Peak Cortisol Level in Shift Work Disorder

Normal Cortisol Rhythm vs. Shift Work Disruption

• The normal circadian nadir of cortisol secretion is lost in shift workers, particularly those working night shifts 1

Testing Considerations

• Late night salivary cortisol (LNSC) testing should not be performed in patients with disruption of the normal day/night cycle, such as night-shift workers 1
• The dexamethasone suppression test (DST) is the preferred diagnostic test for evaluating cortisol status in shift workers and patients with disrupted circadian rhythm due to uneven sleep schedules 2

Clinical Implications

• For shift workers requiring cortisol evaluation, the timing of sample collection should be adjusted according to their work pattern rather than standard time-based protocols 3