Effect of oral vitamin C ingestion on the vascular endothelial function and oxidative stress marker exposed to after transient heat-not-burn tobacco smoking / 体力科学

Heat-not-burn (HNB) tobacco smoking has spread throughout the market. While it is suggested that HNB tobacco smoking reduces the vascular endothelial function and is associated with a high risk of developing cardiovascular disease. The antioxidant of vitamin C may attenuate the unfavorable effects of HNB tobacco smoking. In the present study, we examined the effect of oral vitamin C ingestion on the flow-mediated dilation (FMD) at the brachial artery and oxidative stress markers in patients before and after transient HNB tobacco smoking. Twelve healthy adult males underwent high-resolution ultrasonography of the brachial artery and evaluations of reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) before and after a single session of HNB smoking. FMD was used to examine the endothelial function and the oxidative stress and antioxidant status were determined by using a FRES4 analyzer. In this randomized, crossover, controlled trial, measurements were performed on 2 different days 20 min after the oral administration of 1000 mg of ascorbic acid (VC trial) or a placebo (P trial). Although the FMD values decreased after a single HNB smoking session in both trials, the VC trial showed significantly higher values than the P trial at 60 and 120 min after smoking. Whereas the FMD values 120 min after smoking in the P trial were lower compared to the Pre values, there was no difference in the VC trial. These results suggested that the ingestion of vitamin C might suppress the decrease in the endothelial function caused by a single HNB smoking.

Effect of vitamin C ingestion on the vascular endothelial function exposed to transient passive smoking / 体力科学

As well as active smoking, passive smoking is associated with a high risk of developing cardiovascular disease. The antioxidant vitamin C may inhibit the unfavorable effects of passive smoking. In this study, we investigated the effects of vitamin C ingestion on changes in the flow-mediated dilatation (FMD) at the brachial artery in patients exposed to transient passive smoking. The study participants included seven healthy adult males who were examined by high-resolution ultrasonography of the brachial artery before and after 15-minute of passive smoking. FMD was used to examine the endothelial function. Randomized crossover controlled trial, measurements were performed on two different days 120-minute after the oral administration of 1000mg of ascorbic acid (VC trial) or a placebo (P trial). Although the FMD values decreased after passive smoking in both trials, the FMD values of the VC trial were higher than those of the P trial, with significant differences between the trials observed immediately and 30-minute after passive smoking. The results of this study suggested that the ingestion of vitamin C may suppress the decrease in the vascular endothelial function caused by transient passive smoking.

Influence of repetition exercise requiring less work than continuous exercise on the vascular endothelial function / 体力科学

High-intensity interval exercise leads to greater improvements in the vascular endothelial function than continuous exercise at moderate intensity. However, few studies have been performed on the effects of repetition exercise consisting of high-intensity exercise followed by complete rest on the arterial function. Therefore, the purpose of this study was to investigate the effects of repetition exercise on the vascular endothelial function determined by flow-mediated vasodilation (FMD). Eleven healthy male subjects completed two exercise sessions on a cycle ergometer in a counterbalanced order. The exercise sessions were 20 min cycling at 50% maximal work rate (Wmax) (continuous exercise, CE) and 20 × 20-sec intervals at 100%Wmax interspersed with 40-sec intervals at complete rest (repetition exercise, RE). Before and after each protocol, the brachial systolic and diastolic blood pressure were measured in the supine position. Relative FMD was assessed at rest and 30 and 60 min after each exercise regimen, and then the normalized FMD (nFMD) was calculated from the peak shear rate. The FMD significantly increased 30 min after RE (8.2 ± 1.5% to 11.5 ± 3.1%, p<0.01) and non-significantly increased 30 min after CE (7.5 ± 1.6% to 8.1 ± 2.1%, n.s.) before returning to baseline at 60 min after both exercise regimens. The FMD value at 30 min after RE was significantly greater than that at 30 min after CE (p<0.01). The nFMD (a.u.) significantly increased 30 min after RE (1.38 ± 0.64 to 2.00 ± 0.94, p<0.05) and non-significantly increased 30 min after CE (1.20 ± 0.54 to 1.49 ± 0.57, n.s.) before returning to baseline at 60 min after both exercise regimens. These results suggest that repetition exercise may lead to an acute improvement in the vascular endothelial function.

