Age-associated alteration of muscle oxygenation measured by near infrared spectroscopy during exercise

Reactive hyperemia half-time response is associated with skeletal muscle oxygen saturation changes during cycling exercise

We investigated the relationship between muscle microvascular responses during reactive hyperemia as assessed using near-infrared spectroscopy (NIRS) with changes in skeletal muscle oxygen saturation during exercise. Thirty young untrained adults (M/W: 20/10; 23 ± 5 years) completed a maximal cycling exercise test to determine exercise intensities performed on a subsequent visit separated by seven days. At the second visit, post-occlusive reactive hyperemia was measured as changes in NIRS-derived tissue saturation index (TSI) at the left vastus lateralis muscle. Variables of interest included desaturation magnitude, resaturation rate, resaturation half-time, and hyperemic area under the curve. Afterwards, two 4-minute bouts of moderate intensity cycling followed by one bout of severe intensity cycling to fatigue took place while TSI was measured at the vastus lateralis muscle. TSI was averaged across the last 60-s of each moderate intensity bout then averaged together for analysis, and at 60-s into severe exercise. The change in TSI (∆TSI) during exercise is expressed relative to a 20 W cycling baseline. On average, the ΔTSI was -3.4 ± 2.4 % and -7.2 ± 2.8 % during moderate and severe intensity cycling, respectively. Resaturation half-time was correlated with the ΔTSI during moderate (r = -0.42, P = 0.01) and severe (r = -0.53, P = 0.002) intensity exercise. No other reactive hyperemia variable was found to correlate with ΔTSI. These results indicate that resaturation half-time during reactive hyperemia represents a resting muscle microvascular measure that associates with the degree of skeletal muscle desaturation during exercise in young adults.

Age-Related Changes in Skeletal Muscle Oxygen Utilization

The cardiovascular and skeletal muscle systems are intrinsically interconnected, sharing the goal of delivering oxygen to metabolically active tissue. Deficiencies within those systems that affect oxygen delivery to working tissues are a hallmark of advancing age. Oxygen delivery and utilization are reflected as muscle oxygen saturation (SmO2) and are assessed using near-infrared resonance spectroscopy (NIRS). SmO2 has been observed to be reduced by ~38% at rest, ~24% during submaximal exercise, and ~59% during maximal exercise with aging (>65 y). Furthermore, aging prolongs restoration of SmO2 back to baseline by >50% after intense exercise. Regulatory factors that contribute to reduced SmO2 with age include blood flow, capillarization, endothelial cells, nitric oxide, and mitochondrial function. These mechanisms are governed by reactive oxygen species (ROS) at the cellular level. However, mishandling of ROS with age ultimately leads to alterations in structure and function of the regulatory factors tasked with maintaining SmO2. The purpose of this review is to provide an update on the current state of the literature regarding age-related effects in SmO2. Furthermore, we attempt to bridge the gap between SmO2 and associated underlying mechanisms affected by aging.

The use of near-infrared spectroscopy in the diagnosis of peripheral artery disease: A systematic review

BACKGROUND

Peripheral arterial disease is a stenosis or occlusion of peripheral arteries that results in compromised blood flow and muscle ischemia. The available diagnostic methods are mostly used to measure and visualize blood flow and are not useful in the evaluation of perfusion, especially in diabetic patients, which is now considered to be a research priority by most of the vascular societies around the world as this is still a relatively poorly studied phenomenon.

OBJECTIVE

The aim of this review is to explore the clinical significance of muscle tissue oxygenation monitoring in lower-extremity peripheral artery disease diagnosis using the near-infrared spectroscopy method.

METHODS

A systematic search in PubMed, CINAHL, and Cochrane databases was performed to identify clinical near-infrared spectroscopy (NIRS) studies in English and Russian, published until September 2019, involving muscle tissue oxygenation in peripheral arterial disease (PAD). The manuscripts were reviewed by two researchers independently and scored on the quality of the research using MINORS criteria.

RESULTS

After screening 443 manuscripts, 23 studies (n = 1580) were included. NIRS-evaluated recovery time seems to be more accurate than ankle-brachial index in diabetic patients to differentiate between moderate and severe claudication. Consistent findings across all the included studies showed that both the oxygenation and deoxygenation rates as well as the recovery times varied from patient to patient and therefore were not suitable for standardization.

CONCLUSIONS

The clinical relevance of routine use of NIRS to diagnose PAD is unproven; therefore, its use is not currently part of standard-of-care for patients with PAD since the absolute values seem to vary significantly, depending on the outside conditions. More data need to be provided on the possible use of NIRS monitoring intraoperatively where the conditions can be more controlled.

Relative variability in muscle activation amplitude, muscle oxygenation, and muscle thickness: Changes with dynamic low-load elbow flexion fatigue and relationships in young and older females

In repetitive upper limb activities, variability of muscle activity (a feature of motor variability) is linked to upper limb fatigability. Prior studies suggest that the variability response may change with age and could be related to the oxygen saturation of hemoglobin within the muscle. We determined, in female adults, how age affects adjustments in movement-to-movement variability of electromyograph (EMG) amplitude (RMS), oxygenation, and thickness with fatigue, and explored how these responses were related. Fifteen young (23.3 ± 3.1 years) and ten older (62.8 ± 6.9 years) females completed repeated trials of low-load, isokinetic, concentric/eccentric elbow flexion until maximal torque ≤ 70% of baseline. Movement-to-movement variability of EMG RMS in concentric phases of movement was quantified by the coefficient of variation (EMG CV), and muscle oxygenation and thickness (MTH) were quantified using near-infrared spectroscopy, and B-mode ultrasonography. Age*Time and Spearman ρ analyses were conducted. Age did not affect fatigability or Time-related changes in muscular measures (p > 0.05). Biceps brachii and brachialis EMG CV decreased, biceps brachii HbO₂ decreased and did not fully recover, and biceps brachii and brachialis MTH increased. Higher initial brachialis EMG CV was related to less blunted oxygenation in young females (p = 0.021). Oxygenation responses were related to altered anterior deltoid EMG CV in young females but altered biceps brachii and brachialis EMG CV in older females. Age was not associated with changes in EMG CV, oxygenation, or thickness at similar performance fatigability in the concentric/eccentric elbow flexion task studied. Adjustments in biceps brachii oxygenation were linked to changes in EMG CV more local to the site of fatigue with older age.

Skeletal Muscle Deoxygenation and Its Relationship to Aerobic Capacity During Early and Late Stages of Aging

The aim of this study was to compare muscle O₂ dynamics during exercise among elderly (n = 10, age: 73 ± 3 years), middle-aged (n = 9, age: 50 ± 6 years), and young (n = 10, age: 25 ± 3 years) adults. The subjects performed ramp bicycle exercise until exhaustion. Muscle O₂ saturation (SmO₂) and relative changes from rest in oxygenated hemoglobin/myoglobin (∆oxy-Hb/Mb), deoxygenated hemoglobin/myoglobin (∆deoxy-Hb/Mb), and total hemoglobin concentration (∆total-Hb) were monitored continuously at the vastus lateralis muscle by near-infrared spatial resolved spectroscopy. At given absolute workloads, SmO₂ and ∆oxy-Hb/Mb were significantly lower in elderly than the other groups, while ∆deoxy-Hb/Mb, ∆total-Hb, and pulmonary O₂ uptake (VO₂) were similar among the three groups. In contrast, there were no significant differences in muscle O₂ dynamics during submaximal exercise between middle-aged and young subjects. Muscle O₂ dynamics may be relatively preserved in early stages of aging, although muscle deoxygenation is enhanced in late stages of aging, probably due to reduced convective O₂ supply. Moreover, change in SmO₂ was significantly positively correlated with peak VO₂ in the elderly, while a significant negative relationship was observed in middle-aged and young subjects. In late stages of aging, diminished peak VO₂ may be caused by attenuated convective O₂ transport, while reduced peak VO₂ can be explained by lowered muscle O₂ extraction in early stages of aging.

