1.Effect of acute short-term high and moderate-intensity interval exercise on pulse wave velocity
Kenichi Deguchi ; Hajime Miura
Japanese Journal of Physical Fitness and Sports Medicine 2014;63(5):475-480
Interval training has a beneficial effect for treating the cardiovascular disease. However, it is not clarify the effects of different exercise intensity and duration on arterial function. In the present study, we evaluated the effect of acute short-term high and moderate-intensity interval exercise on pulse wave velocity. Thirteen healthy men were randomly assigned to perform both acute interval exercise (IE; cycling for 24.6 min at 80%VO2max and 50%VO2max) and acute continuous moderate-intensity exercise (CME; cycling for 30 min at 50%VO2max). The IE and CME protocols were designed such that the exercises resulted in the same workload during each session. The brachial systolic and diastolic blood pressure (SBP and DBP), and brachial to ankle pulse wave velocity (baPWV) were obtained in the supine position using an automatic pulse wave form analyzer at pre- and post-exercise. In IE, baPWV at post-exercise decreased significantly compared with pre-exercise value (1181.9±119.2 cm・sec-1 vs. 1108.4±109.4 cm・sec-1, p<0.01). In CME, however, it was not significantly different between pre- and post-exercise values (1173.5±137.1 cm・sec-1 vs. 1164.8±96.0 cm・sec-1, p=ns). No significant differences in SBP and DBP were found both protocols. These results suggest that acute short-term high and moderate-intensity interval exercise was more effective in reducing baPWV compared with acute continuous exercise.
2.INFLUENCE OF LOW-INTENSITY CIRCUIT TRAINING ON ARTERY STIFFNESS IN FEMALE
Japanese Journal of Physical Fitness and Sports Medicine 2005;54(3):205-210
The aerobic training reduces the artery stiffness and systolic blood pressure. The anaerobic training such as resistance training, however, is associated with higher artery stiffness. We hypothesized that low-intensity circuit training might improve the large artery stiffness. The purpose of this study was to determine the effects of long-term low-intensity circuit training on artery stiffness in sedentary women. Twenty healthy women divided into two groups (training group and control group). In the training group, subjects asked to perform the resistance exercises consisted of arm curls, bench presses, lateral pull-downs, leg presses and squats 3 days per week for 2 months. They conducted 5 sets at 30% of their 10RM. Aerobic capacity (ventilatory threshold [VT]), muscle strength, resting blood pressure, and arterial stiffness index (brachial-ankle Pulse Wave Velocity [baPWV]) were evaluated before and after training period. After the low-intensity circuit training, work rate at VT was significantly increased (108.6±25.6W to 128.1±24.3W). The baPWV was significantly decreased (988.7±80.5cm · sec-1 to 895.7±62.6cm · sec-1). In control group, however, there were no significant differences during same duration. These results suggested that long-term low-intensity circuit training attenuates the large artery stiffness in healthy women. This kind of exercise may have great potential to lower the risks of circulatory illness in aged men.
3.Characteristics of cardiorespiratory responses to the latter stage of a simulated triathlon.
HAJIME MIURA ; KAORU KITAGAWA ; TOSHIHIRO ISHIKO
Japanese Journal of Physical Fitness and Sports Medicine 1994;43(5):381-388
The most characteristic feature of the triathlon is integration of the three endurance activities including of swimming, cycling and running, into a continuous task. So, it is necessary to identify the cardiorespiratory responses during the triathlon to develop a beneficial training program. Twelve male triathletes conducted a simulated triathlon test in a laboratory. This test consisted of continuous swimming, cycling and running using a flumepool, a bicycle ergometer and a treadmill, respectively. The exercise intensity and duration were 60% of maximal oxygen uptake during swimming, cycling and running for 30, 75 and 45 min, respectively. The results demonstrated that the residual effects of the prior exercise stage were observed during the latter exercise stage : The prior swimming stage produced an increment of oxygen uptake and heart rate during the cycling stage ; Prior swimming and cycling stages increased oxygen uptake, minute ventilation, heart rate and ventilatory equivalent to those during the running stage. These results suggest that the residual effects of the preceding exercise decreased the mechanical and respiratory efficiency by increasing the physiological demands of conducting the subsequent exercise. Therefore, triathletes are recommended to train themselves in a continuous task rather than separately.
