Longitudinal follow-up to near final height of auxological changes in girls with idiopathic central precocious puberty treated with gonadotropin-releasing hormone analog and grouped by pretreatment body mass index level.

Purpose: Reported changes in body mass index (BMI) in central precocious puberty (CPP) during and after gonadotropin-releasing hormone analog (GnRHa) treatment are inconsistent. We, therefore, investigated auxological parameters in GnRHa-treated girls with idiopathic CPP (ICPP) until attainment of near final height (NFH).

Methods: From the medical records of 59 ICPP girls who attained NFH after GnRHa therapy, auxological changes were compared between overweight (BMI≥85th percentile) and normal-weight (BMI<85th percentile) groups. BMIs were changed into standard deviation scores (BMISDSs) for subject chronologic age (BMISDS-CA) and bone age (BMISDS-BA).

Results: The incidence of overweight including obesity was high at the start of therapy (35.6%). The predicted adult height (PAH) at start of therapy was significantly shorter than the midparental height (MPH), whereas PAH at end of therapy approached MPH, and NFH was greater than MPH. Height velocity (HV) in the overweight group was higher during GnRHa therapy than that in the normal-weight group, but those in the two groups were not different after therapy until NFH. Both BMISDS-CA and BMISDS-BA increased significantly during therapy, but both BMISDSs decreased significantly after therapy until NFH. At NFH, neither BMISDS was different from that at baseline. In the normal-weight group, both BMISDSs increased during therapy and were maintained until NFH. In the overweight group, neither BMISDS changed during therapy, but there was a decrease after therapy until NFH.

Conclusions: The different patterns of BMISDS change during and after GnRHa therapy until NFH between the 2 groups were related to the different HV during GnRHa therapy.