Early pubertal timing is common among adolescent girl-to-boy sex reassignment applicants

Long-term exposure to exogenous phthalate, masculinity and femininity trait, and gender identity in children: a Chinese 3-year longitudinal cohort study

BACKGROUND

Phthalate esters (PAEs) are known to have hormone-like properties, and there is a growing trend of children expressing a gender identity different from assigned sex. However, there has been limited research in the potential links between PAEs exposure and gender identity.

METHODS

A total of 571 children (278 boys) completed the follow-up from Oct 2017 to Oct 2020 in Childhood Blood Pressure and Environmental Factors (CBPEF) cohort in Xiamen, China. Urinary PAE metabolites were measured at three time of visits using ultraperformance liquid chromatography-tandem mass spectrometry. The Children's Sex Role Inventory scale was used to assess gender identity (masculinity, femininity, androgyny and undifferentiated), and Tanner definition was used to define puberty timing. Generalized linear models and log-binomial regression were used to assess the relationships between PAEs exposure, gender trait scores and gender identity.

RESULTS

Overall, the concentration of most PAEs in more than 90% of participants was above the limit of detection values. In visit 1, there were 10.1% boys with femininity and 11.3% girls with masculinity; while these figures increased to 10.8% and 12.3% during follow-up, respectively. Early puberty onset accounted for 24.8% and 25.6% among boys and girls. Long-term exposure to mono-2-ethylhexyl phthalate (MEHP) (β = 1.20, 95%CI = 0.13, 2.28), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) (β = 1.25, 95%CI = 0.22, 2.28) and mono-2-ethyl-5-oxohexyl phthalate (MEOHP) (β = 1.40, 95%CI = 0.24, 2.56) was associated with the increased differences of femininity trait scores in boys who enter puberty earlier, prolonged exposure to di(2-ethylhexyl) phthalate (DEHP) might also have such a positive impact (β = 1.38, 95%CI = 0.36, 2.41). For gender identity, persistent exposure to low molecular weight phthalates (LMWP) was negatively associated with undifferentiated type among boys entering puberty earlier (RR = 0.18, 95%CI = 0.05, 0.75, P < 0.05), and most of the PAE metabolites exposures showed risk ratios > 1 for their femininity.

CONCLUSION

Long-term exposure to PAEs increase the femininity trait scores in boys with early onset of puberty. Although the mechanisms remain to be determined, environmental pollution might have subtle, yet measurable effects on childhood gender identity. Reducing these chemicals exposure has important public implications on gender development.

Family Characteristics, Transgender Identity and Emotional Symptoms in Adolescence: A Population Survey Study

Sociodemographic and psychosocial family factors have profound implications for adolescent development, identity formation and mental health during the adolescent years. We explored the associations of sociodemographic and psychosocial family factors with transgender identity in adolescence and the role of these factors in the associations between gender identity and emotional disorders. Data from a large adolescent population survey from Finland were analysed using logistic regression models. Reporting transgender identity was associated with mother's low level of education, accumulating family life events, lack of family cohesion, perceived lack of family economic resources and female sex. A lack of family cohesion further differentiated between adolescents reporting identifying with the opposite sex and those reporting non-binary/other gender identification. The associations between transgender identity, depression and anxiety were attenuated but did not level out when family factors were controlled for. Transgender identity in adolescence is associated with socioeconomic and psychosocial family factors that are known correlates of negative outcomes in mental health and psychosocial well-being. However, transgender identification is also associated with emotional disorders independent of these family factors.

Gender incongruence and timing of puberty: a population-based cohort study

OBJECTIVE

To study whether the timing of puberty in adolescents who reported gender incongruence (incongruence between birth-assigned sex and self-identified gender) was different from those adolescents who reported gender congruence.

DESIGN

Population-based cohort study using data from the Danish National Birth Cohort.

SETTING

Not applicable.

PATIENT(S)

Birth-assigned boys and girls born between 2000 and 2003, who self-reported gender incongruence at 11 years (N = 10,046) and their pubertal developmental stages from age 11 years to every 6 months throughout puberty were included.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE

Mean age differences in months at reaching Tanner stages 2-5 for breast or genital development and pubic hair, voice break, first ejaculation, menarche, axillary hair, acne, and the average difference at attaining all pubertal milestones (primary outcome).

RESULT(S)

In total, 549 (5.5% ) adolescents reported part or full gender incongruence at 11 years. Tendencies toward earlier timing of puberty were observed in adolescents who reported part gender incongruence (average difference, birth-assigned boys: -3.2 months [95% confidence interval {CI}: -6.7; 0.3]; birth-assigned girls: -2.0 months [95% CI: -3.9; -0.1]). Tendencies toward earlier timing of puberty were observed in adolescents who reported full gender incongruence (average difference, birth-assigned boys: -2.4 months [95% CI: -5.0; 0.4]; birth-assigned girls: -1.9 months [95% CI: -5.1; 1.2]).

CONCLUSIONS

The results from this study indicated that birth-assigned boys and girls who reported either part or full gender incongruence tended to reach puberty slightly earlier than those adolescents who reported gender congruence at 11 years of age. Knowledge on the timing of puberty among adolescents who experience gender incongruence is essential to inform mutual decision-making in clinical settings.

