Effects of Exercise Training on Noninvasive Cardiac Measures in Patients Undergoing Long-term Hemodialysis: A Randomized Controlled Trial

The role of exercise training on cardiovascular risk factors and heart disease in patients with chronic kidney disease G3-G5 and G5D: a Clinical Consensus Statement of the European Association of Preventive Cardiology of the ESC and the European Association of Rehabilitation in Chronic Kidney Disease

Cardiovascular (CV) morbidity and mortality is high in patients with chronic kidney disease (CKD). Most patients reveal a high prevalence of CV risk factors such as diabetes or arterial hypertension and many have manifest cardiovascular disease (CVD), such as coronary artery disease and chronic heart failure with an increased risk of clinical events including sudden cardiac death. Diabetes mellitus and hypertension contribute to the development of CKD and the prevalence of CKD is in the range of 20-65% in diabetic and 30-50% in hypertensive patients. Therefore, prevention and optimal treatment of CV risk factors and comorbidities are key strategies to reduce CV risk and improve survival in CKD. Beyond common CV risk factors, patients with CKD are often physically inactive and have low physical function leading to subsequent frailty with muscle fatigue and weakness, sarcopenia and increased risk of falling. Consequently, the economic health burden of CKD is high, requiring feasible strategies to counteract this vicious cycle. Regular physical activity and exercise training (ET) have been shown to be effective in improving risk factors, reducing CVD and reducing frailty and falls. Nonetheless, combining ET and a healthy lifestyle with pharmacological treatment is not frequently applied in clinical practice. For that reason, this Clinical Consensus Statement reviews the current literature and provides evidence-based data regarding the role of ET in reducing CV and overall burden in patients with CKD. The aim is to increase awareness among cardiologists, nephrologists, and healthcare professionals of the potential of exercise therapy in order to encourage implementation of ET in clinical practice, eventually reducing CV risk and disease, as well as reducing frailty in patients with CKD G3-G5D.

Quantifying the dose-response relationship between exercise and health-related quality of life in patients undergoing haemodialysis: A meta-analysis

Objective

This meta-analysis aims to explore the dose-response relationship of aerobic exercise or aerobic combined resistance exercise on cardiopulmonary function in maintenance hemodialysis（MHD）, with the goal of aiding in the formulation of precise exercise prescriptions.

Methods

A literature search up to August 18, 2023, was conducted in databases including Web of Science, among others, focusing on the effects of exercise interventions on cardiopulmonary function in hemodialysis patients.Two researchers independently conducted literature screening, data extraction, and an assessment of study methodology quality. A dose-response meta-analysis was carried out using a one-stage cubic spline mixed-effects model, followed by stratified analyses based on intervention period, intervention method, and exercise environment.

Results

A nonlinear dose-response relationship was observed between exercise and 6-minute walk test (6WMT) as well as peak oxygen uptake (VO2Peak) in hemodialysis patients. The optimal exercise dose for the 6WMT across the full exposure range was 922 METs-min/week, with VO2Peak increasing with the dose. The effects were influenced by the type of exercise, intervention period, and exercise environment. An exercise dose of 500 METs-min/week and 619 METs-min/week was found sufficient to achieve the minimal clinically important differences (MCID) for 6WMT and VO2Peak, respectively.

Conclusion

There is a significant association between the dose of exercise and its effects. With appropriate adjustment of variables, even low-dose exercise can lead to clinically significant improvements in cardiopulmonary function.

Effect of Intradialytic Exercise on Cardiovascular Outcomes in Maintenance Hemodialysis: A Systematic Review and Meta-Analysis

Key Points

Individuals receiving hemodialysis have high rates of cardiovascular disease not explained by traditional cardiovascular risk factors. Intradialytic exercise improves cardiovascular outcomes, including arterial resistance, BP, and heart rate variability. Clinicians should consider including intradialytic aerobic exercise programs in hemodialysis care to supplement broader treatment plans.

