On the quest for a biomechanism of transsexualism: is there a role for BDNF?

The role of the pediatrician in the management of the child and adolescent with gender dysphoria

Gender dysphoria is a clinical condition characterized by significant distress due to the discordance between biological sex and gender identity. Currently, gender dysphoria is also found more frequently in children and adolescents, thanks to greater social sensibleness and new therapeutic possibilities. In fact, it is estimated that the prevalence of gender dysphoria in pediatric age is between 0.5% and 2% based on the statistics of the various countries. Therefore, the pediatrician cannot fail to update himself on these issues and above all should be the reference figure in the management of these patients. Even if the patient must be directed to a referral center and be followed up by a multidisciplinary team, the treating pediatrician will care to coordinate the clinical and therapeutic framework. The aim of the present report is therefore to integrate literature data with our clinical experience to propose a new clinical approach in which the pediatrician should be the reference in the care of these patients, directing them towards the best therapeutic approach and staying in contact with the specialists of the referral center.

Theories on the Link Between Autism Spectrum Conditions and Trans Gender Modality: a Systematic Review

While research on the prevalence of co-occurring autism spectrum conditions (ASC) and trans gender modality (TGM) is available, less is known about the underlying mechanism of this association. Insight is needed to improve treatment of trans autistic people. This review provides an overview of theories on the ASC-TGM link and the available evidence for/against them published between January 2016 and October 2020. A systematic search was performed in PubMed, PsycINFO, Web of Science, and Scopus. This resulted in 36 studies, in which 15 theories were identified. Results indicate all theories lack substantial empirical support. Unlikely and promising theories were identified. The most promising theories were those on resistance to social norms and weakened sex differences. Future directions are provided.

Gender dysphoria: prejudice from childhood to adulthood, but no impact on inflammation. A cross-sectional controlled study

INTRODUCTION

Gender dysphoria (GD) is characterized by a marked incongruence between experienced gender and one's gender assigned at birth. Transsexual individuals present a higher prevalence of psychiatric disorders when compared to non-transsexual populations, and it has been proposed that minority stress, i.e., discrimination or prejudice, has a relevant impact on these outcomes. Transsexuals also show increased chances of having experienced maltreatment during childhood. Interleukin (IL)-1β, IL-6, IL-10 and tumor necrosis factor-alpha (TNF-α) are inflammatory cytokines that regulate our immune system. Imbalanced levels in such cytokines are linked to history of childhood maltreatment and psychiatric disorders. We compared differences in IL-1β, IL-6, IL-10 and TNF-α levels and exposure to traumatic events in childhood and adulthood in individuals with and without GD (DSM-5).

METHODS

Cross-sectional controlled study comparing 34 transsexual women and 31 non-transsexual men. They underwent a thorough structured interview, assessing sociodemographic information, mood and anxiety symptoms, childhood maltreatment, explicit discrimination and suicidal ideation. Inflammatory cytokine levels (IL-1β, IL-6, IL-10 and TNF-α) were measured by multiplex immunoassay.

RESULTS

Individuals with GD experienced more discrimination (p = 0.002) and childhood maltreatment (p = 0.046) than non-transsexual men. Higher suicidal ideation (p < 0.001) and previous suicide attempt (p = 0.001) rates were observed in transsexual women. However, no differences were observed in the levels of any cytokine.

CONCLUSIONS

These results suggest that transsexual women are more exposed to stressful events from childhood to adulthood than non-transsexual men and that GD per se does not play a role in inflammatory markers.

Effects of Sex Hormone Treatment on the Metabolic Syndrome in Transgender Individuals: Focus on Metabolic Cytokines

CONTEXT

Hormonal treatment in transgender persons affects many components of the metabolic syndrome (MS).

OBJECTIVE

To determine the role of direct hormonal effects, changes in metabolic cytokines, and body composition on metabolic outcomes.

DESIGN, SETTING, AND PARTICIPANTS

24 transwomen and 45 transmen from the European Network for the Investigation of Gender Incongruence were investigated at baseline and after 12 months of hormonal therapy.

OUTCOME MEASURES

Best predictors for changes in components of MS, applying least absolute shrinkage and selection operator regression.

RESULTS

In transwomen, a decrease in triglyceride levels was best explained by a decrease in fat mass and an increase in fibroblast growth factor 21 (FGF-21); the decrease in total and low-density lipoprotein cholesterol levels was principally due to a decrease in resistin. A decrease in high-density lipoprotein cholesterol depended on an inverse association with fat mass. In contrast, in transmen, an increase in low-density lipoprotein cholesterol was predicted by a decrease in FGF-21 and an increase in the waist/hip ratio; a decrease in the high-density lipoprotein/total cholesterol ratio depended on a decline in adiponectin levels. In transwomen, worsened insulin resistance and increased early insulin response seemed to be due to a direct treatment effect; however, improvements in hepatic insulin sensitivity in transmen were best predicted by a positive association with chemerin, resistin, and FGF-21 and were inversely related to changes in the waist/hip ratio and leptin and adipocyte fatty acid-binding protein levels.

