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, 17100 mu g/kg/day) or a standard dose in a preceding 2-year study. After achieving near mid-parental heightSDS, 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 2years. The dose remained unchanged in 33 children initially randomized to receive a standard dose (FIX, 43 mu g/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 heightSDS is achieved to avoid overtreatment in terms of metabolic outcome.
2012. Vol. 77, no 3, 407-415 p.