Comparison of cortisol samples in the first two weeks of life in preterm infants.
BACKGROUND
Growing literature on negative childhood stress emphasizes the need to understand cortisol values from varying biomarker samples.


OBJECTIVE
This work aimed to examine cortisol samples for usability, associations, and individual stability in neonates.


METHODS
The sample consisted of preterm infants (n=31).


METHODS
Analyses on cortisol collected from cord blood and from saliva and urine samples on days 1, 7, and 14 included Spearman correlations and paired t-tests.


RESULTS
Usability rates were 80.6% (cord blood), 85.9% (saliva), and 93.5% (urine). Salivary and urinary cortisol levels had significant correlation on day 1 only (p=0.004). Significant differences in individual stability of cortisol concentrations existed except in urine on days 1 and 7 and in saliva on days 7 and 14.


CONCLUSIONS
Usability was highest for urine samples. We found little correlation between cortisol sample levels at each time; individual stability of cortisol concentrations was minimal. Interpretation of cortisol findings in all studies should be performed cautiously.
Tiffany A
TA
Moore
Kendra K
KK
Schmid
Jeffrey A
JA
French
D000367:Age Factors; D015415:Biomarkers / Q000032:analysis / Q000097:blood / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis* / Q000097:blood / Q000378:metabolism / Q000652:urine; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood / Q000378:metabolism / Q000652:urine; D008137:Longitudinal Studies; D008297:Male; D012463:Saliva / Q000737:chemistry
D015415:Biomarkers; D006854:Hydrocortisone