Gender Dimorphism in Transgender Youth – Hormonal Therapy and the Balance Between Muscle, Adipose Tissue and Cardiometabolic Alterations
2The Nutrition and Dietetics Unit, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
3Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
4The Psychological Services, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Aim:
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). We sought to explore the association between muscle-to-fat ratio (MFR) and the risk for metabolic syndrome components in transgender youth.
Methods:
Body composition was assessed in 71 transgender female (birth-assigned male) and 149 transgender male (birth-assigned female) adolescents (mean age 15.9±2.5years) by bioelectrical impedance analysis (Tanita MC-780MA, GMON Professional Software) and MFR z-scores were calculated. GEE binary logistic models were applied for metabolic syndrome components.
Results:
MFR z-scores 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 BP. Higher MFR z-scores (OR=0.40,95%CI[0.21,0.76],P=0.005) were associated with lower odds of elevated TG. 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. 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.
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.
