A FOUR DAY CORTICOTROPHIN-SUPPRESSION TEST

Abstract

ABSTRACT A four day ACTH-suppression test was performed in 58 patients showing symptoms often associated with hypercorticism and in 25 cases of Cushing's syndrome. The non Cushing patients suffered from obesity, hypertension, plethora, diabetes and mental disturbances in various combinations and/or conditions related to hypertrichosis and menstrual disorders. Some of them also showed an increased basal excretion of 17-ketosteroids. Triamcinolone, in doses of 4 mg and 8 mg every six hours or 2 mg of dexamethasone every six hours, induced a good suppression of adrenocortical function in the non Cushing patients. This was demonstrated by chromatographic analysis of 24 different 24-hour urine samples collected on the third or fourth day of the test. In these cases – selected at random from the 58 non Cushing patients – the mean excretion of tetrahydroderivatives of cortisone and cortisol was < 0.3 mg/day (range 0.0–1.2 mg/day). Only traces of dehydroepiandrosterone and 11-oxy-17-ketosteroids were found. In all cases, 17-ketogenic steroids, Porter-Silber chromogens and 17-ketosteroids were determined by routine methods and the results are discussed with regard to the presence of non specific chromogens. There was no difference in the urinary excretion of steroids during the administration of 16 mg and 32 mg respectively of triamcinolone and of 8 mg of dexamethasone daily. In 9 of 11 cases of non-tumourous Cushing's syndrome, triamcinolone in a dose of 4 mg every six hours did not suppress the urinary excretion of 17-ketogenic steroids, Porter-Silber chromogens or 17-ketosteroids normally. In two cases, however, there was a normal suppression according to the criteria chosen. In one case of non-tumourous Cushing's syndrome, suppression could not be demonstrated during the administration of triamcinolone in a dose of 16 mg every six hours for four days. Because of the varying degrees of suppression found in Cushing's syndrome, the diagnostic conclusions drawn from the ACTH-suppression test should be made with caution. Marked variation in the basal excretion of steroids adds to the difficulties as do the limitations of the test imposed by unspecificity of the methods used in evaluating the adrenocortical function.