Background: There are inconsistencies in the results reported in a small number of previous studies into growth hormone (GH) treatment of short children with idiopathic short stature (ISS.
Patients and Methods: Our study included 20 prepubertal (Tanner 1) or peri-pubertal (Tanner 2) children with short stature (HtSDS < -2) and/or HtSDS > 1SD below their mid parental height SD (MPHtSDS), slow Growth velocity( < -1), with normal Peak GH to provocation ( 15.58 +/- 6.95 ng/dl), normal IGF-ISDS (-0.9 +/- 0.6 ), Tanner 1 (n = 15, Tanner 2 = 3, Tanner 3 = 2) and no bone age delay. We treated all the children for 2.5 +/- 1.5 years with rhGH 0.4 mg/kg/day and assessed their linear growth at the end of this period in relation to different possible modifying factors.
Results: Our children on GH therapy increased their HtSDS by 0.77 +/- 0.5 at the end of the treatment period (2.5 +/- 1.5 years). The effects of different factors on their growth response are summarized in table.
|HtSDS MPHtSDS before GH Therapy||HtSDS MPHTSDS after GH therapy||HtSDS gain after GH therapy|
|Ht SDS < -2.5||-1.20||-0.20*#||0.98#|
|HtSDS >- 2.5 <-2||-0.93||-0.32*||0.60|
|More than 1SD below their MPHtSDS before GH therapy||-1.5||-0.57*#||0.88#|
|Less than 1SD below their MPHtSDS before GH therapy||-0.71||-0.1*||0.62|
|IGF-I increment > 150%||-1.2||-0.4*||0.7|
|IGF-I increment < 150%||-1.1||-0.25*||0.83|
|GH response > 15 ng/dl||-1.13||-0.29*||0.8|
|GH response < 15 ng/dl||-1.07||-0.37*||0.69|
|Stayed prepubertal during therapy||-1.34||-0.27*||0.71|
|Proceeded to Tanner 3 & 4 during therapy||-1.36||-0.37*||0.78|
|Age < 9 years at the start of GH||-1.2||-0.1*#||1.1#|
|Age > 9 years at the start of GH||-1.04||-0.45*||0.58|
|*=P<0.05 before vs after therapy, #= P < 0.05 comparing different groups|
Discussion: Children below 9 years with HtSDS < -2.5 and those whose HtSDS was 1SD or more below MPHtSDS grew better on GH therapy compared to older children and those with HtSDS > -2.5 and were less than 1SD from their MPHTSD.
Conclusion: Growth response to GH therapy in short children with normal GH-IGF-I axis, appears to be significantly better in those younger than 9 years, with HtSDS < -2.5 for the population and with HtSDS > 1SDS below their MPHTSDS.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology