Efeitos da terapia hormonal de afirmação de gênero na conectividade cerebral

Abstract

Background: There has been an increase in the number of transgender and gender diverse (TGD) people seeking gender-affirming hormone therapy (GAHT). Few studies have examined the effects of GAHT on brain connectivity. The hormonal effects on the brain may be through its influence on intrinsic connectivity. Objectives: To characterize the effects of GAHT on patterns of brain’s intrinsic connectivity of the default mode network (DMN) and salience network (SN) in TGD individuals. Methods: A prospective study of TGD individuals, assigned male at birth (AMAB) and assigned female at birth (AFAB), before and after GAHT was conducted. Participants were scanned using functional magnetic imaging at rest baseline and 6 months after GAHT. restingstate Functional Connectivity (rs-FC) maps were generated for each participant. Regions of interest were generated for key nodes anchoring DMN and SN, specifically the posterior cingulate cortex (PCC) and the dorsal anterior insula (dAI). Baseline and 6-month rs-FC maps were then compared, generating a single group level map of significant differences between timepoints for each seed, PCC and dAI, at p < 0.05, uncorrected. Results: 14 TGD individuals (AMAB n = 7, AFAB n = 7), mean age 27.68 (23.44 – 30.52) were enrolled. In the AMAB group, there was an increase in rs-FC from the PCC seed to the precuneus (within DMN) and a decrease in rs-FC from the dAI seed to the mid cingulate cortex and orbitofrontal cortex (within SN) after estradiol and antiandrogen use 93 (p_uncorr < 0.05). In the AFAB group, there was a significant decrease in rs-FC from the PCC seed to the precuneus, superior frontal gyrus, parahippocampal gyrus, and insula (within the DMN and between the DMN and SN) after testosterone use (p_uncorr < 0.05). Additionally, rs-FC from the dAI seed to the amygdala, insula, and anterior cingulate cortex (within the SN) significantly decreased after GAHT with testosterone (p_uncorr < 0.05). Conclusions: Our findings suggest that GAHT can influence patterns of intrinsic connectivity within brain networks involved in emotional and cognitive process in TGD individuals. This study highlights the brain's remarkable capacity to adapt in response to GAHT.