Evaluation of Muscle Mass and Strength in Children and Adolescents with Disorders of Sex Development

The aim of this study was to evaluate muscle mass and strength in children and adolescents with disorders of sex development (DSD) whose sex assignment was determined by a multidisciplinary team, comparing these parameters both among the DSD cases and with healthy controls, and to assess the impact of hormone replacement therapy (HRT) on these outcomes.

78 DSD cases and 118 healthy controls were included. Gender assignment followed multidisciplinary council decisions; some DSD cases underwent gender-appropriate surgical interventions, and HRT was initiated as puberty approached. Participants were divided into four age groups (<5, 5-10, 10-15, and ≥15 years), and anthropometric measures, pubertal status, muscle mass and strength, skinfold thickness, and sex hormone profiles were assessed.

Among DSD cases, 30.8% had 46,XX DSD, 53.8% had 46,XY DSD, and 15.4% had mixed gonadal dysgenesis (MGD); ambiguous genitalia was the most common referral reason, and CYP21A2 was the most frequently identified mutation. In individuals aged ≥15 years, 46,XX DSD cases, regardless of gender of rearing, had lower height standard deviation scores (SDS) than healthy peers, whereas 46,XY DSD cases raised as females had higher height SDS than other DSD subgroups (p<0.01). In Individuals aged ≥15 years, muscle strength was highest in 46,XY DSD males and healthy males (p<0.01). Participation in sports was associated with higher muscle mass in both groups (p=0.03). Muscle strength correlated positively with serum testosterone (p< 0.001, R = 0.563).

Chromosomal sex predominantly influenced final height, whereas muscle strength aligned with gender of rearing and testosterone levels.