Endocrine Abstracts

Introduction.: The diagnosis of GH deficiency (GHD) is based on decreased GH peak in stimulating tests (GHST). Recently, GHD has been re-defined as secondary IGF1 deficiency (IGFD). However, IGF1 may increase during GH therapy in the patients with normal GH peak in GHST, suggesting a diagnosis of non-primary IGFD (npIGFD).

The aim of the study was to compare GH therapy effectiveness in children with GHD and with npIGFD (responding to GH administration despite normal results of GHST).

Patients and methods: The analysis comprised 300 children (228 boys and 72 girls), with short stature and i)severe GHD (sGHD) – GH peak <5 ng/ml, height SDS at GH therapy onset (HoSDS) −3.20±0.87 (mean±S.D.), n=43; ii) partial GHD (pGHD) – GH peak 5–10 ng/ml, HoSDS −3.06±0.78, n=188; and iii) npIGFD – GH peak >10 ng/ml, decreased IGF1 (i.e. IGF1 SDS <−1.0), increasing significantly during generation test, HoSDS – 3.11±0.70, n=69.

All the patients were treated with GH in a dose of 0.18±0.03 mg/kg per week up to the attainment of final height (FH).

Selected auxological indices of GH therapy effectiveness were compared: i) FH SDS for age and sex; ii) FH SDS corrected by target height SDS (corrFH SDS); and iii) an increase of FH SDS with respect to HoSDS (ΔHSDS).

Results: The attained FH SDS was slightly worse in npIGFD (−1.48±0.89) than in sGHD (−1.38±1.25) but better than in pGHD (−1.62±0.83), while corrFH SDS was similar in all the Groups (−0.32±0.87 vs −0.38±1.09 vs −0.39±0.97 respectively). Moreover, ΔHSDS was similar in npIGFD (1.62±0.88) and sGHD (1.68±1.56), being even better than in pGHD (1.42±0.95). All the differences among the groups were insignificant.

Conclusion: It seems that GH therapy should be considered in children with IGFD, responding to GH despite normal results of GHST, because the efficacy of treatment is similar as in GHD.