Serum lipids and estrogen receptor gene polymorphisms in male-to-female transsexuals: effects of estrogen treatment

Cross-sex hormonal replacement: Some effects over mitochondria

Transgender is a term for people whose gender identity or expression differs from their natal sex. These individuals often seek cross-hormonal therapy to simulate the individual´s desired gender. However, the use of estrogens and testosterone has side effects such as a higher propensity to cancer, weight changes and cardiovascular diseases. Testosterone has also been linked with hypertension. Still, little is known about the outcomes and prevalence of metabolic perturbations in the trans community. Here we aim to analyze if cross-administering sexual hormones affects heart mitochondrial function. Mitochondria produces the ATP needed for heart function. In fact, different studies show that mitochondrial dysfunction precedes cardiac damage. In this work we used either female rats castrated and injected with testosterone or male rats castrated and injected with estrogens for 4 months. We performed an electrocardiogram, and then we isolated heart mitochondria to measure the rate of oxygen consumption, calcium fluxes, membrane potential, superoxide dismutase activity, lipoperoxidation and cytokines. We detected wide modifications in all parameters associated to cross-hormonal administration.

Association between serum estradiol and cardiovascular health among transgender adults using gender-affirming estrogen therapy

Gender-affirming estrogen therapy (GAET) is commonly used for feminization in transgender and nonbinary (TNB) individuals, yet the optimal rate of change (ROC) in estradiol levels for cardiovascular health is unclear. We examined the association between serum estradiol levels and cardiovascular-related mortality, adverse events, and risk factors in TNB adults using GAET. Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, and Web of Science were systematically searched (inception-April 2023) for original articles reporting serum estradiol levels and cardiovascular-related mortality, adverse events, and risk factors in TNB adults using GAET. Data extraction was completed in duplicate following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Stratified random effect meta-analyses using serum estradiol ROC (serum estradiolbaseline - serum estradiolfollow-up/study duration) was used to assess longitudinal studies (low, 0 < ROC ≤ 1 pg/mL/mo; moderate, 1 < ROC ≤ 3 pg/mL/mo; high, ROC ≥ 3 pg/mL/mo). Thirty-five studies (13 cross-sectional, 19 cohort, and 3 trials) were included. Two studies collectively reported 50 cardiovascular-related deaths, and four collectively reported 23 adverse cardiovascular events. Nineteen studies reporting cardiovascular risk factors were meta-analyzed by ROC stratum (low = 5; moderate = 6; high = 8), demonstrating an association between moderate [0.40, 95% confidence interval (CI): 0.22, 0.59 kg/m2, I2 = 28.2%] and high (0.46, 95% CI: 0.15, 0.78 kg/m2; I2 = 0.0%) serum estradiol ROC and increased body mass index. High (-6.67, 95% CI: -10.65, -2.68 mg/dL; I2 = 0.0%) serum estradiol ROC was associated with decreased low-density lipoproteins. Low (-7.05, 95% CI: -10.40, -3.70 mmHg; I2 = 0.0%) and moderate (-3.69, 95% CI: -4.93, -2.45 mmHg; I2 = 0.0%) serum estradiol ROCs were associated with decreases in systolic blood pressure. In TNB adults using GAET, serum estradiol ROC may influence cardiovascular risk factors, which may have implications for clinical cardiovascular outcomes.NEW & NOTEWORTHY In this systematic review and meta-analysis of 35 studies involving 7,745 participants, high rates of serum estradiol change were associated with small increases in body mass index. Moderate to high rates of change were associated with decreases in low-density lipoprotein. Low rates of change were associated with small decreases in systolic blood pressure. Rate of serum estradiol change in adults using gender-affirming estrogen therapy may influence cardiovascular risk factors, though further research is warranted.

The Breast Response to Estrogenic Stimulation in Transwomen Classification: Evaluation of Breast Response to Estrogenic Stimulation in Transwomen

BACKGROUND

Hormone therapy with exogenous estrogen and/or spironolactone is commonly used in transfemales to induce breast development. However, inherent differences in adult male and female anatomy create persistent deformities and inadequate gender congruency despite glandular breast development. This includes nipple characteristics, position of inframammary fold, and the distribution of breast tissue. Accordingly, the Tanner stages do not accurately reflect these persistent deformities because they relate to breast development in transwomen. Herein, we describe a classification system for breast development in transwomen treated with hormone therapy.

