Effects of intradialytic exercise on cardiopulmonary capacity in chronic kidney disease: systematic review and meta-analysis of randomized clinical trials

Comparisons of Intradialytic Exercise Versus Home-Based Exercise in Hemodialysis Patients: A Narrative Review

With the increasing prevalence of end-stage kidney disease, the number of patients requiring hemodialysis (HD) continues to rise. While life-sustaining, HD is often associated with adverse effects such as muscle loss, physical deconditioning, fatigue, and compromised health-related quality of life (HRQoL). Recent research suggests that intradialytic exercise (IDE) and home-based exercise (HBE) may mitigate these adverse effects and improve patient outcomes. However, the existing literature mainly focuses on the outcomes of both exercises, whereas the comparison of types is often omitted. Hence, this review consolidates findings from studies investigating the effectiveness, implementation, safety, feasibility, and adherence of different types of IDE and HBE in HD patients. Overall, the current literature bolsters the significance of IDE and HBE for improving health in HD patients. IDE and HBE enhance physical function, cardiopulmonary capacity, HRQoL, and cognitive well-being. Some research proposed an indirect link between IDE and survival rates. Despite these benefits, challenges remain in implementing these exercise modalities, including patient adherence and the feasibility of routine exercise during HD sessions. Integrating these exercises into routine care allows healthcare providers to enhance outcomes for HD patients. Further research is suggested to optimize exercise protocols and explore long-term effects and cost-effectiveness.

Physical exercise: a polypill against chronic kidney disease

We are currently facing a pandemic of physical inactivity that might contribute to the growing prevalence of chronic kidney disease (CKD). Here, we summarize currently available evidence on the association between physical activity and CKD, and also review the effects of exercise intervention in affected patients. Physical activity/exercise might act as a polypill against CKD, preventing its development or even exerting beneficial effects once it is established (i.e. improvements in patients' physical fitness and cardiovascular risk, as well as in kidney function). Exercise benefits are also found at advanced CKD stages or in patients under hemodialysis. The biological mechanisms behind the clinical evidence are also discussed. An active lifestyle appears as a cornerstone in CKD prevention and management.

The Acute, Combined, and Separate Effects of Cold Hemodialysis and Intradialytic Exercise in Insulin Sensitivity and Glucose Disposal

Hemodialysis (HD) patients suffer from multiple health problems, including severe insulin resistance. Both cold dialysis and intradialytic exercise training could elicit health benefits; however, it is still unknown whether the combination of those two approaches could enhance overall health. The current study aimed to evaluate the separate and combined acute effects of a single session of cold dialysis and intradialytic exercise in parameters related to insulin sensitivity and glucose disposal. Ten HD patients (57.2 ± 14.9 years) participated in the study. Each patient participated in four different scenarios during HD: a) typical dialysis with dialysate temperature at 37°C (TD), b) cold dialysis with dialysate temperature at 35°C, c) typical HD combined with a single exercise bout, d) cold dialysis combined with a single exercise bout. Glucose disposal and insulin resistance were assessed immediately after the end of the HD session. None of the examined parameters significantly differed between the four scenarios ( p > 0.05). However, slight numerical changes and moderate to high effect size ( d : 0.50-0.85) were observed between TD versus cold dialysis and TD versus TD + exercise in glucose and insulin disposal rates. A single session of cold and TD with intradialytic exercise may provide an "acute" time-efficient stimulus for consecutively improving glucose disposal and insulin sensitivity.

The effects of exercise training interventions on depression in hemodialysis patients

Purpose

Depression considerably influences the clinical outcomes, treatment compliance, quality of life, and mortality of hemodialysis patients. Exercise plays a beneficial role in depressive patients, but its quantitative effects remain elusive. This study aimed to summarize the effects of exercise training on depression in patients with end-stage renal disease undergoing hemodialysis.

Methods

The PUBMED, EMBASE, and Cochrane Library databases were systematically searched from inception to April 2023 to identify published articles reporting the effect of exercise training on the depression level of patients with End-Stage Renal Disease undergoing hemodialysis. Data were extracted from the included studies using predefined data fields by two independent researchers. The Cochrane Handbook for Systematic Reviews of Interventions and Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies were employed for quality evaluation.

Results

A total of 22 studies enrolling 1,059 patients who participated in exercise interventions were included. Hemodialysis patients exhibited superior outcomes with intradialytic exercise (SMD = -0.80, 95% CI: -1.10 to -0.49) and lower levels of depression following aerobic exercise (SMD = -0.93, 95%CI: -1.32 to -0.55) compared to combined exercise (c - 0.85, 95% CI: -1.29 to -0.41) and resistance exercise (SMD = -0.40, 95%CI: -0.96 to 0.17). Regarding exercise duration, patients manifested lower depression levels when engaging in exercise activities for a duration exceeding 6 months (SMD = -0.92, 95% CI: -1.67 to -0.17). Concerning the duration of a single exercise session, the most significant improvement was noted when the exercise duration exceeded 60 min (SMD = -1.47, 95% CI: -1.87 to -1.06).

