Lower Cutoffs Improve the Diagnostic Performance of Desmopressin-Stimulated Bilateral Inferior Petrosal Sinus Sampling for Cushing Disease: A Prospective Cohort Study
Authors' conclusion
DDAVP-stimulated BIPSS showed excellent diagnostic performance for differentiating CD from EAS and provides a practical alternative stimulation strategy when corticotropin-releasing hormone is unavailable. Lower DDAVP-specific ACTH ratio cutoffs improved sensitivity without compromising specificity and may reduce false-negative diagnoses of CD in patients with ACTH-dependent Cushing syndrome.
Study context
- Population
- Patients with adrenocorticotropic hormone (ACTH)-dependent Cushing syndrome undergoing DDAVP-stimulated bilateral inferior petrosal sinus sampling (BIPSS), tertiary pituitary center (Peking Union Medical College Hospital), China, October 2023–December 2024167 with definitive diagnosis
- Participants
- 181 patients
- Exposure
- Traditional vs optimized ACTH ratio cutoffs for DDAVP-stimulated BIPSS
- Outcome
- Diagnostic accuracy for differentiating CD from ectopic ACTH syndrome (EAS); final diagnosis by histopathology and/or biochemical remission
Methodological detailssingle-centre, observational, consecutive patients, diagnostic accuracy
- Single-centre
- Observational
- Consecutive patients
- Diagnostic accuracy
Main finding
As reported in the abstract
Diagnostic performance of BIPSS (CD vs EAS)
| Strategy | Sensitivity | Specificity |
|---|---|---|
| Traditional cutoffs | 91.5% | 100.0% |
| Lower cutoffs | 97.4% | 100.0% |
Sensitivity
Traditional cutoffs91.5%
Lower cutoffs97.4%
Specificity
Traditional cutoffs100.0%
Lower cutoffs100.0%
- Overall discrimination of BIPSS (AUC)
- 0.994
Observational data: associations, not effects.
Further findings
Timing of peak IPS:P
- Most peak IPS:P values occurred at 3 to 5 min post-DDAVP
False-negative results
- Associated with absent intersinus lateralization and low IPS ACTH levels
Original publication
Lower Cutoffs Improve the Diagnostic Performance of Desmopressin-Stimulated Bilateral Inferior Petrosal Sinus Sampling for Cushing Disease: A Prospective Cohort Study. Endocr Pract. Published 24 June 2026. doi:10.
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