Department of Endocrinology, Key Laboratory of Endocrinology of National Health Commission, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
Eight-year Program of Clinical Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
Endocr Pract. 2024 Nov;30(11):1059-1065. doi: 10.1016/j.eprac.2024.08.006. Epub 2024 Aug 24.
Copeptin stimulation tests can be used in the differential diagnosis of polyuria-polydipsia syndrome. Current stimulation methods rely on intravenous or subcutaneous administration. Oral stimulus can further simplify the diagnostic approach. The levodopa stimulation test is widely used in the evaluation of growth hormone deficiency, and the dopamine pathway was reported to be associated with arginine vasopressin secretion. This study aims to investigate the effect of oral levodopa on copeptin secretion.
This study was a prospective observational single-center cohort study. Patients <18 years old with short stature and no symptoms of polyuria or polydipsia undergoing the levodopa stimulation test for suspected growth hormone deficiency were recruited from May 2023 to Nov 2023. Copeptin and growth hormone were measured at 0, 30, 60, 90, and 120 min during the levodopa test. The insulin tolerance test with copeptin and growth hormone measured at the same time points was conducted in part of patients.
Forty-four participants were included in the final analysis. In the levodopa stimulation test, the median (interquartile range) copeptin concentration increased from 5.20 (3.51, 8.25) pmol/L to a maximum of 19.36 (8.97, 108.08) pmol/L (P < .001), 3.94 (1.41, 13.88) times that of the baseline (P < .001). Compared with the insulin tolerance test, peak copeptin in the levodopa test was significantly higher (34.61 [13.67, 98.96] vs 8.88 [7.14, 15.42] pmol/L, P = .009). Higher copeptin was associated with a larger dose of levodopa.
Oral levodopa could be used to stimulate copeptin.
copeptin 刺激试验可用于多尿多饮综合征的鉴别诊断。目前的刺激方法依赖于静脉或皮下给药。口服刺激剂可以进一步简化诊断方法。左旋多巴刺激试验广泛应用于生长激素缺乏症的评估，而多巴胺途径与精氨酸加压素分泌有关。本研究旨在探讨口服左旋多巴对 copeptin 分泌的影响。
这是一项前瞻性观察性单中心队列研究。2023 年 5 月至 2023 年 11 月期间，招募了因疑似生长激素缺乏症而接受左旋多巴刺激试验的矮小且无多尿或多饮症状的<18 岁患者。在左旋多巴试验期间的 0、30、60、90 和 120 分钟测量 copeptin 和生长激素。部分患者同时进行胰岛素耐量试验并测量 copeptin 和生长激素。
最终分析纳入 44 名参与者。在左旋多巴刺激试验中，c肽浓度中位数（四分位距）从 5.20（3.51，8.25）pmol/L 升高至 19.36（8.97，108.08）pmol/L（P<0.001），最大升高 3.94 倍（P<0.001）基线值。与胰岛素耐量试验相比，左旋多巴试验中 copeptin 的峰值明显更高（34.61[13.67，98.96]vs 8.88[7.14，15.42]pmol/L，P=0.009）。更高的 copeptin 与左旋多巴的更大剂量相关。
口服左旋多巴可用于刺激 copeptin。
