Objective: Few studies have evaluated metabolic outcomes following growth hormone (GH) treatment in short prepubertal children during different periods of growth. Previously, we found that individualized GH dosing in the catch-up period reduced the variation in fasting insulin levels by 34% compared with those receiving a standard GH dose. We hypothesized that the GH dose required to maintain beneficial metabolic effects is lower during the prepubertal growth phase after an earlier catch-up growth period.
Design: Short prepubertal children with isolated GH deficiency or idiopathic short stature were randomized to individualized GH treatment (range, 17-100 μg/kg/day) or a standard dose in a preceding 2-year study. After achieving near mid-parental height(SDS) , children receiving an individualized dose were randomized to either a 50% reduced individualized dose (RID, n = 28) or an unchanged individualized dose (UID, n = 37) for 2 years. The dose remained unchanged in 33 children initially randomized to receive a standard dose (FIX, 43 μg/kg/day).We evaluated whether the variations in metabolic parameters measured during maintenance growth diminished in RID compared with UID or FIX.
Results: We observed less variation in fasting insulin levels (-50%), insulin sensitivity as assessed by homoeostasis model assessment (-55·1%), lean soft tissue (-27·8%) and bone mineral content (-31·3%) in RID compared with UID (all P < 0·05), but no differences compared with FIX.
Conclusions: Continued reduced individualized GH treatment after the catch-up growth period is safe and reduces hyperinsulinism. Individualized GH dose can be reduced once the desired height(SDS) is achieved to avoid overtreatment in terms of metabolic outcome.
© 2012 Blackwell Publishing Ltd.