To Örebro University

Background/Aims: Growth hormone (GH) treatment regimens do not account for the pubertal increase in endogenous GH secretion. This study assessed whether increasing the GH dose and/or frequency of administration improves pubertal height gain and adult height (AH) in children with low GH secretion during stimulation tests, i. e. idiopathic isolated GH deficiency.

Methods: A multicenter, randomized, clinical trial (No. 88-177) followed 111 children (96 boys) at study start from onset of puberty to AH who had received GH(33) mu g/kg/day for >= 1 year. They were randomized to receive 67 mu g/kg/day (GH(67)) given as one (GH(67x1); n = 35) or two daily injections (GH(33x2); n = 36), or to remain on a single 33 mu g/kg/day dose (GH(33x1); n = 40). Growth was assessed as height SDS gain for prepubertal, pubertal and total periods, as well as AH SDS versus the population and the midparental height.

Results: Pubertal height SDS gain was greater for patients receiving a high dose (GH(67), 0.73) than a low dose (GH(33x1), 0.41, p < 0.05). AH(SDS) was greater on GH(67) (GH(67x1), -0.84; GH(33x2), -0.83) than GH(33) (-1.25, p < 0.05), and height SDS gain was greater on GH(67) than GH(33) (2.04 and 1.56, respectively; p < 0.01). All groups reached their target height SDS.

Conclusion: Pubertal height SDS gain and AH SDS were dose dependent, with greater growth being observed for the GH(67) than the GH(33) randomization group; however, there were no differences between the once-and twice-daily GH(67) regimens. (C) 2014 S. Karger AG, Basel.