Growth Hormone Secretory Status Evaluated by Growth Hormone Peak after Two Pharmacological Growth Hormone Release Stimuli Did Not Significantly Influence the Two-Year Catch-Up Growth Induced by Growth Hormone Therapy in 318 Prepubertal Short Children with Idiopathic Growth Retardation

Abstract

Background/Aims: In prepubertal short children with idiopathic growth retardation, growth hormone (GH) peak after GH release stimuli classifies patients as growth hormone- deficient (GHD) or non-GHD. This study compared a 2-year growth response to GH therapy in 318 prepubertal short children. Methods: Patients were classified as: severe GHD (GH peaks <5 ng/ml after 2 stimuli; n = 54), mild GHD (GH peaks <10 ng/ml, but one or two between 5 and 10 ng/ml; n = 140), dissociated GH release (GH peak ≧10 ng/ml after 1 stimulus and <10 ng/ml after the other; n = 89), and normal GH release (GH peaks ≧10 ng/ml after 2 stimuli; n = 35). Results: Two-year height gain did not differ statistically among the 4 groups: 1.39 ± 0.51 SD, 16.4 ± 2.3 cm; 1.23 ± 0.56 SD, 15.8 ± 2.1 cm; 1.18 ± 0.53 SD, 15.3 ± 2.0 cm, and 1.14 ± 0.53 SD, 15.4 ± 2.0 cm, respectively, as was also the case for bone age gain: 2.5 ± 0.6, 2.4 ± 0.7, 2.6 ± 0.7 and 2.3 ± 0.5 years, respectively. Conclusions: Our results suggest that GH release stimuli are of little help for deciding on GH therapy in the clinical management of prepubertal short children with idiopathic growth retardation, while well-defined anthropometric and biochemical criteria may be useful.

Height Gain at Adult-Height Age in 184 Short Patients Treated with Growth Hormone from Prepubertal Age to Near Adult-Height Age is Not Related to GH Secretory Status at GH Therapy Onset

“…128 (70.0%) patients, a proportion of which had been included in other clinical studies [1,15,16], stemmed from a single center (Pediatric Endocrine Unit of the University Children's Hospital Vall d'Hebron, Barcelona), 46 from 13 Catalan centers and the remaining 10 from one Basque center. Procedures for the diagnosis and follow-up of these children were similar at all these hospitals.…”

“…In short prepubertal children with growth retardation and normal gastrointestinal, kidney, liver, metabolic, pulmonary and thyroid functions and in whom skeletal abnormalities and known causes of short stature have been ruled out, GH release after paired GH secretory stimuli classifies them as severe idiopathic isolated GH-deficient (severe IIGHD), mild idiopathic isolated GH-deficient (mild IISGHD), dissociated GH release (DGHR) and normal GH release (NGHR) [1]. Moreover, birth length and/or weight classified them as born adequate for gestational age (AGA) or small for gestational age (SGA).…”

“…However, they are used for diagnosis and for deciding on GH therapy since no better alternatives are currently available for the evaluation of GH secretion in clinical practice [1,3,9,10,11,12,13,14]. …”

“…We suggested that in the clinical management of these children, GH-release stimuli are of little help for deciding on GH therapy and pointed out that long-term studies evaluating the adult-height gain would be necessary to confirm or deny our suggestion [1]. …”

Clonidine Plus GHRH Administration for Diagnosing Growth Hormone Deficiency in Children

“…In addition, classical provocative tests are unable to characterize the various GH-deficient states. Therefore, the utility of these tests continues to be a matter of controversy [30]. In fact, more than 30 different stimuli for analyzing GH secretion have been already described [31].…”