Conclusion

Our study determined that exercise can alleviate depression symptoms in hemodialysis patients. This study established the varying impacts of different exercise parameters on the reduction of depression levels in hemodialysis patients and is anticipated to lay a theoretical reference for clinicians and nurses to devise tailored exercise strategies for interventions in patients with depression.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database, with registration number CRD42023434181.

Cardiorespiratory fitness and mortality risk in patients receiving hemodialysis: a prospective cohort

BACKGROUND

Kidney failure reduces life expectancy by one-third compared with the general population, and cardiovascular complications and poor cardiorespiratory fitness (CRF) are the main causes. We aimed to evaluate the association between severely low CRF and all-cause mortality risk in HD patients.

METHODS

This observational prospective cohort study followed-up patients receiving HD from August 2015 until March 2022. Cardiorespiratory fitness was evaluated through the cardiopulmonary exercise test, and the peak oxygen uptake (VO2peak) value was used to determine severely low CRF (< 15 mL∙kg-1∙min-1). Cox regression and univariate Kaplan-Meier analysis were used to evaluate the association of severely low CRF with mortality risk and survival rate.

RESULTS

Forty-eight patients were followed-up for a median of 33.0 [14.3 - 49.3] months. A total of 26 patients had severely low CRF. During the follow-up period, 11 patients (22.92%) died from all causes. From these, eight (30.8%) had severely low CRF. Even so, severely low CRF was not associated with crude death rates for patients stratified by CRF levels (p = 0.189), neither in unadjusted (HR 2.18; CI 95% 0.58-8.23) nor in adjusted (HR 1.32; CI 95% 0.31-5.59) Cox proportional hazard models. As a continuous variable, VO2peak was not associated with mortality risk (HR 1.01; CI 95% 0.84-1.21). Univariate Kaplan-Meier analysis showed that patients with severely low CRF did not have significantly worse survival rates than those with mild-moderate CRF (p = 0.186).

CONCLUSION

Our findings indicated that severely low CRF was not associated with all-cause mortality in patients on HD. Despite severely low CRF being prevalent, larger cohort studies are needed to establish strong conclusions on its association with all-cause mortality.

Efficacy of six exercise-based interventions for individuals undergoing hemodialysis: a network meta-analysis of randomized clinical trials

BACKGROUND

Evidence comparing different exercise modalities in individuals undergoing hemodialysis remains incipient. Our aim was to conduct a systematic review and network meta-analysis of randomized clinical trials to compare and synthesize the efficacy of five different intradialytic exercise modalities and home-based training in this population.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Studies were searched in PubMed/MEDLINE, Cochrane Library, Embase, Cinahl, and Scopus from their inception to 19 September 2022. We used traditional random-effects models and Bayesian network meta-analysis models. The risk of bias was assessed using the RoB v.2.0 tool, and the assessment of confidence in the results through the Confidence in Network Meta-Analysis (CINeMA) tool.

RESULTS

Seventy-eight studies involving 3326 participants were included. Our network meta-analysis showed that combined training was the intervention with the best performance to increase VO2 peak [mean difference (MD) = 3.94 ml/kg/min; 95% credible interval (CrI), 2.38 to 5.76] and to reduce diastolic blood pressure (MD = -5.19 mmHg; 95%CrI, -9.35 to -0.96) compared to the usual care group. Inspiratory muscle training was the intervention that most improved the 6-minute walk test distance (MD = 70.97 m; 95%CrI, 18.09 to 129.87). C-reactive protein decreased in resistance training (MD = -2.6 mg/l; 95%CrI, -4.97 to -0.33) and aerobic training (MD = -1.4 mg/l; 95%CrI, -3.15 to -0.06). Kt/V improved in aerobic training (MD = 0.11; 95%CrI, 0.02 to 0.18), and SF-36 physical functioning outcomes improved in resistance training (MD = 10.66 points; 95%Crl, 1.91 to 20.22). No intradialytic exercise modality was superior to others or comparable with home-based training in improving the evaluated outcomes. Subgroup analysis revealed that exercise interventions >12 weeks improved functional capacity more than interventions ≤12 weeks, and that combined training reduces diastolic blood pressure only after 12 weeks of follow-up. Furthermore, our results suggest that moderate or moderate-to-vigorous intensity training leads to more pronounced improvements in functional capacity, whereas mild or mild-to-moderate intensity training does not have the same effect. In this review, most of the included studies were assessed as having some concern, which resulted in a low to very low level of confidence in the overall findings.

CONCLUSIONS

Both intradialytic training and home-based training can promote benefits for individuals undergoing hemodialysis, with no evidence of the superiority of either training modality over the other.

Nurses' and medical doctors' attitudes towards exercise for people with chronic kidney disease in Denmark

BACKGROUND

Implementation of exercise training in people with kidney failure may be affected by clinicians' attitudes.

