Psychosomatic Medicine 12:225-228 (1950)
© 1950 American Psychosomatic Society

Measures of Stress Responsivity in Younger and Older Men

¹ Worcester Foundation for Experimental Biology and the Department of Physiology; Tufts Medical College; Presented at the Annual Meeting of the Association for Research in Nervous and Mental Disease, December, 1949, New York.

Fifty-four younger men (median age 32 years) and thirty older men (median age 77 years) underwent under basal condition one or more of a series of four standard acute stress tests. Measurements of various urine and blood constituents were made for a prestress period, a stress period, and a poststress period. The data on those urinary constituents particularly representative of adrenocortical activity (17-ketosteroids, neutral reducing lipids, potassium, sodium, uric acid) demonstrate a significantly lowered basal (prestress) output rate on a time basis inthe older men. This difference between the two groups disappears when these urinary variables are calculated in terms of the creatinine output except for the 17-ketosteroid excretion which remains significantly higher in the younger group. Adrenocortical response to pituitary adrenocorticotrophin (ACTH) is, on an output per unit time basis, quantitatively greater in the older men, but correction in terms of creatinine output abolishes this difference, and a slightly greater mean adrenal responsivity in the younger group is suggested, not only in the ACTH test, but also in the pursuit meter test. No significant difference in the two groups could be found in the mean data for the various urinary and blood indices in the glucose tolerance and targetball frustration tests. A total response index (TRI) indicative of total adrenocortical responsivity is generally slightly lower in the older group, but not significantly so. The distribution of TRI values among the individuals taking the stress tests is similar in the two groups, and the order of stressfulness of the four tests in terms of the TRI is identical in the two groups. It is suggested that men surviving to old age without overt ill health or infirmity may preserve relatively intact pituitary-adrenal mechanism involved in response to acute stress.