1 Augusta University - University of Georgia Medical Partnership, USA.
2 University of Alabama Birmingham, USA.
Eur J Prev Cardiol. 2019 Mar;26(5):471-480. doi: 10.1177/2047487318795192. Epub 2018 Aug 28.
Supervised treadmill exercise for claudication in peripheral arterial disease is effective but poorly tolerated because of ischemic leg pain. Near infrared spectroscopy allows non-invasive detection of muscle ischemia during exercise, allowing for characterization of tissue perfusion and oxygen utilization during training.
We evaluated walking time, muscle blood flow, and muscle mitochondrial capacity in patients with peripheral artery disease after a traditional pain-based walking program and after a muscle oxygen-guided walking program.
Patients with peripheral artery disease trained thrice weekly in 40-minute-long sessions for 12 weeks, randomized to oxygen-guided training ( n = 8, age 72 ± 9.7 years, 25% female) versus traditional pain-based training ( n = 10, age 71.6 ± 8.8 years, 20% female). Oxygen-guided training intensity was determined by maintaining a 15% reduction in skeletal muscle oxygenation by near infrared spectroscopy rather than relying on symptoms of pain to determine exercise effort. Pain free and maximal walking times were measured with a 12-minute Gardner treadmill test. Gastrocnemius mitochondrial capacity and blood flow were measured using near infrared spectroscopy. Baseline pain-free walking time was similar on a Gardner treadmill test (2.5 ± 0.9 vs. 3.6 ± 1.0 min, p = 0.5). After training, oxygen-guided cohorts improved similar to pain-guided cohorts (pain-free walking time 6.7 ± 0.9 vs. 6.9 ± 1.1 min, p < 0.01 for change from baseline and p = 0.97 between cohorts). Mitochondrial capacity improved in both groups but more so in the pain-guided cohort than in the oxygen-guided cohort (38.8 ± 8.3 vs. 14.0 ± 9.3, p = 0.018). Resting muscle blood flow did not improve significantly in either group with training.
Oxygen-guided exercise training improves claudication comparable to pain-based training regimens. Adaptations in mitochondrial function rather than increases in limb perfusion may account for functional improvement. Increases in mitochondrial oxidative capacity may be proportional to the degree of tissue hypoxia during exercise.
外周动脉疾病患者跛行时，监督下的跑步机运动是有效的，但由于腿部缺血性疼痛而难以耐受。近红外光谱可在运动过程中无创检测肌肉缺血，从而在训练过程中对组织灌注和氧利用进行特征描述。
我们评估了外周动脉疾病患者在传统基于疼痛的步行计划和肌肉氧指导的步行计划后，步行时间、肌肉血流和肌肉线粒体容量的变化。
患者每周进行三次 40 分钟的训练，共 12 周，随机分为氧指导训练组（n=8，年龄 72±9.7 岁，女性占 25%）和传统基于疼痛的训练组（n=10，年龄 71.6±8.8 岁，女性占 20%）。氧指导训练强度通过近红外光谱保持骨骼肌氧合减少 15%来确定，而不是依赖疼痛症状来确定运动强度。使用 12 分钟 Gardner 跑步机测试测量无疼痛和最大步行时间。使用近红外光谱测量比目鱼肌线粒体容量和血流。基线时，Gardner 跑步机测试的无疼痛步行时间相似（2.5±0.9 分钟 vs. 3.6±1.0 分钟，p=0.5）。训练后，氧指导组和疼痛指导组的无疼痛步行时间均有所改善（无疼痛步行时间 6.7±0.9 分钟 vs. 6.9±1.1 分钟，与基线相比变化均有统计学意义（p<0.01），两组间无统计学差异（p=0.97））。两组的线粒体容量均有所改善，但疼痛指导组的改善程度大于氧指导组（38.8±8.3 对 14.0±9.3，p=0.018）。两组的静息肌肉血流在训练后均无明显改善。
氧指导运动训练改善跛行的效果与基于疼痛的训练方案相当。适应线粒体功能而不是增加肢体灌注可能是功能改善的原因。线粒体氧化能力的增加可能与运动过程中的组织缺氧程度成正比。
