Bone age evaluation in an ethnically diverse cohort of children with premature adrenarche.

Background: Bone age (BA) assessment is an essential tool in pediatric endocrinology, used to assess growth and perturbations in pubertal onset. BA advancement is common in children with premature adrenarche (PA), potentially leading to additional evaluation or intervention. The extent to which BA advancement reflects variation in metabolic and demographic factors, including body mass index (BMI), sex, race, and ethnicity, remains insufficiently characterized.

Methods: We conducted a retrospective chart review of 296 children (72% female, mean age 7.3 ± 1.6 years) with isolated PA seen at a tertiary pediatric endocrinology clinic. Absolute and standardized BA advancement were analyzed in relation to BMI, sex, race, and ethnicity. Multivariate linear regression adjusted for age and covariates.

Results: BA advancement was greater in children with obesity (19.2 ± 15.1 months) versus those below the 95th% (11.4 ± 13.5), and in males (19.9 ± 14.3) versus females (12.4 ± 14.3). White race was associated with lower advancement (p = 0.02). BMI (p < 0.0001), male sex (p < 0.0001), and Hispanic vs. White ethnicity (p = 0.023) significantly affected standardized BA advancement.

Conclusion: BMI, sex, and race/ethnicity influence BA advancement in PA, supporting individualized interpretation and further study of clinical implications.

Impact: Bone age (BA) advancement is an important consideration in the diagnostic workup of children with premature adrenarche. In this diverse cohort, BMI status, sex, race, and ethnicity were significantly associated with BA advancement, suggesting that both metabolic and demographic factors influence skeletal maturation. While BA advancement in obesity and premature adrenarche is recognized, this study underscores their combined effects and the variability across populations. These findings point to limitations in current BA standards and support the need for individualized interpretation. Further research should explore how BA advancement in obesity and across ethnic groups affects adult height and long-term outcomes.