Uncovering the effects of gender affirming hormone therapy on skeletal muscle and epigenetics: protocol for a prospective matched cohort study in transgender individuals (the GAME study)

Current opinions invited review: testosterone and transgender medicine

PURPOSE OF REVIEW

Transgender individuals have a gender identity incongruent with their sex assigned at birth. Social, medical and surgical methods are often affirming. This review focuses on updates from the last 18 months mainly in testosterone use in masculinising gender-affirming hormone therapy (GAHT) in postpubertal adults, and also antiandrogens for suppression or blockade of endogenous testosterone in feminising GAHT. Mental and sexual healthcare are vital for many transgender patients, but are not the focus of this review.

RECENT FINDINGS

There has been a considerable increase in publications regarding testosterone GAHT in recent years, though narrative reviews, opinion pieces and case series continue to dominate. There has also been a notable increase in prospective studies and valuable data particularly from large longitudinal cohorts and studies aiming to refine GAHT prescribing and better understand long-term effects on aspects such as fertility, cardiometabolic and bone health as well as adverse effects.

SUMMARY

Testosterone GAHT is life changing. Increased research will help GAHT optimisation, and improve understanding of tissue-specific impacts and long-term safety. Longer-term data, prospective studies and utilisation of novel research tools and approaches are needed to enrich our understanding and prescribing of testosterone and its blockers in GAHT.

Musculoskeletal and cardiovascular considerations for transgender athletes

OBJECTIVE

Participation in athletics is essential for the overall well-being of transgender athletes and should be included as part of gender-affirming care. Surveys show physicians and athletic trainers want to provide appropriate care for transgender athletes but lack the proper knowledge and training to do so. Gender Affirming Hormone Therapy (GAHT) is part of gender-affirming care, yet the effects of GAHT on the cardiovascular and musculoskeletal health of transgender athletes is not well-understood. The purpose of this review was to discuss important musculoskeletal and cardiovascular considerations unique to transgender athletes and improve physician understanding in caring for transgender athletes.

METHODS

A representative selection of literature on the effects of GAHT on cardiovascular and musculoskeletal health was included in this review.

RESULTS

Estrogen therapy may increase the risk of venous thromboembolism (VTE) and stroke, and decrease blood pressure levels among transgender women, while studies on lipid profile are inconsistent among both transgender men and women. Transgender women receiving GAHT may also be at greater risk for bone fracture and ligamentous injuries.

CONCLUSION

Exercise is essential for the well-being of transgender individuals and special considerations regarding the cardiovascular and musculoskeletal health of transgender athletes should be incorporated into standard medical education. Educational programs for transgender patients and their support team should focus on preventative measures that can be taken to reduce the risk of adverse musculoskeletal and cardiovascular events. The PPE is an invaluable tool available to physicians to monitor the health and safety of transgender athletes and should be regularly updated as research on the health of transgender individuals continues to grow. Longitudinal and prospective studies should examine the effects of GAHT on the musculoskeletal and cardiovascular health of transgender athletes. Lastly, health care providers play an important role in the advancement of gender-neutral policies.

Chiropractic Care for a Posterior Tibialis Tendon Tear in a Transgender Male Athlete with Gender-Affirming Hormone Therapy

Objective

The purpose of this case study was to report the management of a patient with posterior tibialis tendon injury concurrent with gender-affirming hormone therapy (GAHT).

Clinical Features

A 31-year-old transgender male presented to a chiropractic clinic with spontaneous, right medial foot pain following running that day. Medical history revealed bilateral congenital pes planus and intramuscular administration of testosterone for 8 years. Physical examination revealed swelling and tenderness around the medial and lateral malleoli and anterior ankle and along the medial longitudinal arch. Plantarflexion and dorsiflexion strength measured 4 out of 5. An 8 out of 10 pain level affected weight-bearing activities and sleep. Lower extremity functional scale measured 81% disability. Multimodal imaging was used in the patient's workup. Diagnostic ultrasound revealed a grade 2 tear of the posterior tibialis tendon adjacent to the medial malleolus along with additional sites of tendinosis. Referral to orthopedist and subsequent magnetic resonance imaging of the right foot and ankle confirmed the diagnosis of grade 2 tear in the posterior tibialis tendon.

