Background/Aims: Salivary cortisol has been widely used to assess childhood stress. Yet, there is no consensus on reference concentrations, awakening response, guideline compliance and contribution of sampling factors to the variation in children's salivary cortisol levels. Methods: Samples were collected from 444 Belgian children participating in the ChiBS study (5-11 years old) on two consecutive weekdays at four moments: awakening, 30 min later, 60 min later and in the evening. A checklist requested awakening time, collection hours and guideline compliance. Results: Reference values were determined. Mixed model analyses revealed that age, time compliance and awakening time contributed significantly to the variance in cortisol levels. In only 52.5% of the children a cortisol morning increase was observed. Participants with no morning increase showed higher awakening but lower post-awakening concentrations on that day, and the morning response showed a small negative correlation with the time lag between first and second sampling. Conclusion: This study emphasizes the importance of excluding extreme time deviation and correcting for age and awakening time. Appearance of a cortisol morning increase was only found in approximately half of the children, suggesting the absence of the cortisol awakening response as a general characteristic. Also, this could partially be explained by poor time compliance.

Keywords:
Awakening response, Children, Compliance, Reference values, Salivary cortisol
1.
Fries E, Dettenborn L, Kirschbaum C: The cortisol awakening response (CAR): facts and future directions. Int J Psychophysiol 2009;72:67-73.
2.
Gozansky WS, Lynn JS, Laudenslager ML, Kohrt WM: Salivary cortisol determined by enzyme immunoassay is preferable to serum total cortisol for assessment of dynamic hypothalamic-pituitary-adrenal axis activity. Clin Endocrinol (Oxf) 2005;63:336-341.
3.
Levine A, Zagoory-Sharon O, Feldman R, Lewis JG, Weller A: Measuring cortisol in human psychobiological studies. Physiol Behav 2007;90:43-53.
4.
Osika W, Friberg P, Wahrborg P: A new short self-rating questionnaire to assess stress in children. Int J Behav Med 2007;14:108-117.
5.
Rosmalen JG, Oldehinkel AJ, Ormel J, de Winter AF, Buitelaar JK, Verhulst FC: Determinants of salivary cortisol levels in 10-12 year old children; a population-based study of individual differences. Psychoneuroendocrinology 2005;30:483-495.
6.
Pruessner JC, Wolf OT, Hellhammer DH, Buske-Kirschbaum A, von Auer K, Jobst S, Kaspers F, Kirschbaum C: Free cortisol levels after awakening: a reliable biological marker for the assessment of adrenocortical activity. Life Sci 1997;61:2539-2549.
7.
Jessop DS, Turner-Cobb JM: Measurement and meaning of salivary cortisol: a focus on health and disease in children. Stress 2008;11:1-14.
8.
Wust S, Wolf J, Hellhammer DH, Federenko I, Schommer N, Kirschbaum C: The cortisol awakening response - normal values and confounds. Noise Health 2000;2:79-88.
9.
Kudielka BM, Broderick JE, Kirschbaum C: Compliance with saliva sampling protocols: electronic monitoring reveals invalid cortisol daytime profiles in noncompliant subjects. Psychosom Med 2003;65:313-319.
10.
Kudielka BM, Wust S: Human models in acute and chronic stress: assessing determinants of individual hypothalamus-pituitary-adrenal axis activity and reactivity. Stress 2010;13:1-14.
11.
Adam EK, Kumari M: Assessing salivary cortisol in large-scale, epidemiological research. Psychoneuroendocrinology 2009;34:1423-1436.
12.
Hansen AM, Garde AH, Persson R: Sources of biological and methodological variation in salivary cortisol and their impact on measurement among healthy adults: a review. Scand J Clin Lab Invest 2008;68:448-458.
13.
Hanrahan K, McCarthy AM, Kleiber C, Lutgendorf S, Tsalikian E: Strategies for salivary cortisol collection and analysis in research with children. Appl Nurs Res 2006;19:95-101.
14.
Ahrens W, Bammann K, Siani A, Buchecker K, De Henauw S, Iacoviello L, Hebestreit A, Krogh V, Lissner L, Marild S, Molnar D, Moreno LA, Pitsiladis YP, Reisch L, Tornaritis M, Veidebaum T, Pigeot I: The IDEFICS cohort: design, characteristics and participation in the baseline survey. Int J Obes 2011;35(suppl 1):S3-S15.