CONCLUSIONS

The effects of hormonal therapy on different components of the MS are sex-specific and involve a complex interplay of direct hormonal effects, changes in body composition, and metabolic cytokine secretion.

High impact of sleeping problems on quality of life in transgender individuals: A cross-sectional multicenter study

INTRODUCTION

Studies in the general population suggest that determinants of QoL are often sex-dependent. Sex-dependent analyses of QoL in transgender populations have not been performed so far.

AIM

To identify sex-specific and potentially modifiable determinants of QoL in transgender patients.

METHODS

In this cross-sectional multicentre study including 82 transwomen (TW) and 72 transmen (TM) at different treatment stages, we investigated potential determinants for QoL focusing on the impact of mood (BDI, STAI-X), sleep quality (PSQI), chronic pain (GPQ), body image (FBeK) and social support (SSS).

MAIN OUTCOME MEASURE

Health-related quality of life measured with the Short Form (36) Health Survey (SF-36).

RESULTS

The age-adjusted SF-36 total score and its subscales did not significantly differ between TM and TW. Using a multivariate regression analysis approach, we identified common but also sex-dependent determinants for QoL (Adjusted R2 = 0.228; 0.650 respectively). Accounting for general characteristics such as age, BMI and treatment status, sleep quality according to the PSQI was an independent and strong determinant of QoL in both sexes (β = -0.451, p = 0.003 TM; β = -0.320; p = 0.0029 TW). Chronic pain was a significant independent predictor of QoL in TM (β = -0.298; p = 0.042) but not in TW. In contrast, anxiety (β = -0.451; p< 0.001) being unemployed (β = -0.206; p = 0.020) and insecurity about the own appearance (FBeK) (β = -0.261; p = 0.01) were independent predictors of QoL in TW. The rate of those reporting high sleep disturbances (PSQI ≥5) was high with 79.2% in TW and 81.2% in TM. Accordingly, age-adjusted QoL was also significantly lower in those reporting poor sleep in both sexes.

CONCLUSIONS

Sleep strongly affected QoL in both genders, while other factors, like pain and body image, seem to be gender specific in transgender individuals.

12-months metabolic changes among gender dysphoric individuals under cross-sex hormone treatment: a targeted metabolomics study

Metabolomic analyses in epidemiological studies have demonstrated a strong sexual dimorphism for most metabolites. Cross-sex hormone treatment (CSH) in transgender individuals enables the study of metabolites in a cross-gender setting. Targeted metabolomic profiling of serum of fasting transmen and transwomen at baseline and following 12 months of CSH (N = 20/group) was performed. Changes in 186 serum metabolites and metabolite ratios were determined by targeted metabolomics analysis based on ESI-LC-MS/MS. RandomForest (RF) analysis was applied to detect metabolites of highest interest for grouping of transwomen and transmen before and after initiation of CSH. Principal component analysis (PCA) was performed to check whether group differentiation was achievable according to these variables and to see if changes in metabolite levels could be explained by a priori gender differences. PCA predicted grouping of individuals-determined by the citrulline/arginine-ratio and the amino acids lysine, alanine and asymmetric dimethylarginine - in addition to the expected grouping due to changes in sex steroids and body composition. The fact that most of the investigated metabolites did, however, not change, indicates that the majority of sex dependent differences in metabolites reported in the literature before may primarily not be attributable to sex hormones but to other gender-differences.

Ophthalmic Disparities in Transgender Patients

Transgender individuals experience unique challenges with regards to discrimination and access to health care. Further, their unique health-care needs and challenges lead to greater rates of morbidity. This article seeks to review the unique biology of transgender patients and the effects of cross-sex hormone therapy on ophthalmic and non-ophthalmic pathology. Attention is given to topics in neuro-ophthalmology, oculoplastics, and retinal disease.

Serum brain-derived neurotrophic factor (BDNF) is not regulated by testosterone in transmen

Brain morphology significantly differs between the sexes. It has been shown before that some of these differences are attributable to the sex-specific hormonal milieu. Brain-derived neurotrophic factor (BDNF) is involved in myriads of neuroplastic processes and shows a sexual dimorphism. Transsexual persons may serve as a model to study sex steroid-mediated effects on brain plasticity. We have recently demonstrated that serum levels of BDNF are reduced in transwomen following 12 months of cross-sex hormone treatment. We now wanted to look at the effects of testosterone treatment on BDNF in transmen. In contrast to our initial hypothesis, BDNF levels did not significantly change, despite dramatic changes in the sex-hormonal milieu. Our data indicate that testosterone does not seem to play a major role in the regulation of BDNF in females.

