The two main differential diagnoses of central diabetes insipidus are nephrogenic diabetes insipidus and primary polydipsia. Reliable distinction between those entities is essential as treatment differs substantially with the wrong treatment potentially leading to serious complications. Past diagnostic measures using the indirect water deprivation test had several pitfalls, resulting in a low diagnostic accuracy.

With the introduction of copeptin, a stable and reliable surrogate marker for arginine vasopressin, diagnosis of diabetes insipidus was new evaluated. While unstimulated basal copeptin measurement reliably diagnoses nephrogenic diabetes insipidus, a stimulation test is needed to differentiate patients with central diabetes insipidus from patients with primary polydipsia. Stimulation can either be achieved through hypertonic saline infusion or arginine infusion. While the former showed high diagnostic accuracy and superiority over the indirect water deprivation test in a recent validation study, the diagnostic accuracy for arginine-stimulated copeptin was slightly lower, but superior in test tolerance. In summary of the recent findings, a new copeptin based diagnostic algorithm is proposed for the reliable diagnosis of diabetes insipidus.

中枢尿崩症的两种主要鉴别诊断是肾原性尿崩症和原发性多饮症。这些实体之间的可靠区分至关重要，因为治疗方法有很大差异，错误的治疗方法可能导致严重的并发症。过去使用间接水剥夺测试的诊断措施存在多个陷阱，导致诊断准确性较低。

随着精氨酸加压素稳定，可靠的替代指标copeptin的引入，对尿崩症的诊断有了新的评估。尽管未经刺激的基础肽素测量可以可靠地诊断出肾病性尿崩症，但仍需要进行刺激试验以将中枢性尿崩症患者与原发性多视症患者区分开。刺激可以通过高渗盐水或精氨酸输注来实现。尽管前者在最近的一项验证研究中显示出比间接脱水试验更高的诊断准确性和优越性，但精氨酸刺激的肽素的诊断准确性稍低，但测试耐受性更高。总结最近的发现，提出了一种新的基于肽素的诊断算法，用于尿崩症的可靠诊断。