Background: Treating central precocious puberty with GnRH agonist (GnRHa) to increase height gain is well-established. Although not recommended, GnRHa have also been used in patients with IGHD at onset of puberty yet there are few data on its efficacy.
Objective and hypotheses: Growth prediction models derived from KIGS (Pfizer International Growth Database) may provide an opportunity to estimate additional height gain produced by pubertal blockade.
Method: Growth data from all idiopathic GH deficiency (IGHD) patients in KIGS treated with GH and GnRHa (with start and end dates) were analyzed. From total pubertal growth (TPG) prediction models, we know the estimates for the effect of age at start of puberty, boys=−3.97 cm/year and girls=−3.68 cm/year (1). Therefore, we can estimate the effect of GnRHa by adjusting the model effect accordingly. By replacing the model effect with the actual cm in height, while on GnRHa, an estimated height gain can be calculated.
Results: All results are summarized in the Tabl: Pubertal growth in a cohort of IGHD patients treated with GH and GnRHa.
|Boysa (n=84)||Girlsa (n=113)|
|Start of GH|
|Age at start of puberty||11.4||10.3|
|(girls B2, boys testicular volume >3 ml)|
|Start of GnRHa|
|End of GnRHa|
|Delta Ht (cm)||9.3||9.3|
|Delta Ht (cm) adjusted per KIGS model||2.7||3.0|
|Duration of GnRHa (years)||1.6||1.7|
|aAll are median values.|
Conclusion: With addition of GnRHa to treat relatively early puberty in GH-treated children with IGHD, the estimated additional median gain in adult height is 2 cm/year on GnRHa (boys=1.8 cm/year and girls=2.2 cm/year). Our data show that this therapeutic concept may not achieve the expected benefit in height according to the TPG model.
18 Sep 2014 - 20 Sep 2014