METHODS

Ninety-nine transfemale patients who underwent breast augmentation from 2014 to 2018 were retrospectively reviewed and categorized using a novel scheme, the Breast Response to Estrogenic Stimulation in Transwomen (BREST) scale. Preoperative demographics, anatomic measurements, surgical technique, and postoperative results were also compared among BREST types.

RESULTS

Most patients were rated as BREST type II (25%) or type IV (37%). The BREST scale exhibited moderate interrater reliability (κ = 0.58) between 3 plastic surgeons. Objective breast measurements such as sternal notch-to-nipple distance and nipple-to-inframammary fold distance correlated with the BREST scale. Multivariate logistical regression identified the nipple-to-inframammary fold distance and different between the bust and chest circumference as the strongest predictors of BREST type (odds ratio, 2.57 and 1.96, respectively). Body mass index was not a predictor of BREST type after controlling for confound variables on multivariate analysis.

CONCLUSIONS

The BREST scale uniquely captures the differences in breast phenotypes in transgender women according to hormone therapy response. Although some subjectivity exists with moderate interrater reliability, the BREST scale correlates with objective breast measurements. The BREST scale provides a transwoman-specific metric allowing for a common language in assessment of transgender breast development and optimal communication among providers, different specialties, and insurance companies.

Sex Steroids and Cardiovascular Outcomes in Transgender Individuals: A Systematic Review and Meta-Analysis

BACKGROUND

Transgender individuals receive cross-sex hormonal therapy to induce desired secondary sexual characteristics despite limited data regarding its effects on cardiovascular health.

METHODS

A comprehensive search of several databases up to 7 April 2015 was conducted for studies evaluating the effect of sex steroid use on lipids, myocardial infarction, stroke, venous thromboembolism (VTE), and mortality in transgender individuals. Pairs of reviewers selected and appraised the studies. A random-effects model was used to pool weighted mean differences and 95% confidence intervals (CIs).

RESULTS

We found 29 eligible studies with moderate risk of bias. In female-to-male (FTM) individuals, sex steroid therapy was associated with statistically significant increases in serum triglyceride (TG) levels at 3 to 6 months and at ≥24 months (21.4 mg/dL; 95% CI: 0.14 to 42.6) and in low-density lipoprotein cholesterol (LDL-C) levels at 12 months and ≥24 months (17.8 mg/dL; 95% CI: 3.5 to 32.1). High-density lipoprotein cholesterol (HDL-C) levels decreased significantly across all follow-up periods (highest at ≥24 months, -8.5 mg/dL; 95% CI: -13.0 to -3.9). In male-to-female (MTF) individuals, serum TG levels were significantly higher at ≥24 months (31.9 mg/dL; 95% CI: 3.9 to 59.9) without any changes in other parameters. Few myocardial infarction, stroke, VTE, and death events were reported (more frequently in MTF individuals).

CONCLUSIONS

Low-quality evidence suggests that sex steroid therapy may increase LDL-C and TG levels and decrease HDL-C level in FTM individuals, whereas oral estrogens may increase TG levels in MTF individuals. Data about important patient outcomes remain sparse.

Bone in trans persons

PURPOSE OF REVIEW

We provide an update of bone health in trans persons on cross-sex hormonal therapy. This drastic hormonal reversal will have direct but also indirect effects on bone, through body composition changes.

RECENT FINDINGS

Recent evidence suggests that trans women, even before the start of any hormonal intervention, already have a lower bone mass, a higher frequency of osteoporosis, and a smaller bone size vs. natal men. During cross-sex hormonal treatment, bone mass was maintained or gained in trans women. In trans men, bone metabolism seemed to increase during short-term testosterone therapy, but no major changes have been found in bone density. On long-term testosterone therapy, larger cortical bone size was observed in trans men vs. natal women.