Prebiotic Effect of Lycopene and Dark Chocolate on Gut Microbiome with Systemic Changes in Liver Metabolism, Skeletal Muscles and Skin in Moderately Obese Persons

Lycopene rich food and dark chocolate are among the best-documented products with a broad health benefit. This study explored the systemic effect of lycopene and dark chocolate (DC) on gut microbiota, blood, liver metabolism, skeletal muscle tissue oxygenation and skin. 30 volunteers were recruited for this trial, 15 women and 15 men with a mean age of 55 ± 5.7 years and with moderate obesity, 30 < BMI < 35 kg/m². They were randomized and divided into five equal interventional groups: three received different formulations of lycopene, one of them with a 7 mg daily dose and two with 30 mg; another group was given 10 g of DC with 7 mg lycopene embedded into its matrix, and the last group received 10 g DC. The trial was double-blinded for the three lycopene groups and separately for the 2 DC groups; the trial lasted for 1 month. By the end of the trial there were dose-dependent changes in the gut microbiota profile in all three lycopene groups with an increase of relative abundance of, e.g., Bifidobacterium adolescentis and Bifidobacterium longum. This was also accompanied by dose-dependent changes in the blood, liver metabolism, skeletal muscle and skin parameters. Consumption of DC resulted in increased relative abundance of, e.g., Lactobacillus and a reduction of corneocyte exfoliation. This is the first study which reports the prebiotic potential of lycopene and DC.

Systematic review of quantitative imaging biomarkers for neck and shoulder musculoskeletal disorders

Background

This study systematically summarizes quantitative imaging biomarker research in non-traumatic neck and shoulder musculoskeletal disorders (MSDs). There were two research questions: 1) Are there quantitative imaging biomarkers associated with the presence of neck and shoulder MSDs?, 2) Are there quantitative imaging biomarkers associated with the severity of neck and shoulder MSDs?

Methods

PubMed and SCOPUS were used for the literature search. One hundred and twenty-five studies met primary inclusion criteria. Data were extracted from 49 sufficient quality studies.

Results

Most of the 125 studies were cross-sectional and utilized convenience samples of patients as both cases and controls. Only half controlled for potential confounders via exclusion or in the analysis. Approximately one-third reported response rates. In sufficient quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied. The literature synthesis suggested that neck muscle size may be decreased in neck pain, and trapezius myalgia and neck/shoulder pain may be associated with reduced vascularity in the trapezius and reduced trapezius oxygen saturation at rest and in response to upper extremity tasks. Reduced vascularity in the supraspinatus tendon may also be a feature in rotator cuff tears. Five of eight studies showed an association between a quantitative imaging marker and MSD severity.

Conclusions

Although research on quantitative imaging biomarkers is still in a nascent stage, some MSD biomarkers were identified. There are limitations in the articles examined, including possible selection bias and inattention to potentially confounding factors. Recommendations for future studies are provided.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1694-y) contains supplementary material, which is available to authorized users.

The influence of adipose tissue on spatially resolved near-infrared spectroscopy derived skeletal muscle oxygenation: the extent of the problem

OBJECTIVE

Near-infrared spectroscopy (NIRS) measurements of tissue oxygen saturation (StO₂) are useful for the assessment of skeletal muscle perfusion and function during exercise, however, they are influenced by overlying skin and adipose tissue. This study explored the extent and nature of the influence of adipose tissue thickness (ATT) on StO₂.

APPROACH

NIR spatially resolved spectroscopy (SRS) derived oxygenation was measured on vastus lateralis in 56 patients with chronic heart failure (CHF) and 20 healthy control (HC) subjects during rest and moderate intensity exercise with simultaneous assessment of oxygen uptake kinetics (τ [Formula: see text]). In vitro measurements were performed on a flow cell with a blood mixture with full oxygen saturation (100%), which was gradually decreased to 0% by adding sodium metabisulfite. Experiments were repeated with 2 mm increments of porcine fat layer between the NIRS device and flow cell up to 14 mm.

MAIN RESULTS

Lower ATT, higher τ [Formula: see text], and CHF were independently associated with lower in vivo StO₂ in multiple regression analysis, whereas age and gender showed no independent relationship. With greater ATT, in vitro StO₂ was reduced from 100% to 74% for fully oxygenated blood and increased from 0% to 68% for deoxygenated blood.

SIGNIFICANCE

This study shows that ATT independently confounds NIR-SRS derived StO₂ by overestimating actual skeletal muscle oxygenation and by decreasing its sensitivity for deoxygenation. Because physiological properties (e.g. presence of disease and slowing of τ [Formula: see text]) also influence NIR-SRS, a correction based on optical properties is needed to interpret calculated values as absolute StO₂.

Exercise, ageing and the lung

This review provides a pulmonary-focused description of the age-associated changes in the integrative physiology of exercise, including how declining lung function plays a role in promoting multimorbidity in the elderly through limitation of physical function. We outline the ageing of physiological systems supporting endurance activity: 1) coupling of muscle metabolism to mechanical power output; 2) gas transport between muscle capillary and mitochondria; 3) matching of muscle blood flow to its requirement; 4) oxygen and carbon dioxide carrying capacity of the blood; 5) cardiac output; 6) pulmonary vascular function; 7) pulmonary oxygen transport; 8) control of ventilation; and 9) pulmonary mechanics and respiratory muscle function. Deterioration in function occurs in many of these systems in healthy ageing. Between the ages of 25 and 80 years pulmonary function and aerobic capacity each decline by ∼40%. While the predominant factor limiting exercise in the elderly likely resides within the function of the muscles of ambulation, muscle function is (at least partially) rescued by exercise training. The age-associated decline in pulmonary function, however, is not recovered by training. Thus, loss in pulmonary function may lead to ventilatory limitation in exercise in the active elderly, limiting the ability to accrue the health benefits of physical activity into senescence.

Influence of muscle fibre composition on muscle oxygenation during maximal running

Aims

To investigate the relationship between muscle oxygenation (specifically, the levels of oxygenated haemoglobin and myoglobin [oxyHb/Mb]) during maximal running and muscle fibre composition, and to determine whether muscle fibre composition can be non-invasively estimated from oxyHb/Mb levels during maximal running.

Methods

Eight male runners (, 60.9± 4.6 mL·kg⁻¹·min⁻¹) performed an incremental running test on a treadmill. OxyHb/Mb levels of the vastus lateralis during maximal running were measured by near-infrared spectroscopy (NIRS). Muscle fibre composition of the vastus lateralis was determined from muscle biopsy samples from the same region measured by NIRS, and the fibre types were classified as type I, type IIa, or type IIb fibres using traditional pH-sensitive ATPase staining. Type I and type IIa fibres together were defined as oxidative fibres.

Results

OxyHb/Mb levels during running were lowest at exhaustion in all participants. OxyHb/Mb levels at exhaustion were positively correlated with the percentages of type I fibres (r=0.755, p<0.05) and oxidative fibres (r=0.944, p<0.01).

Conclusions

We conclude that higher oxyHb/Mb levels at exhaustion during maximal running are correlated with a higher percentage of oxidative fibres, indicating the potential importance of oxidative fibres in the maintenance of oxyHb/Mb levels during maximal running. Additionally, muscle fibre composition could be non-invasively estimated from oxyHb/Mb levels during maximal running tests in runners.

Investigating the adaptation of muscle oxygenation to resistance training for elders and young men using near-infrared spectroscopy

PURPOSE

The purpose of this study was to investigate the differences in resistance training adaptation on muscle oxygenation between young and elderly subjects. Groups of eleven trained young, untrained young, trained elderly, and untrained elderly (UTE) were recruited.

METHODS

Muscle oxygenation of the vastus lateralis muscle during 20 % maximal voluntary isometric contraction was observed using near-infrared spectroscopy. The oxygen saturation (SpO2) kinetics in the contraction and recovery phases was modeled with a tangential model to extract ΔSpO2 and inflection time (IF). The median frequencies of SpO2 data representing the change of tissue oxygenation oscillation were compared.

RESULTS

The ΔSpO2 values for the trained groups (12.00 ± 7.86%) were significantly higher than those for the untrained groups (5.91 ± 4.36%, P < 0.05), and those for the young groups (11.63 ± 7.52%) were significantly higher than those for the older groups (6.29 ± 4.70%, P < 0.05). In the recovery phase, the IF was significantly longer for the elderly groups (10.32 ± 4.39 s, P < 0.05) than that for the young groups (6.31 ± 3.69 s). The median frequency of tissue oxygenation oscillation was significantly lower for the TE group (0.41 ± 0.12 Hz, P < 0.05) than that for the UTE group (0.57 ± 0.13 Hz).

