Muscle mitochondrial capacity in high‐ and low‐fitness females using near‐infrared spectroscopy

Rationale 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. Objective 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. Method and results 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. Conclusions 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.

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Methodological considerations for near-infrared spectroscopy to assess mitochondrial capacity after spinal cord injury

Journal of Spinal Cord Medicine ◽

10.1080/10790268.2019.1631585 ◽

2019 ◽

Vol 43 (5) ◽

pp. 623-632 ◽

Cited By ~ 1

Author(s):

Mina P. Ghatas ◽

Matthew E. Holman ◽

Ashraf S. Gorgey

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Cord Injury ◽

Methodological Considerations ◽

Mitochondrial Capacity

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Reproducibility of near-infrared spectroscopy measurements of oxidative function and postexercise recovery kinetics in the medial gastrocnemius muscle

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2013-0347 ◽

2014 ◽

Vol 39 (5) ◽

pp. 521-529 ◽

Cited By ~ 29

Author(s):

William M. Southern ◽

Terence E. Ryan ◽

Mary A. Reynolds ◽

Kevin McCully

Keyword(s):

Blood Flow ◽

Oxygen Consumption ◽

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Plantar Flexion ◽

Medial Gastrocnemius ◽

Muscle Oxygen ◽

Oxidative Function ◽

Mitochondrial Capacity

The purpose of this study was to assess the reproducibility of resting blood flow, resting oxygen consumption, and mitochondrial capacity in skeletal muscle using near-infrared spectroscopy (NIRS). We also determined the influence of 2 exercise modalities (ergometer and rubber exercise bands) on the NIRS measurements. Fifteen young, healthy participants (5 female, 10 male) were tested on 2 nonconsecutive occasions within an 8-day period. The NIRS device was placed on the medial gastrocnemius. Venous and arterial occlusions were performed to obtain blood flow and oxygen consumption. A series of repeated arterial occlusions was used to measure the recovery kinetics of muscle oxygen consumption after ∼7–10 s of voluntary plantar flexion exercise. Resting blood flow had mean coefficients of variation (CV) of 42% and 38% for bands and ergometer, respectively, and resting metabolism had mean CVs of 17% and 12% for bands and ergometer, respectively. The recovery time constant of oxygen consumption (day 1 bands and ergometer: 23.2 ± 3.7 s, 27.6 ± 6.5 s, respectively; day 2 bands and ergometer: 25.5 ± 5.4 s, 25.0 ± 4.9 s, respectively) had mean CVs of 10% and 11% for bands and ergometer, respectively. We conclude that measurements of oxygen consumption and mitochondrial capacity using NIRS can be obtained with good reproducibility.

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Reliability and Validity of Near-Infrared Spectroscopy Mitochondrial Capacity Measurement in Skeletal Muscle

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk3020019 ◽

2018 ◽

Vol 3 (2) ◽

pp. 19 ◽

Cited By ~ 2

Author(s):

◽

Keyword(s):

Skeletal Muscle ◽

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Near Infrared ◽

Reliability And Validity ◽

Capacity Measurement ◽

Mitochondrial Capacity

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Effectiveness of 6-Ischemic Cuff Near Infrared Spectroscopy Mitochondrial Capactity Test

10.20944/preprints201904.0314.v1 ◽

2019 ◽

Author(s):

Maxwell Sumner ◽

Indrajit Das ◽

Elizabeth K. Pryor ◽

Kevin McCully

Keyword(s):

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Rate Constants ◽

Near Infrared ◽

Current Method ◽

Data Sets ◽

Curve Fit ◽

Total Data ◽

Mitochondrial Capacity ◽

Analysis Protocol

Near-Infrared Spectroscopy (NIRS) has been used to measure muscle mitochondrial capacity. The current method requires as many as 22 short ischemic occlusions to generate a recovery curve for mitochondrial capacity.  PURPOSE: To determine the effectiveness of using a 6-occlusion analysis protocol to study muscle mitochondrial capacity.  METHOD: Two independent, unidentified data sets were analyzed (bicep n=48, forearm n=41) from previous studies using a NIRS device (Artinis, Ltd.). Both data sets had two recovery tests that included 22 ischemic occlusions.  A recovery rate used to indicate mitochondrial capacity was calculated two different ways (simultaneously).  Each sample was analyzed with a MATLAB program; with a curve-fit for the 22 ischemic occlusions and curve matching for the first six ischemic cuffs and an end resting value. The two resulting rate constants were compared using correlations, both for the two data sets, good and bad fitting data, using the best 5 of 6 points for the 6 cuff approach.  RESULTS: The rate constants were not significantly different between the 22 cmuff and 6 cuff for the total data sets:  bicep (1.43+0.32min-1, 1.44+0.35min-1, p=0.56), forearm (1.94+0.42min-1, 1.95+0.44min-1, p=0.76). The average bicep rate constants, when compared to each other, had an equation of y=1.07x-0.09, R2=0.90. The average forearm rate constants, when compared to each other, had an equation of 0.98x+0.02, R2=0.93. CONCLUSIONS: The 6-Cuff analysis provided the same results as the longer 22-cuff. The 6-cuff approach is both shorter in time and uses less ischemic occlusion periods, increasing the practicality of the NIRS mitochondrial capacity test.

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