Fitness Level‐ and Sex-Related Differences in Macrovascular and Microvascular Responses during Reactive Hyperemia

Abstract

Purpose: Reactive hyperemia (RH) is widely used for the investigation of macrovascular (flow-mediated dilation, or FMD) and microvascular (near-infrared spectroscopy-vascular occlusion test, or NIRS-VOT) function. Mixed results have been reported on fitness level-and sexrelated differences in FMD outcomes, and little is known about microvascular differences in untrained and chronically trained males and females. Methods: Fifteen chronically trained (CT: 8 males, 7 females) and 16 untrained (UT: 8 males, 8 females) individuals participated in this study. Aerobic fitness (V ˙O2max ) was assessed during a cycling incremental exercise test to volitional exhaustion. FMD and NIRS-VOT were performed simultaneously on the lower limb investigating superficial femoral artery and vastus lateralis muscle, respectively. Results: %FMD was not different between groups (CT males, 4.62 ± 1.42; CT females, 4.15 ± 2.23; UT males, 5.10 ± 2.53; CT females, 3.20 ± 1.67). Peak blood flow showed greater values in CT versus UT ( P ≤ 0.0001) and males versus females ( P = 0.032). RH blood flow area under the curve was greater in CT versus UT ( P = 0.001). At the microvascular level, desaturation and reperfusion rates were faster in CT versus UT ( P = 0.018 and P = 0.013) and males versus females ( P = 0.011 and P = 0.005). V ˙O2max was significantly correlated with reperfusion rate ( P = 0.0005) but not with %FMD. Conclusions: Whereas NIRS-VOT outcomes identified fitness-and sex-related differences in vascular responses, %FMD did not. However, when RH-related outcomes from the FMD analysis were considered, fitness-and/or sex-related differences were detected. These data highlight the importance of integrating FMD and NIRS-VOT outcomes for a more comprehensive evaluation of vascular function.

Metabolic and microvascular function assessed using near‐infrared spectroscopy with vascular occlusion in women: age differences and reliability

“…Consequently, the NIRS-VOT has been used in several studies as a tool to assess skeletal muscle metabolic and microvascular function, and has been shown to be sensitive to changes in altitude (Martin et al, 2013), altered microcirculatory function in sepsis (Stout & Crawford, 1988), the presence of CVD risk factors (de Oliveira et al, 2019;Rosenberry et al, 2018), aerobic fitness levels, sex differences (Rasica et al, 2022) and body fatness (Soares & Murias, 2018).…”

Energetic Contributions Including Gender Differences and Metabolic Flexibility in the General Population and Athletes

“…The difference between males and females is especially pronounced in type II fibers, which results in a greater ratio of type II fiber mass to type I fiber mass in males, including higher PCr pool, La − production and elimination, and oxidative capacity [ 14 , 42 , 43 , 44 , 45 ]. On the other hand, greater skeletal muscle microvascular reactivity in the form of microvascular dilation and arterial diameter resulting in greater blood flow may affect gender differences in reperfusion capacity, which are also positively associated with cardiovascular fitness [ 14 , 37 , 46 , 47 , 48 ]. The abovementioned factors might differentially influence metabolic energy contributions between males and females in GP and A.…”

“…Fat and carbohydrate oxidations, including glucose and lactate, also play key roles in cardiac metabolism [ 13 ]. These metabolic responses, such as oxidative exercise capacity, are associated with the cardiovascular system/health [ 14 ]. The produced lactate is re-metabolized via mitochondrial lactate oxidation, which involves monocarboxylic transporter-1, its chaperone as the cluster of differentiation 147 (CD147), which is an ancillary protein, as well as mitochondrial dehydrogenase and cytochrome oxidase [ 5 , 10 , 13 , 15 ].…”

Association between Femoral Artery Flow-Mediated Dilation and Muscle Oxygen Saturation Parameters in Healthy, Young Individuals

“…The flow-mediated dilation in the superficial femoral artery was assessed according to guidelines presented elsewhere [ 14 , 15 ]. A two-dimensional ultrasound with color and spectral Doppler (Prosound Alpha 6 ® , Aloka Co., Tokyo, Japan) and a linear transducer with a frequency of 5.0 to 13.0 MHz (model UST-5413, Aloka Co., Tokyo, Japan) were used.…”