CONCLUSIONS

The increased ΔSpO2 in trained groups during muscle contraction may be due to lower microvascular O2 pressure. The lower median frequency for the TE group indicates that tissue oxygenation oscillation significantly trended toward low-frequency oscillation, possibly resulting from the enhancement of vascular function.

Near infrared spectroscopy describes physiologic payback associated with excess postexercise oxygen consumption in healthy controls and children with complex congenital heart disease

Exercise creates a physiologic burden with recovery from such effort crucial to adaptation. Excess postexercise oxygen consumption (EPOC) refers to the body's increased metabolic need after work. This investigation was designed to determine the role of near infrared spectroscopy (NIRS) in the description of exercise recovery in healthy controls (NL) and children with congenital heart disease (CHD). Subjects were recruited with exercise testing performed to exhaustion. Exercise time (EXT), heart rate (HR), and oxygen consumption (VO(2)) were measured. Four-site NIRS (brain, kidney, deltoid, and vastus lateralis) were measured during exercise and into recovery to establish trends. Fifty individuals were recruited for each group (NL = 26 boys and 24 girls; CHD = 33 boys and 17 girls). Significant differences existed between EXT, VO(2), and peak HR (P < 0.01). NIRS values were examined at four distinct intervals: rest, peak work, and 2 and 5 min after exercise. Significant cerebral hyperemia was seen in children with CHD post exercise when compared to normal individuals in whom redistribution patterns were directed to somatic muscles. These identified trends support an immediate compensation of organ systems to re-establish homeostasis in peripheral beds through enhanced perfusion. Noninvasive NIRS monitoring helps delineate patterns of redistribution associated with EPOC in healthy adolescents and children with CHD.

Age-related blood flow changes in the rat intrinsic laryngeal muscles

CONCLUSIONS

These results indicate that a deceased laryngeal blood flow (BF) could be one contributing factor to age-related phonatory and airway dysfunction.

OBJECTIVE

Studies of non-laryngeal muscles suggest that decreased BF may contribute to an age-related decline in muscle performance. We hypothesized that there is an age-related BF decrease to the intrinsic laryngeal muscles.

MATERIALS AND METHODS

Intrinsic laryngeal muscle BF was measured in young (3-6 months old; n=11) and old (28-30 months old; n=21) male Fischer 344 rats during quiet respiration using the radiolabeled microsphere technique.

RESULTS

BF to the posterior cricoarytenoid (PCA) was very high even during this submaximal recruitment, consistent with its specialization for oxidative metabolism and fatigue resistance. The results demonstrated significant (p<0.05) age-related BF decreases in the thyroarytenoid (young, 163; old, 64 ml/min/100 g), cricothyroid (young, 104; old, 52 ml/min/100 g), and PCA (young, 404; old, 235 ml/min/100 g).

Measurement of regional tissue bed venous weighted oximetric trends during exercise by near infrared spectroscopy

BACKGROUND

Cardiopulmonary exercise testing (CPET) is limited to children able to tolerate the equipment. Modification of instrumentation to reduce invasiveness will open CPET to a wider population. Near Infrared Spectroscopy (NIRS) devices measure regional oxyhemoglobin saturation (rSO2). We aim to predict anaerobic threshold (AT) during CPET using multiorgan NIRS monitoring.

METHODS AND RESULTS

Nineteen subjects were recruited. NIRS probes were placed on the forehead, para vertebral space, vastus lateralis, and deltoid muscle (rSO2 C, rSO2 R, rSO2 L and rSO2 A). rSO2 was recorded at six second intervals at rest, exercise, and through a five minute recovery period. The AT was computed using the v-slope method. AT was also predicted using NIRS data by identifying the inflection point of the rSO2 trends for all the four sites. AT can be estimated by the point of slope change of rSO2 R, rSO2 C and the four-site composite measure.

CONCLUSIONS

Multisite NIRS monitoring of visceral organs is a potential predictor of AT. This allows for monitoring in all forms of exercise over a wide age range.

