A cross-validation of near-infrared spectroscopy measurements of skeletal muscle oxidative capacity with phosphorus magnetic resonance spectroscopy

Abstract

The purpose of this study was to cross-validate measurements of skeletal muscle oxidative capacity made with near-infrared spectroscopy (NIRS) measurements to those made with phosphorus magnetic resonance spectroscopy ((31)P-MRS). Sixteen young (age = 22.5 ± 3.0 yr), healthy individuals were tested with both (31)P-MRS and NIRS during a single testing session. The recovery rate of phosphocreatine was measured inside the bore of a 3-Tesla MRI scanner, after short-duration (∼10 s) plantar flexion exercise as an index of skeletal muscle oxidative capacity. Using NIRS, the recovery rate of muscle oxygen consumption was also measured using repeated, transient arterial occlusions outside the MRI scanner, after short-duration (∼10 s) plantar flexion exercise as another index of skeletal muscle oxidative capacity. The average recovery time constant was 31.5 ± 8.5 s for phosphocreatine and 31.5 ± 8.9 s for muscle oxygen consumption for all participants (P = 0.709). (31)P-MRS time constants correlated well with NIRS time constants for both channel 1 (Pearson's r = 0.88, P < 0.0001) and channel 2 (Pearson's r = 0.95, P < 0.0001). Furthermore, both (31)P-MRS and NIRS exhibit good repeatability between trials (coefficient of variation = 8.1, 6.9, and 7.9% for NIRS channel 1, NIRS channel 2, and (31)P-MRS, respectively). The good agreement between NIRS and (31)P-MRS indexes of skeletal muscle oxidative capacity suggest that NIRS is a valid method for assessing mitochondrial function, and that direct comparisons between NIRS and (31)P-MRS measurements may be possible.

Impairments in microvascular function and skeletal muscle oxygenation in women with gestational diabetes mellitus: links to cardiovascular disease risk factors

“…During exercise, TSI and HHb indices were used as indices of muscle oxygenation and microvascular O 2 extraction [27,28]. Handgrip and NIRS oxygenation measurements have been shown to be valid and highly reliable [16,18,[29][30][31].…”

Cellular, molecular and physiological effects of post-resistance exercise cold water immersion: Implications for subsequent perofrmance

“…At this penetration depth, the corresponding NIRS signal mainly reflects the metabolic and hemodynamic changes of the muscle (Ferrari et al, 2004). The NIRS method is both reliable and valid for the measurement of muscle oxidative metabolism (Ryan et al, 2013). The coefficient of variation for test-retest reliability of resting SmO 2 was 2.3% in this investigation.…”

“…A different approach was adopted in this study by measuring changes in SmO 2 desaturation and resaturation in response to MVCs, which is sufficient to block blood flow and thus O 2 delivery to muscle (Sadamoto et al, 1983). This allowed us to separate O 2 consumption from O 2 delivery (Ryan et al, 2013). The SmO 2 ½ DT during MVC increased following active recovery, whereas it remained unchanged or tended to decrease after cold water immersion.…”

“…Previous research has used near infra-red spectroscopy (NIRS) to measure muscle oxyhemoglobin saturation (SmO 2 ) as a measure of tissue oxygenation, and total hemoglobin (tHb) concentration as a measure of muscle blood volume after cold water immersion Tseng et al, 2013;Stanley et al, 2014). Changes in SmO 2 provide information on the balance between O 2 consumption and delivery in muscle (Ryan et al, 2013). To distinguish O 2 consumption from O 2 delivery, it is necessary to block O 2 delivery to muscle through arterial occlusions (Ryan et al, 2013) maximal voluntary isometric contractions (Muthalib et al, 2010).…”

“…Changes in SmO 2 provide information on the balance between O 2 consumption and delivery in muscle (Ryan et al, 2013). To distinguish O 2 consumption from O 2 delivery, it is necessary to block O 2 delivery to muscle through arterial occlusions (Ryan et al, 2013) maximal voluntary isometric contractions (Muthalib et al, 2010). This approach provides a means to obtain novel information on how cold water immersion might affect muscle O 2 consumption and reactive hyperemia during and following muscle contraction (Ferrari et al, 2011).…”