Adherence to Exercise Training and Physical Function in Older Adults Diagnosed with Knee Osteoarthritis.

Background: Knee osteoarthritis (KOA) provokes pain, muscle weakness, and consequent impairment in activities of daily living. On the other hand, adherence to exercise training (ET) is associated with the attenuation of the impairments. The aims of the present study were to a) investigate adherence to ET in older adults with KOA diagnosed attending public service; and b) to analyze the physical function of the older adults with KOA who did not adhere to the ET in public service. Methods: The adherence to ET programs was analyzed retrospectively from each patient's date of KOA diagnosis. After assessing the adherence to ET, the physical function of these older adults diagnosed with KOA (n=19) was analyzed and compared with another group composed of asymptomatic sedentary older adults without evidence of KOA (ASKOA) (n=17). Results: Although all older adults with KOA received guidelines to practice ET, only 58% were able to start a program. Additionally, 100% of the sample could not perform ET uninterruptedly. According to the findings, close to 80% of older adults had difficulties scheduling ET sessions in public places. Subjects with KOA (12.1±3.1; IC95%:10.6-13.6) had worse lower limb functional capacity than ASKOA (8.1±1.0; IC95%:7.6-8.6; p<.001; δ=4.0 sec; d=1.7). Likewise, they had a lower dynamic balance than KOA (12.4±2.7; IC95%:11.1-13.7 vs. 8.0±1.1; IC95%:7.4-8.6; p<.001; δ=4.4 sec; d=2.1). Conclusions: The investigated sample has a lack of ET adherence by difficulties in scheduling ET sessions in public places. In addition, it demonstrated impairment in physical function in older adults with KOA.

Autonomic dysfunction in COVID-19 patients receiving mechanical ventilation: A cross-sectional study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) can damage cardiac tissue by increasing troponin levels and inducing arrhythmias, myocarditis, and acute coronary syndrome. OBJECTIVES: To analyze the impact of COVID-19 on cardiac autonomic control in mechanically ventilated intensive care unit (ICU) patients. DESIGN AND SETTING: This cross-sectional analytical study of ICU patients of both sexes receiving mechanical ventilation was conducted in a tertiary hospital. METHODS: Patients were divided into COVID-19-positive (COVID(+)) and COVID-19-negative (COVID(-)) groups. Clinical data were collected and heart rate variability (HRV) records obtained using a heart rate monitor. RESULTS: The study sample comprised 82 subjects: 36 (44%) in the COVID(-) group (58.3% female; median age, 64.5 years) and 46 (56%) in the COVID(+) group (39.1% females; median age, 57.5 years). The HRV indices were lower than the reference values. An intergroup comparison identified no statistically significant differences in the mean normal-to-normal (NN) interval, standard deviation of the NN interval, or root mean square of successive differences in NN intervals. The COVID(+) group had an increased low frequency (P = 0.05), reduced high frequency (P = 0.045), and increased low frequency/high frequency (LF/HF) ratio (P = 0.048). There was a weak positive correlation between LF/HF and length of stay in the COVID(+) group. CONCLUSION: Patients who received mechanical ventilation had lower overall HRV indices. COVID(+) patients who received mechanical ventilation had lower vagal HRV components. These findings likely indicate clinical applicability, as autonomic control impairments are associated with a greater risk of cardiac death.

Effect of High-Intensity Interval Training on Exercise Capacity, Blood Pressure, and Autonomic Responses in Patients With Hypertension: A Systematic Review and Meta-analysis.