Influence of arm-cranking exercise with electrical muscle stimulation on arterial stiffness / 体力科学

Endurance exercises such as cycling and running are useful for improving the arterial function and preventing cardiovascular disease (CVD). However, subjects suffering from spinal cord injury (SCI) or lower limb osteoarthritis (OA) cannot perform these kinds of lower limb exercises. Recently, electrical muscle stimulation (EMS) has been shown to be able to increase the muscle strength and blood flow and improve the peripheral circulation. Arm-cranking exercises with EMS may therefore be able to reduce the risk of CVD for patients with SCI and lower OA. However, this point has not been fully clarified. The purpose of this study was to assess the effect of submaximal arm-cranking exercise with EMS on arterial stiffness. Ten healthy young subjects performed submaximal arm-cranking exercise alone (A) and submaximal arm-cranking exercise with EMS (A+E). In the A+E trial, the submaximal arm-cranking exercise was performed at 30%VO2 max for 20 min while EMS was applied to their thigh and calf muscles during the exercise. The brachial-ankle pulse wave velocity (ba-PWV), systolic and diastolic blood pressure (SBP/DBP) and heart rate (HR) were measured before and after each exercise. Immediately after the exercise session, the HR of the subjects in the A+E trial was significantly elevated in comparison to those in the A trial. The SBP and DBP did not differ between the two trials to a statistically significant extent. In the A+E trial, the ba-PWV was significantly reduced immediately after exercise in comparison to the A trial (1082.6 ± 105.9 cm·sec-1 vs. 1191.7 ± 86.7 cm·sec-1, p < 0.05). These findings suggest that arm-cranking exercise with EMS reduces arterial stiffness and might be useful for reducing the risk of CVD.

Effects of acute aerobic repetition exercise on the vascular endothelial function / 体力科学

<p>High-intensity interval exercise (IE) leads to greater improvements in the arterial function than continuous exercise at moderate intensity (CE). However, few studies have been performed on the effects of the repetition exercise (RE) on the vascular endothelial function. The purpose of this study was to compare the effects of CE vs. IE vs. RE during aerobic exercise on the vascular endothelial function determined by flow-mediated vasodilation (FMD). Ten healthy male subjects randomly performed 3 trials as follows: CE (20-min cycling at 50%W_max), IE (10 × 1-min intervals cycling at 75%W_max interspersed with 1-min intervals cycling at 25%W_max), and RE (30 × 20-sec intervals cycling at 100%W_max interspersed with 20-sec intervals at rest). FMD was assessed at rest and 30 and 60 min after each exercise, and then the normalized FMD (nFMD) was calculated from the peak shear rate. The nFMD (a.u.) significant increased 30 min after IE (1.2 ± 0.2 to 3.0 ± 1.0, p<0.05) and increased 30 min after CE (1.0 ± 0.2 to 1.4 ± 0.2, n.s.) and returned to baseline at 60 min after both exercises, while the nFMD decreased 30 min after RE (1.3 ± 0.2 to 1.2 ± 0.1, n.s.) and was sustained at 60 min. The nFMD value at 30 min after IE was significantly greater than that at 30 min after RE (3.0 ± 1.0 versus 1.2 ± 0.1, p<0.05). These results suggest that RE may lead to a less improvement in the vascular endothelial function than CE and IE.</p>

Correlation of functional fitness with arterial stiffness in community middle-aged and older women / 体力科学

<p>Habitual exercise is important for improving or maintaining the arterial function with age. However, the role of functional fitness on arterial stiffness in the elderly is unclear. This study was conducted to examine the relationships between functional fitness and arterial stiffness in elderly woman. Four hundred and seventy-nine elderly woman participated in the present investigation. The systolic/diastolic blood pressure and brachial to ankle pulse wave velocity were obtained in the supine position using an automatic pulse wave form analyzer. Four items of functional fitness (standing/sitting, walking, hand working, and self-care working) were assessed. The measurement variables were calculated for five chronological classifications (60~64, 65~69, 70~74, 75~79 and 80 yrs or over). The four items of functional fitness and brachial to ankle pulse wave velocity increased linearly with age. A multiple stepwise regression analysis revealed that systolic blood pressure (β= 0.366), age (β= 0.225), heart rate (β= 0.188), body mass index (β= -0.102), and standing/sitting (β= 0.098) were independent contributors to brachial to ankle pulse wave velocity, accounting for 29.6% of the variability. The physical function, especially standing/sitting, influences the arterial function in elderly women.</p>