Psychosomatic medicine
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Psychosomatic medicine · Mar 1999
Comparative StudyImpact of gender, menstrual cycle phase, and oral contraceptives on the activity of the hypothalamus-pituitary-adrenal axis.
Results from animal and human studies suggest that disregulations of the hypothalamus-pituitary-adrenal (HPA) axis are involved in several behavioral, circulatory, endocrine, and immune disorders with clear-cut gender differences in disease prevalence. The aim of the present study was to investigate sex-specific HPA response patterns with a focus on the contribution of gonadal steroids as possible mediators. ⋯ We conclude that gender, menstrual cycle phase, and OC use exert important effects on HPA responsiveness to psychosocial stress in healthy subjects. Although men seem to have a stronger hypothalamic drive in response to stressful stimulation than women, differences in salivary-free cortisol levels, at least in part, may be explained by estradiol-induced changes in corticosteroid-binding protein levels. ACTH and cortisol secretion is not affected by OC use per se but the amount of bioavailable unbound cortisol ("free") is greatly reduced in this group of women after stimulation. Inasmuch as none of these differences between the study groups emerged in total blood cortisol levels, we strongly advocate for the simultaneous measurement of free and total cortisol levels in future studies on HPA functioning.