Comparison of effects between the combined and classic dexamethasone suppression test on diagnosis of Cushing's syndrome / 中国实用内科杂志

ABSTRACT

Objective To evaluate effects of the combined and classic dexamethasone suppression test(DST)on the diagnosis of Cushing's syndrome.Methods Retrospective analysis was made about the results of DST from 152 patients of Cushing syndrome with surgically confirmed causes in recent 10 years.Results The diagnosis accuracy of overnight low dose DST,classic low dose DST and of combined low dose DST was 97.5%,96.1%and 97.6% respectively for determining diagnosis of Cushing's syndrome.No obvious difference was found in three groups(P=0.86).The diagnosis accuracy of 31 cases of classic and 17 cases of combined high dose DST was 80.6%(25/31)and 76.4% respectively without obvious difference(P =0.73)for locating diagnosis of Cushing's disease.The diagnosis accuracy of classic and combined high dose DST was 94.2% and 95.5% respectively without obvious difference(P =0.83)for locating diagnosis of ACTH independent Cushing's syndrome.Sensitivity and specificity for Cushing's disease were 81.5% and 92.5% in classic low dose and high dose DST and 77.8% and 95.5% in combined low dose and high dose DST.Conclusion Compared to the classic DST,combined DST has the advantages of double controls,simplicity and saving time.Because diagnosis accuracy of combined DST is in accordance with the classic DST,it is recommended to be a routine for diagnosing Cushing's syndrome.