Testosterone administration increases leukocyte-endothelium interactions and inflammation in transgender men

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.

Transgender healthcare: metabolic outcomes and cardiovascular risk

Transgender identity is often associated with gender dysphoria and minority stress. Gender-affirming hormone treatment (GAHT) includes masculinising or feminising treatment and is expected to be lifelong in most cases. Sex and sex hormones have a differential effect on metabolism and CVD in cisgender people, and sex hormone replacement in hypogonadism is associated with higher vascular risk, especially in ageing individuals. Using narrative review methods, we present evidence regarding metabolic and cardiovascular outcomes during GAHT and propose recommendations for follow-up and monitoring of metabolic and cardiovascular risk markers during GAHT. Available data show no increased risk for type 2 diabetes in transgender cohorts, but masculinising GAHT increases lean body mass and feminising GAHT is associated with higher fat mass and insulin resistance. The risk of CVD is increased in transgender cohorts, especially during feminising GAHT. Masculinising GAHT is associated with a more adverse lipid profile, higher haematocrit and increased BP, while feminising GAHT is associated with pro-coagulant changes and lower HDL-cholesterol. Assigned male sex at birth, higher age at initiation of GAHT and use of cyproterone acetate are separate risk factors for adverse CVD markers. Metabolic and CVD outcomes may improve during gender-affirming care due to a reduction in minority stress, improved lifestyle and closer surveillance leading to optimised preventive medication (e.g. statins). GAHT should be individualised according to individual risk factors (i.e. drug, dose and form of administration); furthermore, doctors need to discuss lifestyle and preventive medications in order to modify metabolic and CVD risk during GAHT. Follow-up programmes must address the usual cardiovascular risk markers but should consider that biological age and sex may influence individual risk profiling including mental health, lifestyle and novel cardiovascular risk markers during GAHT.

Metabolic and cardiovascular risks of hormone treatment for transgender individuals

Identifying metabolic and cardiovascular risks of gender-affirming hormone therapy (GAHT) is challenging due to other confounding variables that affect patient outcomes and the diversity of treatment regimes. Masculinising hormone therapy produces atherogenic lipid profiles, while effects on other metabolic parameters are not consistent. There is insufficient evidence to conclude if cardiovascular disease risk among transmen is increased. The effects of feminising hormone therapy on metabolic parameters do not demonstrate a consistent pattern in the available literature. However, the risk of venous thromboembolism is greater in transwomen than in cis-gender men and women with a possible increase in cardiovascular disease risk. It is recommended to discuss the potential effects of GAHT on cardiovascular health and encourage patients seeking GAHT to adopt a healthy lifestyle. Performing baseline and periodic assessments of cardiovascular risk factors would enable early identification and interventions. In high-risk individuals, the cardiovascular effects of hormonal regimes might impact the treatment decision.

Changes in Blood Lipids Following Initiation of Gender Affirming Hormone Therapy: A Systematic Review and Meta-Analysis

Aim

The aim of this study was to conduct a systematic review and meta-analysis of changes in low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), total cholesterol, and triglycerides following initiation of feminizing or masculinizing gender affirming hormone therapy (GAHT).

Methods

A search of Ovid MEDLINE, Embase, Web of Science, SCOPUS, and CINAHL databases identified potentially relevant articles published from 1990 through 2024. Both observational and randomized trials of adults receiving feminizing or masculinizing GAHT with baseline and follow-up measures were included. Articles were reviewed for eligibility using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 guidelines. The risk of bias in each study was quantified using the NHLBI Study Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group. Random effects models were used to compute the before-and-after meta-differences in mean values for each parameter along with the I2 statistic to assess heterogeneity of results.

Results

Thirty-five studies met the criteria for inclusion in the meta-analysis. Masculinizing GAHT was associated with significant changes in serum lipids from baseline up through the 60-month timepoint with meta-difference of means (95% CI) estimates of 26.2mg/dL (23.3,29.0) for LDL-C, 26.1mg/dL (22.8,29.4) for total cholesterol, 30.7mg/dL (6.9,54.6) for triglycerides and -9.4mg/dL (-12.1, -6.7) for HDL-C. Studies evaluating the effects of feminizing GAHT on balance demonstrated no notable changes in HDL-C or triglycerides while the results for LDL-C and total cholesterol were inconsistent. Heterogeneity of results ranged from minimal (I2 = 0%) to substantial (I2 = 90%).

Conclusions

While the results for transfeminine individuals on GAHT appear somewhat reassuring, transmasculine patients receiving testosterone may benefit from closer monitoring of lipid profiles.

