Endocrine Abstracts

Introduction: GH therapy in children with normal GH peak in stimulation tests (GHST) is still a matter of discussion. Recently, GH deficiency (GHD) has been defined as secondary IGF1 deficiency (IGFD), however GHST still remain the main procedure in diagnosing GHD.

The aim of present study was to compare GH therapy effectiveness in the patients with normal results of GHST (normGH) and with isolated partial GHD (pGHD), with respect to IGF-I secretion before treatment.

Patients and methods: Analysis comprised 75 patients (56 boys), age 12.1±2.9 years (mean±S.D.) with short stature, GH peak in GHST >10 ng/ml and excluded primary IGFD by IGF1 generation test (normGH group), compared with 182 patients (142 boys), age 12.3±2.7 years, with GH peak in GHST 5–10 ng/ml (pGHD group). In each patient IGF-I concentration before treatment was assessed. The patients with normGH and with pGHD were qualified according to IGF1 S.D. for age and sex into the following subgroups:

i) normGH1 and pGHD1 – IGF1 SDS <−2.0 (severe IGFD);

ii) normGH2 and pGHD2 – IGF1 SDS between −2.0 and −1.0 (partial IGFD);

iii) normGH3 and pGHD3 – IGF1 SDS >−1.0 (no IGFD).

All the patients were treated with GH during 4.9±2.6 years, up to final height (FH). In each patient FH SDS increase with respect to height SDS before treatment (ΔHSDS) was calculated.

Results: The best ΔHSDS was in normGH1 (1.86±0.93) and pGHD1 (1.65±0.89), the worse in normGH3 (0.99±0.71). Similar ΔHSDS was observed in normGH2 (1.44±0.77), pGHD2 (1.29±0.77) and pGHD3 (1.44±0.92). There was no significant difference in ΔHSDS between normGH1 and pGHD1 (P=0.42), between normGH2 and pGHD2 (P=0.49), and between normGH3 and pGHD3 (P=0.10).

Conclusion: The effectiveness of GH therapy was better in the patients with decreased IGF-I secretion before treatment, being the highest in severe IGFD and almost independent from the results of GHST.