title: Salivary and serum cortisol and relation to blood pressure in infancy and early childhood in very-low-birth-weight infants.
abstract: BACKGROUND
  Programming of the hypothalamic-pituitary-adrenal (HPA) axis possibly explains the relation between intrauterine growth restriction (IUGR) and/or preterm birth and elevated blood pressure in later life. Very-low-birth-weight infants (birth weight <1,500 g) have high prevalence of raised blood pressure, already in early childhood. We investigated cortisol levels, relation to blood pressure and reliability of salivary cortisol in infancy and early childhood in very-low-birth-weight infants.
  
  
  METHODS
  We included 41 children, participating in the randomized controlled Neonatal Insulin Replacement Therapy in Europe (NIRTURE) trial. Serum and salivary samples for cortisol measurement (immunoassay) were taken simultaneously at 6 mo and separately at 2 y corrected age. Blood pressure was measured at 2 y corrected age.
  
  
  RESULTS
  Serum cortisol was significantly correlated to systolic and diastolic blood pressure in boys and in the early-insulin treated group. At 2 y corrected age serum cortisol was significantly higher in the early-insulin group compared to the standard care group. At 6 mo corrected age salivary cortisol was significantly correlated to serum cortisol.
  
  
  CONCLUSIONS
  In very-low-birth-weight boys, the positive correlation between cortisol and blood pressure is present at 2 y corrected age. Early insulin therapy could affect programming of the HPA axis. Salivary cortisol mirrors serum levels at 6 mo corrected age.
authors.affiliation: Department of Pediatrics, Albert Schweitzer Hospital, Dordrecht, The Netherlands.
authors.forename: Miranda
authors.initials: M
authors.lastname: de Jong
authors.affiliation: Department of Pediatrics, Division of Neonatology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Anneke
authors.identifier: http://orcid.org/0000-0003-1820-3511
authors.initials: A
authors.lastname: Cranendonk
authors.affiliation: Department of Pediatrics, Division of Neonatology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Mirjam M
authors.initials: MM
authors.lastname: van Weissenbruch
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D001724:Birth Weight; D001794:Blood Pressure; D002657:Child Development; D002675:Child, Preschool; D005060:Europe; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000254:growth & development / Q000378:metabolism*; D007223:Infant; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008297:Male; D010913:Pituitary-Adrenal System / Q000254:growth & development / Q000378:metabolism*; D012463:Saliva / Q000378:metabolism*; D012737:Sex Factors; D013997:Time Factors
chemical_list: D015415:Biomarkers; D006854:Hydrocortisone