URINARY CORTISOL EXCRETION IN STRESS SITUATIONS AND IN PATIENTS WITH CUSHING'S SYNDROME

Abstract

SUMMARY Measurements of urinary free cortisol were made in convalescent subjects and in patients with established Cushing's syndrome and the results compared with those in acutely ill patients, in pregnancy and in surgical patients. Cortisol was measured in urine after paper chromatography, each measurement being corrected for losses according to the recovery of added internal standard (tritiated cortisol). In a number of cases, the diurnal rhythm of cortisol excretion was also examined and the results related to plasma 11-hydroxycorticosteroid levels and measurements of renal function. The mean 24 hr. urinary cortisol excretion in 13 convalescent subjects was 74μg. (range 35–98 μg./24 hr.) and all showed a well-marked diurnal rhythm. Patients with Cushing's syndrome excreted more than normal amounts of cortisol, even when plasma 11-hydroxycorticosteroids were in the normal range; there was a marked reversal in the diurnal rhythm of cortisol excretion. In 13 acutely ill medical patients with pyrexia, four only showed unequivocal increases in cortisol excretion although there was frequently an upset in the diurnal rhythm. The duration of the illness, rather than the severity, appeared to be an important factor so far as the response of the adrenals was concerned. A consistent increase in cortisol excretion was found in pregnancy but there was no significant difference between the day and night excretion of cortisol. The response to the stress of surgical trauma was largely dependent upon the severity of the operative procedure. The importance of emotional stress immediately before operation was shown in 4 out of 14 patients.