1. Effects of Greater Central Arterial Stiffness on Cardiovagal Baroreflex Sensitivity in Resistance-Trained Men.
- Author
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Nakamura, Nobuhiro and Muraoka, Isao
- Subjects
ARTERIAL diseases ,BAROREFLEXES ,SYSTOLIC blood pressure ,BODY mass index ,CAROTID artery ,CAROTID artery physiology ,RESISTANCE training ,BLOOD pressure ,BODY composition ,EXERCISE tests ,GRIP strength ,CARDIOVASCULAR system physiology ,ULTRASONIC imaging ,HUMAN research subjects ,MUSCLE contraction ,CROSS-sectional method ,MEN ,HEALTH outcome assessment ,VALSALVA'S maneuver ,INFORMED consent (Medical law) ,COMPARATIVE studies ,PEARSON correlation (Statistics) ,T-test (Statistics) ,BIOELECTRIC impedance ,MUSCLE strength ,DESCRIPTIVE statistics ,RESEARCH funding ,TONOMETRY ,HEMODYNAMICS ,STATISTICAL correlation ,DATA analysis software - Abstract
Background: Compared with age-matched untrained men, resistance-trained men who have undergone long duration training (> 2 years) at a high frequency (> 5 days/week) may be lower cardiovagal baroreflex sensitivity (BRS) because of central arterial stiffening. Therefore, the purpose of this study was to examine the effect of greater central arterial stiffness in resistance-trained men on cardiovagal BRS in a cross-sectional study to compare resistance-trained men with age-matched untrained men. Methods: This cross-sectional study included resistance-trained men (n = 20; age: 22 ± 3; body mass index: 26.7 ± 2.2) and age-matched untrained men (control group: n = 20; age: 25 ± 2; body mass index: 23.7 ± 2.4). The β-stiffness index and arterial compliance were assessed at the right carotid artery using a combination of a brightness mode ultrasonography system for the carotid artery diameter and applanation tonometry for the carotid blood pressure. And, the cardiovagal BRS was estimated by the slope of the R–R interval and systolic blood pressure during Phase II and IV of Valsalva maneuver (VM). The participants maintained an expiratory mouth pressure of 40 mmHg for 15 s in the supine position. Results: The β-Stiffness index was significantly higher in the resistance-trained group than in the control group (5.9 ± 1.4 vs. 4.4 ± 1.0 a.u., P < 0.01). In contrast, the resistance-trained group had significantly lower arterial compliance (0.15 ± 0.05 vs. 0.20 ± 0.04 mm
2 /mmHg, P < 0.01) and cardiovagal BRS during Phase IV of VM (9.0 ± 2.5 vs. 12.9 ± 5.4 ms/mmHg, P < 0.01) than the control group and. Moreover, cardiovagal BRS during Phase IV of VM was inversely and positively correlated with the β-stiffness index (r = − 0.59, P < 0.01) and arterial compliance (r = 0.64, P < 0.01), respectively. Conclusion: Resistance-trained group had greater central arterial stiffness and lower cardiovagal BRS Phase IV compared with control group. Moreover, the central arterial stiffening was related to cardiovagal BRS Phase IV. These results suggest that greater central arterial stiffness in resistance-trained men may be associated with lower cardiovagal BRS. Trial Registration University hospital Medical Information Network (UMIN) in Japan, UMIN000038116. Registered on September 27, 2019. [ABSTRACT FROM AUTHOR]- Published
- 2021
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