The Effect of an Alerting Odorant on Human Cortisol Secretion during Sleep

Abstract

The effect of an alerting odorant on the secretion of salivary cortisol during sleep and after awakening was investigated. Salivary cortisol was assessed because this glucocorticoid represents activation of the hypothalamus-pituitary-adrenal (HPA) system, which is a dominant stress reaction pathway in the body. Subjects were exposed to an alerting odorant, Thesaron^®, during a 6h sleep period but not after awakening. Surprisingly, cortisol secretion after awakening was found to be suppressed, as well as during sleep. Exposure of this alerting aroma during sleep may have an impact on cortisol secretion after awakening by suppressing HPA activity after awakening.