Daily associations between salivary cortisol and electroencephalographic-assessed sleep: a 15-day intensive longitudinal study
- PMID: 38587464
- PMCID: PMC11381568
- DOI: 10.1093/sleep/zsae087
Daily associations between salivary cortisol and electroencephalographic-assessed sleep: a 15-day intensive longitudinal study
Abstract
Study objectives: Current evidence suggests that cortisol levels are bi-directionally associated with sleep. However, the daily, naturalistic cortisol-sleep associations remain unclear, as current evidence is mostly cross-sectional. This study tested whether pre-sleep cortisol predicts sleep duration and quality, and whether these sleep parameters predict the following day's diurnal cortisol slope using a 15-day intensive longitudinal design with electroencephalographic measures and saliva sampling.
Methods: Ninety-five young adults (Mage = 20.48 ± 1.59 years) provided saliva samples at awakening and pre-sleep over 14 consecutive days, providing 2345 samples (85% viable). The Z-Machine Insight + was used to record over 900 nights of total sleep time (TST) and sleep efficiency (SE). Multilevel models tested these data at the between- and within-person levels.
Results: Higher pre-sleep cortisol predicted shorter TST (p < .001) and lower SE (p < .001) at the within-person level. Individuals with shorter average TST (p = .007) or lower average SE (p < .001) had flatter diurnal cortisol slopes, compared to those with longer average TST or higher average SE. Follow-up analyses showed that individuals with shorter average TST (vs. longer average TST) had higher pre-sleep cortisol levels (p = .01).
Conclusions: Our findings provide evidence that pre-sleep cortisol is associated with sleep duration and quality at the within-individual level. Furthermore, individuals with short or poor sleep had flatter diurnal cortisol slopes. Although the effect sizes are small, these findings show the naturalistic associations between sleep and cortisol in a relatively healthy sample. These findings suggest that sleep maintains the regulation of the stress-response system, which is protective against mental and physical disorders.
Keywords: cortisol; daily design; home EEG; sleep.
© The Author(s) 2024. Published by Oxford University Press on behalf of Sleep Research Society.
Figures



Comment in
-
Rhythms in cortisol mediate sleep and circadian impacts on health.Sleep. 2024 Sep 9;47(9):zsae151. doi: 10.1093/sleep/zsae151. Sleep. 2024. PMID: 38963818 Free PMC article. No abstract available.
Similar articles
-
The effect of sample site and collection procedure on identification of SARS-CoV-2 infection.Cochrane Database Syst Rev. 2024 Dec 16;12(12):CD014780. doi: 10.1002/14651858.CD014780. Cochrane Database Syst Rev. 2024. PMID: 39679851 Free PMC article.
-
Diurnal cortisol slopes and mental and physical health outcomes: A systematic review and meta-analysis.Psychoneuroendocrinology. 2017 Sep;83:25-41. doi: 10.1016/j.psyneuen.2017.05.018. Epub 2017 May 24. Psychoneuroendocrinology. 2017. PMID: 28578301 Free PMC article.
-
Diurnal cortisol and rumination: Examining gender differences.Psychoneuroendocrinology. 2025 Sep;179:107517. doi: 10.1016/j.psyneuen.2025.107517. Epub 2025 Jun 12. Psychoneuroendocrinology. 2025. PMID: 40517526
-
Home treatment for mental health problems: a systematic review.Health Technol Assess. 2001;5(15):1-139. doi: 10.3310/hta5150. Health Technol Assess. 2001. PMID: 11532236
-
Salivary cortisol measures across the clinical stages of psychosis: An individual participant data (IPD) meta-analysis.Psychoneuroendocrinology. 2025 Mar;173:107283. doi: 10.1016/j.psyneuen.2025.107283. Epub 2025 Jan 18. Psychoneuroendocrinology. 2025. PMID: 39869966
Cited by
-
Management of Osilodrostat Therapy in Patients With Cushing's Syndrome: A Modified Delphi Consensus Panel.J Endocr Soc. 2025 Jun 27;9(8):bvaf103. doi: 10.1210/jendso/bvaf103. eCollection 2025 Aug. J Endocr Soc. 2025. PMID: 40620482 Free PMC article.
-
Rhythms in cortisol mediate sleep and circadian impacts on health.Sleep. 2024 Sep 9;47(9):zsae151. doi: 10.1093/sleep/zsae151. Sleep. 2024. PMID: 38963818 Free PMC article. No abstract available.
-
Visual light flicker stimulation: enhancing alertness in sleep-deprived rats.Front Neurosci. 2024 Jun 5;18:1415614. doi: 10.3389/fnins.2024.1415614. eCollection 2024. Front Neurosci. 2024. PMID: 38903600 Free PMC article.
References
-
- Saxbe DE. A field (researcher’s) guide to cortisol: tracking HPA axis functioning in everyday life. Health Psychol Rev. 2008;2(2):163–190. doi: 10.1080/17437190802530812 - DOI
-
- Garde AH, Karlson B, Hansen AM, Persson R, Åkerstedt T.. The role of saliva cortisol measurement in health and disease. Oak Park: Bentham Science Publishers Oak Park; 2012.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources