F Chiarelli, H Delemarre-van de Waal, L Ghizzoni and I Hughes
M Wasniewska, T Arrigo, M Cisternino, F De Luca, L Ghizzoni, M Maghnie and M Valenzise
OBJECTIVE: To investigate which pretreatment variables most significantly affect long-term growth response to GH therapy in children with apparently idiopathic GH deficiency (GHD) treated from a similar and very young age (less than 2 years), for the same period (7 years) and with the same therapeutic protocol. DESIGN AND METHODS: Twelve children with either isolated GHD or multiple pituitary hormone deficiency were treated with biosynthetic human GH (0.7IU/kg per week) and were examined every 6 months. Height measurements were performed by Harpenden stadiometers. Bone age was evaluated every 12 months. RESULTS: The onset of therapy was followed in all patients by an important height gain, which attained its zenith during the first year of treatment and became progressively less evident during the next 4 years. Cumulative height gain was 3.0+/-1.7SDS. Thanks to the therapy, at the end of the 7-year treatment period, average height in the entire series was not significantly far from mean target height (TH) (-0.7+/-1.3 vs -0. 3+/-0.4SDS) and average predicted height (PH) (-0.2+/-1.4SDS) was very close to TH. A stepwise regression analysis showed that both catch-up growth under therapy and PH at the end of the 7-year treatment period were positively influenced by birth weight (BW). CONCLUSIONS: a) Our 7-year prospective study on GHD infants treated with GH from less than 2 years of age confirmed the importance of early diagnosis and treatment of GHD in childhood. b) The influence of BW on growth response to GH therapy in GHD children persists over time, at least when treatment is begun from less than 2 years of age.
MF Messina, F De Luca, M Wasniewska, M Valenzise, F Lombardo and L Ghizzoni
Data concerning final height (FH) in isolated growth hormone deficiency type 1A (IGHD1A) are scanty and controversial. In this paper we report the FH outcome of two girls with IGHD1A who were treated either with GH only (first patient) or with GH during the first 8 years and successively with IGF-I (second patient). In the first patient, FH was only slightly subnormal and slightly taller with respect to target height (TH). Surprisingly, FH was severely subnormal and very far from TH in the patient who underwent IGF-I therapy for >5 years: an auxological outcome similar to the one recently reported in the only two cases in the literature of patients with IGHD1A who have been treated with IGF-I until near FH achievement. We conclude that IGHD1A could have a very heterogeneous phenotypic expression in terms of FH and that IGF-I therapy, even though initiated some years before puberty onset and prolonged for more than 5 years, may not be able to ensure the normalization of height prognosis and the achievement of an FH close to TH.
J Bellone, L Ghizzoni, G Aimaretti, C Volta, MF Boghen, S Bernasconi and E Ghigo
Bellone J, Ghizzoni L, Aimaretti G, Volta C, Boghen MF, Bernasconi S, Ghigo E. Growth hormonereleasing effect of oral growth hormone-releasing peptide 6 (GHRP-6) administration in children with short stature. Eur J Endocrinol 1995;133:425–9. ISSN 0804–4643
Growth hormone-releasing peptide 6 (GHRP-6) is a synthetic hexapeptide with a potent GH-releasing activity after intravenous, subcutaneous, Intranasal and oral administration in man. Previous data showed its activity also in some patients with GH deficiency. The aim of our study was to verify the GH-releasing activity of oral GHRP-6 administration on GH secretion in children with normal short stature. The effect of oral GHRP-6 (300 μg/kg) was compared with that of the maximally effective dose of intravenous GH-releasing hormone (GHRH-29, 1 μg/kg). As the GHRH-induced GH rise in children is potentiated by arginine (ARG), even when administered by oral route at low dose (4 g), we studied also the interaction of oral GHRP-6 and ARG administration. We studied 13 children (nine boys and four girls aged 6.2–10.5 years, pubertal stage I) with normal short stature (height less than –2 sd score; height velocity more than –2 sd score; normal bone age; insulin-like growth factor I > 70 μg/l), In a first group of children (N = 7), oral GHRP-6 administration induced a GH response (mean ± sem, peak at 60 min vs baseline: 18.8 ±3.0 vs 1.1 ± 0.3 μg/l, p < 0.0006; area under curve: 1527.3 ± 263.9 μgl−1 h) which was similar to that elicited by GHRH (peak at 45 min vs baseline: 20.8 ±4.5 vs 2.2±0.9 μg/l, p <0.007; area under curve: 1429.4 ± 248.2 μgl−1 h−1). In a second group of children (N = 6), the GH response to oral GHRP-6 administration (peak at 75 min vs baseline: 18.5 ±5.1 vs 1.5 ± 0.6 μg/l, p < 0.01; area under curve: 1598.5 ± 289.3 μgl−1 h−1) was not modified by co-administration of oral ARG (peak at 90 min vs baseline: 15.2 ±5.6 vs 0.9±0.3 μg/l, p < 0.002; area under curve: 1327.8 ± 193.2 μgl−1 h−1). The amount of GH released and the timing of the somatotrope response after the oral administration of GHRP-6 were similar in the two groups. In conclusion, the present data show that in normal short children the oral administration of GHRP-6 is able to increase GH secretion to an extent similar to that observed after intravenous administration of the maximally effective GHRH dose. Moreover, in contrast to GHRH, the effect of GHRP-6 is not enhanced by low-dose oral ARG. As this amino acid likely acts via inhibition of hypothalamic somatostatin release, our data suggest that a decrease in the somatostatinergic activity does not improve the GH-releasing effect of GHRP-6 in childhood, at variance with that observed after GHRH. Our results suggest that GHRP-6 could be clinically useful to stimulate GH secretion in short children.
