Day-to-Day Differences in Cortisol Levels and Molar Cortisol-to-DHEA Ratios among Working Individuals

Cortisol and dehydroepiandrosterone (DHEA) are the main products of adrenocortical activity in response to the adrenocorticotrophic hormone (ACTH).2][3] The act of awakening stimulates cortisol secretion, 4 an event that is called the cortisol awakening response (CAR). 5Cortisol levels and CAR are established indices of stress responses that have been used in various fields of research. 6A steroid, 17α-hydroxypregnenolone, is a co-precursor for the biosynthesis of cortisol and DHEA in the adrenal cortex. 7DHEA has been described to function as an anti-glucocorticoid. 8,9 Thus, the cortisol-to-DHEA ratio (C/D ratio) is accepted as an index of steroidogenic balance and is used as a reliable adrenocortical index of allostatic states, 10 psychosomatic disorders, 11-13 and anxiety and negative mood. 14ome investigations have observed no differences in the daytime cortisol levels between workdays and the weekend. 15,168][19][20] These four studies have shown that CAR patterns are the same on