Gender-affirming hormone therapy and cardiovascular health in transgender adults

A growing number of people identify as transgender and gender non-binary in the USA and worldwide. Concomitantly, an increasing number of patients are receiving gender-affirming hormone therapy (GAHT) to achieve gender congruence. GAHT has far-ranging effects on clinical and subclinical markers of cardiovascular risk. Transgender patients also appear to be at higher risk for cardiovascular diseases compared to their cisgender peers and the impact of gender-affirming therapy on cardiovascular health is unclear. Studies on the effect of GAHT on cardiovascular outcomes are confounded by differences in GAHT regimens and methodological challenges in a diverse and historically hard-to-reach population. Current cardiovascular guidelines do not incorporate gender identity and hormone status into risk stratification and clinical decision-making. In this review, we provide an overview on the cardiometabolic impact and clinical considerations of GAHT for cardiovascular risk in transgender patients.

Androgen exposure impairs neutrophil maturation and function within the infected kidney

Urinary tract infections (UTIs) in men are uncommon yet carry an increased risk for severe pyelonephritis and other complications. In models of Escherichia coli UTI, C3H/HeN mice develop high-titer pyelonephritis (most with renal abscesses) in a testosterone-dependent manner, but the mechanisms underlying this phenotype are unknown. Here, using female mouse models, we show that androgen exposure impairs neutrophil maturation in the upper and lower urinary tract, compounded by a reduction of neutrophil function within the infected kidney, enabling persistent high-titer infection and promoting abscess formation. Following intravesical inoculation with uropathogenic E. coli (UPEC), kidneys of androgen-exposed C3H mice showed delayed local pro-inflammatory cytokine responses while robustly recruiting neutrophils. These were enriched for an end-organ-specific population of aged but immature neutrophils (CD49d+, CD101-). Compared to their mature counterparts, these aged immature kidney neutrophils exhibited reduced function in vitro, including impaired degranulation and diminished phagocytic activity, while splenic, bone marrow, and bladder neutrophils did not display these alterations. Furthermore, aged immature neutrophils manifested little phagocytic activity within intratubular UPEC communities in vivo. Experiments with B6 conditional androgen receptor (AR)-deficient mice indicated rescue of the maturation defect when AR was deleted in myeloid cells. We conclude that the recognized enhancement of UTI severity by androgens is attributable, at least in part, to local impairment of neutrophil maturation in the urinary tract (largely via cell-intrinsic AR signaling) and a kidney-specific reduction in neutrophil antimicrobial capacity.IMPORTANCEAlthough urinary tract infections (UTIs) predominantly occur in women, male UTIs carry an increased risk of morbidity and mortality. Pyelonephritis in androgen-exposed mice features robust neutrophil recruitment and abscess formation, while bacterial load remains consistently high. Here, we demonstrate that during UTI, neutrophils infiltrating the urinary tract of androgen-exposed mice exhibit reduced maturation, and those that have infiltrated the kidney have reduced phagocytic and degranulation functions, limiting their ability to effectively control infection. This work helps to elucidate mechanisms by which androgens enhance UTI susceptibility and severity, illuminating why male patients may be predisposed to severe outcomes of pyelonephritis.

Transformation or replacement - Effects of hormone therapy on cardiovascular risk

Hormone therapy (HT) is important and frequently used both regarding replacement therapy (HRT) and gender affirming therapy (GAHT). While HRT has been effective in addressing symptoms related to hormone shortage, several side effects have been described. In this context, there are some studies that show increased cardiovascular risk. However, there are also studies reporting protective aspects of HT. Nevertheless, the exact impact of HT on cardiovascular risk and the underlying mechanisms remain poorly understood. This article explores the relationship between diverse types of HT and cardiovascular risk, focusing on mechanistic insights of the underlying hormones on platelet and leukocyte function as well as on effects on endothelial and adipose tissue cells.

Sex differences in vascular endothelial cells

Endothelial cells are important constituents of blood vessels and play a critical role in vascular homeostasis. They do not only control the exchanges between the blood and the surrounding tissues, but are also essential in regulating blood flow, modulating immune-cell trafficking and controlling vascular growth and repair. Endothelial dysfunction leads to cardiovascular diseases and is characterized by deficiency in secretion of vasodilator molecules, elevated reactive oxygen species (ROS), expression of adhesion molecules and excretion of proinflammatory cytokines. The sex hormones, estrogens, androgens and progestogens, regulate endothelial functions. Because cardiovascular disease risk increases after menopause, it is believed that female hormones, estrogens and progestogens promote endothelial cell health and function whereas androgens, the male hormones, might be detrimental. However, as illustrated in the present review, the picture might not be that simple. In addition, sex influences endothelial cell physiology independently of sex hormones but at genetic level.

