CORTISOL PRODUCTION-RATE AND THE URINARY-EXCRETION OF 17-HYDROXYCORTICOSTEROIDS, FREE CORTISOL, AND 6-BETA-HYDROXYCORTISOL IN HEALTHY ELDERLY MEN AND WOMEN

Background. Although many workers have tested adrenal function in the elderly, few have studied the effect of aging on cortisol production r ate or urinary free cortisol or 6beta-hydroxycortisol excretion, and n one have published comparisons of these variables between old people o f defined health status and young people. Methods. We have measured co rtisol production rate and the urinary excretion of free cortisol, 6be ta-hydroxycortisol, 17-hydroxycorticosteroids (Porter-Silber chromogen s) and creatinine in elderly men and women screened by the SENIEUR pro tocol and in young men; 17-hydroxycorticosteroid and 6beta-hydroxycort isol excretion were also measured in young women. The period of measur ement was 24 h or, usually, 48 h. Results. Only 6beta-hydroxycortisol excretion was affected by aging; it was lower in the elderly men and w omen than in their younger counterparts. Urinary free cortisol excreti on was lower in the elderly women than in the elderly men. There were no significant differences between groups in cortisol production rate or 17-hydroxycorticosteroid excretion. Excretion and (over the first 2 4 h) clearance of creatinine were lower in the old women than in the o ld men. The cortisol-related variables tended to be positively correla ted with each other and with the relevant creatinine-related variables in the elderly subjects; over the first but not the second 24 h, most of the correlations were significant in the men and women combined. C onclusions. With the exception of 6beta-hydroxycortisol, the data agre e with measurements of plasma cortisol and the results of adrenal func tion tests in showing little change in hypothalamic-pituitary-adrenal function with aging in healthy people.