Goldman M B, Robertson G L, Luchins D J, Hedeker D
University of Chicago Pritzker School of Medicine, Illinois 60637, USA.
J Clin Endocrinol Metab. 1996 Apr;81(4):1465-70. doi: 10.1210/jcem.81.4.8636352.
To determine whether polydipsia is responsible for the altered water excretion in the subset of polydipsic schizophrenic patients who develop hyponatremia, the regulation of antidiuretic function was assessed in polydipsic schizophrenic patients with hyponatremia (n = 5), polydipsic schizophrenic patients without hyponatremia (n = 5), nonpolydipsic schizophrenic patients (n = 6), and normal controls (n = 8). The severity and duration of polyuria were similar in the two polydipsic groups. After oral water loading, maximal free water clearance was similar across all four groups. Free water clearance diminished, however, at lower plasma osmolalities in the hyponatremic polydipsics (P < 0.02) and at higher plasma osmolalities in the normonatremic polydipsics (P < 0.05) relative to that in the nonpolydipsic schizophrenics and normal subjects. The increase in plasma vasopressin after osmotic stimulation with hypertonic saline was slightly, but significantly (P < 0.02), blunted in both polydipsic groups. Hyponatremia occurs in some polydipsic schizophrenics because the relationship between free water clearance to plasma osmolality/sodium is shifted to the left. Polydipsia per se is not responsible for this still unexplained shift.
为了确定烦渴是否导致了出现低钠血症的烦渴型精神分裂症患者水排泄的改变，我们对低钠血症的烦渴型精神分裂症患者（n = 5）、无低钠血症的烦渴型精神分裂症患者（n = 5）、非烦渴型精神分裂症患者（n = 6）和正常对照者（n = 8）的抗利尿功能调节进行了评估。两个烦渴组的多尿严重程度和持续时间相似。口服水负荷后，所有四组的最大自由水清除率相似。然而，相对于非烦渴型精神分裂症患者和正常受试者，低钠血症的烦渴者在较低血浆渗透压时自由水清除率降低（P < 0.02），而正常钠血症的烦渴者在较高血浆渗透压时自由水清除率降低（P < 0.05）。用高渗盐水进行渗透刺激后，两个烦渴组血浆血管加压素的增加略有但显著（P < 0.02）减弱。一些烦渴型精神分裂症患者出现低钠血症是因为自由水清除率与血浆渗透压/钠之间的关系向左移动。烦渴本身并非这种仍无法解释的变化的原因。
