High concentrations of matrix metalloproteinase-2 (MMP-2) and −9 (MMP-9) are associated with inflammation early after stroke. In chronic stages, the elevation of some cytokines is related to the presence of co-morbid conditions in these individuals. In addition to this, some characteristics such as sensorimotor impairment, atrophy, and sedentary lifestyle predispose the system to an inflammatory response. To quantify MMP-2 and −9 serum activity in chronic post-stroke individuals and correlate it with variables of physical activity level, body composition, functional and walking capacity, and with inflammatory biomarkers. Additionally, gelatinase activity was characterized according to motor impairment. Fourteen patients with stroke onset >6 months and seven healthy individuals were enrolled in this study. The clinical assessment included: body composition, measure by bioelectrical impedance analyzer; Fugl-Meyer Motor Assessment Scale; six-minute and ten-meter walk tests, and physical activity level assessed by the StepWatch® Activity Monitor. Blood samples were collected from antecubital vein and serum MMP-2 and −9 activity was analyzed using gelatin Zymography, and the TNFα, IL-6, IL-1β, IL-10 biomarkers using ELISA kits. Chronic post-stroke individuals presented an increased activity of MMP-2 and −9 compared to healthy individuals. Positive correlations with time and steps in low cadence and negative ones with medium cadence and peak activity index were observed. According to the motor impairment, the MMP-2 activity was increased in the mild-moderate group compared to the control group. Increased gelatinases in chronic post-stroke individuals could describe an inflammation process related to the limited capacity of walking in high intensities.

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 (MRT_OFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to V˙O2 kinetics response (MRT_ONand MRT_OFF) in post-stroke populations. The main objective of this study was to determine whether the MTR_ONand MRT_OFFare 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 (MTR_ON) and recovery (MRT_OFF) were analyzed by the monoexponential model and corrected by a work rate (wMRT_ONand 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_OFFwas 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.

Purpose/Aim: Cardiovascular function is controlled and regulated by a functional brain-heart axis. Although the exact mechanism is not fully understood, several studies suggest a hemispheric asymmetry in the neural control of cardiovascular function. Thus, the purpose of this study was to examine whether endothelial function and arterial compliance differ between individuals with left- and right-sided strokes.Materials and Methods: This was a cross-sectional exploratory study. Thirty individuals more than 6 months after stroke participated in the study. The endothelial function was assessed by ultrasound-measured flow-mediated dilation of the nonparetic arm brachial artery (baFMD). The arterial stiffness was assessed by measuring carotid-femoral pulse wave velocity (cfPWV) and central aortic pulse wave analysis [augmentation index (AIx), augmentation index normalized to a heart rate of 75 bpm (AIx@75) and reflection magnitude (RM)] using applanation tonometry. Results: Participants with right-sided stroke had worse endothelial function than those with left-sided stroke. This difference (baFMD = 2.51%) was significant (p = 0.037), and it represented a medium effect size (r = 0.38). Likewise, they had higher arterial stiffness than those with left-sided stroke. This difference (AIx = 10%; RM = 7%) was significant (p = 0.011; p = 0.012), and it represented a medium effect size (r = 0.48; r = 0.47).Conclusions: Our findings suggest that individuals with right-sided stroke have reduced endothelial function and arterial compliance compared to those with left-sided stroke. These data may indicate that those with right-sided strokes are more susceptible to cardiovascular events.

Objective and reliable measurements to investigate daily behavior patterns in people with stroke could help therapeutic interventions after a stroke. To evaluate whether the Activity Monitoring for Rehabilitation (AMoR) platform has adequate concurrent validity and reliability for step counting and time spent sitting/lying in people post-stroke and to investigate its percentage accuracy for step counting at different walking speeds. Cross-sectional observational study. Fifty chronic post-stroke subjects used the AMoR platform and SAM simultaneously while a Video camera recorded the same activities during clinical trials. Spearman’s correlation coefficient, the mean absolute percentage error, the intraclass correlation coefficient and Bland-Altman plot analyses were used to estimate the validity and reliability of the AMoR platform and StepWatch^TM Activity Monitor (SAM). The accuracy percentage was calculated for each device and plotted as a function of the walking speed during the 10-meter walk test (10MWT). There was a very high correlation for step counting in all tests and a high correlation for time spent sitting/lying. The mean absolute percentage error values remained below 4% for step counting and time sitting/lying. The AMoR platform also showed excellent reliability for step counting and sitting/lying time, with values within the limit of agreement in the Bland-Altman plots. A high percentage of accuracy for step counting in the AMoR platform was observed during the 10MWT. The AMoR platform is valid and reliable for step counting and time spent sitting/lying, with a high percentage of accuracy at different walking speeds in the post-stroke population.