title: A very low dose intravenous dexamethasone suppression test as an index of glucocorticoid sensitivity.
abstract: OBJECTIVE
  The wide variability of responses to corticotherapy suggests a role for individual recognition of steroid sensitivity in order to customize treatment. Oral dexamethasone (DEX) administration may be hindered by the rate of its intestinal absorption and the liver first-passage effect. In this study we suggest that an intravenous very low dose DEX suppression test (VLD IV-DST) can be used as an index for glucocorticoid (GC) sensitivity.
  
  
  METHODS
  We evaluated 87 normal subjects: 44 prepubertal children, 23 adolescents and 20 adults with a VLD IV-DST using 20 mug/m(2) of DEX (dose able to recognize GC sensitivity). Cortisol was initially measured at several time-points after DEX prompting us to establish its nadir and subsequent simplification of the test by measuring cortisol at baseline and after 120 min.
  
  
  RESULTS
  Baseline cortisol was similar in adolescents and in adults, but lower in children. There was a spectrum of individual responses in all age groups. The percent reduction of cortisol after 120 min was different in these three age groups, with median values of 44.4% in children, 25.9% in adolescents and 61.6% in adults.
  
  
  CONCLUSIONS
  This simplified VLD IV-DST using 20 mug/m(2) of DEX is useful to evaluate individual sensitivity to GC in different age groups.
authors.affiliation: Pediatric Endocrinology Unit, Pediatric Department, Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, Brazil.
authors.forename: Cláudia Dutra Costantin
authors.initials: CD
authors.lastname: Faria
authors.forename: Jayme F
authors.initials: JF
authors.lastname: Cobra
authors.forename: Tatiane
authors.initials: T
authors.lastname: Sousa E Silva
authors.forename: Murilo Rezende
authors.initials: MR
authors.lastname: Melo
authors.forename: Mylene Neves
authors.initials: MN
authors.lastname: Rocha
authors.forename: Lílian Sukusima
authors.initials: LS
authors.lastname: Hayashi
authors.forename: Thelma Gomes
authors.initials: TG
authors.lastname: Faria
authors.forename: Julio Antonio
authors.initials: JA
authors.lastname: de Souza e Almeida
authors.forename: Cláudio Elias
authors.initials: CE
authors.lastname: Kater
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Longui
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003907:Dexamethasone / Q000008:administration & dosage; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011965:Receptors, Glucocorticoid / Q000187:drug effects*
chemical_list: D011965:Receptors, Glucocorticoid; D003907:Dexamethasone; D006854:Hydrocortisone