[Restitutive effect of sleep on chronic performance stress]

During a polysomnographic (2 nights) sleep registration of 5 chronically stressed compared to 5 control persons 24 h blood cortisol values and salivary cortisol at daytime were measured and compared with measured stress vulnerability. While daytime cortisol levels were reduced under stress conditions, during night sleep combined with a significant change in sleep architecture cortisol excretion raised markedly compared to controls, and the cortisol response to CRF provocation is no more blunted but activated beyond controls, demonstrating the restitutive and protective effect of sleep.