RESUMO
OBJECTIVE: The aim of this study is to determine the cutoff values of gonadotropin response to gonadotropin-releasing hormone analogs (GnRHas) corresponding to the activation of the hypothalamic-pituitary-gonadal axis that could differentiate central precocious puberty (CPP) from premature thelarche (PT) and using the electrochemiluminescence assay method. METHODS: A total of 49 girls underwent the stimulation test with an intramuscular injection of 3.75 mg leuprolide acetate. Based on the clinical and laboratory characteristics, they were divided into two groups: CPP (n = 22) and PT (n = 27). Baseline estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were collected before GnRHa administration and LH and FSH at 60 and 120 min, respectively, after GnRHa administration. RESULTS: The girls with CPP presented an increased height Z-score, advanced bone age, and higher baseline LH, FSH, estradiol, and LH/FSH ratio in relation to PT (p < 0.001). Stimulated LH differed significantly between the two groups, and the LH cutoff values were ≥4.29 IU/L (p < 0.001) and ≥3.95 IU/L at 60 and 120 min, respectively (p < 0.001). The LH peak was found at 60 min after stimulation. CONCLUSIONS: The GnRHa test is effective in distinguishing CPP from PT, and a single sampling, at 60 min, with LH concentrations above 4.29 may be the parameter of choice with the advantage of greater convenience and practicality.
Assuntos
Puberdade Precoce , Feminino , Hormônio Foliculoestimulante , Hormônio Liberador de Gonadotropina , Gonadotropinas , Humanos , Hormônio Luteinizante , Puberdade Precoce/diagnóstico , Puberdade Precoce/tratamento farmacológicoRESUMO
Se define Telarquía Precoz como la aparición del botón mamario antes de los ocho años en ausencia de otros signos de pubertad. En los primeros años de vida puede ser secundaria al fenómeno de la minipubertad, mientras que en la etapa escolar podría ocurrir debido a la interacción entre disruptores endocrinológicos y la obesidad. Una parte importante se mantiene estacionaria o revierte, mientras que un pequeño porcentaje puede evolucionar hacia la pubertad precoz. Se debe realizar una anamnesis y examen físico adecuado buscando otros signos puberales, una buena curva de crecimiento y puede complementarse con imágenes y con un seguimiento para intentar determinar aquellas pacientes que evolucionarán hacia la pubertad precoz.
Premature thelarche is defined as the breast bud appearance before eight years, without other signs of puberty development. During the first years of life it can be secondary to the minipuberty phenomenon, while during school period it's usually secondary to the interaction between endocrine disruptors and obesity. Although most of cases remain stable or regresses, a small percentage can evolve to precocious puberty. An appropriate clinical history and physical exam looking for other signs of precocious puberty must be held, complemented with the correspondent follow up and images studies, in order to diagnose patients that will evolve to precocious puberty.
Assuntos
Humanos , Feminino , Pré-Escolar , Criança , Puberdade Precoce/diagnóstico , Puberdade Precoce/etiologia , Puberdade Precoce/epidemiologia , Exame Físico , Algoritmos , Disruptores Endócrinos/efeitos adversos , Displasia Fibrosa Poliostótica , Anamnese , Obesidade/complicaçõesRESUMO
In order to establish cut-off limits and to distinguish isolated premature thelarche (IPT) from precocious puberty (PP), we evaluated data from 79 girls with premature thelarche, comparing basal and stimulated LH and FSH serum concentrations with those from 91 healthy girls. A GnRH stimulation test was performed in 10 normal girls and in 42 with premature thelarche. Comparison among groups was performed by Kruskal-Wallis and Dunns tests. LH values were significantly greater in girls with IPT than in control groups. Basal gonadotropin concentrations were higher in patients with PP than in controls, but not different from patients with IPT. Peak LH levels after GnRH stimulation distinguished those two groups, with a cut-off value of 4.0 IU/L, but still with minimal overlap. In conclusion, a girl with premature thelarche and LH peak value above 4.5 IU/L has, indeed, PP, but values between 3.5 and 4.5 IU/L point to careful follow-up.
Com o objetivo de estabelecer o valor de corte e distinguir telarca precoce isolada (TPI) de puberdade precoce (PP), avaliamos 79 meninas com telarca precoce, comparando as dosagens basais e pós-estímulo de LH e FSH com grupo-controle. O teste de estímulo com GnRH foi realizado em 10 meninas normais e em 42 com telarca precoce. Os testes de Kruskal-Wallis and Dunn foram usados na comparação dos grupos. Os níveis de LH foram significativamente mais elevados no grupo com TPI, quando comparados com controles. As gonadotrofinas basais foram mais elevadas naquelas com PP que nos controles, mas não diferiram do grupo com TPI. O pico de LH após GnRH distinguiu estes dois grupos, com valor de corte de 4,0 UI/L, apesar de pequena sobreposição. Concluímos que uma menina com telarca precoce e LH pós-estímulo acima de 4,5 UI/L apresenta PP, mas valores entre 3,5 e 4,5 UI/L requerem seguimento cuidadoso.