Desmopressin stimulation test shows promise in diagnosing Cushing’s syndrome

The desmopressin stimulation test (DST) shows significant promise as a non-invasive diagnostic tool for accurately identifying the underlying cause of ACTH-dependent Cushing’s syndrome, particularly in distinguishing between Cushing’s disease and ectopic ACTH syndrome, according to a study.

Researchers evaluated 23 patients with ACTH-dependent Cushing’s syndrome who underwent DST, bilateral inferior petrosal sinus sampling (BIPSS), and transsphenoidal surgery (TSS). The study assessed DST’s diagnostic performance using two definitions of a positive result.

DST demonstrated strong sensitivity and overall accuracy when compared with BIPSS. The positive predictive value (PPV) was high, though negative predictive value (NPV) suggested some false negatives.

DST showed good sensitivity and perfect PPV against TSS, albeit with limited NPV. The likelihood ratios highlighted the test’s diagnostic value.

The test exhibited perfect discriminatory power with an area under the curve of 1.000 for percent ACTH and 0.983 for percent cortisol.

Reference
Valizadeh M, Rahmani F, Nikoohemmat M, et al. Diagnostic Accuracy of the Desmopressin Stimulation Test in the Comprehensive Assessment of ACTH-Dependent Cushing’s Syndrome: A Comparative Analysis with BIPSS and TSS. Endocr Res. 2024;1-11. doi: 10.1080/07435800.2024.2381720. Epub ahead of print. PMID: 39030706.