Liau Ben-Yi, Yeh Shoou-Jeng, Chiu Chuang-Chien, Tsai Yu-Chou
Graduate Institute of Electrical and Communications Engineering, Feng Chia University, Taichung, Taiwan, ROC.
Med Biol Eng Comput. 2008 Jan;46(1):1-9. doi: 10.1007/s11517-007-0243-5. Epub 2007 Sep 14.
Cerebral autoregulation (CA) was assessed by chaotic analysis based on mean arterial blood pressure (MABP) and mean cerebral blood flow velocity (MCBFV) in 19 diabetics with autonomic neuropathy (AN) and 11 age-matched normal subjects. MABP in diabetics dropped significantly in response to tilting (91.6 +/- 14.9 vs. 74.1 +/- 13.4 mmHg, P < 0.05). Valsalva ratio of heart rate was reduced in diabetics compared to normal (1.1 +/- 0.1 vs. 1.5 +/- 0.2, P < 0.05). It indicated AN affects the vasomotor tone of peripheral vessels and baroreflex. Nonlinear results showed higher correlation dimension values of MABP and MCBFV in diabetics compared to normal, especially MABP (3.7 +/- 2.3 vs. 2.0 +/- 0.8, P < 0.05). It indicated CA is more complicated in diabetics. The lower Lyapunov exponent and the higher Kolmogorov entropy values in diabetics indicated less predictable behavior and higher chaotic degree. This study suggests impaired autoregulation would be more chaotic and less predictable.
基于平均动脉血压（MABP）和平均脑血流速度（MCBFV），采用混沌分析方法对19例患有自主神经病变（AN）的糖尿病患者和11例年龄匹配的正常受试者的脑自动调节（CA）功能进行了评估。糖尿病患者在倾斜试验时MABP显著下降（91.6±14.9 vs. 74.1±13.4 mmHg，P<0.05）。与正常受试者相比，糖尿病患者心率的乏氏比值降低（1.1±0.1 vs. 1.5±0.2，P<0.05）。这表明自主神经病变影响外周血管的血管舒缩张力和压力反射。非线性结果显示，与正常受试者相比，糖尿病患者MABP和MCBFV的关联维数值更高，尤其是MABP（3.7±2.3 vs. 2.0±0.8，P<0.05）。这表明糖尿病患者的脑自动调节功能更为复杂。糖尿病患者较低的Lyapunov指数和较高的Kolmogorov熵值表明其行为的可预测性较低且混沌程度较高。本研究提示，受损的自动调节功能会更加混沌且更难以预测。