OBJECTIVES

To investigate Danish nephrology nurses' and medical doctors' attitudes towards: exercise for people undergoing dialysis; use of physical activity interventions in chronic kidney disease; and to compare Danish and previously reported Australian nurse attitudes.

DESIGN

Cross-sectional survey.

PARTICIPANTS

Nurses and medical doctors from the nephrology field in Denmark.

MEASUREMENTS

The questionnaire attitudes towards exercise in dialysis, and questions about exercise advice, counselling and interventions.

RESULTS

Nephrology nurses (n = 167) and 17 medical doctors (women 92%, age 47 ± 11 years) from 19 dialysis units participated. There were no differences between nurses' and medical doctors attitudes about training. Ninety-five % and 88% of nurses and medical doctors, respectively, agreed that most people undergoing dialysis could benefit from exercise. Exercise training was offered to people undergoing haemodialyses in 88% of 17 departments. Danish nurses reported more positive attitudes than Australian towards exercise (p < 0.05). Ninety-five % and 86% of the Danish and Australian nurses, respectively, agreed/strongly agreed that most people undergoing dialysis could benefit from exercise. Six % and 35% of the Danish and Australian nurses, respectively, agreed/strongly agreed that most people with dialysis were too sick to exercise.

CONCLUSION

Danish nephrology nurses and medical doctors had mostly positive attitudes to exercise training to people undergoing dialysis, and exercise to people with dialysis was offered frequently. Danish and Australian nurses had positive attitudes to exercise to people undergoing dialysis, it was however more positive in Danish nurses.

Effects of resistance training on patients with End-Stage Renal Disease: an umbrella review with meta-analysis of the pooled findings

OBJECTIVES

This umbrella review aimed to review the effects of resistance training on patients with end-stage renal disease and assess the methodological quality of the available literature.

METHODS

An umbrella review and meta-meta-analysis was performed. A systematic search was conducted until May 2022. Article selection, quality assessment, and risk of bias assessment were performed by two independent reviewers. The meta-meta-analyses were performed with a random-effects model and the summary statistics were presented in the form of a forest plot with a weighted compilation of all standardized mean differences and corresponding 95% confidence interval. Twenty-four reviews were eventually included. The protocol was registered in the international registry PROSPERO (CRD42022321702).

RESULTS

Resistance training showed positive effects on functional capacity (g = 0.614), aerobic capacity (g = 0.587), health-related quality of life (g = 0.429), and peak force (g = 0.621). Fifteen of the included studies (63%) presented low risk of bias, and the remaining studies (37%) showed unclear risk of bias.

CONCLUSION

Resistance training in patients undergoing hemodialysis is an intervention that shows positive results regarding physical and functional outcomes. The quality level of the literature is inconclusive, but the included studies present low risk of bias.

How is exercise being prescribed for patients on hemodialysis? A scoping review

BACKGROUND

Exercise is important for patients on hemodialysis, but details and descriptions on how it is prescribed are lacking. We reviewed the existing literature and described how exercise is being prescribed for patients on hemodialysis.

METHODS

A scoping review according to the JBI and PRISMA-ScR guidelines was conducted. MEDLINE, EMBASE and other databases were searched from inception until December 2021. Websites, books, and guidelines were also searched. We included evidence from patients on hemodialysis, describing exercise protocols, in all settings and designs.

RESULTS

Two hundred and eighty-five studies were included, yielding 327 exercise protocols. Aerobic (38.8%) and strength (21.4%) were the most prescribed exercise types. Exercise was mainly prescribed during dialysis (71.0%) and delivered within the first half of the session (94.6%). Although 33.3% of the exercise protocols did not report whether there was supervision or not, those that did were mostly delivered by physiotherapists (20.5%) and exercise physiologists (17.4%). The most followed exercise training principles were type (99.0%) and frequency (93.2%), whereas progression was adopted in 40.7% protocols. The most prescribed frequency and duration were three times/week (79.9%) and 30-60-min (69.2%) sessions, respectively. Exercise intensity was predominantly prescribed in moderate cut-offs (72.3%), mostly assessed by subjective methods (47.5%).

CONCLUSIONS

Aerobic and strength were the most prescribed exercise types, mainly during dialysis. Interventions were mostly supervised by physiotherapists and exercise physiologists. Future exercise protocols for patients on hemodialysis should adopt recommended exercise principles, especially with systematic progression.

Effects of intradialytic inspiratory muscle training at different intensities on diaphragm thickness and functional capacity: clinical trial protocol in patients undergoing haemodialysis

INTRODUCTION

Patients with end-stage renal disease (ESRD) undergoing haemodialysis (HD) commonly present with a sedentary behaviour and reduced functional capacity, factors that can compromise their prognosis. Intradialytic inspiratory muscle training (IMT) can increase respiratory muscle strength and, consequently, improve functional capacity, besides being easy to apply, cheap and performed in a supervised setting. However, few studies show the effects of this type of training applied at different intensities in this population. This study aims to compare the effects of IMT at different intensities in adults with ESRD undergoing HD.

METHODS AND ANALYSIS

A randomised, double-blind, sham-controlled trial will be conducted on 36 subjects randomly allocated into three groups: IMT at intensities of 30% or 50% of maximal inspiratory pressure (intervention groups), or 10% of maximal inspiratory pressure (sham-IMT). All the interventions will be supervised and performed three times per week, for 12 weeks, totalling 36 sessions. The primary outcomes are the 6-minute walk test, diaphragm thickness and the response of VO₂peak post-intervention. Respiratory muscle strength, 24-hour ambulatory blood pressure measurement and the Kidney Disease Quality of Life 36-item short form survey will be evaluated as secondary outcomes.

ETHICS AND DISSEMINATION

This study has been approved by the Research Ethics Committee of the Hospital de Clínicas de Porto Alegre (ID: 2020-0458). The results of this study will be disseminated by conference presentations and peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04660383.

EFFECT OF TAI-JI PRACTICE ON THE HEALTH OF THE ELDERLY

ABSTRACT Introduction: The practice of Tai-ji has shown a positive effect on the physical functions of the elderly and has been promoted as a recommended daily activity for middle-aged and elderly individuals. However, there is still no scientific evidence about its cardiorespiratory benefits. Objective: Study the effect of Tai-ji on the cardiorespiratory function and physical fitness of the elderly. Methods: A group of elderly people from the same community and in good health, considered suitable for sports experiments was divided into the experimental group for Tai-ji exercise and the control group for vigorous walking exercise. Each week, the Tai-ji exercise with eight steps and the vigorous walking exercise was performed three times in each group. Results: After six weeks of Tai-ji exercise with eight steps of five methods, the vital capacity, maximal oxygen consumption, maximal voluntary ventilation, and oxygen pulse of the experimental group were significantly increased, and the systolic and diastolic pressures were significantly reduced, evidencing an improvement in the performance of the cardiopulmonary function. Conclusion: Tai-ji exercise is beneficial for the cardiopulmonary function and physical health of the elderly and is scientifically useful for improving the mental health level and quality of life of the elderly. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

The optimal exercise modality and intensity for hemodialysis patients incorporating Bayesian network meta-analysis and systematic review

Background: Physical inactivity is highly prevalent in patients with hemodialysis, and a large body of evidence reported the positive effect of different exercise modalities on their health outcomes. However, the effective dosage of exercise for hemodialysis patients still requires verification.

Objective: We aimed to determine the most effective exercise intensity and modality for improvements in physical function, blood pressure control, dialysis adequacy, and health-related quality of life for hemodialysis patients.

Design: Systematic review with network meta-analysis of randomized trials.

Data sources: Five electronic databases (PubMed, EMBASE, Web of Science, Cochrane CENTRAL, and Scopus) were searched for randomized controlled trials. Data extraction and quality appraisal were conducted by two authors independently. Data were analyzed by the R (version.3.6.2) and the Stata (version.15.0).

Result: We included 1893 patients involving four exercise modalities and six exercise intensities. Combined training (aerobic exercise plus resistance exercise) has been the top-ranking exercise modality for improving the 6-min walk test (6MWT) (surface under the cumulative ranking curve analysis (SUCRA) score, 90.63), systolic blood pressure control (SUCRA score, 77.35), and diastolic pressure control (SUCRA score, 90.56). Moreover, the top-ranking exercise intensity was moderate–vigorous for 6MWT (SUCRA score, 82.36), systolic blood pressure (SUCRA score, 77.43), and diastolic blood pressure (SUCRA score, 83.75). Regarding dialysis adequacy and health-related quality of life, we found no exercise modality or intensity superior to the placebo.

Conclusion: This network meta-analysis indicated that combined training and moderate–vigorous intensity might be the most effective interventions to improve 6MWT and blood pressure control. This finding helps further guide clinical exercise prescriptions for hemodialysis patients.

Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021268535].

Therapeutic effects of exercise interventions for patients with chronic kidney disease: an umbrella review of systematic reviews and meta-analyses

OBJECTIVE

To conduct an overview of meta-analyses evaluating the impact of exercise interventions on improving health outcomes in patients with chronic kidney disease (CKD).

DESIGN

An umbrella review of systematic review and meta-analyses of intervention trials was performed.

DATA SOURCES

PubMed, Web of Science, Embase and the Cochrane Database of Systematic Reviews were searched from inception to 9 March 2021 for relevant articles.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible meta-analyses compared the effects of usual care with and without exercise in patients with CKD. Health outcomes included those related to cardiovascular risk factors, physical fitness, dialysis-related symptoms, dialysis adequacy and health-related quality of life. Systematic reviews and meta-analyses that included fewer than 3 RCTs or fewer than 100 participants were excluded from the analysis.

RESULTS

A total of 31 eligible systematic reviews and meta-analyses were included that assessed 120 outcomes. For physical fitness, there was a moderate effect size for cardiorespiratory fitness, muscle strength and body composition and small effect size for muscle endurance. The effect sizes for cardiovascular risk factors, dialysis-related symptoms and health-related quality of life outcomes were small. According to the Grading of Recommendations Assessment, Development and Evaluation framework, most outcomes were low or very low quality.

CONCLUSION

Exercise appears to be a safe way to affect concomitant cardiovascular risk factors, such as blood pressure, improve physical fitness and health-related quality of life and reduce dialysis-related symptoms in patients with CKD.

PROSPERO REGISTRATION NUMBER

CRD42020223591.

Cardiovascular Effects of Home Dialysis Therapies: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage kidney disease. Currently, thrice-weekly in-center hemodialysis for 3 to 5 hours per session is the most common therapy worldwide for patients with treated kidney failure. Outcomes with thrice-weekly in-center hemodialysis are poor. Emerging evidence supports the overarching hypothesis that a more physiological approach to administering dialysis therapy, including in the home through home hemodialysis or peritoneal dialysis, may lead to improvement in several cardiovascular risk factors and cardiovascular outcomes compared with thrice-weekly in-center hemodialysis. The Advancing American Kidney Health Initiative, which has a goal of increasing the use of home dialysis, is aligned with the American Heart Association's 2024 mission to champion a full and healthy life and health equity. We conclude that incorporation of interdisciplinary care models to increase the use of home dialysis therapies in an equitable manner will contribute to the ultimate goal of improving outcomes for patients with kidney failure and cardiovascular disease.

Implementing a resistance training programme for patients on short daily haemodialysis: A feasibility study

BACKGROUND

Kidney failure patients receiving haemodialysis experience protein-energy wasting, muscle mass loss and physical function impairment. Intradialytic exercise interventions seem to modify these features, but they are often not implemented as a clinical routine.

OBJECTIVE

To investigate the feasibility of implementing a supervised intradialytic resistance training programme as a clinical routine for patients receiving short daily haemodialysis.

DESIGN

A prospective longitudinal study.

PARTICIPANTS

Eighteen patients in a supervised intradialytic resistance training programme for 8 months.

MEASUREMENTS

It consisted of a warm-up, lower- and upper-limb resistance exercises and a cool-down. Patients performed the resistance training during the first half of haemodialysis, twice a week, supervised by exercise physiologists and physiotherapists. The feasibility was assessed by the total and partial adherences, the reasons for refusing or for not exercising and the intradialytic complications.

RESULTS

From a total of 953 potential exercise sessions, 759 were performed, with a 79.6% adherence rate. In the first 9 weeks, the adherence rate was 86.6% and the lowest rate was in the 19-27 weeks (73.5%). The main intradialytic complication during exercise sessions was hypotension (n = 31; 4.1%). The highest number of complications was reported during the first 9 weeks (n = 27; 9.1%). The main reasons for refusing or for not performing the intradialytic exercise sessions were clinical complications previous to exercise time (n = 63; 32.5%) and self-reported indisposition (n = 62; 32.0%).

CONCLUSIONS

The intradialytic resistance training programme, supervised by exercise physiologists and physiotherapists, had very low complications, achieved a high long-term adherence rate and showed to be feasible as a clinical routine for patients receiving short daily haemodialysis.

Cardiopulmonary exercise testing to observe subclinical abnormalities in cardiopulmonary function in patients undergoing peritoneal dialysis

BACKGROUND

Decreased cardiorespiratory fitness (CRF) related to cardiopulmonary function increases the risk of cardiovascular disease in patients with end-stage kidney disease. Thus, early detection of the cause of impaired cardiopulmonary function in patients undergoing peritoneal dialysis (PD) is of important clinical significance.

METHODS

In this cross-sectional study, Symptom-restricted cardiopulmonary exercise testing (CPET) was performed in 30 patients undergoing PD and in 23 age- and sex-matched healthy control subjects.A fixed workload was added every minute until fatigue, and breath-by-breath respiratory gas was analyzed with an automated gas analyzer at 10-second intervals.

RESULTS

The peak oxygen uptake ( 16.39±0.83 vs 25.77±1.33 ml/kg/min p<0.001) and the oxygen uptake at the anerobic threshold of patients undergoing PD (9.61±0.34 vs 14.55± 0.64 ml/kg/min; p<0.001) were lower than in healthy control subjects, and both of these parameters correlated with body mass index and left atrial dimension. A steeper minute ventilation / carbon dioxide production slope (27.20±0.68 vs 24.29±0.69；p<0.01) and a lower end-tidal carbon dioxide partial pressure (37.93±0.54 vs 41.27±0.83mmHg；p<0.05) were observed in patients undergoing PD. The oxygen pulse and oxygen uptake efficiency slope was smaller in patients undergoing PD. The Maximum heart rate (126.07±4.01 vs 149.96±5.29 bpm；p<0.01) and 1-minute heart rate recovery (13.93±1.52 vs 24.39±1.61bpm；p<0.01) were also lower in patients undergoing PD.

CONCLUSION

Subclinical cardiopulmonary dysfunction may exist in patients with PD, and a reduction in CRF in patients undergoing PD is affected by both central and peripheral functions. CPET has potential value in revealing the mechanism of impaired CRF and in discovering subclinical abnormalities in cardiopulmonary function. This article is protected by copyright. All rights reserved.

Aerobic Exercise Increases Vascular Diameter of Arteriovenous Fistula in Hemodialysis Patients

INTRODUCTION

A healthy arteriovenous fistula (AVF) depends on adequate vessel diameter which can be maintained through aerobic exercises. A randomized crossover study was conducted to evaluate the acute effects of aerobic exercise on a cycle ergometer on AVF vascular diameter, through ultrasound, and on blood pressure (BP).

METHODS

Eight hemodialysis (HD) patients completed 2 different occasions in random order with a 7-day washout: (a) exercising moment, in which 30-min aerobic exercise was performed on a cycle ergometer; and (b) resting moment, which was performed 30-min with the patient sitting in a chair. Both occasions were evaluated 1-h before the second weekly HD day.

RESULTS

A significant increase in AVF vascular diameter induced by 30-min aerobic exercise was found (1.15 ± 0.56 to 1.47 ± 0.66 cm; p = 0.042), whereas systolic (p = 0.105) and diastolic BP (p = 0.366) did not change.

CONCLUSIONS

We can conclude that acute aerobic exercise was shown to be effective in improving the AVF vascular diameter in HD patients. The aerobic exercise benefits in endothelium-dependent vasodilation which may be an effective, practical, and economic strategy to maintain AVF patency.

Effects of intradialytic exercise for advanced-age patients undergoing hemodialysis: A randomized controlled trial

Previous reports have shown the benefits of intradialytic exercise to patients undergoing hemodialysis. However, most of those studies assessed the effects of exercise in middle-aged patients and little is known about advanced-age patients undergoing hemodialysis. Therefore, the present randomized controlled trial was performed to determine the effectiveness of exercise therapy in advanced-age patients undergoing hemodialysis. This non-blinded, randomized controlled parallel trial enrolled a total of 101 patients who were randomly assigned to intradialytic exercise (n = 51) or usual care (n = 50) groups. The training program included both resistance and aerobic exercises and was performed three times per week for 6 months. The aerobic exercise intensity was adjusted to a target Borg score of 13 for 20 minutes. Four types of resistance exercises were performed using elastic tubing, with three sets of 10 exercises performed at moderate intensity (13/20 on the Borg scale). The usual care group received standard care. Lower extremity muscle strength, Short Physical Performance Battery score, and 10-m walking speed were the outcomes and were evaluated before the hemodialysis session and after 6 months of training. There were statistically significant improvements in Short Physical Performance Battery score (effect size, 0.57; 95% confidence interval, 0.15‒1.95) in the exercise group relative to the control group. There were no statistically significant differences in lower extremity muscle strength or in the 10-m walking speed between the two groups. These findings suggest that 6 months of intradialytic training could improve physical function in older patients undergoing hemodialysis.

Intradialytic periodized exercise improves cardiopulmonary fitness and respiratory function: A randomized controlled trial

BACKGROUND

Chronic kidney disease (CKD) is a factor that predisposes to gradual physical deconditioning from its early stages leading to cardiorespiratory fitness and musculoskeletal system impairment. We evaluated the effects of combined and periodized intradialytic exercise training on cardiopulmonary fitness and respiratory function in HD subjects.

METHODS

A randomized controlled trial with HD subjects was allocated into two groups: exercise group (EXG) and usual care group (UCG). EXG performed a 12-week combined and periodized intradialytic training. UCG maintained the HD routine.

RESULTS

Thirty-nine HD subjects were analyzed (EXG = 20; UCG = 19). The EXG in comparison with the UCG showed improvements in peak oxygen consumption (Δ3.1[0.4-5.5] vs. -0.2[-2.0-1.5] ml/kg/min; p = 0.003), forced expiratory volume in the first second (Δ0.1[-0.0-0.1] vs. -0.0[-0.1-0.0] L; p = 0.022), forced vital capacity (Δ0.1[0.0-0.2] vs. -0.1[-0.2-0.0] L; p = 0.005), peak expiratory flow (Δ0.4[-0.7-1.2] vs. -0.1[-0.5-0.2] L; p = 0.046), and maximal inspiratory pressure (Δ7.35[-8.5-17.5] vs. -4.0[-18.0-12.0] cmH₂ O; p = 0.028). The EXG, different from the UCG, did not worsen the maximal expiratory pressure (Δ0.1[-8.8-7.5] vs. -2.5[-15.0-9.0] cmH₂ O; p = 0.036). Besides, EXG showed a significant improvement in quadriceps strength (32.05 ± 10.61 vs. 33.35 ± 11.62 kg; p = 0.042).

CONCLUSIONS

The combined and periodized intradialytic exercise training improved cardiopulmonary fitness, respiratory function, inspiratory muscle strength, and quadriceps strength, beyond maintaining the expiratory muscle strength in HD subjects.

