This thesis includes a study of 125 patients which was conducted at the department of obstetrics and gynecology of the general hospital of Vienna (AKH Wien), division of gynecology, endocrinology and reproductive medicine under the survey of Prof. DDr. Johannes Huber. The thesis has confirmed a decline of dehydroepiandrosterone-sulfate (DHEA-S) levels corresponding to age. Also, in postmenopausal women, not only the total concentration of DHEA decreases, but also the circadian oscillations of DHEA-S concentrations flatten. The synthesis of cortisol shows no change in postmenopausal women....