{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T15:11:07Z","timestamp":1781277067916,"version":"3.54.1"},"reference-count":29,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,6,6]],"date-time":"2025-06-06T00:00:00Z","timestamp":1749168000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Differentiating central diabetes insipidus (CDI), nephrogenic diabetes insipidus (NDI), and primary polydipsia (PP) in pediatric patients with polyuria\u2013polydipsia syndrome (PPS) remains a clinical challenge. The water deprivation test (WDT) is the traditional gold standard; however, it is time-consuming, burdensome, and prone to equivocal results. Stimulated copeptin, a surrogate marker of vasopressin, has emerged as a promising diagnostic alternative. We conducted a prospective, observational, cross-sectional study involving 27 pediatric patients (ages 2\u201317) presenting with PPS. Each patient underwent a WDT with desmopressin and hypertonic saline infusion (3% NaCl) for stimulated copeptin testing. Diagnostic accuracy was assessed using clinical diagnoses as a reference. The WDT showed high accuracy with an area under the curve (AUC) of 0.97, and there was an increased optimal threshold of \u226514% urine osmolality after desmopressin acetate (1-deamino-8-D-arginine vasopressin, DDAVP) administration (sensitivity 88.9%, specificity 100%). Stimulated copeptin at a threshold of &lt;6.5 pmol\/L demonstrated 100% sensitivity and specificity (AUC = 1.00) for CDI versus PP. Basal copeptin \u226521.4 pmol\/L accurately identified all NDI cases. The agreement between the WDT and copeptin was low (\u03ba = 0.06, McNemar p = 0.021), suggesting that copeptin has greater specificity, particularly for borderline or partial CDI. These results support the use of stimulated copeptin as a first-line diagnostic tool in pediatric PPS, offering improved objectivity, tolerability, and diagnostic clarity compared with the WDT. Basal copeptin also demonstrated excellent performance in rapid noninvasive NDI identification.<\/jats:p>","DOI":"10.3390\/ijms26125449","type":"journal-article","created":{"date-parts":[[2025,6,6]],"date-time":"2025-06-06T09:02:03Z","timestamp":1749200523000},"page":"5449","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Comparative Diagnostic Performance of Copeptin After Hypertonic Saline Infusion Versus Water Deprivation Test in Pediatric Patients with Polyuria\u2013Polydipsia Syndrome"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7420-256X","authenticated-orcid":false,"given":"Diana-Andreea","family":"Ciortea","sequence":"first","affiliation":[{"name":"Faculty of Medicine and Pharmacy, \u201cDunarea de Jos\u201d University of Galati, 800201 Galati, Romania"},{"name":"\u201cMaria Sklodowska Curie\u201d Emergency Clinical Hospital for Children, 041451 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-8838-8817","authenticated-orcid":false,"given":"Carmen Loredana","family":"Petrea (Clive\u021bi)","sequence":"additional","affiliation":[{"name":"Faculty of Medicine and Pharmacy, \u201cDunarea de Jos\u201d University of Galati, 800201 Galati, Romania"},{"name":"\u201cSf Ioan\u201d Emergency Clinical Hospital for Children, 800487 Galati, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Iolanda Cristina","family":"Vivisenco","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, \u201cCarol Davila\u201d University of Medicine and Pharmacy, 030167 Bucharest, Romania"},{"name":"Department of Pediatrics, Emergency Clinical Hospital for Children \u201cGrigore Alexandrescu\u201d, 011743 Bucharest, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sorin Ion","family":"Berbece","sequence":"additional","affiliation":[{"name":"Faculty of Medicine and Pharmacy, \u201cDunarea de Jos\u201d University of Galati, 800201 Galati, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8327-1364","authenticated-orcid":false,"given":"Gabriela","family":"Gur\u0103u","sequence":"additional","affiliation":[{"name":"Faculty of Medicine and Pharmacy, \u201cDunarea de Jos\u201d University of Galati, 800201 Galati, Romania"},{"name":"\u201cSf Ioan\u201d Emergency Clinical Hospital for Children, 800487 Galati, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M\u0103d\u0103lina Nicoleta","family":"Matei","sequence":"additional","affiliation":[{"name":"Faculty of Medicine and Pharmacy, \u201cDunarea de Jos\u201d University of Galati, 800201 Galati, Romania"},{"name":"\u201cSf Ioan\u201d Emergency Clinical Hospital for Children, 800487 Galati, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aurel","family":"Nechita","sequence":"additional","affiliation":[{"name":"Faculty of Medicine and Pharmacy, \u201cDunarea de Jos\u201d University of Galati, 800201 Galati, Romania"},{"name":"\u201cSf Ioan\u201d Emergency Clinical Hospital for Children, 800487 Galati, Romania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1016\/S0140-6736(19)31255-3","article-title":"Arginine-Stimulated Copeptin Measurements in the Differential Diagnosis of Diabetes Insipidus: A Prospective Diagnostic Study","volume":"394","author":"Winzeler","year":"2019","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"700","DOI":"10.1016\/S2213-8587(22)00219-4","article-title":"Central Diabetes Insipidus from a Patient\u2019s Perspective: Management, Psychological Co-Morbidities, and Renaming of the Condition: Results from an International Web-Based Survey","volume":"10","author":"Atila","year":"2022","journal-title":"Lancet Diabetes Endocrinol."},{"key":"ref_3","unstructured":"Feingold, K.R., Ahmed, S.F., Anawalt, B., Blackman, M.R., Boyce, A., Chrousos, G., Corpas, E., de Herder, W.W., Dhatariya, K., and Dungan, K. 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