adverse metabolic phenotype, including abdominal obesity, insulin resistance, type 2 diabetes mellitus, non-alcoholic fatty liver disease and an increased risk of cardiovascular disease. Here, we review the impact of androgens on metabolic target tissues in an attempt to unravel the complex mechanistic links with metabolic dysfunction; we also evaluate clinical studies examining the associations between metabolic disease and disorders of androgen metabolism in men and women. We conceptualise that an equilibrium between androgen effects on adipose tissue and skeletal muscle underpins the metabolic phenotype observed in female androgen excess and male androgen deficiency. Androgens induce adipose tissue dysfunction, with effects on lipid metabolism, insulin resistance and fat mass expansion, while anabolic effects on skeletal muscle may confer metabolic benefits. We hypothesise that serum androgen concentrations observed in female androgen excess and male hypogonadism are metabolically disadvantageous, promoting adipose and liver lipid accumulation, central fat mass expansion and insulin resistance.

Hormone therapy for transgender patients

Many transgender men and women seek hormone therapy as part of the transition process. Exogenous testosterone is used in transgender men to induce virilization and suppress feminizing characteristics. In transgender women, exogenous estrogen is used to help feminize patients, and anti-androgens are used as adjuncts to help suppress masculinizing features. Guidelines exist to help providers choose appropriate candidates for hormone therapy, and act as a framework for choosing treatment regimens and managing surveillance in these patients. Cross-sex hormone therapy has been shown to have positive physical and psychological effects on the transitioning individual and is considered a mainstay treatment for many patients. Bone and cardiovascular health are important considerations in transgender patients on long-term hormones, and care should be taken to monitor certain metabolic indices while patients are on cross-sex hormone therapy.

Endocrine care of transpeople part II. A review of cross-sex hormonal treatments, outcomes and adverse effects in transwomen

The treatment of transwomen relies on the combined administration of anti-androgens or GnRH analogues to suppress androgen production and thereby reduce male phenotypic characteristics together with oestrogens to develop female characteristics. In transwomen, synthetic oestrogens such as ethinyl oestradiol, as well as conjugated equine oestrogens (CEE), should be avoided to minimize thromboembolic risks especially in older transwomen and in those with risk factors. Currently, available short- and long-term safety studies suggest that cross-sex hormonal therapy (CHT) can be considered safe in transwomen improving the well-being and quality of life of these individuals. Long-term monitoring should aim to decrease cardiovascular risks and should include prostate and breast cancer screenings.

(Patho)physiology of cross-sex hormone administration to transsexual people: the potential impact of male-female genetic differences

There is a limited body of knowledge of desired and undesired effects of cross-sex hormones in transsexual people. Little attention has been given to the fact that chromosomal configurations, 46,XY in male-to-female transsexuals subjects (MtoF) and 46,XX in female-to-male transsexual subjects (FtoM), obviously, remain unchanged. These differences in their genomes cause sex differences in the functions of cells. This study reviews sex differences in metabolism/cardiovascular pathology, immune mechanisms, bone (patho)physiology and brain functions and examines whether they are, maybe partially, determined by genetic mechanisms rather than by (cross-sex) hormones. There do not appear to be major genetic impacts on the changes in bone physiology. Also immune functions are rather unaffected and the evidence for an increase of autoimmune disease in MtoF is preliminary. Brain functions of transsexuals may have differed from controls before cross-sex hormones; they do undergo shifts upon cross-sex hormone treatment, but there is no evidence for changes in sex-specific brain disease. The prevalence of cardiovascular disease is higher in MtoF receiving oestrogens than in FtoM receiving androgens. While type of oestrogen and route of administration might be significant, it is reasonable to speculate that nonhormonal/genetic factors play a role.