Adrenal incidentalomas are referred as clinically silent adrenal masses discovered incidentally during diagnostic testing or treatment for conditions not related to suspicion of adrenal disease. Certain percent of them are hormonally active and autonomous cortisol secretion is reported with increasing frequency. The aim of the study was to assess value of 1mg-DST in subclinical Cushings syndrome (CS) compared to the other forms of adrenal incidentalomas. We have evaluated 164 patients with adrenal incidentalomas confirmed by CT or MR imaging. After endocrine evaluation, by multiple criteria, 25 of them were classified as subclinical CS, subsequently confirmed by histology. Dexamethasone 1 mg was administered at 11 PM and blood samples for cortisol were taken at 8 AM following day. Statistic analysis was done using ROC curve analysis. Subclinical CS: 25 patients (21 females, 4 males), mean age 54.0±8.9 years, BMI 27.3±3.8 kg/m2, post 1mg-DST cortisol 233.0±161.8 nmol/l; midnight cortisol 238.2 ±137.9 nmol/l and basal ACTH 6.6±2.8 pg/ml. Other forms of incidentalomas: 139 patients (92 females, 47 males), mean age 55.6±10.9 years, BMI 29.5±4.9 kg/m2, post 1 mg-DST cortisol 48.7±22.7 nmol/l; midnight cortisol 93.8±45.0 nmol/l and basal ACTH 17.8±11.7 pg/ml. Area under ROC curve was 0.9885±0.0154 (95% CI 0.93400.9980). For cortisol cut-off level of 80 nmol/l test sensitivity is 95.9% and specificity is 91.0%. 1mg-DST remains reliable tool in diagnosis of subclinical hypercorticism.
01 - 05 Apr 2006
European Society of Endocrinology