CONTEXT: Despite the well-known positive effects of exercise in hypertensive patients, the best mode of exercise is still under discussion. OBJECTIVE: A systematic review of the literature, synthesizing data on the effects of high-intensity interval training (HIIT) on peak oxygen consumption (VO2 peak), blood pressure (BP), cardiac autonomic modulation, and resting heart rate (HR) in patients with hypertension. DATA SOURCES: MEDLINE (via PubMed), CENTRAL, PEDro database, and SciELO (from the earliest date available to December 31, 2020). STUDY SELECTION: Randomized controlled trials (RCTs) that evaluated the effects of HIIT in hypertensive patients. STUDY DESIGN: Systematic review and meta-analysis. LEVEL OF EVIDENCE: Level 2. DATA EXTRACTION: Mean differences (MDs) with a 95% CI were calculated, and heterogeneity was assessed using the I2 test. RESULTS: Nine RCTs encompassing 569 patients met the eligibility criteria and were included in the systematic review. Five trials compared supervised HIIT with moderate-intensity continuous training (MICT) and a control; 1 trial compared HIIT with MICT, and 3 compared HIIT with a control. In comparison with MICT, HIIT improved VO2 peak MD (3.3 mL.kg-1.min-1; 95% CI, 1.4-5.3; N = 130). In comparison with controls, HIIT improved VO2 peak MD (4.4 mL.kg-1.min-1; 95% CI, 2.5-6.2; N = 162). CONCLUSION: Despite the low quality of the evidence, HIIT is superior to MICT in improving VO2 peak in patients with hypertension. HIIT effectively improved VO2 peak, BP, and resting HR when compared with controls. HIIT appears to be safe only when performed in a supervised manner for stage 1 hypertension patients without associated risk factors.

Autonomic dysfunction in COVID-19 patients receiving mechanical ventilation: A cross-sectional study

ABSTRACT BACKGROUND: Coronavirus disease 2019 (COVID-19) can damage cardiac tissue by increasing troponin levels and inducing arrhythmias, myocarditis, and acute coronary syndrome. OBJECTIVES: To analyze the impact of COVID-19 on cardiac autonomic control in mechanically ventilated intensive care unit (ICU) patients. DESIGN AND SETTING: This cross-sectional analytical study of ICU patients of both sexes receiving mechanical ventilation was conducted in a tertiary hospital. METHODS: Patients were divided into COVID-19-positive (COVID(+)) and COVID-19-negative (COVID(-)) groups. Clinical data were collected and heart rate variability (HRV) records obtained using a heart rate monitor. RESULTS: The study sample comprised 82 subjects: 36 (44%) in the COVID(-) group (58.3% female; median age, 64.5 years) and 46 (56%) in the COVID(+) group (39.1% females; median age, 57.5 years). The HRV indices were lower than the reference values. An intergroup comparison identified no statistically significant differences in the mean normal-to-normal (NN) interval, standard deviation of the NN interval, or root mean square of successive differences in NN intervals. The COVID(+) group had an increased low frequency (P = 0.05), reduced high frequency (P = 0.045), and increased low frequency/high frequency (LF/HF) ratio (P = 0.048). There was a weak positive correlation between LF/HF and length of stay in the COVID(+) group. CONCLUSION: Patients who received mechanical ventilation had lower overall HRV indices. COVID(+) patients who received mechanical ventilation had lower vagal HRV components. These findings likely indicate clinical applicability, as autonomic control impairments are associated with a greater risk of cardiac death.

Cardiovascular Autonomic Responses to Aerobic, Resistance and Combined Exercises in Resistance Hypertensive Patients.

Here, we report the acute effects of aerobic (AER), resistance (RES), and combined (COM) exercises on blood pressure, central blood pressure and augmentation index, hemodynamic parameters, and autonomic modulation of resistant (RH) and nonresistant hypertensive (NON-RH) subjects. Twenty participants (10 RH and 10 NON-RH) performed three exercise sessions (i.e., AER, RES, and COM) and a control session. Hemodynamic (Finometer®, Beatscope), office blood pressure (BP), and autonomic variables (accessed through spectral analysis of the pulse-to-pulse BP signal, in the time and frequency domain-Fast Fourrier Transform) were assessed before (T0), one-hour (T1), and twenty-four (T2) hours after each experimental session. There were no changes in office BP, pulse wave behavior, and hemodynamic parameters after (T0 and T1) exercise sessions. However, AER and COM exercises significantly reduced sympathetic modulation in RH patients. It is worth mentioning that more significant changes in sympathetic modulation were observed after AER as compared to COM exercise. These findings suggest that office blood pressure, arterial stiffness, and hemodynamic parameters returned to baseline levels in the first hour and remained stable in the 24 hours after the all-exercise sessions. Notably, our findings bring new light to the effects of exercise on RH, indicating that RH patients show different autonomic responses to exercise compared to NON-RH patients. This trial is registered with trial registration number NCT02987452.

A validation study of a smartphone application for heart rate variability assessment in asymptomatic adults.

