Mayrovitz H N, Larsen P B
Miami Heart Research Institute, Department of Vascular Research, Miami Beach, Florida 33140, USA.
Microvasc Res. 1996 Sep;52(2):115-26. doi: 10.1006/mvre.1996.0048.
Lower extremity transcutaneous oxygen tension (TcPO2) is used in diagnostic and prognostic indicator of tissue perfusion and is reduced in diabetes mellitus. Since cardiac output, leg blood flow and microvascular perfusion each can singly or jointly effect tissue oxygenation, the relative importance of macro- vs microvascular factors has not been resolved. To clarify this issue we compared TcPO2 levels in diabetic and nondiabetic subjects in whom cardiac output, leg pulsatile blood flow, and microcirculatory perfusion parameters were noninvasively measured. In 60 diabetic and 60 nondiabetic subjects the following measurements were done on both legs during a single session evaluation: foot dorsum TcPO2 at 45 degrees using laser-Doppler, ankle-brachial index using Doppler ultrasound (ABI), and pulsatile leg blood flow using magnetic resonance flowmetry; cardiac output was determined using transthoracic bioimpedance. The diabetic and nondiabetic groups were determined to have nonsignificant differences (mean +/- SEM, DM vs NODM) with respect to age (63.3 +/- 1.1 vs 60.1 +/- 1.5 years), cardiac output (5.5 +/- 0.2 vs 5.5 +/- 0.2 l/min), leg blood flow (1.6 +/- 0.05 vs 1.7 +/- 0.06 ml/min/100 cc) and ABI. Although macrocirculatory values were equivalent, microvascular function indicators were significantly reduced in the diabetic group: TcPO2 (51.9 +/- 1.4 vs 62.9 +/- 1.3 mmHg); MVR 76.7 +/- 1.5 vs 84.9 +/- 0.9%) and were correlated only in diabetics (r2 = 0.48, P < 0.001). The findings suggest a primary linkage between the diabetic TcPO2 deficit and the microcirculatory submaximal vasodilatory response, with little if any role of macrocirculatory factors.
下肢经皮氧分压（TcPO2）用于组织灌注的诊断和预后指标，在糖尿病患者中会降低。由于心输出量、腿部血流和微血管灌注各自都能单独或共同影响组织氧合，大血管与微血管因素的相对重要性尚未得到解决。为了阐明这个问题，我们比较了糖尿病患者和非糖尿病患者的TcPO2水平，这些患者的心输出量、腿部搏动血流和微循环灌注参数均通过无创测量获得。在60名糖尿病患者和60名非糖尿病患者中，在单次评估期间对双腿进行了以下测量：使用激光多普勒仪在45度时测量足背TcPO2，使用多普勒超声测量踝臂指数（ABI），使用磁共振血流仪测量腿部搏动血流；使用经胸生物阻抗法测定心输出量。糖尿病组和非糖尿病组在年龄（63.3±1.1岁 vs 60.1±1.5岁）、心输出量（5.5±0.2 vs 5.5±0.2升/分钟）、腿部血流（1.6±0.05 vs 1.7±0.06毫升/分钟/100立方厘米）和ABI方面无显著差异。尽管大循环值相当，但糖尿病组的微血管功能指标显著降低：TcPO2（51.9±1.4 vs 62.9±1.3毫米汞柱）；微血管反应性（MVR）76.7±1.5 vs 84.9±0.9%），且仅在糖尿病患者中存在相关性（r2 = 0.48，P < 0.001）。这些发现表明糖尿病患者TcPO2不足与微循环亚最大舒张反应之间存在主要联系，大循环因素几乎没有作用。