Effects of Intradialytic Exercise on Dialytic Parameters, Health-Related Quality of Life, and Depression Status in Hemodialysis Patients: A Randomized Controlled Trial

Exercise is fundamentally important in managing chronic diseases and improving health-related quality of life (HRQL). However, whether intradialytic exercise is safe through assessment of changes in dialytic parameters and has a positive impact on HRQL and depression status of hemodialysis patients requires further research with diverse racial and cultural populations to identify. This study aimed to evaluate the effects of intradialytic exercise on dialytic parameters, HRQL, and depression status in hemodialysis patients. A randomized controlled trial was conducted at a medical center in Northern Taiwan. Sixty-four hemodialysis patients were recruited using stratified random sampling. Participants were randomized into an experimental group (EG, n = 32) or a control group (CG, n = 32). The EG received a 12-week intradialytic exercise program while the CG maintained their usual lifestyles. Dialytic parameters, HRQL, and depression status were collected at baseline and at 12 weeks. The results indicated no differences in the dialytic parameters from the baseline between both groups. However, the EG had increased HRQL (ß = 22.6, p < 0.001) and reduced depression status (ß = −7.5, p = 0.02) at 12 weeks compared to the CG. Therefore, a 12-week intradialytic exercise regime is safe and effective in improving HRQL and reducing depression status for hemodialysis patients.

Intradialytic exercise in end-stage renal disease: An umbrella review of systematic reviews and/or meta-analytical studies

OBJECTIVES

This umbrella review aimed to understand the clinical benefits and adverse events associated with different modalities of intradialytic exercise in patients with end-stage renal disease undergoing hemodialysis.

DATA SOURCES

The search was performed until September 10th, 2020 on Scopus, Web of Science, the Cochrane Database, CINAHL, and PubMed.

METHODS

This umbrella review was conducted following the PRISMA guideline statement. The methodological quality of the reviews was assessed with the AMSTAR-2. Standardized mean differences with 95% confidence intervals were estimated. The I-squared statistic was used to assess heterogeneity and the Eggers' test was performed to test asymmetry/small-study effects.

RESULTS

Eleven reviews were included and 48 unique meta-analyses were examined. Nine were supported by suggestive evidence (P < 0.05, small heterogeneity, absence of small-study effects, and excess significance bias). Clinical benefits were found for functional capacity associated with aerobic exercise (d = 0.81; k = 6), resistance training (d = 0.58; k = 6), neuromuscular electrical stimulation (d = 0.70; k = 5), and inspiratory muscle training (d = 1.13; k = 2), measured by the distance covered in the 6-minutes walking test. This outcome was also associated with aerobic exercise (d = 0.28; k = 7) and combined exercise, measured by VO2peak (d = 1.01; k = 5) and by the duration of the cardiopulmonary test (d = 1.07; k = 4). Isometric quadriceps muscle strength improved with neuromuscular electrical stimulation (d = 1.19; k = 7) while patients' perception of vitality improved with combined exercise (d = 0.60; k = 3).

CONCLUSIONS

Suggestive evidence was found for the associations between various modalities of intradialytic exercise and functional capacity. Combined exercise was associated with improvements in physical and psychosocial variables. Few or no adverse events were reported.

The role of physical activity and miRNAs in the vascular aging and cardiac health of dialysis patients

Cardiovascular comorbidities are independent risk factors for mortality in dialysis patients. MicroRNA signaling has an important role in vascular aging and cardiac health, while physical activity is a primary nonpharmacologic treatment for cardiovascular comorbidities in dialysis patients. To identify the relationships between muscle function, miRNA signaling pathways, the presence of vascular calcifications and the severity of cardiovascular comorbidities, we initially enrolled 90 subjects on hemodialysis therapy and collected complete data from 46 subjects. A group of 26 subjects inactiv group (INC) was monitored during 12 weeks of physical inactivity and another group of 20 patients exercise group (EXC) was followed during 12 weeks of intradialytic, moderate intensity, resistance training intervention applied three times per week. In both groups, we assessed the expression levels of myo‐miRNAs, proteins, and muscle function (MF) before and after the 12‐week period. Data on the presence of vascular calcifications and the severity of cardiac comorbidities were collected from the patients’ EuCliD^® records. Using a full structural equitation modelling of the total study sample, we found that the higher the increase in MF was observed in patients, the higher the probability of a decrease in the expression of miR‐206 and TRIM63 and the lower severity of cardiac comorbidities. A reduced structural model in INC patients showed that the higher the decrease in MF, the higher the probability of the presence of calcifications and the higher severity of cardiac comorbidities. In EXC patients, we found that the higher the increase in MF, the lower the probability of higher severity of cardiovascular comorbidities.