Background

Cardiovascular disease is the leading cause of death among people with kidney failure on hemodialysis, for whom improving cardiovascular health is a research priority. Intradialytic myocardial stunning is common and associated with adverse cardiovascular events. Intradialytic exercise may mitigate intradialytic myocardial stunning and improve cardiovascular structure and function. This systematic review investigated the effect of intradialytic exercise on cardiovascular outcomes in adults undergoing maintenance hemodialysis (PROSPERO CRD42018103118).

Methods

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically searched MEDLINE, Embase, Cochrane CENTRAL, SportDiscus, and PEDro databases from 1960 until June 2022, for randomized and nonrandomized studies investigating the effect of intradialytic exercise programs on objective cardiovascular outcomes, prespecified as primary or secondary outcomes. The primary outcome was arterial resistance.

Results

Of 10,837 references identified, 32 met eligibility criteria. These studies investigated the effect of intradialytic exercise on arterial resistance (eight studies), BP (20 studies), myocardial structure and function (seven studies), endothelial function (two studies), sympathetic overactivity (nine studies), biomarkers of cardiac injury (three studies), and cardiovascular hospitalization and mortality (two studies). Most studies used aerobic exercise as the intervention and usual care (no exercise) controls. Meta-analysis of intradialytic exercise versus usual care resulted in a statistically significant reduction in arterial resistance measured by pulse wave velocity with mean difference −1.63 m/s (95% confidence interval, −2.51 to −0.75). Meta-analyses for diastolic BP, left ventricular ejection fraction, and low-frequency/high-frequency ratio measure of heart rate variability also showed statistically significant improvements with exercise. There was no significant difference in change in systolic BP, augmentation index, and left ventricular mass index between groups.

Conclusions

Intradialytic exercise programming resulted in a clinically meaningful improvement to pulse wave velocity, a component of arterial resistance. Improvements in several physiologic measures of cardiovascular health, including diastolic BP, left ventricular ejection fraction, and heart rate variability measured by the low-frequency/high-frequency ratio were also observed. The effects of intradialytic exercise on major adverse cardiovascular events remains uncertain.

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.

Combined aerobic and resistance exercise in maintenance hemodialysis patients: A meta-analysis

Exercise brings many benefits to patients undergoing maintenance hemodialysis (MHD), but the effect of combined aerobic and resistance exercise remains unclear. English and Chinese databases (PubMed, Cochrane Library, Embase, Web of Science, CNKI, VIP, Wan Fang, and CBM) were searched from inception to January 2023 to retrieve qualified randomized controlled trials. The literature selection, data extraction, and risk of bias assessment of included studies were conducted independently by two reviewers. Meta-analysis was performed using RevMan 5.3 software. A total of 23 studies with 1214 participants were included, and 17 of the interventions were conducted during dialysis. Results showed that combined aerobic and resistance exercise (CARE) improved the peak oxygen uptake, six-minute walking test, 60 s sit-to-stand test (STS), 30 s STS, dialysis adequacy, five (out of eight) domains and physical component summary of health-related quality of life (HRQOL) measured by the Medical Outcomes Study Short Form-36, blood pressure, and hemoglobin for MHD patients compared with usual care. No significant changes were found in the mental component summary of HRQOL, C-reactive protein, creatinine, potassium, sodium, calcium, and phosphate. Subgroup analysis showed that intradialytic CARE ameliorated more outcomes, except for handgrip strength and hemoglobin, than non-intradialytic ones. CARE is an effective way to improve physical function, aerobic capacity, dialysis adequacy, and HRQOL for MHD patients. Strategies should be implemented by clinicians and policymakers to motivate patients to do more exercise. Well-designed clinical trials are warranted to explore the effectiveness of non-intradialytic CARE.

The Contribution of Muscle Innate Immunity to Uremic Cachexia

Protein energy wasting (PEW) is a common complication both in chronic kidney disease (CKD) and end-stage kidney disease (ESKD). Of note, PEW is one of the stronger predictors of morbidity and mortality in this patient population. The pathogenesis of PEW involves several mechanisms, including anorexia, insulin resistance, acidosis and low-grade inflammation. In addition, "sterile" muscle inflammation contributes to PEW at an advanced CKD stage. Both immune and resident muscle cells can activate innate immunity; thus, they have critical roles in triggering "sterile" tissue inflammation. Toll-like receptor 4 (TLR4) can detect endogenous danger-associated molecular patterns generated or retained in blood in uremia and induce a sterile muscle inflammatory response via NF-κB in myocytes. In addition, TLR4, though the activation of the NLRP3 inflammasome, links the sensing of metabolic uremic stress in muscle to the activation of pro-inflammatory cascades, which lead to the production of IL-1β and IL-18. Finally, uremia-induced accelerated cell senescence is associated with a secretory phenotype that favors fibrosis in muscle. Targeting these innate immune pathways could lead to novel therapies for CKD-related PEW.

Estimation of pulmonary artery systolic pressure in hemodialysis patients and its association with cardiorespiratory fitness and pulmonary function

PURPOSE

To evaluate the estimated pulmonary arterial systolic pressure (PASP) through transthoracic echocardiography in hemodialysis (HD) patients and associate it with cardiorespiratory fitness and pulmonary function.

METHODS

This study was a cross-sectional analysis of HD patients that performed evaluations of cardiac function, cardiorespiratory fitness, and pulmonary function, through transthoracic echocardiography, cardiopulmonary exercise test, spirometry, and manovacuometry, respectively. All patients underwent the evaluations on a non-dialysis day.

RESULTS

Thirty-five HD patients were evaluated and separated according to the presence of probable pulmonary hypertension (PH) (estimated PASP ≥ 35 mmHg) or not (estimated PASP < 35 mmHg). Those HD patients with probable PH had the worst cardiorespiratory fitness, evaluated by the peak oxygen consumption (VO_2peak) (17.11 ± 4.40 versus 12.90 ± 2.73 mL/kg/min; p = 0.011), and pulmonary function, evaluated by absolute and predicted of forced vital capacity (FVC) (85.52 ± 12.29 versus 71.38 ± 11.63%; p = 0.005) and absolute and predicted of forced expiratory volume in the first second (FEV₁) (83.37 ± 14.98 versus 69.21 ± 13.48%; p = 0.017). The secondary analysis showed that estimated PASP was correlated with VO_2peak (r = - 0.508; p = 0.002), FVC (r = - 0.450; p = 0.007), and FEV₁ (r = - 0.361; p = 0.033). Moreover, the adjusted odds ratio by HD vintage, dry weight and gender showed that increments in VO_2peak (OR 1.62; CI 95% 1.04-2.54; p = 0.034), FVC (OR 39.67; CI 95% 1.74-902.80; p = 0.021), and FEV₁ (OR 39.54; CI 95% 1.89-826.99; p = 0.018) were associated with 1-fold and 39-fold higher chance, respectively, for not having PH. However, all these associations were lost when age was included in the analysis.

CONCLUSIONS

The HD patients with probable PH had the worst cardiorespiratory fitness and pulmonary function. Exploratory analyses showed that greater cardiopulmonary fitness was associated with better cardiac function. Moreover, increments in cardiorespiratory fitness and pulmonary function may increase the chance of not having PH.

Effects of Home-Based Exercise Training on Cardiac Autonomic Neuropathy and Metabolic Profile in Diabetic Hemodialysis Patients

Background: This study aimed to investigate the effects of a home-based exercise training program on Cardiac Autonomic Neuropathy (CAN) and metabolic profile in Diabetic Kidney Disease (DKD) patients undergoing maintenance hemodialysis (HD). Method: Twenty-eight DKD patients undergoing hemodialysis were randomly assigned into two groups. The exercise (EX) group followed a 6-month combined exercise training program at home, while the control (CO) group remained untrained. All participants at baseline and the end of the study underwent cardiopulmonary exercise testing (CPET), biochemical tests for glucose and lipid profile, and 24-h electrocardiographic monitoring for heart rate variability (HRV) analysis and heart rate turbulence (HRT). Results: At the end of the study, compared to the CO, the EX group showed a significant increase in serum high-density lipoprotein (HDL) by 27.7% (p = 0.01), peak oxygen uptake (VO2peak) by 9.3% (p < 0.05), the standard deviation of R-R intervals (SDNN) by 34.3% (p = 0.03), percentage of successive RR intervals higher than 50ms (pNN50) by 51.1% (p = 0.02), turbulence slope (TS) index by 18.4% (p = 0.01), and decrease in (glycated hemoglobin) HbA1c by 12.5% (p = 0.04) and low-frequency power LF (ms2) by 29.7% (p = 0.01). Linear regression analysis after training showed that VO2peak was correlated with SDNN (r = 0.55, p = 0.03) and HF (r = 0.72, p = 0.02). Multiple regression analysis indicated that the improvement of sympathovagal balance and aerobic capacity depended on patients’ participation in exercise training. Conclusion: In conclusion, a 6-month home-based mixed-type exercise program can improve cardiac autonomic function and metabolic profile in DKD patients on HD.

Correlation between acylcarnitine/free carnitine ratio and cardiopulmonary exercise test parameters in patients with incident dialysis

Objective: Diminished physical capacity is common and progressive in patients undergoing dialysis, who are also prone to deficiency in carnitine, which plays a pivotal role in maintaining skeletal muscle and cardiac function. The present study aimed to evaluate the association of carnitine profile with exercise parameters in patients with incident dialysis. Design and Methods: This was a single-center cross-sectional study including 87 consecutive patients aged 20-90 years who were initiated on dialysis in Keio University Hospital between December 2019 and December 2022 and fulfilled the eligibility criteria. Exercise parameters were evaluated via cardiopulmonary testing (CPX) using the electronically braked STRENGTH ERGO 8 ergometer, whereas the carnitine profile was assessed by determining serum free carnitine (FC), acylcarnitine (AC) levels and AC/FC ratio. Results: The mean cohort age was 62.1 ± 15.2 years, with male and hemodialysis predominance (70% and 73%, respectively). AC/FC was 0.46 ± 0.15, and CPX revealed peak oxygen consumption (VO₂) of 13.9 ± 3.7 (mL/kg/min) with percent-predicted peak VO₂ of 53.6% ± 14.7% and minute ventilation (VE)/carbon dioxide output (VCO₂) slope of 35.1 ± 8.0. Fully-adjusted multivariate linear regression analysis showed that AC/FC was significantly associated with decreased peak VO₂ (β, -5.43 [95% confidence interval (CI), -10.15 to -0.70]) and percent-predicted peak VO₂ (β, -19.98 [95% CI, -38.43 to -1.52]) and with increased VE/VCO₂ slope (β, 13.76 [95% CI, 3.78-23.75]); FC and AC did not exhibit similar associations with these parameters. Moreover, only AC/FC was associated with a decreased peak work rate (WR), percent-predicted WR, anaerobic threshold, delta VO₂/delta WR, and chronotropic index. Conclusion: In patients on incident dialysis, exercise parameters, including those related to both skeletal muscle and cardiac function, were strongly associated with AC/FC, a marker of carnitine deficiency indicating altered fatty acid metabolism. Further studies are warranted to determine whether carnitine supplementation can improve exercise capacity in patients on incident dialysis.

Comparative efficacy of exercise modalities for cardiopulmonary function in hemodialysis patients: A systematic review and network meta-analysis

Background

To provide reliable evidence to exercise rehabilitation therapists and clinicians, we compared and analyzed the effects of different exercise modalities on cardiopulmonary function in hemodialysis patients using Bayesian network meta-analysis.

