TY - JOUR
T1 - Effects of exercise training on calf muscle oxygen extraction and blood flow in patients with peripheral artery disease
AU - Baker, Wesley B.
AU - Li, Zhe
AU - Schenkel, Steven S.
AU - Chandra, Malavika
AU - Busch, David R.
AU - Englund, Erin K.
AU - Schmitz, Kathryn H.
AU - Yodh, Arjun G.
AU - Floyd, Thomas F.
AU - Mohler, Emile R.
N1 - Publisher Copyright:
© 2017 the American Physiological Society.
PY - 2017/12
Y1 - 2017/12
N2 - We employed near-infrared optical techniques, diffuse correlation spectroscopy (DCS), and frequency-domain nearinfrared spectroscopy (FD-NIRS) to test the hypothesis that supervised exercise training increases skeletal muscle microvascular blood flow and oxygen extraction in patients with peripheral artery disease (PAD) who experience claudication. PAD patients (n = 64) were randomly assigned to exercise and control groups. Patients in the exercise group received 3 mo of supervised exercise training. Calf muscle blood flow and oxygen extraction were optically monitored before, during, and after performance of a graded treadmill protocol at baseline and at 3 mo in both groups. Additionally, measurements of the ankle-brachial index (ABI) and peak walking time (PWT) to maximal claudication were made during each patient visit. Supervised exercise training was found to increase the maximal calf muscle blood flow and oxygen extraction levels during treadmill exercise by 29% (13%, 50%) and 8% (1%, 12%), respectively [P < 0.001; median (25th percentile, 75th percentile)]. These improvements across the exercise group population were significantly higher than corresponding changes in the control group (P < 0.004). Exercise training also increased PWT by 49% (18%, 101%) (P < 0.01). However, within statistical error, the ABI, resting calf muscle blood flow and oxygen extraction, and the recovery half-time for hemoglobin\myoglobin desaturation following cessation of maximal exercise were not altered by exercise training. The concurrent monitoring of both blood flow and oxygen extraction with the hybrid DCS/FD-NIRS instrument revealed enhanced muscle oxidative metabolism during physical activity from exercise training, which could be an underlying mechanism for the observed improvement in PWT. NEW & NOTEWORTHY We report on noninvasive optical measurements of skeletal muscle blood flow and oxygen extraction dynamics before/during/after treadmill exercise in peripheral artery disease patients who experience claudication. The measurements tracked the effects of a 3-mo supervised exercise training protocol and revealed that supervised exercise training improved patient ability to increase microvascular calf muscle blood flow and oxygen extraction during physical activity.
AB - We employed near-infrared optical techniques, diffuse correlation spectroscopy (DCS), and frequency-domain nearinfrared spectroscopy (FD-NIRS) to test the hypothesis that supervised exercise training increases skeletal muscle microvascular blood flow and oxygen extraction in patients with peripheral artery disease (PAD) who experience claudication. PAD patients (n = 64) were randomly assigned to exercise and control groups. Patients in the exercise group received 3 mo of supervised exercise training. Calf muscle blood flow and oxygen extraction were optically monitored before, during, and after performance of a graded treadmill protocol at baseline and at 3 mo in both groups. Additionally, measurements of the ankle-brachial index (ABI) and peak walking time (PWT) to maximal claudication were made during each patient visit. Supervised exercise training was found to increase the maximal calf muscle blood flow and oxygen extraction levels during treadmill exercise by 29% (13%, 50%) and 8% (1%, 12%), respectively [P < 0.001; median (25th percentile, 75th percentile)]. These improvements across the exercise group population were significantly higher than corresponding changes in the control group (P < 0.004). Exercise training also increased PWT by 49% (18%, 101%) (P < 0.01). However, within statistical error, the ABI, resting calf muscle blood flow and oxygen extraction, and the recovery half-time for hemoglobin\myoglobin desaturation following cessation of maximal exercise were not altered by exercise training. The concurrent monitoring of both blood flow and oxygen extraction with the hybrid DCS/FD-NIRS instrument revealed enhanced muscle oxidative metabolism during physical activity from exercise training, which could be an underlying mechanism for the observed improvement in PWT. NEW & NOTEWORTHY We report on noninvasive optical measurements of skeletal muscle blood flow and oxygen extraction dynamics before/during/after treadmill exercise in peripheral artery disease patients who experience claudication. The measurements tracked the effects of a 3-mo supervised exercise training protocol and revealed that supervised exercise training improved patient ability to increase microvascular calf muscle blood flow and oxygen extraction during physical activity.
KW - Claudication
KW - Diffuse correlation spectroscopy
KW - Exercise training
KW - Near-infrared spectroscopy
KW - Peripheral artery disease
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U2 - 10.1152/japplphysiol.00585.2017
DO - 10.1152/japplphysiol.00585.2017
M3 - Article
C2 - 28982943
AN - SCOPUS:85038620485
SN - 8750-7587
VL - 123
SP - 1599
EP - 1609
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 6
ER -