Low postoperative copeptin may predict diabetes insipidus onset
Low copeptin levels in patients undergoing pituitary surgery may be indicative of postoperative diabetes insipidus, while high levels of copeptin appear to essentially rule out this diagnosis, according to recent findings.
In the prospective, multicenter observational cohort study, Miriam Christ-Crain, MD, PhD, of the University Hospital Basel in Switzerland, and colleagues evaluated 205 consecutive patients undergoing surgery for sellar lesions or tumors located near the hypothalamus or pituitary gland. The patients underwent surgery at any of three tertiary centers in Switzerland and Canada between 2011 and 2013.
The researchers measured postoperative copeptin levels on a daily basis until discharge from the hospital. The researchers used logistic regression to evaluate the relationship between postoperative copeptin levels and the onset of diabetes insipidus.
Overall, 24.4% of the patients developed diabetes insipidus postoperatively. Patients who developed diabetes insipidus had significantly lower copeptin levels (2.9 pmol/L) compared with those who did not develop diabetes insipidus (10.8 pmol/L; P < .001).
Following accounting for factors known to contribute to diabetes insipidus, logistic regression indicated a strong association between postoperative copeptin concentrations and diabetes insipidus (adjusted OR = 1.41; 95% CI, 1.16-1.73).
On postoperative day 1, diabetes insipidus was seen in 22 of the 27 patients with copeptin less than 2.5 pmol/L, but in only one of the 40 patients with copeptin greater than 30 pmol/L.
According to the researchers, these findings support the potential utility of copeptin measurements as a marker for diabetes insipidus in patients undergoing pituitary procedures.
“These findings suggest that copeptin represents a new, early and reliable single marker for postoperative [diabetes insipidus] in the postpituitary surgery setting, where no such marker currently is known,” the researchers wrote. “Postoperative copeptin measurements appear to provide important information for risk stratification and may identify patients benefitting from closer inpatient observation and patients in whom safe hospital discharge is possible,” – by Jennifer Byrne
Disclosure: Christ-Crain reports financial ties with Thermo Scientific Biomarkers. See the full study for a list of all other authors’ relevant financial disclosures.