Cross-sex hormone treatment in male-to-female transsexual persons reduces serum brain-derived neurotrophic factor (BDNF)

Serum levels of brain-derived neurotrophic factor (BDNF) are reduced in male-to-female transsexual persons (MtF) compared to male controls. It was hypothesized before that this might reflect either an involvement of BDNF in a biomechanism of transsexualism or to be the result of persistent social stress due to the condition. Here, we demonstrate that 12 month of cross-sex hormone treatment reduces serum BDNF levels in male-to-female transsexual persons independent of anthropometric measures. Participants were acquired through the European Network for the Investigation of Gender Incongruence (ENIGI). Reduced serum BDNF in MtF thus seems to be a result of hormonal treatment rather than a consequence or risk factor of transsexualism.

Transgender transitioning and change of self-reported sexual orientation

OBJECTIVE

Sexual orientation is usually considered to be determined in early life and stable in the course of adulthood. In contrast, some transgender individuals report a change in sexual orientation. A common reason for this phenomenon is not known.

METHODS

We included 115 transsexual persons (70 male-to-female "MtF" and 45 female-to-male "FtM") patients from our endocrine outpatient clinic, who completed a questionnaire, retrospectively evaluating the history of their gender transition phase. The questionnaire focused on sexual orientation and recalled time points of changes in sexual orientation in the context of transition. Participants were further asked to provide a personal concept for a potential change in sexual orientation.

RESULTS

In total, 32.9% (n = 23) MtF reported a change in sexual orientation in contrast to 22.2% (n = 10) FtM transsexual persons (p = 0.132). Out of these patients, 39.1% (MtF) and 60% (FtM) reported a change in sexual orientation before having undergone any sex reassignment surgery. FtM that had initially been sexually oriented towards males ( = androphilic), were significantly more likely to report on a change in sexual orientation than gynephilic, analloerotic or bisexual FtM (p = 0.012). Similarly, gynephilic MtF reported a change in sexual orientation more frequently than androphilic, analloerotic or bisexual MtF transsexual persons (p =0.05).

CONCLUSION

In line with earlier reports, we reveal that a change in self-reported sexual orientation is frequent and does not solely occur in the context of particular transition events. Transsexual persons that are attracted by individuals of the opposite biological sex are more likely to change sexual orientation. Qualitative reports suggest that the individual's biography, autogynephilic and autoandrophilic sexual arousal, confusion before and after transitioning, social and self-acceptance, as well as concept of sexual orientation itself may explain this phenomenon.

Gender identity disorder and schizophrenia: neurodevelopmental disorders with common causal mechanisms?

Gender identity disorder (GID), recently renamed gender dysphoria (GD), is a rare condition characterized by an incongruity between gender identity and biological sex. Clinical evidence suggests that schizophrenia occurs in patients with GID at rates higher than in the general population and that patients with GID may have schizophrenia-like personality traits. Conversely, patients with schizophrenia may experience alterations in gender identity and gender role perception. Neurobiological research, including brain imaging and studies of finger length ratio and handedness, suggests that both these disorders are associated with altered cerebral sexual dimorphism and changes in cerebral lateralization. Various mechanisms, such as Toxoplasma infection, reduced levels of brain-derived neurotrophic factor (BDNF), early childhood adversity, and links with autism spectrum disorders, may account for some of this overlap. The implications of this association for further research are discussed.

Psychopathological profiles in transsexuals and the challenge of their special status among the sexes

OBJECTIVE

Investigating psychopathological profiles of transsexuals raises a very basic methodological question: are control groups, which represent the biological or the phenotypic sex, most suited for an optimal evaluation of psychopathology of transsexuals?

METHOD

Male-to-female (MtF) (n=52) and female-to-male transsexuals (FtM) (n=32), receiving cross-sex hormone treatment, were compared with age matched healthy subjects of the same genetic sex (n=178) and with the same phenotypic sex (n=178) by means of the Symptom Check List-90-Revisited instrument (SCL-90-R). We performed analyses of covariance (ANCOVA) to test for group and sex effects. Furthermore, we used a profile analysis to determine if psychopathological symptom profiles of transsexuals more closely resemble genotypic sex or phenotypic sex controls.

RESULTS

Transsexual patients reported more symptoms of psychopathological distress than did healthy control subjects in all subscales of the SCL-90-R (all p<0.001), regardless of whether they were compared with phenotype or genotype matched controls. Depressive symptoms were more pronounced in MtF than in FtM (SCL-90-R score 0.85 vs. 0.45, p = 0.001). We could demonstrate that FtM primarily reflect the psychopathological profile of biological males rather than that of biological females (r = 0.945), while MtF showed a slightly higher profile similarity with biological females than with biological males (r = 0.698 vs. r = 0.685).

CONCLUSION

Our findings suggest that phenotypic sex matched controls are potentially more appropriate for comparison with the psychopathology of transsexual patients than are genetic sex matched controls.