BACKGROUND: Assessment of heart rate variability (HRV) is an effective non-invasive tool to obtain data on cardiac autonomic modulation and may be assessed by a range of devices, including mobile applications. Objective: This study aimed to validate a smartphone application by comparing the R-R intervals (RRi) obtained by the app with a classic electrocardiogram (ECG)-derived reference condition Methods: Fifteen asymptomatic adults (24.9±3.4 years) underwent an orthostatic challenge during which RRi were simultaneously recorded by a freeware smartphone application and by an ECG recorder. Pearson correlation coefficients (r) and coefficients of determination (r 2) were calculated to determine the degree of association between the two electronic devices. Two-way repeated measures analysis of variance and Bland-Altman analysis were used to calculate the measurement consistency and agreement, respectively, between the two methods. Effect size was also used to estimate the magnitude of the differences. RESULTS: The number of RRi from asymptomatic adults recorded by the ECG and by the free smartphone application was similar at rest in supine position (13,149 vs. 13,157; P = 0.432) and during orthostatic challenge (10,666 vs. 10,664 P = 0.532). RRi in milliseconds from both devices presented a near perfect correlation in the supine position (r = 0.999; Confidence Interval [CI] at 95%: 0.999-0.999; P < 0.0001) and during orthostatic challenge (r = 0.988; 95% CI: 0.988-0.989; P < 0.0001). A negative bias of -0.526 milliseconds (95% limits of agreement [LoA] from -4.319 to 3.266 milliseconds) was observed in supine position between ECG and the smartphone application. On the other hand, a positive bias of 0.077 milliseconds (95% LoA from -10.090 to 10.240 milliseconds) during the orthostatic challenge was observed. CONCLUSIONS: Our results cross-validated a freeware smartphone application with the ECG-derived reference condition for asymptomatic adults at rest in the supine position and during orthostatic challenge.

Combined Aerobic and Resistance Exercises Evokes Longer Reductions on Ambulatory Blood Pressure in Resistant Hypertension: A Randomized Crossover Trial.

AIM: The present study compared the acute effects of aerobic (AER), resistance (RES), and combined (COM) exercises on blood pressure (BP) levels in people with resistant hypertension (RH) and nonresistant hypertension (NON-RH). METHODS: Twenty patients (10 RH and 10 NON-RH) were recruited and randomly performed three exercise sessions and a control session. Ambulatory BP was monitored over 24 hours after each experimental session. RESULTS: Significant reductions on ambulatory BP were found in people with RH after AER, RES, and COM sessions. Notably, ambulatory BP was reduced during awake-time and night-time periods after COM. On the other hand, the effects of AER were more prominent during awake periods, while RES caused greater reductions during the night-time period. In NON-RH, only RES acutely reduced systolic BP, while diastolic BP was reduced after all exercise sessions. However, the longest postexercise ambulatory hypotension was observed after AER (~11 h) in comparison to RES (~8 h) and COM (~4 h) exercises. CONCLUSION: Findings of the present study indicate that AER, RES, and COM exercises elicit systolic and diastolic postexercise ambulatory hypotension in RH patients. Notably, longer hypotension periods were observed after COM exercise. In addition, NON-RH and RH people showed different changes on BP after exercise sessions, suggesting that postexercise hypotension is influenced by the pathophysiological bases of hypertension.

Dynamic Resistance Training Improves Cardiac Autonomic Modulation and Oxidative Stress Parameters in Chronic Stroke Survivors: A Randomized Controlled Trial.

