TY - JOUR
T1 - Cardiorespiratory factors related to the increase in oxygen consumption during exercise in individuals with stroke
AU - Oyake, Kazuaki
AU - Baba, Yasuto
AU - Ito, Nao
AU - Suda, Yuki
AU - Murayama, Jun
AU - Mochida, Ayumi
AU - Kondo, Kunitsugu
AU - Otaka, Yohei
AU - Momose, Kimito
N1 - Publisher Copyright:
© 2019 Oyake et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Background Understanding the cardiorespiratory factors related to the increase in oxygen consumption (VO _ 2) during exercise is essential for improving cardiorespiratory fitness in individuals with stroke. However, cardiorespiratory factors related to the increase in VO _ 2 during exercise in these individuals have not been examined using multivariate analysis. This study aimed to identify cardiorespiratory factors related to the increase in VO _ 2 during a graded exercise in terms of respiratory function, cardiac function, and the ability of skeletal muscles to extract oxygen. Methods Eighteen individuals with stroke (aged 60.1 ± 9.4 years, 67.1 ± 30.8 days poststroke) underwent a graded exercise test for the assessment of cardiorespiratory response to exercise. The increases in VO _ 2 from rest to first threshold and that from rest to peak exercise were measured as a dependent variable. The increases in respiratory rate, tidal volume, minute ventilation, heart rate, stroke volume, cardiac output, and arterial-venous oxygen difference from rest to first threshold and those from rest to peak exercise were measured as the independent variables. Results From rest to first threshold, the increases in arterial-venous oxygen difference (β = 0.711) and cardiac output (β = 0.572) were significant independent variables for the increase in VO _ 2 (adjusted R2 = 0.877 p < 0.001). Similarly, from rest to peak exercise, the increases in arterial-venous oxygen difference (β = 0.665) and cardiac output (β = 0.636) were significant factors related to the increase in VO _ 2 (adjusted R2 = 0.923, p < 0.001). Conclusion Our results suggest that the ability of skeletal muscle to extract oxygen is a major cardiorespiratory factor related to the increase in VO _ 2 during exercise testing in individuals with stroke. For improved cardiorespiratory fitness in individuals with stroke, the amount of functional muscle mass during exercise may need to be increased.
AB - Background Understanding the cardiorespiratory factors related to the increase in oxygen consumption (VO _ 2) during exercise is essential for improving cardiorespiratory fitness in individuals with stroke. However, cardiorespiratory factors related to the increase in VO _ 2 during exercise in these individuals have not been examined using multivariate analysis. This study aimed to identify cardiorespiratory factors related to the increase in VO _ 2 during a graded exercise in terms of respiratory function, cardiac function, and the ability of skeletal muscles to extract oxygen. Methods Eighteen individuals with stroke (aged 60.1 ± 9.4 years, 67.1 ± 30.8 days poststroke) underwent a graded exercise test for the assessment of cardiorespiratory response to exercise. The increases in VO _ 2 from rest to first threshold and that from rest to peak exercise were measured as a dependent variable. The increases in respiratory rate, tidal volume, minute ventilation, heart rate, stroke volume, cardiac output, and arterial-venous oxygen difference from rest to first threshold and those from rest to peak exercise were measured as the independent variables. Results From rest to first threshold, the increases in arterial-venous oxygen difference (β = 0.711) and cardiac output (β = 0.572) were significant independent variables for the increase in VO _ 2 (adjusted R2 = 0.877 p < 0.001). Similarly, from rest to peak exercise, the increases in arterial-venous oxygen difference (β = 0.665) and cardiac output (β = 0.636) were significant factors related to the increase in VO _ 2 (adjusted R2 = 0.923, p < 0.001). Conclusion Our results suggest that the ability of skeletal muscle to extract oxygen is a major cardiorespiratory factor related to the increase in VO _ 2 during exercise testing in individuals with stroke. For improved cardiorespiratory fitness in individuals with stroke, the amount of functional muscle mass during exercise may need to be increased.
UR - http://www.scopus.com/inward/record.url?scp=85073070908&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85073070908&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0217453
DO - 10.1371/journal.pone.0217453
M3 - Article
C2 - 31596863
AN - SCOPUS:85073070908
SN - 1932-6203
VL - 14
JO - PloS one
JF - PloS one
IS - 10
M1 - e0217453
ER -