The relationship between the menstrual cycle and cortisol secretion: Daily and stress-invoked cortisol patterns.

The menstrual cycle involves significant changes in hormone levels, causing physical and psychological changes in women that are further influenced by stress. The aim of this study was to understand the relationship between menstrual cycle phase and salivary cortisol patterns during the day as well as the salivary cortisol response to the Virtual Reality Version of the Trier Social Stress Test (TSST-VR). Forty two women not taking oral contraceptives (24 in follicular phase and 18 in luteal phase) participated in the study. Five samples of salivary cortisol collected during the day and another five samples of cortisol during the TSST-VR were analyzed. Psychological stress measures and psychopathological symptomatology were also evaluated. A 2 × 4 mixed ANCOVA showed an interaction between the two groups on the TSST-RV invoked cortisol response to the [F(3,42) = 3.681; p = 0.023) where women in luteal phase showed higher cortisol post exposure levels (5.96 ± 3.76 nmol/L) than women in follicular phase (4.31 ± 2.23 nmol/L). No other significant differences were found. Our findings provide evidence that menstrual cycle phase tended to influence cortisol response to laboratory-induced mental stress, with more reactivity observed in the luteal phase.