Stroke survivors are at substantial risk of recurrent cerebrovascular event or cardiovascular disease. Exercise training offers nonpharmacological treatment for these subjects; however, the execution of the traditional exercise protocols and adherence is constantly pointed out as obstacles. Based on these premises, the present study investigated the impact of an 8-week dynamic resistance training protocol with elastic bands on functional, hemodynamic, and cardiac autonomic modulation, oxidative stress markers, and plasma nitrite concentration in stroke survivors. Twenty-two patients with stroke were randomized into control group (CG, n = 11) or training group (TG, n = 11). Cardiac autonomic modulation, oxidative stress markers, plasma nitrite concentration, physical function and hemodynamic parameters were evaluated before and after 8 weeks. Results indicated that functional parameters (standing up from the sitting position (P = 0.011) and timed up and go (P = 0.042)) were significantly improved in TG. Although not statistically different, both systolic blood pressure (Δ = -10.41 mmHg) and diastolic blood pressure (Δ = -8.16 mmHg) were reduced in TG when compared to CG. Additionally, cardiac autonomic modulation (sympathovagal balance-LF/HF ratio) and superoxide dismutase were improved, while thiobarbituric acid reactive substances and carbonyl levels were reduced in TG when compared to the CG subjects. In conclusion, our findings support the hypothesis that dynamic resistance training with elastic bands may improve physical function, hemodynamic parameters, autonomic modulation, and oxidative stress markers in stroke survivors. These positive changes would be associated with a reduced risk of a recurrent stroke or cardiac event in these subjects.

Acute effects of aerobic exercise on the blood pressure of patients after coronary artery bypass grafting.

BACKGROUND: Coronary artery bypass grafting a frequent surgical procedure to treat coronary heart disease, uses the patient's own veins or arteries to bypass narrowed areas and restore blood flow to heart muscle. Cardiac rehabilitation follows this procedure and includes psychological and nutritional support along with the regular practice of physical exercises. OBJECTIVE: The aim of this study was to investigate the acute effects of the aerobic exercise on the blood pressure of patients after coronary artery bypass grafting. METHODS: After 30 days of surgical procedure, 14 patients were assigned to the aerobic exercise group (exercise on the cycle ergometer for 35 minutes), while 8 patients were assigned to the control group (absolute rest for 35 minutes). Blood pressure was measured by a digital automatic device before and after 24 hours of the experiment in both groups. RESULTS: Systolic (P = 0.639) and diastolic (P = 0.103) blood pressures were similar between CG and AEG at baseline. Regarding intragroup differences, no significant changes were observed after 24 hours for SBP in the CG (P = 0.999) and AEG (P = 0.244). On the other hand, significant changes were found for DBP after 24 hours for the CG (P = 0.007) and AEG (P = 0.015). When CG and AEG were compared after 24 hours, no significant differences were found for SBP (P = 0.999) and DBP (P = 0.054). CONCLUSIONS: We found decreased diastolic blood pressure in the aerobic exercise group when the results for pre-training and post-training were compared. However, to support our findings further research is needed, preferably using randomized controlled trials.

Effects of Exercise Training on Cardiovascular and Autonomic Parameters in Stroke Survivors: A Systematic Review

Negative changes in cardiovascular and autonomic variables in stroke survivors have encouraged the global scientific community to focus on investigating therapeutic strategies to mitigate stroke damage. The objective of the present study was to describe the effects of exercise training on cardiovascular and autonomic variables in stroke survivors. We used the PICO (population, intervention, control/comparison, and outcome variables) model for the search of articles in PubMed and Physiotherapy Evidence Databases from 2009 to December 2018. The following data were also recorded: type of study, author, year of publication, participants (time after stroke, sample size, and age) and benefits of exercise training. A total of 544 articles were initially selected, of which nine peer-reviewed articles met the search criteria. These nine studies enrolled 611 participants (middle-aged or elderly), and pointed to positive effects of training on maximal oxygen uptake, peak aerobic capacity, 6-minute walk test and resting heart rate. However, more well-controlled studies are needed to confirm the benefits of exercise training on cardiovascular and autonomic variables in this population

Acute Response to Aerobic Exercise on Autonomic Cardiac Control of Patients in Phase III of a Cardiovascular Rehabilitation Program Following Coronary Artery Bypass Grafting.