15.
van Aken MO, Romijn JA, Miltenburg JA, Lentjes EG: Automated measurement of -salivary cortisol. Clin Chem 2003;49:1408-1409.
16.
Young D, Huth E: SI Units for Clinical Measurement. Philadelphia, American College of Physicians, 1998.
17.
Pruessner JC, Kirschbaum C, Meinlschmid G, Hellhammer DH: Two formulas for computation of the area under the curve represent measures of total hormone concentration versus time-dependent change. Psychoneuroendocrinology 2003;28:916-931.
18.
Fekedulegn DB, Andrew ME, Burchfiel CM, Violanti JM, Hartley TA, Charles LE, Miller DB: Area under the curve and other summary indicators of repeated waking cortisol measurements. Psychosom Med 2007;69:651-659.
19.
Cole TJ, Green PJ: Smoothing reference centile curves: the LMS method and penalized likelihood. Stat Med 1992;11:1305-1319.
20.
Groschl M, Kohler H, Topf HG, Rupprecht T, Rauh M: Evaluation of saliva collection devices for the analysis of steroids, peptides and therapeutic drugs. J Pharm Biomed Anal 2008;47:478-486.
21.
Schulz P, Knabe R: Biological uniqueness and the definition of normality. 2. The endocrine ‘fingerprint' of healthy adults. Med Hypotheses 1994;42:63-68.
22.
Hellhammer J, Fries E, Schweisthal OW, Schlotz W, Stone AA, Hagemann D: Several daily measurements are necessary to reliably assess the cortisol rise after awakening: state and trait components. Psychoneuroendocrinology 2007;32:80-86.
23.
Eek FC, Garde AH, Hansen AM, Persson R, Orbaek P, Karlson B: The cortisol awakening response - an exploration of intraindividual stability and negative responses. Scand J Work Environ Health 2006;15-21.
24.
DeSantis AS, Adam EK, Mendelsohn KA, Doane LD: Concordance between self-reported and objective wakeup times in ambulatory salivary cortisol research. Int J Behav Med 2010;17:74-78.
25.
Raikkonen K, Matthews KA, Pesonen AK, Pyhala R, Paavonen EJ, Feldt K, Jones A, Phillips DI, Seckl JR, Heinonen K, Lahti J, Komsi N, Jarvenpaa AL, Eriksson JG, Strandberg TE, Kajantie E: Poor sleep and altered hypothalamic-pituitary-adrenocortical and sympatho-adrenal-medullary system activity in children. J Clin Endocrinol Metab 2010;95:2254-2261.
26.
Sondeijker FE, Ferdinand RF, Oldehinkel AJ, Veenstra R, Tiemeier H, Ormel J, Verhulst FC: Disruptive behaviors and HPA-axis activity in young adolescent boys and girls from the general population. J Psychiatr Res 2007;41:570-578.
27.
Netherton C, Goodyer I, Tamplin A, Herbert J: Salivary cortisol and dehydroepiandrosterone in relation to puberty and gender. Psychoneuroendocrinology 2004;29:125-140.
28.
Edwards S, Evans P, Hucklebridge F, Clow A: Association between time of awakening and diurnal cortisol secretory activity. Psychoneuroendocrinology 2001;26:613-622.
29.
Freitag CM, Hanig S, Palmason H, Meyer J, Wust S, Seitz C: Cortisol awakening response in healthy children and children with ADHD: impact of comorbid disorders and psychosocial risk factors. Psychoneuroendocrinology 2009;34:1019-1028.
30.
Dockray S, Bhattacharyya MR, Molloy GJ, Steptoe A: The cortisol awakening response in relation to objective and subjective measures of waking in the morning. Psychoneuroendocrinology 2008;33:77-82.
31.
Kertes DA, Gunnar MR: Evening activities as a potential confound in research on the adrenocortical system in children. Child Dev 2004;75:193-204.
32.
Granger DA, Cicchetti D, Rogosch FA, Hibel LC, Teisl M, Flores E: Blood contamination in children's saliva: prevalence, stability, and impact on the measurement of salivary cortisol, testosterone, and dehydroepiandrosterone. Psychoneuroendocrinology 2007;32:724-733.
33.
Gibson EL, Checkley S, Papadopoulos A, Poon L, Daley S, Wardle J: Increased salivary cortisol reliably induced by a protein-rich midday meal. Psychosom Med 1999;61:214-224.
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2011
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