E Ghigo, Divisione di Endocrinologia, Ospedale Molinette, C. so. AM Dogliotti 14, 10126 Torino, Italy
A Vottero, V Rochira, M Capelletti, I Viani, L Zirilli, T M Neri, C Carani, S Bernasconi and L Ghizzoni
Objective: Aromatase, the key enzyme involved in estrogen synthesis, is expressed in a variety of cells and tissues including human peripheral blood leukocytes (PBLs). The present study was designed to evaluate PBL aromatase gene expression in male and female subjects of different age groups. In addition, differences in gene expression during the follicular and luteal phase of the menstrual cycle in women, and before and after testosterone administration in men, were estimated.
Design: Aromatase mRNA and protein were measured in PBLs obtained from young (n = 10) and postmenopausal women (n = 10), men (n = 15), and prepubertal children (n = 10). Aromatase mRNA and protein were also measured during the follicular and luteal phases of the menstrual cycle in women, and before and after the intramuscular administration of 250 mg testosterone enanthate in men.
Methods and Results: Aromatase mRNA measured by real-time PCR in PBLs from women during the follicular phase was significantly higher than during the luteal phase of the menstrual cycle (P < 0.05). In men, PBL aromatase mRNA values increased significantly following testosterone administration (P < 0.05). PBL mRNA aromatase levels in women during the follicular phase and men after testosterone administration were significantly higher (one-way ANOVA; P < 0.05) than in any other group. Children, postmenopausal women, and women during the luteal phase showed the lowest aromatase mRNA expression. The results of the immunoblot analysis confirmed the data obtained by real-time PCR. A positive correlation between PBL aromatase mRNA values and plasma estradiol and estrone levels during the follicular phase of the menstrual cycle was observed in the group of adult women. No other correlations were found.
Conclusions: The aromatase gene is differentially expressed in PBLs from women, men, and prepubertal children, indicating a sexual dimorphism in the enzyme expression and an important role of sex steroids in the modulation of aromatase gene expression.
T Arrigo, F De Luca, M Maghnie, A Blandino, F Lombardo, MF Messina, M Wasniewska, L Ghizzoni and M Bozzola
In this study, perinatal history, postnatal auxological and clinical evolution and endocrine features were retrospectively evaluated in 49 children, adolescents and young adults with apparently idiopathic hypopituitarism. They were divided into two groups according to magnetic resonance images: 32 patients with isolated pituitary hypoplasia (group A) and 17 with pituitary stalk interruption syndrome (group B). The aim of the study was to assess whether these neuroradiological pictures are associated with specific endocrine and clinical patterns. No significant difference in terms of gestational age, intrauterine growth and rates of adverse perinatal events was found between the two groups. Clinical signs documenting the existence of pituitary dysfunction in utero or shortly after birth were either slightly (micropenis, cryptorchidism, cholestatic jaundice) or significantly (hypoglycemia) more frequent in patients in group B. Although diagnosis of hypopituitarism was made significantly earlier in patients in group B, height deficiency at diagnosis was similar in both groups. Endocrine investigations revealed a more severe and widespread impairment of pituitary function among those in group B. The main conclusion is that the postnatal clinical course is more severe when growth hormone deficiency is associated with pituitary stalk interruption syndrome than when the pituitary is only reduced in height, probably because of the more severe and widespread impairment of pituitary function in the former cases.