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Novice Karate Group (ages 8 & up)

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Men generally have an inherent performance advantage over women due to their average greater height and muscle mass and power, as the result of correspondingly different exposures to androgens. Therefore, it is considered fair that in sports men and women compete in separate categories. The question now emerging is whether reassigned transsexuals can compete in fairness with others of their new sex. The pertinent question is how far the previous effects of testosterone in male-to-female transsexuals (M-F) are reversible upon androgen deprivation so that M-F have no advantage over women, and, vice versa, what the effects are of androgen exposure in female-to-male transsexuals (F-M) on variables relevant to competition in sports. Before puberty, boys and girls do not differ in height, muscle and bone mass. Recent information shows convincingly that actual levels of circulating testosterone determine largely muscle mass and strength, though with considerable interindividual diversity. This study analyzed the effects of androgen deprivation in 19 M-F and of androgen administration to 17 F-M on muscle mass, hemoglobin (Hb) and insulin-like growth factor-1 (IGF-1). Before cross-sex hormone administration, there was a considerable overlap in muscle mass between M-F and F-M. In both M-F and F-M, height was a strong predictor of muscle mass. Androgen deprivation of M-F decreased muscle mass, increasing the overlap with untreated F-M, but mean muscle mass remained significantly higher in M-F than in F-M. Androgen administration to F-M increased muscle mass without inducing an advantage over nontreated M-F. The conclusion is that androgen deprivation in M-F increases the overlap in muscle mass with women but does not reverse it, statistically. The question of whether reassigned M-F can fairly compete with women depends on what degree of arbitrariness one wishes to accept, keeping in mind, for instance, that similar blood testosterone levels in men have profoundly different biologic effects on muscle properties, rendering competition in sports intrinsically a matter of how nature endows individuals for this competition.


Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increased attention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white matter microstructure in unprecedented detail. Here, we aimed to study the potential influences of biological sex, gender identity, sex hormones, and sexual orientation on white matter microstructure by investigating transsexuals and healthy controls using diffusion tensor imaging (DTI). Twenty-three female-to-male (FtM) and 21 male-to-female (MtF) transsexuals, as well as 23 female (FC) and 22 male (MC) controls underwent DTI at 3 tesla. Fractional anisotropy, axial, radial, and mean diffusivity were calculated using tract-based spatial statistics (TBSS) and fiber tractography. Results showed widespread significant differences in mean diffusivity between groups in almost all white matter tracts. FCs had highest mean diffusivities, followed by FtM transsexuals with lower values, MtF transsexuals with further reduced values, and MCs with lowest values. Investigating axial and radial diffusivities showed that a transition in axial diffusivity accounted for mean diffusivity results. No significant differences in fractional anisotropy maps were found between groups. Plasma testosterone levels were strongly correlated with mean, axial, and radial diffusivities. However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects' sexual orientation did not change group differences. Our data harmonize with the hypothesis that fiber tract development is influenced by the hormonal environment during late prenatal and early postnatal brain development.

Sex differences in cortical thickness (CTh) have been extensively investigated but as yet there are no reports on CTh in transsexuals. Our aim was to determine whether the CTh pattern in transsexuals before hormonal treatment follows their biological sex or their gender identity. We performed brain magnetic resonance imaging on 94 subjects: 24 untreated female-to-male transsexuals (FtMs), 18 untreated male-to-female transsexuals (MtFs), and 29 male and 23 female controls in a 3-T TIM-TRIO Siemens scanner. T1-weighted images were analyzed to obtain CTh and volumetric subcortical measurements with FreeSurfer software. CTh maps showed control females have thicker cortex than control males in the frontal and parietal regions. In contrast, males have greater right putamen volume. FtMs had a similar CTh to control females and greater CTh than males in the parietal and temporal cortices. FtMs had larger right putamen than females but did not differ from males. MtFs did not differ in CTh from female controls but had greater CTh than control males in the orbitofrontal, insular, and medial occipital regions. In conclusion, FtMs showed evidence of subcortical gray matter masculinization, while MtFs showed evidence of CTh feminization. In both types of transsexuals, the differences with respect to their biological sex are located in the right hemisphere.

Inpatient care for psychiatric disorders was significantly more common among sex-reassigned persons than among matched controls, both before and after sex reassignment. It is generally accepted that transsexuals have more psychiatric ill-health than the general population prior to the sex reassignment.[18], [21], [22], [33] It should therefore come as no surprise that studies have found high rates of depression,[9] and low quality of life[16], [25] also after sex reassignment. Notably, however, in this study the increased risk for psychiatric hospitalisation persisted even after adjusting for psychiatric hospitalisation prior to sex reassignment. This suggests that even though sex reassignment alleviates gender dysphoria, there is a need to identify and treat co-occurring psychiatric morbidity in transsexual persons not only before but also after sex reassignment.

For the purpose of evaluating the safety of sex reassignment in terms of morbidity and mortality, however, it is reasonable to compare sex reassigned persons with matched population controls. The caveat with this design is that transsexual persons before sex reassignment might differ from healthy controls (although this bias can be statistically corrected for by adjusting for baseline differences). It is therefore important to note that the current study is only informative with respect to transsexuals persons health after sex reassignment; no inferences can be drawn as to the effectiveness of sex reassignment as a treatment for transsexualism. In other words, the results should not be interpreted such as sex reassignment per se increases morbidity and mortality. Things might have been even worse without sex reassignment. As an analogy, similar studies have found increased somatic morbidity, suicide rate, and overall mortality for patients treated for bipolar disorder and schizophrenia.[39], [40] This is important information, but it does not follow that mood stabilizing treatment or antipsychotic treatment is the culprit.

Transsexuals experience themselves as being of the opposite sex, despite having the biological characteristics of one sex. A crucial question resulting from a previous brain study in male-to-female transsexuals was whether the reported difference according to gender identity in the central part of the bed nucleus of the stria terminalis (BSTc) was based on a neuronal difference in the BSTc itself or just a reflection of a difference in vasoactive intestinal polypeptide innervation from the amygdala, which was used as a marker. Therefore, we determined in 42 subjects the number of somatostatin-expressing neurons in the BSTc in relation to sex, sexual orientation, gender identity, and past or present hormonal status. Regardless of sexual orientation, men had almost twice as many somatostatin neurons as women (P

The Rametti team used an MRI technique called Diffusion Tensor Imaging to compare homosexual male-to-female transsexuals (n = 18) with nontranssexual, heterosexual control males (n = 19) and with nontranssexual, heterosexual control females (n = 19). They contrasted the male controls with the female controls to identify the sex-dimorphic portions of the brain and then contrasted the homosexual transsexuals with each of the control groups on the dimorphic brain regions so identified. The initial contrasts identified six sex-dimorphic brain regions. The homosexual transsexual sample was intermediate in volume on all six brain structures, significantly different from the male controls on five of the six (and significantly different from the female controls on all six). That is, these male-to-female transsexuals were different from the control males, shifted towards the female direction on all parameters. 041b061a72

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