SUMMARY

Follow-up of bone health and osteoporosis prevention in trans persons is important. We advise active assessment of osteoporosis risk factors including the (previous) use of hormonal therapy. Based on this risk profile and the intended therapy, bone densitometry may be indicated. Long-term use of antiandrogens or gonadotropin-releasing hormone agonists alone should be monitored as trans women may have low bone mass, even prior to treatment. Therapy compliance with the cross-sex hormones is of major concern, especially after gonadectomy. Large-scaled, multicenter, and long-term research is needed to determine a well tolerated dosage of cross-sex hormonal treatment, also in elderly trans persons.

Clinical management of transsexual subjects

Transsexual subjects are individuals who have a desire to live and be accepted as a member of the opposite sex, usually accompanied by a sense of discomfort with, or inappropriateness of, one's anatomic sex, and a wish to have surgery and hormonal treatment to make one's body as congruent as possible with one's preferred sex. They seek to develop the physical characteristics of the desired gender, and should undergo an effective and safe treatment regimen. The goal of treatment is to rehabilitate the individual as a member of society in the gender he or she identifies with. Sex reassignment procedures necessary for the treatment of transsexual patients are allowed in our country, at Medical Services that have a multidisciplinary team composed of a psychologist, a social worker, a psychiatrist, an endocrinologist and surgeons (gynecologists, plastic surgeons, and urologists). Patients must be between 21 to 75 years old and in psychological and hormonal treatment for at least 2 years. Testosterone is the principal agent used to induce male characteristics in female transsexual patients, and the estrogen is the chosen hormone used to induce the female sexual characteristics in male transsexual patients. Based on our 15 years of experience, we can conclude that testosterone and estradiol treatment in physiological doses are effective and safe in female and male transsexual patients, respectively.

Effect of cross-sex hormone treatment on cardiovascular risk factors in transsexual individuals. Experience in a specialized unit in Catalonia

BACKGROUND AND AIMS

Since the onset of cross hormone therapy (CHT) in transsexual individuals, there has been concern about possible chronic side effects. Our objective was to assess baseline differences in lipid profile in individuals with gender identity disorder in relation to prior CHT, and changes in the lipid profile and other cardiovascular (CV) risk factors after 24 months of treatment.

METHODS

Retrospective longitudinal study including all individuals assisted for the first time in the Gender Identity Unit of Catalonia from 2006 to 2010. Socio-demographical, anthropometric and laboratory data were collected.

RESULTS

We evaluated 247 transsexuals, 150 male to female (MtF: 60.7%) and 97 female to male (FtM; 39.3%). At baseline, FtM transsexuals were younger and had started prior CHT less often than MtF (13.4% vs. 64.7%; p<0.001). During follow up, in MtF weight and BMI increased significantly, as well as systolic and diastolic blood pressure, though these latter remained within normal range. No significant differences in lipid profile were observed. FtM transsexuals also presented an increase in weight and BMI, without differences in blood pressure. A general worsening in lipid profile was observed in this group, with increased total cholesterol (166.0 ± 35.1 vs. 175.6 ± 38.2mg/dL; p=0.001), triglycerides (70.6 ± 30.7 vs. 102.3 ± 68.5 mg/dL; p<0.001) and LDL cholesterol (103.8 ± 28.7 vs. 112.8 ± 30.3 mg/dL; p=.013) and decreased HDL cholesterol (52.2 ± 12.2 vs. 45.4 ± 13.8 mg/dL; p=0.001), even though final levels were all within normal range.

CONCLUSION

There is no detectable increase in CV risk factors in MtF transsexuals who were treated with currently prescribed estrogenic compounds, while a slight worsening in lipid profile takes place in the FtM group, though within normal limits.

Familiality of gender identity disorder in non-twin siblings

Familial studies and reports of co-occurrence of gender identity disorder (GID) within a family may help to clarify the question of whether transsexualism is a familial phenomenon. In a sample of 995 consecutive transsexual probands (677 male-to-female [MF] and 318 female-to-male [FM]), we report 12 pairs of transsexual non-twin siblings (nine pairs of MF siblings, two pairs of MF-FM siblings, and one pair of FM siblings). The present study doubles the number of case reports of co-occurrence of transsexualism in non-twin siblings available in the literature. According to our data, the probability that a sibling of a transsexual will also be transsexual was 4.48 times higher for siblings of MF than for siblings of FM transsexual probands, and 3.88 times higher for the brothers than for the sisters of transsexual probands. Moreover, the prevalence of transsexualism in siblings of transsexuals (1/211 siblings) was much higher than the range expected according to the prevalence data of transsexualism in Spain. The study suggests that siblings of transsexuals may have a higher risk of being transsexual than the general population, and that the risk is higher for brothers than sisters of transsexuals, and for siblings of MF than FM transsexuals. Nevertheless, the risk is low.