4.RELATIONSHP BETWEEN OXYGENATION AND MYOELECTRIC ACTIVITY AT VASTUS LATERALIS AND LATERAL GASTROCNEMIUS MUSCLES
HAJIME MIURA ; HIDEO ARAKI ; HIDEKI MATOBA
Japanese Journal of Physical Fitness and Sports Medicine 1999;48(3):413-419
In order to find the cause behind the difference in the pattern of oxygenation between thigh and calf muscles during an incremental cycling exercise, we investigated the relationship between oxygenation and surface myoelectric activity. Five healthy male subjects performed the five 6-min cycling exercises of 50, 100, 150, 200 and 250 watts. We measured oxygenated hemoglobin/myoglobin (oxy-Hb/Mb) on continuous wave near infrared spectroscopy (NIR) and myoelectric activity with surface electrodes (EMG) . The NIR probe and electrodes were positioned on the vastus lateralis muscle (VL) and lateral gastrocnemius muscle (LG) of the right leg. The relative change in oxy-Hb/Mb was estimated by regarding the oxy-Hb/Mb level in the resting condition as 100% and that obtained during thigh occlusion as 0 %. The mean values of oxy-Hb/Mb and integrated EMG (iEMG) determined ranged from 5'30'' to 6'00'' at each work rate. In the VL, the oxy-Hb/Mb level decreased slightly at 50 and 150 watts (99.2±6.8% and 84.6±12.9%), followed by a more prom-inent decrease at 200 and 250 watts (74.9±11.9 and 65.2±9.6%) . The iEMG increased slowly at 50 and 150 watts (24.9±8.8 and 38.0±8.8μV), and a rapid increment occurred at 200 and 250 watts (49.6±13.0 and 57.3±19.6μV) . In the LG, however, the oxy-Hb/Mb level was decreased slightly at 50 and 200 watts (97.3±11.1 and 87.4±6.4%) and a rapid decrement occurred at 250 watts (74.1±6.0%) . The iEMG increased slowly at 50 and 200 watts (18.3±9.4 and 30.5±8.8 μV), and a rapid increment occurred at 250 watts (38.5±8.9 μV) . There was a significant negative correlation between the oxy-Hb/Mb level and iEMG in the VL (r=-0.587, p<0.001) and in the LG (r=-0.599, p<0.001) . From these results, we speculated that the difference in the relative change of oxy-Hb/Mb between the vastus lateralis and the lateral gastrocnemius muscle was due to the difference of increase pattern of muscle activity accompanied by an increase in exercise intensity in these two muscles.
6.Correlation of functional fitness with arterial stiffness in community middle-aged and older women
Yasuaki Tamura ; Hajime Miura ; Yuji Hashimoto ; Miduki Ishikawa ; Ayako Azuma
Japanese Journal of Physical Fitness and Sports Medicine 2016;65(6):533-538
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.
7.Success in Treatment of Pulmonary Fibrosis Caused by Paraquat: Report to Two Cases.
Shunji OHKUBO ; Keiji KIMURA ; Hajime WATANABE ; Masato HAYASHI ; Osamu MIURA ; Shiroh SASAKI
Journal of the Japanese Association of Rural Medicine 1996;45(4):548-554
We report two cases of farm chemical poisoning which were treated successfully. Two elderly men separately swallowed down paraquat/diquat solutions in an attempt to kill themselves, and resultantly developed pulmonary fibrosis. After steroid therapy, clinical symptoms desappeared, although a slight degree of abnormality remained on chest X-rays. Case 1: a 57-year-old man; the amount of ingestion, 100 ml; hospitalized 2 hours after ingestion; shock, (-); urinary PQ reactoin, (2); serum PQ level, 1.14 ug/ml; pulmonary injury at first examinatoin, (-); pulmonary manifestation of symptoms, at day 3 after hospitalization; minimum Pao2, 67.6 mmHg. Case 2: a 65-year-old man; the amount of ingestion, one gulp; hospitalized 27 minutes after ingestion ; shock, (-); urinary PQ reactoin, (3+); serum PQ level, 6.6ug/mg; pulmonary injury at first examination, (-); pulmonary manifestation of symptoms, at day 5 after hospitalization; minimum Pao2, 58.3mmHg. For treatment, gastrointestinal lavage, forced diuresis and direct hemoperfusion were performed in both cases. Steroid pulse therapy was followed by repeated oral administration of large doses of steroid.