Age and Activity Status Affect Muscle Reoxygenation Time after Maximal Cycling Exercise

PURPOSE

The purpose of this study was to determine the interaction of age and habitual physical activity on recovery time of muscle oxygenation following maximal cycling exercise (CycEXmax).

METHODS

Twelve sedentary middle-aged (50+/-6), 13 sedentary elderly (66+/-3), 13 active middle-aged (53+/-5), and 20 active elderly (67+/-5) women participated in this study. We evaluated the peak pulmonary oxygen uptake (VO2peak) during CycEXmax and the half-recovery time of muscle oxygenation (T1/2reoxy time) using near-infrared spectroscopy at the vastus lateralis (VL) during the recovery phase after CycEXmax.

RESULTS

T1/2reoxy time was significantly greater in the elderly subjects than in the middle-aged subjects in both sedentary (P<0.05) and active groups (P<0.01). T1/2reoxy time of the active group was lower (P<0.01) than that of the sedentary group regardless of age. Age was significantly correlated to T1/2reoxy time in both sedentary and active groups (in both sedentary and active groups: P<0.01). The slope of T1/2reoxy time against age in the sedentary group was significantly greater (VL: P<0.05) than that of the active group. VO2peak showed significant inverse correlation with T1/2reoxy time at the VL in both sedentary and active groups. The slope of VO2peak against T1/2reoxy time showed no significant differences between middle-aged and elderly subjects.

CONCLUSION

The results of this study suggest that T1/2reoxy time was prolonged with aging, regardless of habitual physical activity levels. However, habitual physical activity may prevent the age-related prolongation in T1/2reoxy time after CycEXmax. VO2peak appears to be one of the major factors determining T1/2reoxy time, not age.

Muscle Oxygenation Trends During Dynamic Exercise Measured by Near Infrared Spectroscopy

During the last decade, NIRS has been used extensively to evaluate the changes in muscle oxygenation and blood volume during a variety of exercise modes. The important findings from this research are as follows: (a) There is a strong correlation between the lactate (ventilatory) threshold during incremental cycle exercise and the exaggerated reduction in muscle oxygenation measured by NIRS. (b) The delay in steady-state oxygen uptake during constant work rate exercise at intensities above the lactate/ventilatory threshold is closely related to changes in muscle oxygenation measured by NIRS. (c) The degree of muscle deoxygenation at the same absolute oxygen uptake is significantly lower in older persons compared younger persons; however, these changes are negated when muscle oxygenation is expressed relative to maximal oxygen uptake values. (d) There is no significant difference between the rate of biceps brachii and vastus lateralis deoxygenation during arm cranking and leg cycling exercise, respectively, in males and females. (e) Muscle deoxygenation trends recorded during short duration, high-intensity exercise such as the Wingate test indicate that there is a substantial degree of aerobic metabolism during such exercise. Recent studies that have used NIRS at multiple sites, such as brain and muscle tissue, provide useful information pertaining to the regional changes in oxygen availability in these tissues during dynamic exercise. Key words: blood volume, noninvasive measurement

Human tibia Bone Marrow: Defining a Model for the Study of Haemodynamics as a Function of Age by Near Infrared Spectroscopy

A human model allowing the non-invasive study of bone marrow haemodynamics has been developed. A decrease in postischaemic tissue reperfusion capability (postischaemic hyperaemia) as a function of age (range 25-72 years) was observed both in the human tibia and tibialis anterior muscle. In the tibia bone marrow the reperfusion capability started to decrease after 50 years and was lower than for muscle for all the age range. Mean basal muscle O(2) saturation (80.8% at 25 years) decreases as a function of age (-0.35%+/-0.13% per year) whereas it remains constant for bone marrow (84.8+/-2.8%). A Monte Carlo simulation has been performed to evaluate the accuracy of the derived O(2) saturation measurements and has shown that this parameter is robust even in the presence of substantial noise. It has also been demonstrated that it is necessary to use a multi wavelength NIR spectrometer and a second derivative based fitting algorithm to obtain reliable measurements from the bone marrow, and that the tissue scattering changes occurring during the protocol do not allow the use of the standard near infrared spectroscopy algorithms. The human tibia bone marrow model presented here and the related measurement technique should enable access to new areas of physiological research.