Endocrinology Unit, Department of Medicine DIMED, University of Padova, Via Ospedale Civile, 105, 35128, Padova, Italy.
Endocrinology Unit, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy.
Pituitary. 2018 Feb;21(1):50-55. doi: 10.1007/s11102-017-0846-2.
Central diabetes insipidus (DI) is a rare disease characterized by the excretion of excessive volumes of dilute urine due to reduced levels of the antidiuretic hormone arginine vasopressin (AVP), caused by an acquired or genetic defect in the neurohypophysis. The aim of this study was to identify any autonomic dysfunction (AD) in patients with DI as a possible cofactor responsible for their reportedly higher mortality.
The study involved 12 patients (6 females) with central idiopathic DI and a well-controlled electrolyte balance, and 12 controls matched for age, sex and cardiovascular risk factors, who were assessed using the tilt, lying-to-standing, hand grip, deep breath, Valsalva maneuver and Stroop tests.
The tilt test showed a significantly more pronounced decrease in both systolic (- 20.67 ± 18 vs. - 1.92 ± 6.99 mmHg, p = 0.0009) and diastolic blood pressure (- 10.5 ± 14.29 vs. - 1.5 ± 5 mmHg, p = 0.012) in patients than in controls. Three patients with DI had to suspend the test due to the onset of syncope. The lying-to-standing test also revealed a marked reduction in blood pressure in patients with DI (1.05 ± 0.13 vs. 1.53 ± 0.14, p = 0.0001). Similar results emerged for the Valsalva maneuver (Valsalva ratio, 1.24 ± 0.19 vs. 1.79 ± 0.11, p < 0.0001) and deep breath test (1.08 ± 0.11 vs. 1.33 ± 0.08, p < 0.0001).
All the principal autonomic tests performed in the study were concordant in indicating that patients with central DI have an impaired autonomic nervous system function despite a normal hydroelectrolytic balance under desmopressin therapy. This impairment may reflect damage to the autonomic system per se and/or the absence of any vasoactive effect of AVP on vascular smooth muscle. In our opinion, patients with central DI should be educated on how to prevent orthostatic hypotension, and pharmacological treatment should be considered for patients with a more marked impairment.
中枢性尿崩症（DI）是一种罕见的疾病，其特征是由于抗利尿激素血管加压素（AVP）水平降低，导致尿液排出过多的稀释尿液，这是由于神经垂体的获得性或遗传性缺陷引起的。本研究的目的是确定 DI 患者是否存在自主神经功能障碍（AD），因为 AD 可能是导致其报告死亡率较高的一个可能的促成因素。
本研究纳入了 12 名（6 名女性）患有中枢特发性 DI 且电解质平衡良好的患者，以及 12 名年龄、性别和心血管危险因素匹配的对照组患者。通过倾斜试验、卧位到站立位试验、握力试验、深呼吸试验、瓦尔萨尔瓦动作试验和斯特鲁普试验对所有患者进行评估。
倾斜试验显示，与对照组相比，患者的收缩压（-20.67±18 对-1.92±6.99mmHg，p=0.0009）和舒张压（-10.5±14.29 对-1.5±5mmHg，p=0.012）下降更为明显。有 3 名 DI 患者因晕厥发作而不得不暂停试验。卧位到站立位试验也显示 DI 患者的血压明显下降（1.05±0.13 对 1.53±0.14，p=0.0001）。瓦尔萨尔瓦动作试验（瓦尔萨尔瓦比值，1.24±0.19 对 1.79±0.11，p<0.0001）和深呼吸试验（1.08±0.11 对 1.33±0.08，p<0.0001）也得到了类似的结果。
尽管在 desmopressin 治疗下患者的水盐平衡正常，但本研究中进行的所有主要自主神经测试均一致表明，中枢性 DI 患者的自主神经系统功能受损。这种损伤可能反映了自主神经系统本身的损伤，或者 AVP 对血管平滑肌没有任何血管活性作用。在我们看来，应该教育中枢性 DI 患者如何预防直立性低血压，对于自主神经功能障碍更明显的患者，应考虑进行药物治疗。
