伴有自主神经病变的糖尿病对脑血流自动调节功能的影响

Effects of Diabetes Mellitus with Autonomic Neuropathy on the Cerebral Autoregulation

目的观察伴有自主神经病变的糖尿病对脑血流自动调节功能的影响及其变化特征。方法采用经颅多普勒超声(TCD)检测20例伴有自主神经病变的糖尿病患者在体位改变时的大脑中动脉平均血流速度(MCA-Vm)改变,全自动监护仪同时监测患者的平均动脉压(MAP)和心率(HR),并与20例性别、年龄相匹配的健康对照组比较。结果仰卧位时糖尿病组MCA-Vm明显低于对照组(43.83±2.84、49.85±2.73,P<0.01)。由仰卧位快速起坐时,2组MCA-Vm均下降,但糖尿病组的MCA-Vm下降幅度(ΔVm)明显低于对照组(-5.23±1.74、-10.45±2.30,P<0.01),在时间-速度曲线上,糖尿病组的ΔVm曲线较对照组平坦。结论伴有自主神经病变的糖尿病患者脑血流自动调节功能受损,表现为静态体位时脑血流速度降低,体位改变时脑血流速度变化迟缓。

Objective To observe the effects of diabetes mellitus on the cerebral autoregulation and its characteristics.Methods Twenty patients with diabetes mellitus and dysfunction of autonomic nervous system and 20 age and gender matched normal controls were studied.The mean velocity of middle cerebral artery（MCA-Vm） was measured by transcranial Doppler（TCD） in the horizontal supine position,followed by a 5-min supine-to-sit protocol.The mean arterial blood pressure（MAP） and heart rate（HR） were also monitored by full automatic monitor.Results MCA-Vm was lower in patients with diabetes mellitus compared with normal controls in supine position（43.83±2.84 vs 49.85±2.73,P0.01）.During postural change from supine to sit,MCA-Vm was significantly decreased in both groups,but it declined gradually and less steeply in patients with diabetes mellitus than in normal controls（-5.23±1.74 vs-10.45±2.30,P0.01）.Conclusion Diabetes mellitus with autonomic neuropathy may affect cerebral autoregulation,characterized by lower cerebral blood flow velocity in static position and decreased vasomotor responses during postural changes.