ECE2011 Poster Presentations Pituitary (111 abstracts)
Copeptin in the differential diagnosis of the polydipsia–polyuria syndrome: revisiting the direct and indirect water deprivation tests
W K Fenske 1 , M Quinkler 2 , U Haagen 3 , J Papassotiriou 3 , A F H Pfeiffer 4 , M Fassnacht 1 , S Stoerk 5 & B Allolio 1
1Endocrine and Diabetes Unit, Medical Department, University Hospital of Wuerzburg, Wuerzburg, Germany; 2Clinical Endocrinology, Charité Campus Mitte, Charité University Medicine Berlin, Berlin, Germany; 3B.R.A.H.M.S. AG, Research Department, Berlin, Berlin Hennigsdorf, Germany; 4Division of Endocrinology, Berlin, Germany; 5Department of Internal Medicine I – Cardiology, University of Wuerzburg, Wuerzburg, Germany.
Background: The water deprivation test (WDT) with direct or indirect measurement of plasma vasopressin (AVP) is the method of choice for the differential diagnosis of the polydipsia–polyuria syndrome. In theory, direct measurement of AVP is highly attractive but hampered by technical difficulties.
Objective: To evaluate the utility of copeptin, a surrogate of AVP secretion, in the diagnostic work-up of the polyuria–polydipsia syndrome, and to compare its performance with the current diagnostic standard.
Setting and design: In two tertiary referral centres, 20 healthy subjects and 50 patients with polydipsia–polyuria syndrome underwent WDT with measurements of both plasma AVP and copeptin levels. The reference diagnosis was based on clinical information and treatment response.
Results: Twenty-two patients (44%) were diagnosed with primary polydipsia, 17 (34%) with partial central diabetes insipidus (DI), 9 (18%) with complete central DI, and 2 (4%) with nephrogenic DI. The indirect WDT led to a correct diagnosis in 35/50 patients (70%). The direct WDT with AVP or Copeptin measurement correctly diagnosed 23 patients (46%) or 36 patients (72%), respectively. Baseline copeptin values >20 pmol/l identified patients with nephrogenic DI, and concentrations <2.6 pmol/l indicated complete central DI. The ratio between delta copeptin (8 to 16 h) and serum sodium concentration at 16 h yielded optimal diagnostic accuracy, allowing to also discern partial central DI from primary polydipsia (sensitivity and specificity 87 and 100%, respectively).
Conclusion: Copeptin holds promise as a diagnostic tool in the polyuria–polydipsia syndrome improving significantly the diagnostic accuracy of the direct WDT.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more