title: Diagnostic value of salivary cortisol in the CRH stimulation test in premature infants.
abstract: BACKGROUND
  According to a recent nationwide survey in Japan, a significant proportion of very low birth weight infants (VLBWI) develop late-onset circulatory collapse after the first week of life. Small doses of glucocorticoid are very effective in these patients, and relative adrenal insufficiency is suspected to be the main cause of the condition. Although the CRH test is required to evaluate the hypothalamic-pituitary-adrenal axis, obtaining multiple blood samples is invasive.
  
  
  OBJECTIVE
  The present study was carried out to validate the consistency of the cortisol profiles of matched serum and saliva samples collected as part of the CRH test from VLBWI.
  
  
  METHODS
  In 23 VLBWI with a gestational age of less than 29 wk, we performed CRH tests at 2 wk after birth and at term. Their cortisol values were measured at the baseline and 30 min after the administration of a single dose of human CRH (1 μg/kg) using matched serum and saliva samples.
  
  
  RESULTS
  In 26 CRH tests in 19 infants, we were able to measure both serum and salivary cortisol. Significant correlations were detected between the infants' serum and salivary cortisol values (r=0.78; P<0.0001), the increases in these values induced in response to the CRH test (r=0.81; P<0.0001), and their peak serum and salivary cortisol values (r=0.68; P=0.0001).
  
  
  CONCLUSIONS
  This study indicated that using salivary cortisol measurements for the CRH test could be a reliable method for evaluating the hypothalamic-pituitary-adrenal axis in VLBWI with gestational age of less than 29 wk.
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Kyoto University, 54 Shogoin-kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan. matskura@kuhp.kyoto-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsukura
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kawai
authors.forename: Chieko
authors.initials: C
authors.lastname: Marumo
authors.forename: Kougoro
authors.initials: K
authors.lastname: Iwanaga
authors.forename: Kayo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Minoru
authors.initials: M
authors.lastname: Shibata
authors.forename: Fusako
authors.initials: F
authors.lastname: Niwa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Heike
mesh_terms: D000309:Adrenal Insufficiency / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism / Q000503:physiopathology*; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008297:Male; D010913:Pituitary-Adrenal System / Q000378:metabolism / Q000503:physiopathology*; D012463:Saliva / Q000378:metabolism*
chemical_list: D006854:Hydrocortisone