ESR1 polymorphism is associated with plasma lipid and apolipoprotein levels in Caucasians of the Rochester Family Heart Study

We evaluated six estrogen receptor 1 (ESR1) polymorphisms for association with ten plasma lipid and apolipoprotein traits in 1,847 individuals (941 females and 906 males) in the multi-generation Rochester Family Heart Study using a generalized estimating equation approach. Apolipoprotein A-I (apoA-I), apoA-II, and HDL-cholesterol (HDL-C) were associated with exon 4 rs1801132 (Pro325Pro) genotype (P = 0.0044, P = 0.0048, and P = 0.0035, respectively). Positive correlation between levels of apoA-I, apoA-II, and HDL-C and the number of G alleles was observed in females (P = 0.0120, P = 0.0032, and P = 0.0030), but not males (P > 0.05). Because few studies have evaluated the effect of ESR1 gene polymorphisms on lipid traits in children, we also stratified our sample at the age of 15 years. There was evidence of association between intron 1 single-nucleotide polymorphisms rs9322331 and rs9340799 and apoC-II, and triglycerides (TGs) in youths 15 years and younger. In youths, evidence of association between rs9322331 and rs9340799 and apoC-II was stronger in males (P = 0.0036 and P = 0.0124) than in females (P > 0.05), whereas evidence of association with TG was stronger in females (P = 0.0030 and P = 0.0024) than in males (P > 0.05). These findings suggest that ESR1 variation plays an age- and sex-dependent role in determining plasma lipid and apolipoprotein levels.

Le traitement hormonal des patients transsexuels et ses conséquences métaboliques

Transsexualism is a sexual identity disorder distinguished by the extreme conviction of belonging to the opposite sex with a total disharmony in the original sex. Diagnosis is established when patients respond to three criteria (DSM-IV): 1) Desire to live and to be accepted as members of opposite sex; 2) Presence of sexual identity disorder for minimal two years; 3) Lack of mental disease or chromosomal anomalies. When diagnosis is confirmed, hormonal treatment can be started and so, improve the secondary sexual characters of selected sex. For patients F-M, treatment is composed of testosterone, most commonly esters of testosterone. For patients M-F, treatment consists of estrogens. These estrogens are frequently associated to an anti-androgen (cyproterone acetate) in the pre-reassignment phase. Avoiding the hepatic way, transdermal form is recommended. Hormonal treatments are not devoid of secondary effects: the most frequent one is venous thromboembolism. Considering contraindications and potential complications, each patient must be selected carefully. The endocrinological follow-up is essential and necessary.

Low-dose estrogen treatment suppresses periosteal bone formation in response to mechanical loading

Estrogen and exercise influence cortical bone formation. Both affect bone during growth, but with complex interactions. We hypothesized that estrogen reduces the osteogenic response caused by exercise at the periosteal surface of bone, while it enhances bone formation on the endocortical surface. To test our hypothesis, 16 young (8 weeks old) male Sprague-Dawley rats were randomized into two groups: (1) low-dose 17-alpha ethynylestradiol treatment+bone loading (EE2) or (2) vehicle-treated+bone loading (vehicle). We applied controlled loading to the right ulna at a peak force of 17 N, 2 min/day, 3 days/week for 5 weeks to simulate exercise. The left nonloaded ulna served as an internal control for loading. Mechanical loading increased cortical area (7.7%) and bone mineral content (8%) in the vehicle-treated group (P < 0.05) but only slightly increased cortical area in the EE2 group (P = 0.08). Histomorphometry showed 1 week of mechanical loading increased periosteal bone formation rate by 29% in the vehicle group and this response was reduced (P < 0.05) to only 15% in the EE2 group. At the endocortical surface, there were no differences in the loading response between the vehicle and EE2-treated groups. We conclude low-dose EE2 suppresses the mechanical loading response on the periosteal surface of long bones, but had no effect on the loading response at the endocortical bone surface in growing male rats.