Testosterone administration affects 1H-MRS metabolite spectra in transgender men

BACKGROUND

Recently, a variety of studies using different neuroimaging techniques attempted to identify the existence of a brain endophenotype in people with gender dysphoria (GD). However, despite mounting neuroimaging work, brain gender differences and effects of gender-affirming hormone therapy (GAHT) at the metabolite level remain understudied.

METHODS

Thirty-one transgender men (TM) before and after testosterone administration (7.7 months ± 3.5 months), relative to 30 cisgender men (CM) and 35 cisgender women (CW) underwent magnetic resonance spectroscopy (1H-MRS) at two time points. Two brain regions were assessed, i.e. the lateral parietal cortex and the amygdala/anterior hippocampus. Associated metabolites that were measured include N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), glutamate and glutamine (Glx), myo-inositol (mI), glycine (Gly) and their respective ratios.

RESULTS

A critical time by group interaction revealed an effect of GAHT in the lateral parietal cortex of TM. MI+Gly/Cr ratios decreased upon initiation of GAHT. In addition, NAA/Cr and Cho/Cr ratios were lower in CW when compared to CM in the lateral parietal cortex. Glx levels and Glx/Cr ratios in TM differed from those in CW in the amygdala/anterior hippocampus. Interestingly, pubertal age of onset of gender dysphoria (i.e. GD) in TM differentially affected testosterone-mediated effects on Cr concentration and NAA/Cr ratios when compared to childhood and adult GD onset in the amygdala/anterior hippocampus.

CONCLUSION

This 1H-MRS study demonstrated that testosterone administration shifts mI+Gly/Cr ratios in the parietal cortex. In the amygdala/anterior hippocampus, modulation of metabolite concentrations by age of onset of GD is suggestive for a possible developmental trend.

Lipid profile and risk of cardiovascular disease in adult transgender men receiving cross-sex hormone therapy: a systematic review

CONTEXT

A recent US national survey of the health status of the male transgender population has raised awareness about the little-studied relationship between testosterone hormone therapy in transgender men and cardiovascular outcomes.

OBJECTIVE

The aim of this systematic review was to assess the relationship between cross-sex hormone therapy in transgender men and lipid profiles and cardiovascular risk.

DATA SOURCES

The PubMed, SciELO, SpringerLink, and EBSCOhost databases were searched up to March 2021 for studies assessing the association between cross-sex hormone therapy and the incidence of outcomes related to cardiovascular disease in transgender men over 18 years of age .

DATA EXTRACTION

Data extracted were sorted into clinical data (systolic, diastolic, and mean blood pressure), anthropometric data (body mass index, weight, waist circumference, fat mass, and lean mass), and biochemical data (triglycerides, total cholesterol, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], very low-density lipoprotein cholesterol [VLDL-C], and the HDL-C to LDL-C ratio).

DATA ANALYSIS

Study quality was appraised independently by two reviewers using the Cochrane tools for assessment of methodological quality or risk of bias in nonrandomized studies, and the Newcastle-Ottawa Scale was applied. Of 735 studies identified, 11 were included in the review. Most studies reported no change in cholesterol or triglyceride levels after hormone treatment. A reduction in HDL-C levels was observed in 7 of 11 studies, although this alone cannot be considered a cardiovascular risk factor. Likewise, clinical and anthropometric findings showed no changes predictive of cardiovascular risk.

CONCLUSIONS

Although these findings suggest that hormone therapy may lead to a decrease in HDL-C levels and an increase in LDL-C levels, they are insufficient to establish a relationship with cardiovascular disease. Furthermore, no significant effects on metabolic and anthropometric values were found. Further studies with higher quality and longer follow-up periods are needed to establish cardiovascular risk.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD 42020212560.

Testosterone replacement therapy and cardiovascular disease

The use of testosterone therapy has a complex history of apprehension and questions regarding its safety. Despite an eventual consensus that testosterone therapy was safe and effective, several studies relating to cardiovascular risks emerged in the last decade, rekindling skepticism regarding the safety of testosterone therapy. Given the utility of testosterone therapy in treating the symptoms of hypogonadism, it remains crucial to closely examine the safety of testosterone therapy. The present article synthesizes the current evidence regarding cardiovascular risks that may be associated with testosterone therapy, the potential mechanisms regarding testosterone's efficacy, and future directions in evaluating the safety of its use.

