Adrenocortical responses to submaximal exercise in postmenopausal black and white women

The purpose of this study was to determine whether racial differences exist in the dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), and cortisol concentrations of black and white postmenopausal women at rest and in response to submaximal exercise. Twenty-three postmenopausal women (13 white and 10 black) were studied on 2 occasions. On one occasion subjects rested quietly for 4 hours (control day), whereas on the other occasion after 50 minutes of rest, subjects exercised at 70% of Vo2peak for 30 minutes on a cycle ergometer (exercise day). Blood was sampled at rest, during exercise, and during recovery and assayed for DHEA, DHEAS, and cortisol concentrations. Resting DHEA and cortisol concentrations and integrated area under the curve (AUC) were similar between the black and white women; however, the black women had lower resting DHEAS concentrations compared with the white women (DHEAS, black: 1.32 ± 0.29vwhite: 2.18 ± 0.25 μmol · L−1,P< .05). Regardless of race, DHEA and cortisol AUC increased significantly above resting values (P< .01), but the exercise AUC for DHEA and cortisol were not different between the black and white women (DHEA: 607 ± 133 and 824 ± 108 min × nmol · L−1; cortisol: 9,604 ± 1,247 and 8,076 ± 1,093 min × nmol · L−1, respectively). No exercise-induced change in integrated DHEAS AUC was found in either group. In conclusion, racial differences exist in the resting DHEAS levels of postmenopausal women, but with no racial differences in resting DHEA and cortisol concentrations. Race had no impact on these adrenal hormone responses to submaximal exercise.