Impaired muscle oxygen use at onset of exercise in peripheral arterial disease
Impaired muscle oxygen use at onset of exercise in peripheral arterial disease
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DOI：
10.1016/j.jvs.2004.06.025
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发表时间：
2004-09-01
影响因子：
4.3
通讯作者：
Hiatt, WR
中科院分区：
文献类型：
--
作者：
Bauer, TA;Brass, EP;Hiatt, WR
目标.在外周动脉疾病（PAD）患者中，肌肉代谢异常和动脉闭塞远端氧输送受损可能导致该人群中观察到的运动受限。用近红外光谱法测量的肌肉组织血红蛋白饱和度（StO（2））反映了氧输送和氧使用的相对贡献。因此，StO（2）对运动反应的动力学差异可能有助于深入了解PAD运动损伤的潜在机制。本研究的目的是描述运动开始时PAD患者和健康对照受试者的肌肉氧合反应，并比较StO（2）去饱和的动力学。我们假设在运动开始时，PAD患者StO（2）去饱和的动力学与对照组相比会减慢。材料和方法：来自一所大学中心的6名PAD患者和6名健康对照受试者进行了前瞻性横断面分析，评估了步行运动开始时StO（2）的去饱和动力学。在单独的访视中，受试者进行分级跑台运动和3个恒定功率跑台试验，相当于其峰值运动功率的60%（低）、80%（中）和100%（峰值）。在休息时和从休息到运动的过渡期间测量胃神经肌肉StO（2）反应曲线（InSpectra组织光谱仪）。肌肉StO（2）反应由指数数学模型表征。以运动开始后StO（2）下降的时间常数（相当于StO（2）下降约63%的时间）作为终点值。运动开始时StO（2）反应的定性模式在所有工作速率下患者和对照受试者之间也相似。然而，与对照组相比，PAD患者StO（2）去饱和的动力学时间常数延长（所有工作速率的平均时间常数，21.9 +/- 9.4秒vs 4.9 +/- 2.2秒; P
Objectives. In patients with peripheral arterial disease (PAD), abnormal muscle metabolism and impaired oxygen delivery distal to the arterial occlusions may contribute to the exercise limitation observed in this population. Muscle tissue hemoglobin saturation (StO(2)) measured with near-infrared spectroscopy, reflects the relative contributions of oxygen delivery and oxygen use. Thus differences in the kinetics Of StO(2) in response to exercise may yield important insight into the potential mechanisms associated with the PAD exercise impairment. The purposes of this study were to characterize the muscle oxygenation responses in patients with PAD and in healthy control subjects at the onset of exercise, and to compare the kinetics of StO(2) desaturation. We hypothesized that at the onset of exercise the kinetics of StO(2) desaturation would be slowed in PAD compared with control responses.Material and methods: Six patients with PAD and 6 healthy control subjects from a university center were examined in a prospective cross-sectional analysis that evaluated the desaturation kinetics of StO(2) at the onset of walking exercise. On separate visits subjects performed graded treadmill exercise and 3 constant work rate treadmill tests equivalent to similar to60% (low), similar to80% (medium), and 100% (peak) of their peak exercise work rate. Gastrocnernious muscle StO(2) response profiles (InSpectra tissue spectrometer) were measured at rest and across the rest to exercise transition. Muscle StO(2) responses were characterized by an exponential mathematical model. The end point value was taken as the time constant of StO(2) desaturation after onset of exercise (ie, equivalent to time to reach approximately 63% of StO(2) decrease).Results: The patients with PAD and the control subjects were of similar age and activity level. The qualitative patterns of StO(2) responses at onset of exercise were also similar between patients and control subjects at all work rates. However, the kinetic time constants of StO(2) desaturation were prolonged in patients with PAD versus control subjects (averaged time constant across all work rates, 21.9 +/- 9.4 seconds vs 4.9 +/- 2.2 seconds; P