title: The utility of basal serum LH in prediction of central precocious puberty in girls.
abstract: OBJECTIVE
  The mainstay of distinction between prepubertal girls and girls who are suspected of having central precocious puberty (CPP) is based on gonadotropin measurements after a GnRH stimulation test to evaluate hypothalamic-pituitary-gonadal axis maturity. The objective of this study was to determine whether a single basal gonadotropin measurement carries a useful predictive value in verifying or refuting the diagnosis of CPP.
  
  
  METHODS
  Basal serum LH and FSH were measured by a chemiluminescent immunometric assay in a cohort of girls who had been evaluated for CPP before and after GnRH stimulation test. Peak LH levels higher than 5 IU/l were considered a pubertal response.
  
  
  RESULTS
  Eighty girls with suspected breast development before 8 years of age were enrolled to the study, out of whom 42 had CPP. Low basal serum LH (≤0.1 IU/l) was sufficient to rule out the diagnosis of CPP in 94.7% of the 38 prepubertal girls; the sensitivity of basal LH levels for this purpose was only 64%. The basal FSH and the basal LH to FSH ratio achieved less efficient predictive value with 76 and 71% sensitivity and 73 and 86% specificity respectively.
  
  
  CONCLUSIONS
  A single basal LH measurement may be adequate to confirm but not to refute the presence of CPP in most of the girls who are evaluated for early pubertal signs.
authors.affiliation: Pediatric Endocrinology and Metabolism Unit, Faculty of Health Sciences, Soroka Medical Center, Ben-Gurion University of the Negev, PO Box 151, IL-84101 Beer-Sheva, Israel.
authors.forename: Yehonatan
authors.initials: Y
authors.lastname: Pasternak
authors.forename: Michael
authors.initials: M
authors.lastname: Friger
authors.forename: Neta
authors.initials: N
authors.lastname: Loewenthal
authors.forename: Alon
authors.initials: A
authors.lastname: Haim
authors.forename: Eli
authors.initials: E
authors.lastname: Hershkovitz
mesh_terms: D015415:Biomarkers / Q000097:blood; D002493:Central Nervous System Diseases / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D002648:Child; D003940:Diagnostic Techniques, Endocrine; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005500:Follow-Up Studies; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011629:Puberty, Precocious / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone