Because we previously found increased basal serum cortisol levels in women runners, we examined adrenocortical function in amenorrheic running women (AR), eumenorrheic running women (R), and normal nonexercising women (NC) in further detail. Mean 24-h urinary cortisol levels were significantly elevated (P less than 0.001) in six AR [45.1 +/- 7.2 (+/- SEM) micrograms/24 h] and eight R (38.5 +/- 6.9 micrograms/24 h) compared to four NC (13.9 +/- 2.8 micrograms/24 h). After adrenal suppression with 2 mg dexamethasone, integrated responses and absolute maximal elevations in serum cortisol levels in response to 10 micrograms/m2 exogenous ACTH (1-24) administered as an iv bolus dose, were not significantly different among six AR, six R, and six NC. This dose of ACTH results in maximal steroid release. The disappearance rates of cortisol (5 mg, iv) after dexamethasone suppression were similar in four AR, five R, and four NC and corresponded to a two-compartment model with mean half-lives of 4.9 and 93.8 min, respectively. Cortisol-binding globulin levels were also similar among the groups. These data document higher cortisol secretion and suggest increased ACTH secretion in running women.

No abstract

To evaluate the effects of changing steroid milieu on adrenocortical function, basal levels and responses of cortisol, 17-hydroxyprogesterone (17PO), androstenedione (A), dehydroepiandrosterone (DHEA), and testosterone to exogenous synthetic ACTH were investigated in six normal women during the early follicular (EF) and midluteal (ML) phases of the menstrual cycle and in five women on an oral contraceptive (OC) agent (35 micrograms ethinyl estradiol and 1 mg ethynodiol diacetate, Demulen). Baseline serum steroid and cortisol binding globulin (CBG) levels were measured on days 3-7 and 21-23 of the menstrual cycle in the normal subjects and on days 3-7 of OC treatment cycles. ACTH stimulation (10 micrograms m-2 i.v. bolus) was performed following dexamethasone suppression (0.5 mg p.o. q 6 h X 4). Basal levels of cortisol and CBG as well as cortisol responses to ACTH were increased in OC users relative to normal women tested during both the EF and ML phases of the cycle. In addition, 17PO levels were increased during the ML phase both before and following dexamethasone suppression compared to levels present in the EF phase and in OC users, no doubt because of increased ovarian steroidogenesis.