Ryota Kobayashi

Dr. Ryota Kobayashi

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2020 in Journal of Physical Therapy Science
Verified
Journal Article
Open access
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RKRyota Kobayashi
Ryota Kobayashi
YKYasuo Kasahara
Yasuo Kasahara
TITetsuo Ikeo
Tetsuo Ikeo
KAKenji Asaki
Kenji Asaki
KSKaori Sato
Kaori Sato
THTakeo Hashiguchi
Takeo Hashiguchi
[Purpose] In the present study, we investigated the effects of regular aerobic training with different intensities and durations on new indices of arterial stiffness measured via an upper-arm oscillometric device. [Participants and Methods] We gathered data from 41 middle-aged and older people (age 65.0 ± 11.7 years). Participants were randomly divided into five groups: (1) 15 minutes of low intensity aerobic training (n=10); (2) 30 minutes of low intensity training (n=7); (3) 15 minutes of moderate-intensity training (n=9); (4) 30 minutes of moderate-intensity training (n=8); and (5) a non-training group (n=7). Training was conducted for 8 weeks, three times per week. Arterial pulse wave index, arterial pressure-volume index, brachial-ankle and heart-brachial pulse wave velocity, cardio-ankle vascular index, brachial and ankle blood pressure, heart rate, and peak oxygen uptake were measured before and after the intervention. [Results] All indicators of arterial stiffness and brachial and ankle blood pressure in the exercise groups were significantly lower after versus before the intervention. Peak oxygen uptake did not differ before versus after the intervention. [Conclusion] The present findings indicate that regular aerobic exercise may be important in reducing arterial stiffness regardless of the intensity or duration of aerobic exercise.

15 December 2021 in Nutrients
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Journal Article
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RKRyota Kobayashi
Ryota Kobayashi
MSMiki Sakazaki
Miki Sakazaki
YNYukie Nagai
Yukie Nagai
KAKenji Asaki
Kenji Asaki
THTakeo Hashiguchi
Takeo Hashiguchi
HNHideyuki Negoro
Hideyuki Negoro
Increased arterial stiffness during acute hyperglycemia is a risk factor for cardiovascular disease, but the type of carbohydrate that inhibits it is unknown. The purpose of this study was to determine the efficacy of low-glycemic-index isomaltulose on arterial stiffness during hyperglycemia in middle-aged and older adults. Ten healthy middle-aged and older adult subjects orally ingested a solution containing 25 g of isomaltulose (ISI trial) and sucrose (SSI trial) in a crossover study. In the SSI trial, the brachial–ankle (ba) pulse wave velocity (PWV) increased 30, 60, and 90 min after ingestion compared with that before ingestion (p < 0.01); however, in the ISI trial, the baPWV did not change after ingestion compared with that before ingestion. Blood glucose levels 30 min after intake were lower in the ISI trial than in the SSI trial (p < 0.01). The baPWV and systolic blood pressure were positively correlated 90 min after isomaltulose and sucrose ingestion (r = 0.640, p < 0.05). These results indicate that isomaltulose intake inhibits an acute increase in arterial stiffness. The results of the present study may have significant clinical implications on the implementation of dietary programs for middle-aged and elderly patients.

1 January 2022 in Journal of Physical Therapy Science
Verified
Journal Article
Open access
PDF file
RKRyota Kobayashi
Ryota Kobayashi
KAKenji Asaki
Kenji Asaki
THTakeo Hashiguchi
Takeo Hashiguchi
HNHideyuki Negoro
Hideyuki Negoro
[Purpose] This study aimed to determine the effects of aerobic exercise training frequency on arterial stiffness in postmenopausal females. [Participants and Methods] This study included 45 postmenopausal females randomly assigned to one of the following three groups: 1) low-frequency training group (aerobic exercise training twice per week); 2) high-frequency training group (aerobic exercise training four times per week); and 3) control group (no training). Each group was subjected to an 8-week intervention period. Both traditional and newer indexes were measured immediately before and after the 8-week intervention period. [Results] In the low-frequency training group, carotid-femoral pulse wave velocity and arterial velocity pulse index decreased post 8 weeks compared with those at baseline. In the high-frequency training group, carotid-femoral, brachial-ankle, and heart-brachial pulse wave velocities and arterial velocity pulse and arterial pressure-volume indexes decreased post 8 weeks compared to those at baseline. In the control group, no change in any indices post 8 weeks compared to those at baseline was observed. [Conclusion] Carotid-femoral pulse wave velocity was lower after aerobic training than before training in both the exercise groups. Thus, aerobic exercise training might have a beneficial effect on aortic stiffness, regardless of the training frequency in this population.

1 January 2018 in Journal of Physical Therapy Science
Verified
Journal Article
Open access
PDF file
RKRyota Kobayashi
Ryota Kobayashi
HHHiroyuki Hatakeyama
Hiroyuki Hatakeyama
YHYuto Hashimoto
Yuto Hashimoto
TOTakanobu Okamoto
Takanobu Okamoto
[Purpose] The present study investigates the acute effects of accumulated aerobic exercise on aortic and peripheral pulse wave velocity (PWV) in healthy young males. [Subjects and Methods] We gathered data from 9 healthy young males (age, 23.4 ± 0.6 years) performed aerobic exercise group (AE, 65% peak oxygen uptake; two 15 min bouts of cycling performed with 20 min rest) and control group (CON, seated and resting in a quiet room) on separate days in a randomized, controlled crossover fashion. Carotid-femoral (aortic) and femoral-ankle (peripheral) PWV, carotid augmentation index, carotid, brachial and ankle blood pressure and heart rate were measured before (baseline) and 20 min for both groups. [Results] Aortic and peripheral PWV decreased from baseline at 20 min for the AE group, but not in the CON group. [Conclusion] The present findings indicate that acute accumulated aerobic exercise decreases aortic and peripheral PWV in healthy young males.

25 May 2021 in Cardiology Journal
Verified
Journal Article
Open access
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RKRyota Kobayashi
Ryota Kobayashi
KSKaori Sato
Kaori Sato
MSMiki Sakazaki
Miki Sakazaki
YNYukie Nagai
Yukie Nagai
SISoichiro Iwanuma
Soichiro Iwanuma
THTakeo Hashiguchi
Takeo Hashiguchi
Background: Post-prandial hyperglycemia is associated with higher cardiovascular risk, which causes arterial stiffening and impaired function. Although post-prandial increases in blood glucose are proportional to the level of intake, the acute effects of different glucose intakes on arterial stiffness have not been fully characterized. The present study aimed to determine the acute effects of differences in glucose intake on arterial stiffness. Methods: Six healthy middle-aged and elderly individuals (mean age, 60.0 ± 12.1 years) were orally administered 15, 20, and 25 g of glucose on separate days in a randomized, controlled, cross-over fashion. Brachial-ankle pulse wave velocity, heart-brachial pulse wave velocity, cardio-ankle vascular index, brachial and ankle blood pressure, heart rate, and blood glucose and serum insulin concentrations before and 30, 60, and 90 min after glucose ingestion were measured. Results: Compared to baseline, brachial-ankle pulse wave velocity was higher at 30, 60 and 90 min after ingestion of 25 g glucose, and higher at 90 min after ingestion of 20 g glucose, but at no time points after ingestion of 15 g. Cardio-ankle vascular index was higher at 60 min than at baseline after ingestion of 25 g glucose, but not after ingestion of 15 or 20 g. Conclusions: These results suggest that brachial-ankle pulse wave velocity and cardio-ankle vascular index is affected by the quantity of glucose ingested. Proposed presently is that glucose intake should be reduced at each meal to avoid increases in brachial-ankle pulse wave velocity and cardio-ankle vascular index during acute hyperglycemia. Background: Post-prandial hyperglycemia is associated with higher cardiovascular risk, which causes arterial stiffening and impaired function. Although post-prandial increases in blood glucose are proportional to the level of intake, the acute effects of different glucose intakes on arterial stiffness have not been fully characterized. The present study aimed to determine the acute effects of differences in glucose intake on arterial stiffness. Methods: Six healthy middle-aged and elderly individuals (mean age, 60.0 ± 12.1 years) were orally administered 15, 20, and 25 g of glucose on separate days in a randomized, controlled, cross-over fashion. Brachial-ankle pulse wave velocity, heart-brachial pulse wave velocity, cardio-ankle vascular index, brachial and ankle blood pressure, heart rate, and blood glucose and serum insulin concentrations before and 30, 60, and 90 min after glucose ingestion were measured. Results: Compared to baseline, brachial-ankle pulse wave velocity was higher at 30, 60 and 90 min after ingestion of 25 g glucose, and higher at 90 min after ingestion of 20 g glucose, but at no time points after ingestion of 15 g. Cardio-ankle vascular index was higher at 60 min than at baseline after ingestion of 25 g glucose, but not after ingestion of 15 or 20 g. Conclusions: These results suggest that brachial-ankle pulse wave velocity and cardio-ankle vascular index is affected by the quantity of glucose ingested. Proposed presently is that glucose intake should be reduced at each meal to avoid increases in brachial-ankle pulse wave velocity and cardio-ankle vascular index during acute hyperglycemia.

1 January 2019 in Journal of Clinical Biochemistry and Nutrition
Verified
Journal Article
Open access
PDF file
RKRyota Kobayashi
Ryota Kobayashi
YHYuto Hashimoto
Yuto Hashimoto
TOTakanobu Okamoto
Takanobu Okamoto
The present study investigated the acute effect of a footbath on increases in arterial stiffness after glucose ingestion in healthy young women. Nine healthy young women (aged 18.4 ± 0.2 years; mean ± SE) completed three trials in random order. They started a footbath before 75-g oral glucose ingestion, a footbath after 75-g oral glucose ingestion and no footbath (control) trials. Aortic (carotid–femoral) and leg (femoral–ankle) pulse wave velocity, the carotid augmentation index, carotid, brachial and ankle blood pressure, heart rate, blood glucose levels, insulin levels and sublingual temperature were measured before (baseline) and at 15, 30, 60 and 90 min after the 75-g oral glucose ingestion. Aortic pulse wave velocity and brachial systolic blood pressure did not change from baseline to after the 75-g oral glucose ingestion in all trials. Leg pulse wave velocity and ankle systolic blood pressure were increased from baseline to after the 75-g oral glucose ingestion in the footbath after glucose ingestion and control trials, but not in the footbath before glucose ingestion trial. These results suggest that a footbath effectively suppresses the increase in leg arterial stiffness after glucose ingestion when implemented before glucose ingestion.