Department of Internal Medicine and Clinical Nutrition, Institute of Medicine at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Department of Endocrinology, Sahlgrenska University Hospital, Gothenburg, Sweden.
Clin Endocrinol (Oxf). 2024 Jul;101(1):23-31. doi: 10.1111/cen.15018. Epub 2024 Jan 30.
Plasma copeptin is a relatively new biomarker for evaluation of arginine vasopressin (AVP) secretion. The aim of this study was to test the diagnostic performance of copeptin in patients with polyuria-polydipsia syndrome.
DESIGN, PATIENTS AND MEASUREMENTS: This was a prospective study where 88 patients with polyuria-polydipsia syndrome were evaluated with a water deprivation test (WDT). Weight, urine osmolality, urine specific gravity, and plasma copeptin were collected at baseline, after 8 h, and at termination of the WDT when one of the following had been reached: (i) >3% weight reduction, (ii) urine specific gravity >1.017 or urine osmolality >600 mOsm/kg, or (iii) intolerable adverse symptoms.
Of 88 patients (57 women), 21 (24%) were diagnosed with central diabetes insipidus (cDI), 5 (6%) with nephrogenic DI (nDI), and 62 (71%) with primary polydipsia (PP). Median (interquartile range) copeptin at baseline was 1.7 (1.4-2.5) pmol/L in cDI, 22 (18-65) pmol/L in nDI, and 2.7 (2-4) pmol/L in PP. After 8 h of WDT, the highest copeptin in patients with cDI was 4.0 pmol/L. In patients with PP: (i) 41 had urine osmolality <600 mOsm/kg, 7 (17%) of these had copeptin >4.0 pmol/L, (ii) 21 had urine osmolality ≥600 mOsm/kg, 14 (67%) of these had copeptin >4.0 pmol/L.
Copeptin >4.0 pmol/L after an overnight WDT can be used to rule out cDI and copeptin ≥21 pmol/L at baseline to diagnose nDI. The diagnostic performance of copeptin in the context of the WDT is otherwise limited in the diagnostic work-up of patients with polyuria-polydipsia syndrome.
血浆 copeptin 是评估血管加压素 (AVP) 分泌的相对较新的生物标志物。本研究旨在测试 copeptin 在多尿多饮综合征患者中的诊断性能。
设计、患者和测量：这是一项前瞻性研究，其中 88 例多尿多饮综合征患者接受了禁水试验 (WDT)。在基线、8 小时后和 WDT 结束时采集体重、尿渗透压、尿比重和血浆 copeptin，当达到以下任何一项时结束 WDT：(i)体重减轻>3%，(ii)尿比重>1.017 或尿渗透压>600 mOsm/kg，或 (iii)无法忍受的不良反应。
88 例患者（57 例女性）中，21 例（24%）被诊断为中枢性尿崩症（cDI），5 例（6%）为肾性尿崩症（nDI），62 例（71%）为原发性多饮（PP）。cDI 患者基线时 copeptin 的中位数（四分位距）为 1.7（1.4-2.5）pmol/L，nDI 患者为 22（18-65）pmol/L，PP 患者为 2.7（2-4）pmol/L。WDT 8 小时后，cDI 患者的 copeptin 最高值为 4.0 pmol/L。在 PP 患者中：(i)41 例患者尿渗透压<600 mOsm/kg，其中 7 例（17%）患者的 copeptin>4.0 pmol/L，(ii)21 例患者尿渗透压≥600 mOsm/kg，其中 14 例（67%）患者的 copeptin>4.0 pmol/L。
一夜 WDT 后 copeptin>4.0 pmol/L 可排除 cDI，基线时 copeptin≥21 pmol/L 可诊断 nDI。在多尿多饮综合征患者的诊断评估中，WDT 背景下 copeptin 的诊断性能有限。
