title: Diagnostic utility of testosterone priming prior to dynamic tests to differentiate constitutional delay in puberty from isolated hypogonadotropic hypogonadism.
abstract: BACKGROUND
  Differentiation between constitutional delay in puberty (CDP) and isolated hypogonadotropic hypogonadism (IHH) during adolescence is a great clinical challenge, and the available diagnostic tests are of limited value.
  
  
  OBJECTIVE
  To study the effect of withdrawal of short-term, low-dose testosterone therapy (testosterone priming) on the discriminatory power of dynamic tests for hypothalamo-pituitary-testicular axis to differentiate CDP from IHH.
  
  
  METHODS
  A prospective study (n = 30) consisting of 20 boys with delayed puberty (group A) and 10 patients with IHH (group B).
  
  
  METHODS
  Patients in groups A and B underwent Triptorelin and hCG stimulation tests, prior to and 2 months after withdrawal of 'testosterone priming' (100 mg intramuscularly 4 weekly for 3 months) and were followed up until the onset of puberty or 18 years of age, whichever was earlier.
  
  
  RESULTS
  At baseline, Triptorelin-stimulated 4 h LH, with a cut-off of 2·8 IU/l, and hCG-stimulated day 7 testosterone with a cut-off of 3·8 nmol/l had sensitivities of 80% each, and specificities of 93% and 87%, respectively, to diagnose CDP. After withdrawal of testosterone, a 4 h LH cut-off of 14·7 IU/l and day 7 testosterone cut-off of 10·3 nmol/l had sensitivities of 93% and 88% respectively, and specificity and positive predictive value of 100% each. A basal inhibin B > 94·7 ng/l was discriminatory for diagnosing CDP after withdrawal of testosterone priming.
  
  
  CONCLUSIONS
  Inhibin B levels or 4 h LH after Triptorelin stimulation are the best discriminatory tests to differentiate CDP from IHH, when performed after withdrawal of 'testosterone priming'.
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Suja P
authors.initials: SP
authors.lastname: Sukumar
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Bhansali
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Naresh
authors.initials: N
authors.lastname: Sachdeva
authors.affiliation: Department of Radiodiagnosis, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Chirag Kamal
authors.initials: CK
authors.lastname: Ahuja
authors.affiliation: Department of Radiodiagnosis, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Ujjwal
authors.initials: U
authors.lastname: Gorsi
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Kush Dev Singh
authors.initials: KD
authors.lastname: Jarial
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Rama
authors.identifier: http://orcid.org/0000-0002-6633-923X
authors.initials: R
authors.lastname: Walia
mesh_terms: D000293:Adolescent; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D007006:Hypogonadism / Q000097:blood* / Q000175:diagnosis*; D007265:Inhibins; D007986:Luteinizing Hormone / Q000097:blood; D008186:Luteolytic Agents / Q000008:administration & dosage; D008297:Male; D011237:Predictive Value of Tests; D011628:Puberty, Delayed / Q000097:blood* / Q000175:diagnosis*; D013739:Testosterone / Q000008:administration & dosage*; D017329:Triptorelin Pamoate / Q000008:administration & dosage
chemical_list: D008186:Luteolytic Agents; C422364:inhibin B; D017329:Triptorelin Pamoate; D013739:Testosterone; D007265:Inhibins; D007986:Luteinizing Hormone