Endocrine Abstracts

Introduction: In majority of patients with childhood-onset GH deficiency (GHD), normalisation of GH secretion at the attainment of final height (FH) is observed. However, different criteria for GHD diagnosis may be considered.

The aim of the study was to compare the auxological and hormonal data of the patients with persistent and transient GHD, diagnosed according to different criteria.

Patients and methods: The analysis comprised 150 patients (117 boys), age 12.5±2.7 years (mean±S.D.), with GHD, who completed GH therapy in a dose of 0.18±0.03 mg/kg per week, attained FH and were subjected to re-evaluation of GH secretion in stimulating tests (GH re-test) at the age of 17.3±1.1 years.

In the patients with confirmed and excluded GHD in GH re-test, using the following cut-off levels of GH peak: <3 ng/ml (persistent, severe GHD in adults), <6 ng/ml (GHD in young adults), <10 ng/ml (GHD in children), the following auxological and hormonal data before treatment and indices of GH therapy effectiveness were compared i) height SDS at therapy onset (HoSDS), ii) GH peak and IGF1 SDS before treatment, iii) FH SDS for age and sex, and iv) increase of FH SDS with respect to HoSDS (ΔHSDS).

Results: The patients with GH re-test <6 ng/ml had significantly (P<0.05) lower GH peak (3.9±3.2 ng/ml) and IGF1 SDS (−1.74±2.83) at therapy onset, together with significantly better FH SDS (−0.39±1.19) and ΔHSDS (2.98±2.14) than the patients with GH re-test >6 ng/ml (7.7±3.9 ng/ml, −1.26±1.71, −1.51±0.86 and 1.51±0.90 respectively), with no difference in HoSDS (−3.38±1.08 vs −3.05±0.73). There was no significant difference in GH therapy effectiveness in the patients with GH re-test <3 and 3–6 ng/ml, as well as between ones with GH re-test 6–10 and >10 ng/ml.

Conclusion: The cut-off value 6 ng/ml for GH re-test seems to be the most appropriate for diagnosing persistent GHD in the patients who achieved FH.