The effect of peer education based on adolescent health education on the resilience of children and adolescents: A cluster randomized controlled trial

BACKGROUND

An increasing number of children and adolescents have reported mental health problems, and resilience is a protective factor against these problems. Therefore, the aim of the study is to verify the effect of peer education based on adolescent health education on adolescent resilience.

METHOD

A cluster randomized controlled trial was conducted including 1,613 students who were divided into an intervention group (19 classes, 732 participants) and a control group (24 classes, 881 participants). One-year peer education was performed in the intervention group, and the control group had no interventions. The Resilience Scale for Chinese Adolescents by Yueqin Hu and a self-designed basic information questionnaire were used to collect data. Chi-square test and rank-sum test were used to compare the differences of demographic characteristics between the two groups. A linear mixed model was used to compare the changes of resilience between the two groups after intervention, and the intra-cluster correlation coefficient (ICC) was calculated. A generalized linear mixed model (GLMM) was used to verify the effect of peer education on adolescent resilience. The significance was set at P < 0.05.

RESULTS

After intervention, compared with the control group, the intervention group showed significant improvement in target focus, emotion adjustment, interpersonal assistance and total resilience (P < 0.05). The ICC range was 0.003 to 0.034. The GLMM results indicated that peer education based on adolescent health education had significant effects on adolescents' target focus (β = 0.893, P = 0.002), emotional adjustment (β = 1.766, P < 0.001), interpersonal assistance (β = 1.722, P = 0.016) and total mental resilience (β = 5.391, P < 0.001), and the effect was greater for boys than for girls.

CONCLUSIONS

Peer education based on adolescent health education is effective for improving adolescents' target focus, emotional adjustment, interpersonal assistance, and total resilience, especially for males. Future research should devote more attention to positive cognition and family support as well as gender differences.

Exploring the Interaction Effects of Gender Contentedness and Pubertal Timing on Adolescent Longitudinal Psychological and Behavioral Health Outcomes

Background: Off-time pubertal timing (PT) and non-conforming gender identity have been reported to predict adverse health and well-being in adolescents. However, the joint effects of these two factors are less addressed. We aimed to investigate the main and interaction effects of gender identity, proxied by perceived gender contentedness (GC), and PT on longitudinal adolescent psychological and behavioral outcomes. Methods: Data (N = 1806, Mage = 13.3 ± 0.5 years) come from the Taiwan Youth Project, which prospectively followed a longitudinal cohort of Taiwanese junior high school students from 2000 (wave 1) to 2009 (wave 9). GC was self-reported at waves 1 and 9 in a binary response, and thus 4 GC trajectories were created. PT was defined using the Pubertal Developmental Scale, which mainly measured physical changes in puberty. Multiple linear regression analyses with gender stratification were applied to examine the effects of the GC trajectory and its interaction with PT on the outcomes. Results: A total of 1,562 subjects (86.5%) remained consistently satisfied with their gender, while the GC of 226 subjects (12.6%) changed at some point. Regression analyses found that males with gender dissatisfaction at wave 9 were likely to engage in delinquent behavior, and females in this group were more likely to have lower self-esteem, as compared to those with consistent GC. The interaction effect between the GC trajectory and PT appeared to be associated with smoking and drinking only at wave 1. Conclusions: These findings indicate that healthcare professionals should concentrate on gender non-conforming individuals at early adolescence, navigating them toward a healthy adulthood.

Sexual experiences of clinically referred adolescents with features of gender dysphoria

Gender dysphoria in adolescence could be expected to be associated with delayed sexual development because of the distress related to the sexual characteristics of the body. However, identity challenges may also increase early and risk-taking sexual behaviours among adolescents with gender dysphoria. We studied sexual experiences among 101 adolescents, attending an adolescent gender identity service, desiring gender reassignment. Their experiences were compared to the sexual experiences of the same-aged population, evaluated in a large adolescent survey. A majority of adolescents with gender dysphoria had been in love or had a crush on somebody. Birth assigned females had experiences of romantic relationships twice as commonly as birth assigned males. Otherwise, there was no statistically significant difference in the adolescents' sexual experiences. About half of the subjects had experiences of kissing, and about 40% had intimate (genital) sexual experiences with a partner. Compared to the general adolescent population, adolescents with gender dysphoria were less experienced. Autism spectrum disorder was associated with more delayed sexual development.

Gender dysphoria in adolescence: current perspectives

Increasing numbers of adolescents are seeking treatment at gender identity services in Western countries. An increasingly accepted treatment model that includes puberty suppression with gonadotropin-releasing hormone analogs starting during the early stages of puberty, cross-sex hormonal treatment starting at ~16 years of age and possibly surgical treatments in legal adulthood, is often indicated for adolescents with childhood gender dysphoria (GD) that intensifies during puberty. However, virtually nothing is known regarding adolescent-onset GD, its progression and factors that influence the completion of the developmental tasks of adolescence among young people with GD and/or transgender identity. Consolidation of identity development is a central developmental goal of adolescence, but we still do not know enough about how gender identity and gender variance actually evolve. Treatment-seeking adolescents with GD present with considerable psychiatric comorbidity. There is little research on how GD and/or transgender identity are associated with completion of developmental tasks of adolescence.