Cushing's syndrome. Screening methods in hospitalized patients.
We studied 18 patients with Cushing's syndrome and 25 patients in which Cushing's syndrome was excluded on follow-up to evaluate screening tests for Cushing's syndrome in hospitalized patients. Plasma cortisol values (at 8 AM) were found least helpful yielding 29% false-positive and 60% false-negative values. Diurnal variation of cortisol was present in 30% of patients with Cushing's syndrome and absent in 18% of patients without Cushing's syndrome. When corrected for total urinary creatinine, 24-hour urinary 17-hydroxycorticosteroids were specific (all patients without Cushing's syndrome had normal values) but not very sensitive (two of 12 patients with Cushing's syndrome had normal values). Similarly, 24-hour 17-ketosteroids were of little help with 17% false-positive and 35% false-negative values. Twenty-four-hour urinary free cortisol was both a sensitive and specific screening test for Cushing's syndrome (no false-positive and no false-negative results). We conclude that urinary free cortisol is the most efficient screening method for Cushing's syndrome in hospitalized patients.
D000407:Alabama; D002940:Circadian Rhythm; D003480:Cushing Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D003907:Dexamethasone; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000652:urine; D008297:Male
D003907:Dexamethasone; D006854:Hydrocortisone