Normal Height Velocity Maintained With Reduced Growth Hormone Dose
Considering GH treatment is given to short children for extended periods of time, the ultimate goal is to use the lowest effective dose for the patient after achieving complete catch-up growth.
According to study results published in The Journal of Endocrinology & Metabolism, normal height velocity can be maintained in prepubertal children during the catch-up growth period by reducing growth hormone (GH) dosage by 50%.
To determine how a GH dose reduction during the catch-up growth period affected channel parallel growth with normal height velocity, researchers randomly assigned 98 prepubertal children (average age, 8.5 years) to receive an unchanged individualized GH dose (n = 38), half of their usual individualized dose (n = 27), or a standard weight-based dose of 43 μg/kg/day (n = 33). Of the total population, 33 participants had GH deficiency and 65 did not have GH deficiency during the catch-up growth period.
The researchers' primary outcome was to determine the proportion of intervention participants achieving channel parallel growth (ie, normal height velocity, defined as a ± 0.3 change in height standard deviation score). At the 1-year mark, 85% of the reduced-dose group in the intention-to-treat population maintained normal height velocity compared with 41% (P =.006) in the unchanged dose group and 48% in the weight-based dose group (P =.005).
There were no significant differences between groups for attained mean insulin-like growth factor 1 (IGF-1) standard deviation score at the start of the study or at 1-year follow-up. However, mean standard deviation score for IGF-1 in the reduced-dosage group decreased from 2.3 ± 1.3 at start to 1.5 ± 1.1 at 3 months (P =.002), compared with nonsignificant changes for the unchanged dose group and weight-based group.
The researchers noted several limitations to this study, including the arbitrary decision to reduce GH dosage by 50%.
Despite concluding that their primary goal was achieved, the researchers said, “such a dose reduction must be accompanied by close monitoring [of well-being] and metabolic markers as presently there is no method for estimation of individual GH-responsiveness during the maintenance treatment period before puberty.”
Decker R, Albertsson-Wikland K, Kriström B, et al. GH dose reduction maintains normal prepubertal height velocity after initial catch up growth in short children [published online October 18, 2018]. J Clin Endocrinol Metab. doi:10.1210/jc.2018-01006