OBJECTIVE: The aim of the present study was to investigate the acute response to aerobic exercise on autonomic cardiac control of patients undergoing coronary artery bypass grafting (CABG). METHODS: The study sample consisted of eight patients (age: 58.6±7.7 years; body mass index: 26.7±3.5 kg.m2) who underwent a successful CABG (no complications during surgery and/or in the following weeks). To assess heart rate variability (HRV), participants remained in a supine position with a 30-degree head elevation for 20 minutes. Electrocardiographic signal (protocol with three derivations) was collected from 600 Hz sample rate to obtain beat-to-beat intervals (R-R interval). This assessment was performed before, after one hour and after 24 hours of the exercise session. All patients underwent a 35 minutes aerobic exercise session (AES) (low-moderate intensity) on the cycle ergometer. RESULTS: Significant differences were found in the time domain, with positive changes in root mean square of successive RR interval differences (rMSSD) (ms) (parasympathetic component) (one [P=0.017] and 24 hours [P=0.007] post-session). In the frequency domain, we found a significant difference in high frequency (HF) (ms2) (parasympathetic component) (one hour [P=0.048] post-session). The low frequency (LF)/HF ratio (sympathetic and parasympathetic components with a predominance of the sympathetic component) reached statistical significance only 24 hours (P=0.018) post-session. Additionally, the largest effect size was observed only for the LF/HF ratio at one (d=-0.8) and 24 hours (d=-1.3) after one AES. CONCLUSION: The practice of (acute) aerobic exercise improved autonomic cardiac control in patients undergoing CABG.

Acute response to aerobic exercise on autonomic cardiac control of patients in phase iii of a cardiovascular rehabilitation program following coronary artery bypass grafting

Abstract Objective: The aim of the present study was to investigate the acute response to aerobic exercise on autonomic cardiac control of patients undergoing coronary artery bypass grafting (CABG). Methods: The study sample consisted of eight patients (age: 58.6±7.7 years; body mass index: 26.7±3.5 kg.m2) who underwent a successful CABG (no complications during surgery and/or in the following weeks). To assess heart rate variability (HRV), participants remained in a supine position with a 30-degree head elevation for 20 minutes. Electrocardiographic signal (protocol with three derivations) was collected from 600 Hz sample rate to obtain beat-to-beat intervals (R-R interval). This assessment was performed before, after one hour and after 24 hours of the exercise session. All patients underwent a 35 minutes aerobic exercise session (AES) (low-moderate intensity) on the cycle ergometer. Results: Significant differences were found in the time domain, with positive changes in root mean square of successive RR interval differences (rMSSD) (ms) (parasympathetic component) (one [P=0.017] and 24 hours [P=0.007] post-session). In the frequency domain, we found a significant difference in high frequency (HF) (ms2) (parasympathetic component) (one hour [P=0.048] post-session). The low frequency (LF)/HF ratio (sympathetic and parasympathetic components with a predominance of the sympathetic component) reached statistical significance only 24 hours (P=0.018) post-session. Additionally, the largest effect size was observed only for the LF/HF ratio at one (d=-0.8) and 24 hours (d=-1.3) after one AES. Conclusion: The practice of (acute) aerobic exercise improved autonomic cardiac control in patients undergoing CABG.

Hypertension, Sarcopenia, and Global Cognitive Function in Community-Dwelling Older Women: A Preliminary Study.

The present study aimed to investigate whether sarcopenia interferes in the association between HTN and cognitive function in community-dwelling older women. One hundred and eleven older women were recruited and dichotomized in hypertensive (n=63) and normotensive groups (n=48). Volunteers underwent evaluations of the sarcopenic state (i.e., skeletal muscle mass, short physical performance battery (SPPB), balance), hemodynamic parameters, and global cognitive status (i.e., Mini-Mental State Examination (MMSE)). Data demonstrated that hypertensive patients had lower global cognitive status than normotensive subjects. When volunteers were divided according to sarcopenic status, data demonstrated that hypertensive patients with low performance on SPPB (0.006), low values of sarcopenic index (0.03), and low performance on sit-to-stand (0.09) demonstrated poor cognitive status compared with hypertensive patients with normal values of these variables. In conclusion, data of the current study indicate that the sarcopenic state might interfere in the association among hypertension and poor cognitive status, once a higher frequency of hypertensive patients with low lower limb muscle function (i.e., SPPB and sit-to-stand) and muscle mass index (i.e., Janssen index) was observed in the <24 MMSE segment, in comparison with hypertensive patients with normal results in these parameters.

Novel Combined Training Approach Improves Sleep Quality but Does Not Change Body Composition in Healthy Elderly Women: A Preliminary Study.

