Effects of recombinant human growth hormone on height and skeletal maturation in growth hormone-deficient children with and without severe pretreatment bone age delay

The relative effects of growth hormone (GH) on GH-deficient (GHD) children with and without severely delayed skeletal maturation prior to treatment ar e unclear. Methods: Pre-pubertal GHD children enrolled in the National Coop erative Growth Study were divided into two groups: severe pretreatment BA d elay (BA Z-score less than or equal to-2, group 1) and mild to moderate del ay (BA Z-score between -2 and 0, group 2). BA Z-scores (BAZ), height Z-scor es and predicted adult height (PAH) Z-scores at pubertal onset were determi ned after initiation of recombinant human GH (rhGH) therapy. Results: Heigh t Z-scores increased from baseline to the start of puberty in both groups ( group 1: mean difference of +0.99, males and +1.02, females; group 2: +0.68 , males and +0.75, females). Mean BAZ also increased in all group 1 childre n (+1.62, males and +1.08, females) with no corresponding change in mean BA Z in group 2. PAH Z-scores increased in both groups. There was no evidence of undue advance in BA since mean BAZ remained well below zero in group 1 a nd was unchanged in group 2. Conclusion: rhGH has a beneficial effect on gr owth in prepubertal GHD children at all levels of pretreatment BA delay.