Methods

PubMed, OVID, Web of Science, Cochrane Library, Embase, Scopus, CINAHL, SPORT Discus, SinoMed, CNKI, Wanfang, and VIP were searched from inception to July 20, 2022. We included randomized controlled trials comparing 12 exercise modalities to improve cardiorespiratory fitness in hemodialysis patients. All statistical analysis was performed using STATA and R.

Result

A total of 82 randomized controlled trials involving 4146 maintenance hemodialysis patients were included in this study. The pair-wise meta-analysis showed that all exercise modalities had a positive effect on all indicators of cardiorespiratory capacity. The network meta-analysis demonstrated that Blood flow restriction training (BFRT), Cycle exercise (CE), Inspiratory muscle training (IMT), Combined aerobic and resistance training (CT), and Aerobic training (AT) were significantly better than usual care for 6-min walkability; Medium intensity continuous training (MICT), CT, CE, and AT were considerably better than usual care for VO₂Peak; body and mind training (MBT) and CT significantly improved SBP compared to usual care; and only MBT was significantly better than usual care for DBP. Both the two-dimensional plot and the radar plot demonstrated that CT had the best combined-effect on each index of cardiorespiratory fitness. Subgroup and sensitivity analyses demonstrated the robustness of the results. The evidence was mainly "low" to "very low" for this network meta-analysis.

Conclusion

There is no one exercise that can achieve the best effect on all of the outcomes. The benefits of MBT in decreasing arterial blood pressure are unsurpassed by other exercise methods. The intervention effect of the CT is better and more stable. Electrical muscle stimulation training (MEST) can be employed in individuals who do not wish to exercise actively but may cause an increase in blood pressure. On the basis of the characteristics of different exercise types, guidelines developers, clinicians, and patients may employ them appropriately.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails.

Cardiopulmonary exercise testing in patients with end-stage kidney disease: principles, methodology and clinical applications of the optimal tool for exercise tolerance evaluation

Chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), is associated with an increased risk for cardiovascular events and all-cause mortality. Exercise intolerance as well as reduced cardiovascular reserve is extremely common in patients with CKD. Cardiopulmonary exercise testing (CPET) is a non-invasive, dynamic technique that provides an integrative evaluation of cardiovascular, pulmonary, neuropsychological and metabolic function during maximal or submaximal exercise, allowing the evaluation of functional reserves of these systems. This assessment is based on the principle that system failure typically occurs when the system is under stress and thus CPET is currently considered to be the gold standard for identifying exercise limitation and differentiating its causes. It has been widely used in several medical fields for risk stratification, clinical evaluation and other applications, but its use in everyday practice for CKD patients is scarce. This article describes the basic principles and methodology of CPET and provides an overview of important studies that utilized CPET in patients with ESKD, in an effort to increase awareness of CPET capabilities among practicing nephrologists.

Effects of a Combined Intradialytic Exercise Training Program and Music on Cardiac Autonomic Nervous System Activity in Hemodialysis Patients

This study aimed to examine the effect of an intradialytic exercise program in combination with music on heart rate variability (HRV) indices and functional capacity in patients on maintenance hemodialysis (HD). Methods: Forty HD patients were randomized to four training groups for six months: the combined music and exercise group (Group A), the exercise group (Group B), the music group (Group C), and the control group (Group D). At baseline and after 6 months, all participants underwent both short- (for 30 min) and long- (for 24 h) term measurements of HRV and functional capacity assessment with a 6 min walking test (6MWT). Patients of groups A and C listened to preferred music. Results: Long-term HRV analysis showed that standard deviation of all normal-to-normal RR intervals (SDNN) and the square root of the mean squared differences of successive RR intervals (rMSSD) were significantly higher at the end of the study in groups A (by 13.2% and 47.3%), B (by 15.1% and 50%), and C (by 9.0% and 30.1%), compared to group D (p < 0.05). Values of rMSSD and percentage of RR intervals differing by more than 50 ms from the preceding RR interval (pNN50) were elevated in groups A (by 35.6% and 142.9%), B (by 36.1% and 75%), and C (by 15.2% and 28.6%), compared to baseline measurements (p < 0.05). Also, pNN50 was increased in group A compared to groups B (by 21.4%), C (by 88.9%), and D (by 142.9%) (p < 0.05). Similar results were noted by short-term HRV analysis. Functional capacity was improved at the end of the 6-month study in groups A (by 20.3% and 25.7%) and B (by 15.8% and 21.1%) compared to groups C and D (p < 0.05). Conclusions: Intradialytic exercise combined with music-listening can improve the functional capacity and cardiac autonomic nervous system activity in hemodialysis patients.

Initiation of Dialysis Is Associated With Impaired Cardiovascular Functional Capacity

Background The transition to dialysis period carries a substantial increased cardiovascular risk in patients with chronic kidney disease. Despite this, alterations in cardiovascular functional capacity during this transition are largely unknown. The present study therefore sought to assess ventilatory exercise response measures in patients within 1 year of initiating dialysis. Methods and Results We conducted a cross-sectional study of 241 patients with chronic kidney disease stage 5 from the CAPER (Cardiopulmonary Exercise Testing in Renal Failure) study and from the intradialytic low-frequency electrical muscle stimulation pilot randomized controlled trial cohorts. Patients underwent cardiopulmonary exercise testing and echocardiography. Of the 241 patients (age, 48.9 [15.0] years; 154 [63.9%] men), 42 were predialytic (mean estimated glomerular filtration rate, 14 mL·min-1·1.73 m-2), 54 had a dialysis vintage ≤12 months, and 145 had a dialysis vintage >12 months. Dialysis vintage ≤12 months exhibited a significantly impaired cardiovascular functional capacity, as assessed by oxygen uptake at peak exercise (18.7 [5.8] mL·min-1·kg-1) compared with predialysis (22.7 [5.2] mL·min-1·kg-1; P<0.001). Dialysis vintage ≤12 months also exhibited reduced peak workload, impaired peak heart rate, reduced circulatory power, and increased left ventricular mass index (P<0.05 for all) compared with predialysis. After excluding those with prior kidney transplant, dialysis vintage >12 months exhibited a lower oxygen uptake at peak exercise (17.0 [4.9] mL·min-1·kg-1) compared with dialysis vintage ≤12 months (18.9 [5.9] mL·min-1·kg-1; P=0.033). Conclusions Initiating dialysis is associated with a significant impairment in oxygen uptake at peak exercise and overall decrements in ventilatory and hemodynamic exercise responses that predispose patients to functional dependence. The magnitude of these changes is comparable to the differences between low-risk New York Heart Association class I and higher-risk New York Heart Association class II to IV heart failure.

Using the Intelligent System to Improve the Delivered Adequacy of Dialysis by Preventing Intradialytic Complications

Acute kidney failure patients while detoxificated by hemodialysis (HD) mostly or continuously faced regular problems such as low blood pressure (hypotension), muscle cramps, nausea, or vomiting. Higher intradialytic symptom leads to low-quality HD treatment. Although more known therapeutic interventions are used to relieve the HD side effects, this study was designed to investigate how intelligent systems can make highly beneficial alterations in dialysis facilities and equipment to ease intradialytic complications and help the staff deliver high-quality treatment. A search was performed among relevant research articles based on nonpharmacological intervention methods considered to prevent adverse effects of renal replacement therapy until 2020 in the PubMed databases using the terms “intradialytic complications,” “intradialytic complication interventions,” “nonpharmacological interventions,” “intradialytic exercises,” and “adequacy calculation methods.” Studies included the prevalence of intradialytic complications, different strategies with the aim of preventing complications, the outcome of intradialytic exercises on dialysis symptoms, and dialysis dose calculation methods. The results showed the incidence of hypotension varying between 5% and 30%, fatigue, muscular cramps, and vomiting as the most common complications during dialysis, which greatly affect the outcome of HD sessions. To prevent hypotension, ultrafiltration profiling, sodium modeling, low dialysate temperature, and changing the position to Trendelenburg are some strategies. Urea reduction ratio (URR), formal urea kinetic modeling (FUKM), formal single-pool urea kinetics, and online clearance monitoring (OCM) are methods for calculating the delivered dose of dialysis in which OCM is a low-cost and accessible way to monitor regularly the quality of dialysis delivered. Integration of the chair and HD machine which is in direct contact with the patient provides an intelligent system that improves the management of the dialysis session to enhance the quality of healthcare service.

