DST in healthy volunteers and after sleep deprivation

The dexamethasone suppression test (DST) was performed in 46 healthy volunteers and repeated in nine of them following total sleep deprivation (TSD). While only 2 postdexamethasone cortisol values were insufficiently suppressed (greater than 5 micrograms %) in control DSTs, 5 postdexamethasone cortisol values were above 5 micrograms % following TSD. The mean postdexamethasone value was increased from 1.55 +/- 1.06 to 4.47 +/- 5.86 micrograms % following TSD at 8.00 h. The authors conclude that sleep deprivation as a therapeutic approach and prolonged sleeplessness may bias DST results.