Exercise training in chronic kidney disease-effects, expectations and adherence

There is increasing evidence showing the health benefits of physical activity, such as better survival and possibly even a slower decline in kidney function, in people with chronic kidney disease (CKD). There is convincing evidence that exercise training improves physical function measured as aerobic capacity, muscle endurance strength and balance at all ages and all stages of CKD. In fact, long-term adherence to well-designed and adequately monitored exercise training programmes is high. In general, patients express interest in exercise training and are motivated to improve their physical function and health. A growing number of nephrologists regard physical activity and exercise training as beneficial to patients with CKD. However, many feel that they do not have the knowledge to prescribe exercise training and suppose that patients are not interested. Patients state that support from healthcare professionals is crucial to motivate them to participate in exercise training programmes and overcome medical, physical and psychological barriers such as frailty, fatigue, anxiety and fear. Equally important is the provision of funding by healthcare providers to ensure adequate prescription and follow-up by trained exercise physiologists for this important non-pharmacological treatment.

Cardiorespiratory and skeletal muscle damage due to COVID-19: making the urgent case for rehabilitation

INTRODUCTION

It has become increasingly evident that COVID-19 contributes to multiorgan pathophysiology. The systemic inflammatory response increases both pro-inflammatory cytokine and chemokine levels, leading to immune dysregulation and increasing the likelihood of incurring cardiac and pulmonary injuries.

AREAS COVERED

Longer periods of hospitalization (~20 days) increase susceptibility to ICU-acquired muscle weakness and deconditioning, which decreases muscle function and functional capacity. These conditions affect the quality of life in the post-COVID-19 period and require multi-disciplinary approaches to rehabilitate the cardiopulmonary and musculoskeletal systems of these patients. In this context, this narrative review, which included articles published in the Embase, PEDro and PubMed databases up to December 2020, is focused on discussing the essential role of exercise and rehabilitation health professionals in the COVID-19 recovery process, from hospitalization to hospital discharge, addressing strategies for professionals to mitigate the cardiac and pulmonary impairments associated with hospitalization to home or ambulatory rehabilitation, purposing ways to conduct rehabilitation programs to restore their functional status and quality of life after the infection.

EXPERT OPINION

In the current environment, these findings further point to the vital role of rehabilitation health professionals in the coming years and the urgent need to develop strategies to assist COVID-19 survivors.

Exercise intolerance in kidney diseases: physiological contributors and therapeutic strategies

Exertional fatigue, defined as the overwhelming and debilitating sense of sustained exhaustion that impacts the ability to perform activities of daily living, is highly prevalent in chronic kidney disease (CKD) and end-stage renal disease (ESRD). Subjective reports of exertional fatigue are paralleled by objective measurements of exercise intolerance throughout the spectrum of the disease. The prevalence of exercise intolerance is clinically noteworthy, as it leads to increased frailty, worsened quality of life, and an increased risk of mortality. The physiological underpinnings of exercise intolerance are multifaceted and still not fully understood. This review aims to provide a comprehensive outline of the potential physiological contributors, both central and peripheral, to kidney disease-related exercise intolerance and highlight current and prospective interventions to target this symptom. In this review, the CKD-related metabolic derangements, cardiac and pulmonary dysfunction, altered physiological responses to oxygen consumption, vascular derangements, and sarcopenia are discussed in the context of exercise intolerance. Lifestyle interventions to improve exertional fatigue, such as aerobic and resistance exercise training, are discussed, and the lack of dietary interventions to improve exercise tolerance is highlighted. Current and prospective pharmaceutical and nutraceutical strategies to improve exertional fatigue are also broached. An extensive understanding of the pathophysiological mechanisms of exercise intolerance will allow for the development of more targeted therapeutic approached to improve exertional fatigue and health-related quality of life in CKD and ESRD.

Intradialytic Nutrition and Hemodialysis Prescriptions: A Personalized Stepwise Approach

Dialysis and nutrition are two sides of the same coin—dialysis depurates metabolic waste that is typically produced by food intake. Hence, dietetic restrictions are commonly imposed in order to limit potassium and phosphate and avoid fluid overload. Conversely, malnutrition is a major challenge and, albeit to differing degrees, all nutritional markers are associated with survival. Dialysis-related malnutrition has a multifactorial origin related to uremic syndrome and comorbidities but also to dialysis treatment. Both an insufficient dialysis dose and excessive removal are contributing factors. It is thus not surprising that dialysis alone, without proper nutritional management, often fails to be effective in combatting malnutrition. While composite indexes can be used to identify patients with poor prognosis, none is fully satisfactory, and the definitions of malnutrition and protein energy wasting are still controversial. Furthermore, most nutritional markers and interventions were assessed in hemodialysis patients, while hemodiafiltration and peritoneal dialysis have been less extensively studied. The significant loss of albumin in these two dialysis modalities makes it extremely difficult to interpret common markers and scores. Despite these problems, hemodialysis sessions represent a valuable opportunity to monitor nutritional status and prescribe nutritional interventions, and several approaches have been tried. In this concept paper, we review the current evidence on intradialytic nutrition and propose an algorithm for adapting nutritional interventions to individual patients.