Diagnostic Utility of Copeptin in Pediatric Patients with Polyuria-Polydipsia Syndrome: A Systematic Review and Meta-Analysis

Background: Pediatric patients with polyuria polydipsia syndrome (PPS) represent a diagnostic challenge for clinicians because of the technical difficulties in performing the gold standard water deprivation test (WDT). Copeptin, a stable biomarker representing the C-terminal portion of the polypeptide chain of antidiuretic hormone, proves to be a more reliable diagnostic tool. Objective: To assess the diagnostic accuracy of copeptin baseline dosing, arginine/saline copeptin stimulation tests, and WDT. Establishing the diagnostic utility of copeptin in pediatrics, for differentiating central and nephrogenic diabetes insipidus, and primary polydipsia. Methods: comparative and non-comparative primary studies, relating to children, were included and searched for in PubMed, Cochrane Library, WOS, ScienceDirect, Scopus, Google Scholar, up to August 2024. QUADAS-2 tool was used to assess risk of bias and applicability. Meta-analyses used fixed effect models due to low heterogeneity and the HSROC model. Results: 11 studies included, with an overall Low bias, no significant applicability concerns. The mean pooled sensitivity = 0.98 (95% CI: 0.936–1.025), pooled specificity=0.947 (95% CI: 0.920–0.973), and AUC=0.972 (95% CI: 0.952–0.992), indicating excellent diagnostic accuracy. Conclusion: Stimulation methods for copeptin dosing represent effective and less invasive diagnostic test for children with PPS, and future development of standard copeptin testing protocols are needed.