The relationship between the cortisol awakening response and cortisol reactivity to a laboratory stressor.
Level 4 - case-series / case-control
Cross-sectional observational study examining physiological biomarkers
PubMed 30604472 · doi:10.1111/bjhp.12352
What was done
A cross-sectional study evaluated the relationship between trait cortisol awakening response (CAR) and acute stress reactivity. Salivary cortisol was collected from 54 female participants across five consecutive weekdays at waking (S1) and 30 minutes post-waking to estimate trait CAR. The following week, participants completed the Trier Social Stress Test (TSST) with salivary cortisol measured across the acute stress and recovery phases.
What was found
The abstract reports direction and significance without providing numerical values, confidence intervals, or test statistics. A smaller CAR, lower peak cortisol, and blunted CAR increase were all significantly related to a steep rise and flattened recovery slope in cortisol secretion following the TSST. Lower waking cortisol (S1) was predictive of a blunted rise in cortisol from baseline to immediately post-task.
Why it matters
By measuring CAR across five days rather than a single day, this study connects multi-day trait morning cortisol regulation with acute physiological stress reactivity and post-stress recovery patterns.
Limits
The sample size is small (n = 54) and restricted entirely to females, limiting generalizability. No numerical effect sizes, p-values, or baseline demographic characteristics are reported in the abstract, and potential confounders such as menstrual cycle phase, oral contraceptive use, or exact adherence to home saliva collection protocols are not described.
Cited by
- context A higher peak in the cortisol awakening response in the morning reduces or blunts the magnitude of cortisol spikes caused by stressful events later in the day.