Copeptin as a biomarker and a diagnostic tool in the evaluation of patients with polyuria-polydipsia and hyponatremia

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• 作者：Prof. M. Christ-Crain ; MD ; PhD^a ; ^{mirjam.christ@usb.ch" class="auth_mail" title="E-mail the corresponding author} (Consultant Endocrinology) ; N.G. Morgenthaler ; MD ; PhD^b ; ¹ ; ^{nils.morgenthaler@charite.de" class="auth_mail" title="E-mail the corresponding author} ; W. Fenske ; MD ; PhD ; PD^c ; ² ; ^{WiebkeKristin.Fenske@medizin.uni-leipzig.de" class="auth_mail" title="E-mail the corresponding author} (Junior Research Group Leader)
• 关键词：arginine vasopressin ; copeptin ; polyuria&ndash ; polydipsia syndrome ; diabetes insipidus ; hyponatremia
• 刊名：Best Practice Research Clinical Endocrinology Metabolism
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：30
• 期：2
• 页码：235-247
• 全文大小：1225 K

文摘

Copeptin is part of the 164 amino acid precursor protein preprovasopressin together with vasopressin and neurophysin II. During precursor processing, copeptin is released together with vasopressin. Copeptin concentrations respond as rapidly as vasopressin to changes in osmolality, a decrease in blood pressure or stress and there is a close correlation of vasopressin and copeptin concentrations. For these reasons, copeptin is propagated as a surrogate marker for vasopressin in the differential diagnosis of the polyuria–polydipsia syndromes and hyponatremia. Results of prospective studies show that a baseline copeptin level without prior fluid deprivation >20 pmol/L is able to identify patients with nephrogenic diabetes insipidus, whereas osmotically stimulated copeptin levels differentiate between patients with partial central diabetes insipidus and primary polydipsia with a high sensitivity and specificity >94%. In hyponatremia, low copeptin levels point to primary polydipsia and high levels to hypovolemic hyponatremia. The copeptin to urinary sodium ratio differentiates accurately between volume-depleted and normovolemic disorders.