Cortisol and Dehydroepiandrosterone Response to Adrenocorticotropic Hormone and Frailty in Older Women

BACKGROUND The response to adrenocorticotropic hormone (ACTH) is poorly characterized in old-old adults and may provide insight into the physiologic response to stress. METHODS We performed a standard 250 mcg ACTH stimulation test in a home-based substudy of 51 women aged 85-96 years enrolled in the Women's Health and Aging Study II who were not taking corticosteroids. We examined the cortisol and dehydroepiandrosterone (DHEA) responses at 0, 30, 60, and 120 minutes, overall and by frailty status. RESULTS The peak cortisol response to ACTH could not be determined, with the highest levels at the 120 minute time point. Pre- and post-ACTH stimulated cortisol levels did not differ by frailty status over this time frame, with no difference in the characteristics of the dose-response curves. Pre- and post-ACTH stimulated DHEA levels also did not differ by frailty status, though the dose-response curves suggested divergence after stimulation, with a more rapid DHEA response with increasing frailty. CONCLUSIONS Our data demonstrate a robust cortisol response to ACTH challenge testing, but inadequate negative feedback in old-old women, resulting in prolonged exposure to cortisol. Future studies should examine dynamic cortisol and DHEA responses in this age group, using a less potent ACTH stimulus and longer collection period.