title: Gonadotropin and Estradiol Levels after Leuprolide Stimulation Tests in Brazilian Girls with Precocious Puberty.
abstract: OBJECTIVE
  To determine the best cutoff value on the leuprolide stimulation test for the diagnosis of central precocious puberty (CPP) in a Brazilian population.
  
  
  METHODS
  This observational study included 60 girls with CPP, as shown on the basis of serum concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) before and 3 hours after subcutaneous administration of 500 μg leuprolide acetate and by measuring serum estradiol concentrations 24 hours later. Six months later, each subject was clinically evaluated to determine whether she had experienced progressive or nonprogressive puberty.
  
  
  METHODS
  Analyzing the best cutoff for LH after subcutaneous administration of 500 μg leuprolide acetate.
  
  
  RESULTS
  The best cutoff was a 3-hour LH level of greater than 4.0 mIU/mL, providing the highest sensitivity (73%) and specificity (83.1%), whereas a 3-hour LH level greater than 8.4 mIU/mL had a specificity of 100%. A 24-hour E2 concentration greater than 52.9 pg/mL had a sensitivity of 68% and a specificity of 74%. There was no association between pubertal development and disease progression. Signs such as thelarche and pubarche did not determine the evolution of the disease (P = .17). Clinical condition was associated with bone age/chronological age (P = .01), basal LH (P < .01), 3-hour LH (P = .02), baseline LH/FSH indices (P < .01) and after 3 hours (P < .01), and E2 at 24 hours (P = .02).
  
  
  CONCLUSIONS
  The optimal parameter indicating hypothalamic-pituitary-gonadal axis activation in our sample was a 3-hour LH level greater than 4.0 mIU/mL. A diagnosis of CPP, however, should be based on a set of criteria and not on an isolated measurement, because typical laboratory findings associated with CPP may not be present in all patients.
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil.
authors.forename: Flavia R R
authors.initials: FR
authors.lastname: Junqueira
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil.
authors.forename: Lucia A S
authors.initials: LA
authors.lastname: Lara
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil.
authors.forename: Wellington P
authors.initials: WP
authors.lastname: Martins
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil.
authors.forename: Rui A
authors.initials: RA
authors.lastname: Ferriani
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil.
authors.forename: Ana Carolina J S
authors.initials: AC
authors.lastname: Rosa-E-Silva
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil.
authors.forename: Marcos Felipe S
authors.initials: MF
authors.lastname: de Sá
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, Brazil. Electronic address: romareis@fmrp.usp.br.
authors.forename: Rosana M
authors.initials: RM
authors.lastname: Reis
mesh_terms: D000293:Adolescent; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D004958:Estradiol / Q000097:blood*; D005260:Female; D006065:Gonadotropins, Pituitary / Q000097:blood*; D006801:Humans; D016729:Leuprolide / Q000008:administration & dosage*; D011446:Prospective Studies; D011629:Puberty, Precocious / Q000097:blood / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012741:Sexual Maturation
chemical_list: D006065:Gonadotropins, Pituitary; D004958:Estradiol; D016729:Leuprolide
keywords: Estrogen; GnRH analog testing; Leuprolide stimulation; Luteinizing hormone; Precocious puberty