Copeptin and the syndrome of inappropriate antidiuresis (SIAD) after pituitary transsphenoidal surgery

Abstract

Abstract Objective This study evaluates the predictive value of copeptin for syndrome of inappropriate antidiuresis (SIAD) postpituitary transsphenoidal surgery (TSS). Design Data from 133 consecutive patients undergoing TSS (November 2017–October 2022) at Oxford University Hospitals NHS trust are presented in this retrospective study. Methods Logistic regression (LR) and receiver operating characteristic (ROC) curves were performed to evaluate the diagnostic utility of copeptin. The Mann–Whitney U test was used to compare copeptin levels between the SIAD and no SIAD groups. Results Fourteen patients (10.8%) developed SIAD. Copeptin was available in 121, 53 and 87 patients for Days 1, 241 and 8 post‐TSS, respectively. LR for Day 1 copeptin to predict SIAD gave an odds ratio (OR) of 1.0 (95%CI 42 0.84–1.20, p = .99), area under‐ROC curve (AUC) was 0.49; Day 2 copeptin OR was 0.65 (95%CI 0.39–1.19, 43 p = .77), AUC was 0.57 LR for Day 1 sodium to predict SIAD gave an odds ratio (OR) of 1.0 (95%CI 0.85–1.21, p = .99), AUC was 0.50. Conclusions In conclusion, our data provide no evidence for copeptin as a predictive marker for post‐TSS SIAD.

Keywords

• copeptin
• hyponatraemia
• pituitary transsphenoidal surgery
• syndrome of inappropriate antidiuresis