FP26-2 Copeptin Levels Measured Within 24 Hours After Pituitary Surgery Predict Later Development of Diabetes Insipidus

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: FP26-Neuroendocrinology
Clinical
Sunday, June 16, 2013: 10:45 AM-11:15 AM
Presentation Start Time: 10:50 AM
Room 130 (Moscone Center)

Poster Board SUN-145
Bettina Winzeler*1, Nicole Nigro1, Christian Zweifel2, Birsen Arici1, Martina Bally3, Claudine Angela Blum3, Christopher Kelly1, Luigi Mariani1, Hans Landolt3, Philipp Schuetz3, Beat Mueller3 and Mirjam Christ-Crain1
1University Hospital Basel, Basel, Switzerland, 2Toronto Western Hospital, Toronto, Canada, 3Kantonsspital Aarau, Aarau, Switzerland
Introduction:

Postoperative diabetes insipidus (DI) remains a common complication after pituitary surgery.  Arginine vasopressin (AVP) measurement might contribute to a straightforward diagnosis, though, its measurement is hampered by technical difficulties. Copeptin, the stable C-terminal glycopeptide of the AVP prohormone, is a reliable circulating surrogate of AVP secretion.

We herein aim to elucidate whether copeptin is a helpful marker in the diagnostic approach of DI after pituitary surgery.

Design and Setting:

Prospective multicentre observational study in three tertiary referral centres in Switzerland and Canada.

Material and Methods:

Patients undergoing transsphenoidal or transcranial pituitary surgery were daily monitored for clinical items (i.e. vital signs, balance of fluids) and routine laboratory parameters until discharge. Copeptin levels were measured preoperatively, within 24 hours after surgery and daily until discharge. We also recorded tumour specific features and intraoperative manipulation of the neurohypophysis.

Results:

We present data of 104 patients (mean age 55 years, 58.6 % females) with hormone-inactive (45.2%) and hormone-secreting pituitary adenomas (21.1%), meningiomas (9.6%), Rathke’s cleft cysts (5.8%), craniopharyngeoma (3.8%), pituitary apoplexy (6.7%) or other pathology (7.7%). 79 patients had an uneventful postoperative course without development of DI and 25 patients developed DI between day 1 and day 5 after surgery. Preoperative copeptin levels were similar in patients with or without DI (4.7 pM [IQR 2.1-6.2] vs. 3.4 pM [IQR 2.3-5.6] respectively). Copeptin values measured within 24 hours after surgery were significantly lower in patients developing DI compared to patients with a normal postoperative course (4.3 pM [2.1-9.1] versus 8.7 pM [IQR 4.8-25.1], p<0.001). A copeptin level within 24 hours after surgery <2.7 pM had a specificity of 90% with a sensitivity of 48% to predict DI. In patients with an uneventful postoperative course surgery–induced stress led to an increase of copeptin of +3.3 pM [IQR 0.6-19.1]. In contrast, in patients with later DI copeptin values decreased after surgery (-0.013 pM [IQR -1-1.8]). A lack of copeptin increase despite surgery-induced stress predicted later development of DI with a specificity of 83% and a sensitivity of 54%. In a subset of 68 patients (12 with and 56 without postoperative DI) copeptin values were measured very early (within 2 hours) after surgery; in this subset, a copeptin level <2.6 pM predicted later DI with a specificity of 95% (sensitivity 50%).

Conclusion:

Low postoperative copeptin levels despite surgery-induced stress indicate later DI. Copeptin may become a novel tool in the early goal-directed management of patients after pituitary surgery.

Disclosure: PS: Coinvestigator, Thermofischer (Brahms AG). BM: Consultant, BRAHMS/Thermofisher. Nothing to Disclose: BW, NN, CZ, BA, MB, CAB, CK, LM, HL, MC

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm