BMI-SDS Changes During GnRHa Therapy in 150 Girls with Idiopathic Central Precocious Puberty: Follow-up Through Final Height.

OBJECTIVE

To evaluate longitudinal changes in body mass index-standard deviation score (BMI-SDS) in girls with central precocious puberty (CPP) treated with gonadotropin-releasing hormone analogues from treatment initiation to final adult height.

METHODS

This retrospective study included 150 girls with idiopathic CPP treated with leuprolide acetate and followed to final adult height. BMI-SDS was assessed at treatment initiation, at 1 year of therapy, at treatment completion, and at final adult height. Patients were categorized according to BMI-SDS at the time of diagnosis as underweight, normal weight, overweight (OW), or obese (OB). BMI-SDS was evaluated at predefined time points and examined within baseline weight groups, and transitions between BMI-SDS categories were analyzed across the follow-up period. In addition to baseline weight status, participants were categorized as small for gestational age (SGA) or appropriate for GA (AGA) based on birth weight for gestational age.

RESULTS

In normal-weight girls, BMI-SDS increased significantly during the first treatment year and then declined toward final height, with no difference between baseline and final height. BMI-SDS remained stable in those OW or OB at treatment initiation. BMI-category distribution changed over follow-up (overall p=0.014), OW+OB prevalence increased during treatment (48.6%→56.6%) and decreased by final height (45.3%) (baseline vs final p=0.533). By final height, OB increased (p=0.0076) and OW decreased (p=0.006), while normal-weight prevalence did not differ from baseline (p=0.098). BMI-SDS was lower in SGA than AGA at baseline, year 1, and treatment completion (p=0.04, p=0.04, and p=0.01, respectively), but not at final adult height (p=0.6). In multivariable analysis, baseline BMI-SDS was inversely related to ΔBMI-SDS (treatment end-baseline) (β=-0.174, 95% confidence interval -0.291 to -0.057; p=0.004).

CONCLUSION

In this large cohort of girls with idiopathic CPP followed through final adult height, BMI-SDS showed no sustained increase at final height across baseline weight groups, and the SGA-AGA differences observed earlier were not maintained. Baseline BMI-SDS was the key independent determinant of ΔBMI-SDS (treatment end-baseline), with lower baseline values predicting greater increases.