title: Increases in aldosterone precede those of cortisol during graded exercise.
abstract: The purpose of this study was to determine the intensity threshold needed to elicit increases in plasma aldosterone and cortisol during graded exercise in humans. Seven male volunteers performed a maximal oxygen uptake (VO2max) test on a cycle ergometer. Plasma levels of aldosterone, cortisol, angiotensin II, ACTH, and potassium were measured at rest and at each 50 W workload of the exercise test. The results showed that aldosterone significantly (p less than or equal to 0.05) increased from a mean (+/- SE) of 231 +/- 22 pmol/L at rest to 464 +/- 22 pmol/L at exhaustion. Cortisol significantly (p less than or equal to 0.05) increased from 284 +/- 38 nmol/L at rest to 311 +/- 39 nmol/L at exhaustion. More importantly, however, was the fact that aldosterone was significantly increased above the resting level at exercise intensities greater than or equal to 60% VO2max. Cortisol, on the other hand, was only significantly increased at exhaustion (i.e. 100% VO2max). These results clearly show that increases in aldosterone precede those of cortisol during graded exercise in humans. Interestingly, potassium (r = 0.79), ACTH (r = 0.55), and angiotensin II (r = 0.54) were all significantly correlated with aldosterone during exercise. Such a finding seems to suggest that all 3 variables may be important stimuli for aldosterone secretion during graded exercise.
authors.affiliation: San Diego State Heart Institute, CA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Buono
authors.forename: J E
authors.initials: JE
authors.lastname: Yeager
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000704:Analysis of Variance; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D010101:Oxygen Consumption
chemical_list: D000450:Aldosterone; D006854:Hydrocortisone