Hepatic and renal disorders were transient. Pao2 was normal when the patients were discharged. The primary reasons we could save their lives are probably that the amount of PQ ingestion was relatively small, hemodialysis was performed repeatedly at early stages, and that large amounts of steroid were used immediately after the onset of pulmonary fibrosis.
8.Effects of acute aerobic repetition exercise on the vascular endothelial function
Yasuaki Tamura ; Hajime Miura ; Kenichi Deguchi ; Ayako Azuma ; Yuji Hashimoto ; Miduki Ishikawa
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(6):437-444
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%Wmax), IE (10 × 1-min intervals cycling at 75%Wmax interspersed with 1-min intervals cycling at 25%Wmax), and RE (30 × 20-sec intervals cycling at 100%Wmax 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.
9.Randomized, crossover questionnaire survey of acceptabilities of controlled-release mesalazine tablets and granules in ulcerative colitis patients
Keiji YAGISAWA ; Taku KOBAYASHI ; Ryo OZAKI ; Shinji OKABAYASHI ; Takahiko TOYONAGA ; Miki MIURA ; Mari HAYASHIDA ; Eiko SAITO ; Masaru NAKANO ; Hajime MATSUBARA ; Tadakazu HISAMATSU ; Toshifumi HIBI
Intestinal Research 2019;17(1):87-93
BACKGROUND/AIMS: Oral mesalazine is an important treatment for ulcerative colitis (UC), and non-adherence to mesalazine increases the risk of relapse. Controlled-release (CR) mesalazine has 2 formulations: tablets and granules. The relative acceptabilities of these formulations may influence patient adherence; however, they have not been compared to date. This study aimed to evaluate the acceptabilities of the 2 formulations of CR mesalazine in relation to patient adherence using a crossover questionnaire survey. METHODS: UC patients were randomly assigned to 2 groups in a 1:1 ratio. Patients in each group took either 4 g of CR mesalazine tablets or granules for 6 to 9 weeks, and then switched to 4 g of the other formulation for a further 6 to 9 weeks. The acceptability and efficacy were evaluated by questionnaires, and adherence was assessed using a visual analog scale. The difference in acceptabilities between the 2 formulations and its impact on adherence were assessed. RESULTS: A total of 49 patients were prospectively enrolled and 33 patients were included in the analysis. Significantly more patients found the tablets to be less acceptable than the granules (76% vs. 33%, P=0.0005). The granules were preferable to the tablets when the 2 formulations were compared directly (73% vs. 21%, P=0.004), for their portability, size, and numbers of pills. The adherence rate was slightly better among patients taking the granules (94% vs. 91%) during the observation period, but the difference was not significant (P=0.139). CONCLUSIONS: CR mesalazine granules are more acceptable than tablets, and may therefore be a better option for long-term medication.
Colitis, Ulcerative
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Drug Compounding
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Humans
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Medication Adherence
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Mesalamine
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Patient Acceptance of Health Care
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Patient Compliance
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Prospective Studies
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Recurrence
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Tablets
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Ulcer
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Visual Analog Scale
10.Effect of vitamin C ingestion on the vascular endothelial function exposed to transient passive smoking
Ayako AZUMA ; Hajime MIURA ; Mizuki ISHIKAWA
Japanese Journal of Physical Fitness and Sports Medicine 2019;68(2):153-157
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.