ESPE Abstracts

Background: Overweight as a predictor of adverse cardiovascular outcome is of particular interest in gender-affirming healthcare. Transgender populations are at a higher risk for obesity, possibly due to a combination of minority stress, psychiatric comorbidity, and lifestyle differences, such as reluctance to participate in group sports as a consequence of social withdrawal. However, robust auxological data in transgender adolescents is scarce.

Objectives: To evaluate differences in auxological parameters such as bodyweight, height and BMI between transgender and cisgender adolescents.

Methods: Retrospective analysis of auxological data of 186 transgender patients (75% trans male, 25% trans female) at the outpatient clinic for Pediatric Endocrinology at General Hospital Vienna (AKH Wien). All were treatment naïve at initial measurement. Height and weight data were compared to current WHO and Austrian growth standards, defining +1-2 standard deviations (SD) as overweight and >2 SD as obese. Additionally, we tested for confounders, specifically psychiatric comorbidities and medication, using univariate linear regression.

Results: In our untreated transgender population (mean age 15.7 years), 20% were overweight and a further 19% obese. Mean BMI was 0.71 SD above the WHO average (P<0.001). When split by gender identity, this result was more pronounced in the trans male subgroup (+0.76 SD, P<0.001) than in the trans female group (+0.53 SD, P=0.03). While both groups were skewed towards overweight in a normal distribution, the trans female group showed a markedly higher variance in BMI as compared to both cisgender adolescents (P<0.001) and to the trans male group (P=0.03), due to a higher relative number of underweight observations. Transgender patients with a comorbid psychiatric diagnosis had, on average, BMI values which were 0.44 SD higher than those of trans patients without psychiatric comorbidity (P<0.001). However, in our linear regression model, when correcting for psychiatric diagnosis, transgender patients were still significantly overweight (P<0.001).

Conclusions: We observed significantly higher rates of overweight and obesity in our adolescent transgender cohort. The reasons for this are likely complex and multifactorial. In addition, the body dysphoria associated with transgender ideation may put patients at risk for manifest or subclinical eating disorders. Concealment of undesired secondary sex characteristics and decreased circulating sex steroids as a result of either obesity or extreme underweight could be potential secondary gains. This makes eating and exercise behavior a central topic in both transgender care and future research.