Service de Neurologie Vasculaire, Hôpital Rangueil, Toulouse, INSERM U, France.
Auton Neurosci. 2011 Feb 24;160(1-2):59-63. doi: 10.1016/j.autneu.2010.10.001. Epub 2010 Oct 30.
The mechanisms underlying impairment of dynamic cerebral autoregulation in diabetes are not well known. Cardiovascular autonomic neuropathy (CAN) could contribute to dynamic cerebral autoregulation impairment. In this study, we assessed the association between CAN and impairment of dynamic cerebral autoregulation in patients with type 1 diabetes.
We evaluated dynamic cerebral autoregulation (DCA) in patients with type 1 diabetes and no history of cerebrovascular disease. DCA was assessed with transcranial Doppler using the correlation coefficient index Mx method. Mx was calculated from slow changes in mean cerebral blood flow velocity and mean arterial blood pressure. Increase in Mx indicates weaker DCA, with a threshold for impaired DCA above 0.3. Moderate CAN was defined as reduced heart rate variability (HRV) on the following tests: deep controlled breathing, Valsalva maneuver or initiation of active standing. Severe CAN was defined as reduced HRV associated with orthostatic hypotension.
60 patients were included (M/F: 33/27; mean age ± SD: 46 years ± 11.5). 23 patients had moderate CAN and 15 patients severe CAN. DCA was impaired in 37 patients. CAN was associated with impaired DCA (p = 0.005). Impairment of DCA was more pronounced in patients with severe CAN (p = 0.019). Glycosylated haemoglobin (HbA1c) was associated with impaired DCA in univariate analysis (p = 0.05). In multivariate analysis, only CAN was associated with impaired DCA (p = 0.007) whereas HbA1c was not (p = 0.161).
CAN was associated with impaired DCA in type 1 diabetes. The magnitude of DCA impairment increased with the severity of CAN.
糖尿病患者动态脑自动调节功能受损的机制尚不清楚。心血管自主神经病变（CAN）可能导致动态脑自动调节功能受损。在这项研究中，我们评估了 1 型糖尿病患者中 CAN 与动态脑自动调节受损之间的关系。
我们评估了无脑血管疾病史的 1 型糖尿病患者的动态脑自动调节（DCA）。使用经颅多普勒超声通过相关系数指数 Mx 方法评估 DCA。Mx 是从平均脑血流速度和平均动脉血压的缓慢变化中计算得出的。Mx 的增加表示 DCA 较弱，DCA 受损的阈值大于 0.3。中度 CAN 定义为以下测试中心率变异性（HRV）降低：深度控制呼吸、瓦尔萨尔瓦动作或主动站立开始。严重 CAN 定义为与直立性低血压相关的 HRV 降低。
共纳入 60 例患者（男/女：33/27；平均年龄±标准差：46 岁±11.5）。23 例患者有中度 CAN，15 例患者有严重 CAN。37 例患者 DCA 受损。CAN 与 DCA 受损相关（p = 0.005）。严重 CAN 患者的 DCA 受损更明显（p = 0.019）。单因素分析显示糖化血红蛋白（HbA1c）与 DCA 受损相关（p = 0.05）。多因素分析显示，只有 CAN 与 DCA 受损相关（p = 0.007），而 HbA1c 无相关性（p = 0.161）。
CAN 与 1 型糖尿病患者的 DCA 受损相关。DCA 受损的程度随 CAN 的严重程度而增加。
