Several Problems of Growth Hormone Stimulation Test in Clinical Application

No, So Jung; Choi, Jong Sung; Han, Heon Seok

Abstract

PURPOSE: We investigated properness of growth hormone stimulation test (GHST) to diagnose growth hormone deficiency (GHD) in comparison with clinical characteristics.
METHODS
For twenty five GHD children classified by GHST criteria during the recent 5 years, clinical characteristics and laboratory findings were correlated retrospectively through medical records.
RESULTS
Seventeen were idiopathic GHD and 8 were secondary GHD. 1) Among the idiopathic type, 8 had complete GHD (maximal stimulated GH <5 ng/mL), and the others had partial form (GH >5, and <10 ng/mL). For this group, IGF-1, height SDS, and degree of delayed bone age were not correlated with maximal stimulated GH level, while the IGFBP-3 and growth velocity before GH treatment were significantly correlated (P<0.05). Growth velocity was significantly increased from 5.1 to 8.6 cm/yr during treatment (P<0.0001). 2) Variable results were obtained in 5 patients with multiple GHST. One idiopathic patient changed from non GHD to complete GHD during 5 years. One patient operated for craniopharyngioma showed from non to partial, then non GHD. Diffuse brain atrophy patient showed from partial to complete GHD. Two secondary form patients showed from non to partial GHD. 3) Three patients among idiopathic type showed growth velocity more than 5 cm/yr even without GH treatment.
CONCLUSION
IGFBP-3 and growth velocity before treatment might be possible indicators to predict maximal stimulated GH level. In view of the variable results from multiple GHST, auxological and biological data should also be considered in diagnosis.