Intervention and Outcome

The patient elected chiropractic care following the surgical recommendation. Nonpharmacologic management included neuromuscular re-education using whole body vibration therapy, therapeutic exercise, and ankle mortise joint mobilizations. The patient's clinical status improved, and the lower extremity functional scale measured 27% disability.

Conclusion

Although the patient was 31 years old, GAHT is recognized as a risk factor for tendinosis in older adults. An improved understanding of the correlation between tendinosis and GAHT could optimize patient outcomes and clarify the role of musculoskeletal rehabilitation for treatment.

Transgender Women Exhibit a Distinct Stress Echocardiography Profile Compared With Age-Matched Cisgender Counterparts: The Mayo Clinic Women's Heart Clinic Experience

BACKGROUND

Stress echocardiographic (SE) testing is an important modality in cardiovascular risk stratification and obstructive coronary artery disease assessment. Binary sex-based parameters are classically used for the interpretation of these studies, even among transgender women (TGW). Coronary artery disease is a leading cause of morbidity and mortality in this population. Yet, it remains unclear whether TGW exhibit a distinct stress testing profile from their cisgender counterparts.

METHODS

Using a matched case-control study design, the authors compared the echocardiographic stress testing profiles of TGW (n = 43) with those of matched cisgender men (CGM; n = 84) and cisgender women (CGW; n = 86) at a single center. Relevant data, including demographics, comorbidities, and cardiac testing data, were manually extracted from the patients' charts.

RESULTS

The prevalence of hypertension and dyslipidemia was similar between TGW and CGW and lower than that of CGM (P = .003 and P = .009, respectively). The majority of comorbidities and laboratory values were similar. On average, TGW had higher heart rates than CGM (P = .002) and had lower blood pressures than CGM and CGW (P < .05). TGW's double product and metabolic equivalents were similar to those among CGW and lower than those of CGM (P = .016 and P = .018, respectively). On echocardiography, left ventricular end-diastolic and end-systolic diameters among TGW were similar to those of CGW but lower than those of CGM (P = .023 and P = .018, respectively). Measures of systolic and diastolic function, except for exercise mitral valve E/e' ratio, which was lower in TGW than CGW (P = .029), were largely similar among the three groups. There was no difference in the wall motion score index, and therefore, no difference in the percentage of positive SE test results.

CONCLUSIONS

This study shows, for the first time, that TGW have a SE profile that is distinct from that of their cisgender counterparts. Larger, multicenter, prospective studies are warranted to further characterize the SE profile of TGW.

The Heterogeneity of Post-Menopausal Disease Risk: Could the Basis for Why Only Subsets of Females Are Affected Be Due to a Reversible Epigenetic Modification System Associated with Puberty, Menstrual Cycles, Pregnancy and Lactation, and, Ultimately, Menopause?

