title: Baseline and stimulated cortisol levels in preterm infants: is there any clinical relevance?
abstract: OBJECTIVE
  To evaluate the association between the cortisol levels and clinical outcomes in preterm infants.
  
  
  METHODS
  Baseline adrenocorticotropic hormone (ACTH) and cortisol levels and ACTH-stimulated cortisol concentrations after low-dose synthetic ACTH (Synacthen®, 1 μg/kg) were measured in preterm infants <37 weeks of gestational age between the 5th and 7th days of life. Associations between cortisol concentrations and clinical outcomes were examined. The prevalence and prognostic utility of relative adrenal insufficiency (AI) were assessed.
  
  
  RESULTS
  Ninety-eight preterm infants were enrolled. Median baseline cortisol and ACTH levels were 13.7 μg/dl (25th-75th percentile, 9.7-21.1 μg/dl) and 11.5 pg/ml (25th-75th percentile, 6.9-22.6 pg/ml), respectively. Median peak cortisol level after ACTH stimulation was 33.6 μg/dl (25th-75th percentile, 27.2-40.2 μg/dl). The prevalence of relative AI, defined as baseline cortisol <15 μg/dl or Δ-cortisol <9 μg/dl, was 65%. Cortisol levels at baseline and at all time points during the test and relative AI were not associated with mortality or any other clinical outcomes.
  
  
  CONCLUSIONS
  Neither baseline nor ACTH-stimulated cortisol levels were associated with clinical outcomes in preterm infants. A significant proportion of preterm infants hospitalized in the neonatal unit fulfilled the criteria for relative AI; however, relative AI did not affect outcome.
authors.affiliation: Neonatal Intensive Care Unit, Zekai Tahir Burak Maternity Teaching Hospital, Ankara, Turkey. fatmanurselek@yahoo.com
authors.forename: Fatma Nur
authors.initials: FN
authors.lastname: Sari
authors.forename: Evrim Alyamac
authors.initials: EA
authors.lastname: Dizdar
authors.forename: Serife Suna
authors.initials: SS
authors.lastname: Oguz
authors.forename: Nesibe
authors.initials: N
authors.lastname: Andiran
authors.forename: Omer
authors.initials: O
authors.lastname: Erdeve
authors.forename: Nurdan
authors.initials: N
authors.lastname: Uras
authors.forename: Raziye
authors.initials: R
authors.lastname: Memik
authors.forename: Ugur
authors.initials: U
authors.lastname: Dilmen
mesh_terms: D000311:Adrenal Glands / Q000502:physiology*; D000309:Adrenal Insufficiency / Q000175:diagnosis; D000324:Adrenocorticotropic Hormone; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D007363:Intensive Care Units, Neonatal; D008297:Male; D011446:Prospective Studies
chemical_list: D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone