Youngju Choi

Dr. Youngju Choi

orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

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

Representative Publications

View All Publications
1 October 2012 in Nutrition Research
Verified
Journal Article
Open access
NANobuhiko Akazawa
Nobuhiko Akazawa
YCYoungju Choi
Youngju Choi
AMAsako Miyaki
Asako Miyaki
YTYoko Tanabe
Yoko Tanabe
JSJun Sugawara
Jun Sugawara
SMSeiji Maeda
Seiji Maeda
Vascular endothelial function is declines with aging and is associated with an increased risk of cardiovascular disease. Lifestyle modification, particularly aerobic exercise and dietary adjustment, has a favorable effect on vascular aging. Curcumin is a major component of turmeric with known anti-inflammatory and anti-oxidative effects. We investigated the effects of curcumin ingestion and aerobic exercise training on flow-mediated dilation as an indicator endothelial function in postmenopausal women. A total of 32 postmenopausal women were assigned to 3 groups: control, exercise, and curcumin groups. The curcumin group ingested curcumin orally for 8 weeks. The exercise group underwent moderate aerobic exercise training for 8 weeks. Before and after each intervention, flow-mediated dilation was measured. No difference in baseline flow-mediated dilation or other key dependent variables were detected among the groups. Flow-mediated dilation increased significantly and equally in the curcumin and exercise groups, whereas no changes were observed in the control group. Our results indicated that curcumin ingestion and aerobic exercise training can increase flow-mediated dilation in postmenopausal women, suggesting that both can potentially improve the age-related decline in endothelial function.

1 February 2014 in American Journal of Physiology-Heart and Circulatory Physiology
Verified
Journal Article
Open access
PDF file
TMTomoko Matsubara
Tomoko Matsubara
AMAsako Miyaki
Asako Miyaki
NANobuhiko Akazawa
Nobuhiko Akazawa
YCYoungju Choi
Youngju Choi
SRSong-Gyu Ra
Song-Gyu Ra
SMSeiji Maeda
Seiji Maeda
The Klotho gene is a suppressor of the aging phenomena, and the secretion as well as the circulation of Klotho proteins decrease with aging. Although habitual exercise has antiaging effects (e.g., a decrease in arterial stiffness), the relationship between Klotho and habitual exercise remains unclear. In the present study, we investigated the effect of habitual exercise on Klotho, with a particular focus on arterial stiffness. First, we examined the correlation between plasma Klotho concentration and arterial stiffness (carotid artery compliance and β-stiffness index) or aerobic exercise capacity [oxygen uptake at ventilatory threshold (VT)] in 69 healthy, postmenopausal women (50–76 years old) by conducting a cross-sectional study. Second, we tested the effects of aerobic exercise training on plasma Klotho concentrations and arterial stiffness. A total of 19 healthy, postmenopausal women (50–76 years old) were divided into two groups: control group and exercise group. The exercise group completed 12 wk of moderate aerobic exercise training. In the cross-sectional study, plasma Klotho concentrations positively correlated with carotid artery compliance and VT and negatively correlated with the β-stiffness index. In the interventional study, aerobic exercise training increased plasma Klotho concentrations and carotid artery compliance and decreased the β-stiffness index. Moreover, the changes in plasma Klotho concentration and arterial stiffness were found to be correlated. These results suggest a possible role for secreted Klotho in the exercise-induced modulation of arterial stiffness.

29 April 2015 in European Journal of Applied Physiology
Verified
Journal Article
Open access
PDF file
YTYoko Tanabe
Yoko Tanabe
SMSeiji Maeda
Seiji Maeda
NANobuhiko Akazawa
Nobuhiko Akazawa
AZAsako Zempo-Miyaki
Asako Zempo-Miyaki
YCYoungju Choi
Youngju Choi
KNKen Nosaka
Ken Nosaka
Purpose Polyphenolic curcumin is known to have potent anti-inflammatory effects; thus the present study investigated the hypothesis that curcumin ingestion would attenuate muscle damage after eccentric exercise. Methods Fourteen untrained young men (24 ± 1 years) performed 50 maximal isokinetic (120°/s) eccentric contractions of the elbow flexors of one arm on an isokinetic dynamometer and the same exercise with the other arm 4 weeks later. They took 150 mg of curcumin (theracurmin) or placebo (starch) orally before and 12 h after each eccentric exercise bout in a randomised, crossover design. Maximal voluntary contraction (MVC) torque of the elbow flexors, range of motion of the elbow joint, upper-arm circumference, muscle soreness, serum creatine kinase (CK) activity, and plasma interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentration were measured before, immediately after, and 24, 48, 72 and 96 h after each eccentric exercise. Changes in these variables over time were compared between curcumin and placebo conditions by two-way repeated measures ANOVA. Results MVC torque decreased smaller and recovered faster (e.g., 4 days post-exercise: −31 ± 13 % vs. −15 ± 15 %), and peak serum CK activity was smaller (peak: 7684 ± 8959 IU/L vs. 3398 ± 3562 IU/L) for curcumin than placebo condition (P < 0.05). However, no significant differences between conditions were evident for other variables, and no significant changes in IL-6 and TNF-α were evident after exercise. Conclusion It is concluded that theracurmin ingestion attenuates some aspects of muscle damage such as MVC loss and CK activity increase.

1 June 2012 in American Journal of Hypertension
Verified
Journal Article
Open access
PDF file
JSJun Sugawara
Jun Sugawara
NANobuhiko Akazawa
Nobuhiko Akazawa
AMAsako Miyaki
Asako Miyaki
YCYoungju Choi
Youngju Choi
YTYoko Tanabe
Yoko Tanabe
SMSeiji Maeda
Seiji Maeda
Background. Lifestyle modification (i.e., regular physical activity and diet) is effective in preventing the age-related increase in cardiovascular dis

1 April 2010 in American Journal of Hypertension
Verified
Journal Article
Open access
PDF file
MYMutsuko Yoshizawa
Mutsuko Yoshizawa
SMSeiji Maeda
Seiji Maeda
AMAsako Miyaki
Asako Miyaki
MMMaiko Misono
Maiko Misono
YCYoungju Choi
Youngju Choi
HTHirofumi Tanaka
Hirofumi Tanaka
Background. Peripheral conduit artery endothelium-dependent dilatation decreases with aging in humans. Lactotripeptides (LTPs) and regular exercise can

1 November 2009 in American Journal of Physiology-Heart and Circulatory Physiology
Verified
Journal Article
Closed access
PDF file
MYMutsuko Yoshizawa
Mutsuko Yoshizawa
SMSeiji Maeda
Seiji Maeda
AMAsako Miyaki
Asako Miyaki
MMMaiko Misono
Maiko Misono
YCYoungju Choi
Youngju Choi
HTHirofumi Tanaka
Hirofumi Tanaka
Central arterial compliance plays an important role in the functional abilities of the vasculature. Two active tripeptides, valine-proline-proline and isoleucine-proline-proline, were isolated from sour milk and were referred to as lactotripeptides (LTP). Because LTP appears to act as an angiotensin-converting enzyme inhibitor, it is plausible to hypothesize that LTP improves arterial compliance. We determined the effects of LTP ingestion alone or in combination with regular aerobic exercise on arterial compliance. A total of 55 postmenopausal women (50–65 yr old) were randomly divided into four groups: placebo, LTP, exercise and placebo (Ex + placebo), or exercise and LTP (Ex + LTP). LTP or placebo was administered orally for 8 wk. The exercise groups completed an 8-wk moderate aerobic exercise intervention. There were no differences in baseline arterial compliance and most other key dependent variables among the groups. Carotid arterial compliance increased significantly in the LTP (0.93 ± 0.07 vs. 0.99 ± 0.08 mm2/mmHg·10−1), Ex + placebo (0.92 ± 0.04 vs. 1.00 ± 0.05 mm2/mmHg·10−1), and Ex + LTP groups (0.86 ± 0.06 vs. 1.00 ± 0.06 mm2/mmHg·10−1), whereas no such changes were observed in the placebo control group (0.86 ± 0.06 vs. 0.85 ± 0.07 mm2/mmHg·10−1). The magnitude of increases in carotid arterial compliance was significantly greater in the Ex + LTP group (19 ± 4%) than in other groups. The improvements in arterial compliance with LTP were associated with the corresponding reductions in arterial blood pressure and plasma angiotensin II concentrations. We concluded that LTP ingestion improves carotid arterial compliance and that the combination of LTP ingestion and regular exercise is additive and synergistic in improving arterial compliance in postmenopausal women.