Chiara Guzzetti1, Anastasia Ibba1, Sabrina Pilia1, Nadia Beltrami2, Natascia Di Iorgi3, Alessandra Rollo4, Nadia Fratangeli3, Giorgio Radetti2, Stefano Zucchini4, Mohamad Maghnie3, Marco Cappa5, Sandro Loche6. 1. SSD Endocrinologia PediatricaOspedale Pediatrico Microcitemico "A. Cao", Cagliari, Italy. 2. Ospedale Generale RegionaleBolzano, Italy. 3. Clinica Pediatrica, Istituto Giannina Gaslini, Universitá di GenovaGenova, Italy. 4. Universitá di BolognaOspedale S.Orsola-Malpighi, Bologna, Italy. 5. UOC di Endocrinologia e DiabetologiaOspedale Pediatrico Bambino Gesú IRCCS, Roma, Italy. 6. SSD Endocrinologia PediatricaOspedale Pediatrico Microcitemico "A. Cao", Cagliari, Italy sandro.loche@aob.it.
Abstract
OBJECTIVE: The diagnosis of GH deficiency (GHD) in children and adolescents is established when GH concentrations fail to reach an arbitrary cut-off level after at least two provocative tests. The objective of the study was to define the optimal GH cut-offs to provocative tests in children and adolescents. DESIGN: Retrospective study in 372 subjects who underwent evaluation of GH secretion. GH and IGF-I were measured by chemiluminescence assay in all samples. Receiver operating characteristic (ROC) analysis was used to evaluate the optimal GH cut-offs and the diagnostic accuracy of provocative tests. METHODS: Seventy four patients with organic GHD (GH peak <10μg/L after two provocative tests) and 298 control subjects (GH response >10μg/L to at least one test) were included in the study. The provocative tests used were arginine, insulin tolerance test (ITT) and clonidine. Diagnostic criteria based on cut-offs identified by ROC analysis (best pair of values for sensitivity and specificity) were evaluated for each test individually and for each test combined with IGF-I SDS. RESULTS: The optimal GH cut-off for arginine resulted 6.5μg/L, 5.1μg/L for ITT and 6.8μg/L for clonidine. IGF-I SDS has low accuracy in diagnosing GHD (AUC=0.85). The combination of the results of provocative tests with IGF-I concentrations increased the specificity. CONCLUSIONS: The results of the ROC analysis showed that the cut-off limits which discriminate between normal and GHD are lower than those commonly employed. IGF-I is characterized by low diagnostic accuracy.
OBJECTIVE: The diagnosis of GH deficiency (GHD) in children and adolescents is established when GH concentrations fail to reach an arbitrary cut-off level after at least two provocative tests. The objective of the study was to define the optimal GH cut-offs to provocative tests in children and adolescents. DESIGN: Retrospective study in 372 subjects who underwent evaluation of GH secretion. GH and IGF-I were measured by chemiluminescence assay in all samples. Receiver operating characteristic (ROC) analysis was used to evaluate the optimal GH cut-offs and the diagnostic accuracy of provocative tests. METHODS: Seventy four patients with organic GHD (GH peak <10μg/L after two provocative tests) and 298 control subjects (GH response >10μg/L to at least one test) were included in the study. The provocative tests used were arginine, insulin tolerance test (ITT) and clonidine. Diagnostic criteria based on cut-offs identified by ROC analysis (best pair of values for sensitivity and specificity) were evaluated for each test individually and for each test combined with IGF-ISDS. RESULTS: The optimal GH cut-off for arginine resulted 6.5μg/L, 5.1μg/L for ITT and 6.8μg/L for clonidine. IGF-ISDS has low accuracy in diagnosing GHD (AUC=0.85). The combination of the results of provocative tests with IGF-I concentrations increased the specificity. CONCLUSIONS: The results of the ROC analysis showed that the cut-off limits which discriminate between normal and GHD are lower than those commonly employed. IGF-I is characterized by low diagnostic accuracy.
Authors: João Soares Felício; Luísa Corrêa Janaú; Marcelle Alves Moraes; Nathalie Abdallah Zahalan; Fabrício de Souza Resende; Manuela Nascimento de Lemos; Norberto Jorge Kzan de Souza Neto; Isabela Imbelloni Farias de Franco; Loyane Tamyres Costa Leitão; Lilian de Souza d'Albuquerque Silva; Maria Clara Neres Iunes de Oliveira; Angélica Leite de Alcântara; Ana Carolina Contente Braga de Souza; Wanderson Maia da Silva; Márcia Costa Dos Santos; Natércia Neves Marques de Queiroz; Lorena Vilhena de Moraes; Antônio Bentes de Figueiredo; Ana Luiza Prieto Farinassi; Luciana Marques da Costa Farias; Danielle Dias da Silva; Karem Miléo Felício; João Felício Abrahão Neto Journal: Front Endocrinol (Lausanne) Date: 2019-09-19 Impact factor: 5.555
Authors: Mohamad Maghnie; José I Labarta; Ekaterina Koledova; Tilman R Rohrer Journal: Front Endocrinol (Lausanne) Date: 2018-01-11 Impact factor: 5.555