title: Relationship between post-awakening salivary cortisol and melatonin secretion in healthy participants.
abstract: We report the relationship between patterns of post-awakening salivary melatonin and cortisol secretion in healthy participants (n = 51; mean age 21.6 ± 5.0 years). Saliva samples were collected within the domestic setting, at 0-, 15-, 30-, and 45-min post-awakening on 2 consecutive typical weekdays. Analyses were undertaken on data with electronically verified sample timing accuracy (<5-min delay between awakening and the start of saliva sampling). Melatonin secretion declined linearly by an average of 29% within the first 45-min post-awakening. In contrast, there was a marked 112% surge in cortisol, characteristic of the cortisol awakening response. No day differences in melatonin or cortisol secretion were observed but melatonin concentrations were lower with later awakening. Despite contrasting post-awakening changes in these hormones, there was a lack of relationship between overall levels or patterns of melatonin and cortisol during this period.
authors.affiliation: a Psychophysiology and Stress Research Group, Department of Psychology, University of Westminster , London , UK.
authors.forename: Natasha
authors.initials: N
authors.lastname: Ramachandran
authors.affiliation: a Psychophysiology and Stress Research Group, Department of Psychology, University of Westminster , London , UK.
authors.forename: Nina
authors.initials: N
authors.lastname: Smyth
authors.affiliation: a Psychophysiology and Stress Research Group, Department of Psychology, University of Westminster , London , UK.
authors.forename: Lisa
authors.initials: L
authors.lastname: Thorn
authors.affiliation: a Psychophysiology and Stress Research Group, Department of Psychology, University of Westminster , London , UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Eardley
authors.affiliation: a Psychophysiology and Stress Research Group, Department of Psychology, University of Westminster , London , UK.
authors.forename: Phil
authors.initials: P
authors.lastname: Evans
authors.affiliation: a Psychophysiology and Stress Research Group, Department of Psychology, University of Westminster , London , UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Clow
mesh_terms: D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D008297:Male; D008550:Melatonin / Q000032:analysis*; D012463:Saliva / Q000737:chemistry; D055815:Young Adult
chemical_list: D008550:Melatonin; D006854:Hydrocortisone
keywords: CAR; Saliva; awakening; biological dawn; circadian; diurnal