Early growth hormone treatment start in childhood growth hormone deficiency improves near adult height: analysis from NordiNet® International Outcome Study

Abstract

Objective

To investigate the effect of age at growth hormone (GH) treatment start on near adult height (NAH) in children with isolated GH deficiency (GHD).

Design

NordiNet® International Outcome Study (IOS) (Nbib960128), a non-interventional, multicentre study, evaluates the long-term effectiveness and safety of Norditropin® (somatropin) (Novo Nordisk A/S) in the real-life clinical setting.

Methods

Patients ( n = 172) treated to NAH (height at ≥18 years, or height velocity <2 cm/year at ≥16 (boys) or ≥15 (girls) years) were grouped by age (years) at treatment start (early (girls, <8; boys, <9), intermediate (girls, 8–10; boys, 9–11) or late (girls, >10; boys, >11)) and GHD severity (<3 ng/mL or 3 to ≤10 ng/mL). Multiple regression analysis was used to evaluate the effect of age at treatment start (as a categorical and continuous variable) on NAH standard deviation score (SDS).

Results

Age at treatment start had a marked effect on NAH SDS; NAH SDS achieved by patients starting treatment early ( n = 40 (boys, 70.0%); least squares mean (standard error) −0.76 (0.14)) exceeded that achieved by those starting later (intermediate, n = 42 (boys, 57.1%); −1.14 (0.15); late, n = 90 (boys, 68.9%); −1.21 (0.10)). Multiple regression analysis showed a significant association between NAH SDS and age at treatment start ( P < 0.0242), baseline height SDS (HSDS) ( P < 0.0001), target HSDS ( P < 0.0001), and GHD severity ( P = 0.0012). Most (78.5%) patients achieved a normal NAH irrespective of age at treatment start.

Conclusions

Early initiation of GH treatment in children with isolated GHD improves their chance of achieving their genetic height potential.