1. Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study.
- Author
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Ribeiro, Jean Alex Matos, Oliveira, Acson Gustavo da Silva, Thommazo-Luporini, Luciana Di, Monteiro, Clara Italiano, Ocamoto, Gabriela Nagai, Catai, Aparecida Maria, Borghi-Silva, Audrey, Phillips, Shane A., and Russo, Thiago Luiz
- Subjects
ERYTHROCYTES ,CARDIOVASCULAR system ,MUSCLE mass ,SKELETAL muscle ,BODY composition ,CROSS-sectional method - Abstract
Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake (V˙O2) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTR
ON ) and during post-exercise recovery (MRTOFF ). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to V˙O2 kinetics response (MRTON and MRTOFF ) in post-stroke populations. The main objective of this study was to determine whether the MTRON and MRTOFF are related to: 1) body composition; 2) arterial compliance; 3) endothelial function; and 4) hematological and inflammatory profiles in chronic post-stroke individuals. Data on oxygen uptake (V˙O2) were collected using a portable metabolic system (Oxycon Mobile® ) during the six-minute walk test (6MWT). The time to achieve 63% of V˙O2 during a steady state (MTRON ) and recovery (MRTOFF ) were analyzed by the monoexponential model and corrected by a work rate (wMRTON and wMRTOFF ) during 6MWT. Correlation analyses were made using Spearman's rank correlation coefficient (rs ) and the bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals. Twenty-four post-stroke participants who were physically inactive took part in the study. The wMRTOFF was correlated with the following: skeletal muscle mass (rs = -0.46), skeletal muscle mass index (rs = -0.45), augmentation index (rs = 0.44), augmentation index normalized to a heart rate of 75 bpm (rs = 0.64), reflection magnitude (rs = 0.43), erythrocyte (rs = -0.61), hemoglobin (rs = -0.54), hematocrit (rs = -0.52) and high-sensitivity C-reactive protein (rs = 0.58), all p < 0.05. A greater amount of oxygen uptake during post-walking recovery is partially related to lower skeletal muscle mass, greater arterial stiffness, reduced number of erythrocytes and higher systemic inflammation in post-stroke individuals. [ABSTRACT FROM AUTHOR]- Published
- 2020
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