For much of human evolution, the average lifespan was <40 years, due in part to disease, infant mortality, predators, food insecurity, and, for females, complications of childbirth. Thus, for much of evolution, many females did not reach the age of menopause (45-50 years of age) and it is mainly in the past several hundred years that the lifespan has been extended to >75 years, primarily due to public health advances, medical interventions, antibiotics, and nutrition. Therefore, the underlying biological mechanisms responsible for disease risk following menopause must have evolved during the complex processes leading to Homo sapiens to serve functions in the pre-menopausal state. Furthermore, as a primary function for the survival of the species is effective reproduction, it is likely that most of the advantages of having such post-menopausal risks relate to reproduction and the ability to address environmental stresses. This opinion/perspective will be discussed in the context of how such post-menopausal risks could enhance reproduction, with improved survival of offspring, and perhaps why such risks are preserved. Not all post-menopausal females exhibit risk for this set of diseases, and those who do develop such diseases do not have all of the conditions. The diseases of the post-menopausal state do not operate as a unified complex, but as independent variables, with the potential for some overlap. The how and why there would be such heterogeneity if the risk factors serve essential functions during the reproductive years is also discussed and the concept of sets of reversible epigenetic changes associated with puberty, pregnancy, and lactation is offered to explain the observations regarding the distribution of post-menopausal conditions and their potential roles in reproduction. While the involvement of an epigenetic system with a dynamic "modification-demodification-remodification" paradigm contributing to disease risk is a hypothesis at this point, validation of it could lead to a better understanding of post-menopausal disease risk in the context of reproduction with commonalities may also lead to future improved interventions to control such risk after menopause.

The Impact of Gender-Affirming Hormone Therapy on Physical Performance

CONTEXT

The inclusion of transgender people in elite sport has been a topic of debate. This narrative review examines the impact of gender-affirming hormone therapy (GAHT) on physical performance, muscle strength, and markers of endurance.

EVIDENCE ACQUISITION

MEDLINE and Embase were searched using terms to define the population (transgender), intervention (GAHT), and physical performance outcomes.

EVIDENCE SYNTHESIS

Existing literature comprises cross-sectional or small uncontrolled longitudinal studies of short duration. In nonathletic trans men starting testosterone therapy, within 1 year, muscle mass and strength increased and, by 3 years, physical performance (push-ups, sit-ups, run time) improved to the level of cisgender men. In nonathletic trans women, feminizing hormone therapy increased fat mass by approximately 30% and decreased muscle mass by approximately 5% after 12 months, and steadily declined beyond 3 years. While absolute lean mass remains higher in trans women, relative percentage lean mass and fat mass (and muscle strength corrected for lean mass), hemoglobin, and VO2 peak corrected for weight was no different to cisgender women. After 2 years of GAHT, no advantage was observed for physical performance measured by running time or in trans women. By 4 years, there was no advantage in sit-ups. While push-up performance declined in trans women, a statistical advantage remained relative to cisgender women.

CONCLUSION

Limited evidence suggests that physical performance of nonathletic trans people who have undergone GAHT for at least 2 years approaches that of cisgender controls. Further controlled longitudinal research is needed in trans athletes and nonathletes.

Implications of gender-affirming endocrine care for sports participation

Many transgender (trans) individuals utilize gender-affirming hormone therapy (GAHT) to promote changes in secondary sex characteristics to affirm their gender. Participation rates of trans people in sport are exceedingly low, yet given high rates of depression and increased cardiovascular risk, the potential benefits of sports participation are great. In this review, we provide an overview of the evidence surrounding the effects of GAHT on multiple performance-related phenotypes, as well as current limitations. Whilst data is clear that there are differences between males and females, there is a lack of quality evidence assessing the impact of GAHT on athletic performance. Twelve months of GAHT leads to testosterone concentrations that align with reference ranges of the affirmed gender. Feminizing GAHT in trans women increases fat mass and decreases lean mass, with opposite effects observed in trans men with masculinizing GAHT. In trans men, an increase in muscle strength and athletic performance is observed. In trans women, muscle strength is shown to decrease or not change following 12 months of GAHT. Haemoglobin, a measure of oxygen transport, changes to that of the affirmed gender within 6 months of GAHT, with very limited data to suggest possible reductions in maximal oxygen uptake as a result of feminizing GAHT. Current limitations of this field include a lack of long-term studies, adequate group comparisons and adjustment for confounding factors (e.g. height and lean body mass), and small sample sizes. There also remains limited data on endurance, cardiac or respiratory function, with further longitudinal studies on GAHT needed to address current limitations and provide more robust data to inform inclusive and fair sporting programmes, policies and guidelines.