RESUMO
Prolactinomas are the most frequent pituitary tumors and may co-secrete GH (growth hormone). IGF-1 (insulin-like growth factor-1) is the main responsible for GH actions and a parameter for the diagnosis of acromegaly. With the objective of identifying through a IGF-1 levels analysis, in the initial evaluation of prolactinoma patients, the existence of mixed tumors [GH and prolactin (PRL)], we studied 7 men and 27 women, aged between 19 and 72 years, confronting them with the results of basal and glucose stimulated (glucose tolerance test--GTT) GH levels, indicated when GH >0.4 ng/mL or IGF-1 levels were elevated. The prevalence of patients with GH >0.4 ng/mL and elevated IGF-1 was higher than expected; however, after GTT, no patient fulfilled the diagnostic criteria for acromegaly. However, we suggest that, they should be submitted to IGF-1 evaluation, due to the risk of GH co-secretion in prolactinomas. Special attention should be paid to those who present a significant decrease of PRL levels without concomitant tumor size reduction.
Assuntos
Biomarcadores Tumorais/sangue , Fator de Crescimento Insulin-Like I/análise , Neoplasias Hipofisárias/sangue , Prolactinoma/sangue , Acromegalia/etiologia , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Ensaio Imunorradiométrico , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/complicações , Prolactinoma/complicações , Tomografia Computadorizada por Raios XRESUMO
Prolactinomas são os tumores hipofisários mais comuns, podendo co-secretar GH (hormônio do crescimento). IGF-1 (fator de crescimento insulina-símile-1) é o principal responsável pelas ações do GH e parâmetro diagnóstico de acromegalia. Objetivando determinar por uma dosagem de IGF-1, na avaliação inicial de pacientes com prolactinoma, ocorrência de tumores mistos [GH e prolactina (PRL)], estudamos 7 homens e 27 mulheres, entre 19 e 72 anos, confrontando-os aos resultados de GH basal e durante teste oral de tolerância à glicose, quando GH basal >0,4 ng/mL ou níveis de IGF-1 alterados. A proporção de pacientes com GH >0,4 ng/mL e IGF-1 elevada foi alta; mas, após administração de 75g de glicose por via oral, nenhum paciente foi diagnosticado como acromegálico. Sugerimos, porém que a dosagem de IGF-1 seja realizada pelo risco de co-secreção de GH nos prolactinomas. Atenção especial para pacientes que apresentem significativa diminuição dos níveis de PRL, sem correspondente regressão do tamanho do adenoma.
Prolactinomas are the most frequent pituitary tumors and may co-secrete GH (growth hormone). IGF-1 (insulin-like growth factor-1) is the main responsible for GH actions and a parameter for the diagnosis of acromegaly. With the objective of identifying through a IGF-1 levels analysis, in the initial evaluation of prolactinoma patients, the existence of mixed tumors [GH and prolactin (PRL)], we studied 7 men and 27 women, aged between 19 and 72 years, confronting them with the results of basal and glucose stimulated (glucose tolerance test - GTT) GH levels, indicated when GH >0.4 ng/mL or IGF-1 levels were elevated. The prevalence of patients with GH >0.4 ng/mL and elevated IGF-1 was higher than expected; however, after GTT, no patient fulfilled the diagnostic criteria for acromegaly. However, we suggest that, they should be submitted to IGF-1 evaluation, due to the risk of GH co-secretion in prolactinomas. Special attention should be paid to those who present a significant decrease of PRL levels without concomitant tumor size reduction.