The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic-hypophysis-gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

Early Fetal Growth Restriction of Both Twins in a Transgender Man

Gender dysphoria affects 0.5% of people worldwide. Transgender men display a divergence between the female genetic sex and the gender male identity. To the best of our knowledge, we describe the first case report with regard to a transgender man with a dichorionic diamniotic twin pregnancy obtained by artificial insemination using donor sperm as a monoparental family, presenting early fetal growth restriction of both twins. The patient is a 35-year-old transgender man who had previously received gender-affirming hormone therapy based on testosterone for five years and had a prior bilateral mastectomy as gender-affirming surgery. Whether assisted reproductive techniques have any influence on obstetrical outcomes among these patients and whether prior long-term intake of gender-affirming hormone therapy has an impact on pregnancy and obstetrical outcomes remain to be elucidated.

Th17 cells-linked mechanisms mediate vascular dysfunction induced by testosterone in a mouse model of gender-affirming hormone therapy

Clinical data point to adverse cardiovascular events elicited by testosterone replacement therapy. Testosterone is the main hormone used in gender-affirming hormone therapy (GAHT) by transmasculine people. However, the cardiovascular impact of testosterone in experimental models of GAHT remains unknown. Sex hormones modulate T cells activation, and immune mechanisms contribute to cardiovascular risk. The present study evaluated whether testosterone negatively impacts female cardiovascular function by enhancing Th17 cells-linked effector mechanisms. Female (8 weeks-old) C57BL/6J mice received testosterone (48 mg.Kg^-1.week^-1) for 8 weeks. Male mice were used for phenotypical comparisons. The hormone-treatment in female mice increased circulating testosterone to levels observed in male mice. Testosterone increased lean body mass and body mass index, and decreased perigonadal fat mass, mimicking clinical findings. After 8 weeks, testosterone decreased endothelium-dependent vasodilation and increased circulating Th17 cells. After 24 weeks, testosterone increased blood pressure in female mice. Ovariectomy did not intensify phenotypical or cardiovascular effects by testosterone. Female mice lacking T and B cells [Rag1 knockout (^-/-)], as well as female mice lacking IL-17 receptor (IL-17Ra^-/-), did not exhibit vascular dysfunction induced by testosterone. Testosterone impaired endothelium-dependent vasodilation in female mice lacking γδ T cells, similarly to the observed in wild type female mice. Adoptive transfer of CD4⁺ T cells restored testosterone-induced vascular dysfunction in Rag1^-/- female mice. Together, these data suggest that CD4⁺ T cells, most likely Th17 cells, are central to vascular dysfunction induced by testosterone in female mice, indicating that changes in immune cells balance are important in the GAHT in transmasculine people.

The relationship between 2D:4D ratio and postpartum adult female variables in a Ghanaian population

OBJECTIVES

Postpartum hematological and anthropometric assessment is a requirement for optimal maternal and child health. The study aimed to determine the relationship between the 2D:4D ratio and postpartum hematological and anthropometric variables in adult females.

METHODS

The study was cross-sectional from December 2020 to April 2021 involving 272 postpartum adult females, aged between 18 and 36 years. The right (2D:4DR) and the left (2D:4DL) digit ratios were measured using computer-assisted analysis. Fasting venous samples were collected at a median (interquartile range) of 111 (44-210) days postpartum and analyzed for total testosterone (TT), estradiol, sex hormone-binding globulin, and complete blood count.

RESULTS

The mean ± standard deviation 2D:4DR and 2D:4DL were 0.94 ± 0.04 and 0.93 ± 0.04, respectively. As expected, the TT (r = -0.198, p = .015) and the free androgen index (FAI: r = -0.186, p = .019) were inversely correlated with the 2D:4DL while free testosterone (FT%: r = -0.157, p = .038) was inversely correlated with the 2D:4DR. The absolute basophile count (BASO: r = -0.124, p = .040) and the Platelet-lymphocyte ratio (PLR: r = -0.153, p = .016) were inversely correlated with the 2D:4DL and the 2D:4DR respectively. In addition, the mean cell volume was inversely correlated with the 2D:4DR (r = -0.139, p = .024) and the 2D:4DL (r = -0.122, p = .045). Moreover, the 2D:4DR was inversely correlated with height (r = -0.164, p = .007). Unexpectedly, the red blood cell count (RBC: r = 0.138, p = .025) was positively correlated with the 2D:4DR.

CONCLUSION

There are significant relationships between the 2D:4D ratio and postpartum female variables. These findings are useful preliminary reference data for postpartum research and subsequent 2D:4D ratio studies.