ESPE Abstracts

Context: Given the importance of sex hormones in metabolic regulation, dynamics in body composition and cardiometabolic alterations may occur in transgender persons receiving gender-affirming hormone (GAH) therapy.

Objectives: Our aim was to explore the association between muscle-to-fat ratio (MFR) and the risk for metabolic syndrome components in transgender youth.

Methods: In 71 transgender female (birth-assigned male) and 149 transgender male (birth-assigned female) adolescents (mean age at first evaluation 15.9±2.5 years), generalized linear models with repeated measures (n=460) were applied for overweight/obesity, elevated blood pressure levels, glucose intolerance and dyslipidemia. Variables entered into the model were age, transgender female, socioeconomic position, family history of cardiovascular disease (CVD), psychiatric comorbidities, dietary pattern, physical activity, sleep, smoking status, alcohol consumption, hormone levels (estradiol and testosterone), GAH therapy duration and MFR z-scores. Body composition was measured by bioelectrical impedance analysis (Tanita MC-780MA and GMON Professional Software) according to birth-assigned sex and MFR z-scores were calculated.

Results: MFR z-score differed in a gender-specific manner; average for transgender females (P=0.536) and below average for transgender males (P<0.001). Transgender females (OR=0.06, 95%CI[0.02,0.23], P<0.001) and higher MFR z-scores (OR=0.02, 95%CI[0.01,0.06], P<0.001) were associated with lower odds of overweight/obesity; higher testosterone levels (OR=1.08, 95%CI[1.02,1.15], P=0.007) were associated with higher odds of overweight/obesity. Longer duration of GAH therapy (OR=1.39, 95%CI[1.03,1.86], P=0.029) and higher testosterone levels (OR=1.04, 95%CI[1.01,1.08], P=0.011) were associated with higher odds of elevated blood pressure levels. Higher MFR z-scores (OR=0.40, 95%CI[0.21,0.76], P=0.005) and favorable dietary pattern (OR=0.36, 95%CI[0.14,0.89], P=0.028) were associated with lower odds of elevated triglyceride (TG) levels. Transgender females (OR=0.01, 95%CI[0.003,0.040], P<0.001) and higher MFR z-scores (OR=0.59, 95%CI[0.42,0.81], P=0.001) were associated with lower odds of low HDL-c levels; higher testosterone levels (OR=1.11, 95%CI[1.05,1.18], P<0.001) were associated with higher odds of low HDL-c levels. Transgender females (OR=0.39, 95%CI[0.20,0.76], P=0.006) and higher MFR z-scores (OR=0.63, 95%CI[0.45,0.87], P=0.005) were associated with lower odds of elevated TG:HDL-c ratio.

Conclusions: Our findings support the notion that GAH-therapy in transgender youth affects the balance between muscle and adipose mass and cardiometabolic alterations in a sex-specific manner. Taking into consideration socioeconomic circumstances, family history of CVD, lifestyle-related factors and psychiatric comorbidities, transgender males remained at an increased risk for cardiometabolic disease. Our observations highlight the importance of targeted medical nutrition intervention in this group of youngsters in attempts to dampen potential detrimental outcomes of GAH-therapy.