RESUMO
We critically evaluated the diagnostic value of IGF-I and IGF-binding protein-3 (IGFBP-3) in GH deficiency (GHD) in children and adults using receiver operating characteristic (ROC) plot analysis. Sixty-six children (chronological age, 1.3-15 yr) were studied: 34 GHD and 32 idiopathic short stature (ISS). Ninety-two adults (chronological age, 18-70 yr) were also evaluated: 72 GHD, 34 of childhood onset (AGHD-CO), and 38 of adult onset (AGHD-AO); and 20 healthy volunteers. The SD score (SDS) for IGF-I was calculated from 596 normal subjects (212 children and 384 adults), and the SDS for IGFBP-3 was calculated from 350 normal subjects (212 children and 138 adults). The ROC plot showed that the best IGF-I SDS cut-off line was -1.65 for children [sensitivity (S), 68%; specificity (Sp), 97%, diagnostic efficiency (DEf), 81%], the cut-off line for AGHD was -1.65 for AGHD-CO (S, 91%; Sp, 100%; DEf, 94%), and the cut-off line for AGHD-AO was -1.80 (S, 81%; Sp, 100%; DEf, 88%). For IGFBP-3 SDS, the best cut-off line was -1.80 for children (S, 90%; Sp, 60%; DEf, 78%); it was -1.45 for AGHD-CO (S, 90%; Sp, 75%; DEf, 82%) and -0.90 for AGHD-AO (S, 90%; Sp, 68%; DEf, 77%). An accurate diagnosis was obtained using IGF-I SDS alone in GHD children 65%; ISS, 97%; AGHD-CO, 92%; AGHD-AO, 86%, with IGFBP-3 SDS alone in GHD children 60%; ISS, 90%; AGHD-CO, 75%; AGHD-AO, 68%. Considering both, an accurate diagnosis was obtained in GHD children 60%; ISS, 87%; AGHD-CO, 71%; AGHD-AO, 64%. In conclusion, our findings support the need to use cut-off lines expressed in SDS obtained using an appropriate statistical methodology for better characterization of the various clinical presentations. IGF-I proved to be more useful because of its good diagnostic efficiency and accuracy in both children and adults, whereas IGFBP-3 did not significantly contribute to the diagnosis of GHD.
Assuntos
Transtornos do Crescimento/sangue , Transtornos do Crescimento/diagnóstico , Hormônio do Crescimento Humano/deficiência , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Curva ROC , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Avaliação como Assunto , Feminino , Humanos , Ensaio Imunorradiométrico/normas , Lactente , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos TestesRESUMO
UNLABELLED: The aim of this study was to evaluate the usefulness of the domperidone test for the difficult diagnosis between functional and tumoral hyperprolactinemia. We evaluated 36 patients, aged 5-18 years, 14 (12 F, 2 M) with hyperprolactinemia (non-tumoral: 10; pituitary adenoma: 4) and 22 individuals as a control group (prepubertal: 5 F, 8 M; pubertal: 4 F, 5 M). Basal prolactin (PRL) (IRMA-DPC), T4 and TSH and PRL 30 min post-domperidone (0.2 mg/kg b. wt i.v.) were measured. Non-tumoral hyperprolactinemic females showed basal PRL: 45 (29-80) (median and range) ng/ml; post-domperidone: 208 (116-290) ng/ml; delta PRL (PRL 30' - PRL 0'): 167 (77-252) ng/ml; and PRL ratio (PRL 30'/PRL 0'): 3.9 (2.3-7.6). Females with pituitary adenoma showed basal PRL: 129 (125-660) ng/ml; post-domperidone: 202 (150-535) ng/ml; delta PRL: 73 (25-135) ng/ml; and ratio: 1.2 (0.8-1.6). Two males, one with a non-tumoral hyperprolactinemia and the other one with a pituitary adenoma, presented, respectively, PRL 0':45, 160; PRL 30':130, 173; delta: 85, 13; ratio: 2.9, 1.1. All non-tumoral patients showed a PRL ratio (30'/0') > 2.3, while no patient with pituitary adenoma had a ratio > 1.6. CONCLUSIONS: PRL response to domperidone allowed us to characterize hyperprolactinemias, although the presence of a blunted response should be confirmed in a larger number of patients with tumors with 'low' PRL levels (dependence on etiology or basal PRL level?).