The aim of this study was to investigate the effects of a novel combined training protocol on sleep quality and body composition of healthy elderly women. The study sample consisted of 8 sedentary elderly individuals with mean (±SD) of 67 (±8) years of age, 96.0 (±7.8) mg/dL fasting blood glucose, 94.4 (±36.1) mg/dL triglycerides, 179.1 (±22.4) mg/dL total cholesterol, 57.2 (±15.7) mg/dL high-density lipoprotein (HDL), 103.1 (±25.2) mg/dL low-density lipoprotein (LDL), 125.3 (±8.4) mmHg systolic blood pressure, and 72.6 (±10.1) mmHg diastolic blood pressure. The training protocol consisted of resistance training exercises (approximately 18-minute duration) combined with aerobic exercises (approximately 26-minute duration), performed interspersed in the same session, for 8 weeks (3 times a week), with a 24-hour interval rest between each session. Continuous variables were expressed as the mean (±standard deviation) and the paired sample t-test compares baseline with final measurement. The results showed a significant improvement (p = 0.01) in quality of sleep (4.9 ± 1.5 versus 3.8 ± 1.8 for total PSQI index) without body significant improvements in the fat-free mass (59.9 ± 4.0 versus 60.5 ± 4.4; p = 0.20) and fat mass (40.1 ± 4.0 versus 39.5 ± 4.4; p = 0.20) in healthy elderly women. In this sense, the novel combined training proposed may be an effective alternative or adjunct to present therapies aimed at improving the sleep quality in this population.

Resistance Training and Stroke: A Critical Analysis of Different Training Programs.

The aim of this study was to carry out a literature review on the overall benefits of resistance training (RT) after stroke and undertake a critical analysis of the resistance exercise programs surveyed (rest interval between sets and exercises, number of sets, number of repetitions, intensity, duration of training, and weekly frequency). To obtain articles for the review, we searched PubMed, Google Scholar, and Physiotherapy Evidence Database (PEDro). Inclusion criteria were considered using the PICO (population, intervention, control/comparison, and outcome variables) model. The following characteristics were recorded for all articles: type of study, author, year of publication, participants (time after stroke, sample size, and age), benefits of RT, and structured resistance exercise programs. Positive effects of training were found on anxiety status, quality of life, muscle hypertrophy, cognitive function, strength, and muscle power. Only 5 studies described the main variables of RT in detail. Lack of control of some variables of RT may negatively affect the results of this practice. The findings of the present study may further inform health and physical conditioning professionals on the importance and necessity of using the main variables in the search for benefits for individuals with stroke.

Exercise training on cardiovascular diseases: Role of animal models in the elucidation of the mechanisms

Abstract Cardiovascular diseases, which include hypertension, coronary artery disease/myocardial infarction and heart failure, are one of the major causes of disability and death worldwide. On the other hand, physical exercise acts in the preventionand treatment of these conditions. In fact, several experiments performed in human beings have demonstrated the efficiency of physical exercise to alter clinical signals observed in these diseases, such as high blood pressure and exercise intolerance. However, even if human studies demonstrated the clinical efficiency of physical exercise, most extensive mechanisms responsible for this phenomenon still have to be elucidated. In this sense, studies using animal models seem to be a good option to demonstrate such mechanisms. Therefore, the aims of the present study are describing the main pathophysiological characteristics of the animal models used in the study of cardiovascular diseases, as well as the main mechanismsassociated with the benefits of physical exercise.(AU)

Inflammatory Mechanisms Associated with Skeletal Muscle Sequelae after Stroke: Role of Physical Exercise.

Inflammatory markers are increased systematically and locally (e.g., skeletal muscle) in stroke patients. Besides being associated with cardiovascular risk factors, proinflammatory cytokines seem to play a key role in muscle atrophy by regulating the pathways involved in this condition. As such, they may cause severe decrease in muscle strength and power, as well as impairment in cardiorespiratory fitness. On the other hand, physical exercise (PE) has been widely suggested as a powerful tool for treating stroke patients, since PE is able to regenerate, even if partially, physical and cognitive functions. However, the mechanisms underlying the beneficial effects of physical exercise in poststroke patients remain poorly understood. Thus, in this study we analyze the candidate mechanisms associated with muscle atrophy in stroke patients, as well as the modulatory effect of inflammation in this condition. Later, we suggest the two strongest anti-inflammatory candidate mechanisms, myokines and the cholinergic anti-inflammatory pathway, which may be activated by physical exercise and may contribute to a decrease in proinflammatory markers of poststroke patients.