Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study

Author(s)

Matos Ribeiro, Jean Alex ^[1] ; da Silva Oliveira, Acson Gustavo ^[1] ; Di Thommazo-Luporini, Luciana ^[1] ; Monteiro, Clara Italiano ^[1] ; Ocamoto, Gabriela Nagai ^[1] ; Catai, Aparecida Maria ^[1] ; Borghi-Silva, Audrey ^[1] ; Phillips, Shane A. ^[2] ; Russo, Thiago Luiz ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Phys Therapy, Sao Carlos - Brazil

^[2] Univ Illinois, Dept Phys Therapy, Coll Appl Hlth Sci, Chicago, IL - USA

• Document type: Journal article
• Source: PLoS One; v. 15, n. 11 NOV 9 2020.
• Web of Science Citations: 0

Abstract

Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake (V9;O2) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTRON) and during post-exercise recovery (MRTOFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to VO2 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 (VO2) were collected using a portable metabolic system (Oxycon Mobile(R)) during the six-minute walk test (6MWT). The time to achieve 63% of VO2 during a steady state (MTRON) and recovery (MRTOFF) were analyzed by the monoexponential model and corrected by a work rate (wMRT(ON) and wMRT(OFF)) during 6MWT. Correlation analyses were made using Spearman's rank correlation coefficient (r(s)) 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 wMRT(OFF) was correlated with the following: skeletal muscle mass (r(s) = -0.46), skeletal muscle mass index (r(s) = -0.45), augmentation index (r(s) = 0.44), augmentation index normalized to a heart rate of 75 bpm (r(s) = 0.64), reflection magnitude (r(s) = 0.43), erythrocyte (r(s) = -0.61), hemoglobin (r(s) = -0.54), hematocrit (r(s) = -0.52) and high-sensitivity C-reactive protein (r(s) = 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. (AU)

• FAPESP's process: 17/13655-6 - Sedentary behaviour and arterial dysfunction in chronic post-stroke subjects
• Grantee: Thiago Luiz de Russo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/22173-5 - Characterization of intracranial pressure by non-invasive method in post-stroke subjects: relationship with sedentarism and cardiovascular system
• Grantee: Gabriela Nagai Ocamoto
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)