Physical Exercise Affects Quality of Life and Cardiac Autonomic Modulation in Patients With Chronic Kidney Failure Submitted to Hemodialysis: A Randomized Clinical Trial

Performing physical exercise during hemodialysis has been debated regarding safety and efficacy for improving life quality for patients with chronic kidney disease (CKD). Thus, we explored the influence of physical exercise during hemodialysis on both autonomic modulation of heart rate and quality of life for patients with CKF in a randomized clinical trial. We randomly allocated participants requiring hemodialysis to an experimental exercise group (EG) and a control no-exercise group (CG) and assessed their quality of life with the Kidney Disease Quality of Life Short Form—KDQOL-SF™ 1.3 and with Polar RS800CX to monitor their heart rate variability (HRV) before and three months after the end of the exercise intervention. EG participants reported a significant increase in their quality of life ( p = .05, physical function, physical aspects, pain, emotional well-being, emotional function; p = .03, energy and fatigue) and showed HRV improvement ( p = .05, RMSSD, SDNN, and SD2; p = .004, SD1) after three months of exercise. Thus, we recommend supervised physical exercise during hemodialysis for carefully selected patients.

Effect of an aerobic and strength exercise combined program on oxidative stress and inflammatory biomarkers in patients undergoing hemodialysis: a single blind randomized controlled trial

BACKGROUND

Chronic kidney disease patients on hemodialysis treatment are characterized by increased levels of inflammatory markers and oxidative stress, in addition to a significant deterioration in physical function. The benefits of physical exercise on the functional capacity of this patients are well known; however, it can also improve the endogenous antioxidant defense system and the inflammatory state, but still very few studies have been carried out. This is the first study to analyze the effect of a 4-month exercise program with combined aerobic and strength training in patients undergoing hemodialysis, under two modalities.

METHODS

Seventy-one patients undergoing hemodialysis were enrolled and randomized in two groups, one of them performing an intra-dialysis exercise program (n = 36), and the other carrying out a home-based exercise program (n = 35). Serum levels of oxidative stress and inflammation biomarkers were determined before and after the intervention.

RESULTS

IL-6 plasma levels showed a significant decrease in the intra-dialysis group after exercise (42.61 ± 9.21 to 26.40 ± 7.84, p = 0.03), while CRP levels decreased significantly in the home-based group (16.12 ± 24.18 to 8.50 ± 11.28, p = 0.03). MCP-1, TNF-α, ICAM-1 and the oxidative stress markers MDA, GSH and GSSG, did not undergo significant changes after the intervention.

CONCLUSION

Four months of combined strength and aerobic endurance exercise improve the inflammatory status of hemodialysis patients by significantly reducing IL-6 levels in those subjects who perform intra-dialysis exercise and CRP levels in those who do it at home.

Exercise training for adults undergoing maintenance dialysis

BACKGROUND

Dialysis treatments weigh heavily on patients' physical and psychosocial health. Multiple studies have assessed the potential for exercise training to improve outcomes in adults undergoing dialysis. However, uncertainties exist in its relevance and sustainable benefits for patient-important outcomes. This is an update of a review first published in 2011.

OBJECTIVES

To assess the benefits and safety of regular structured exercise training in adults undergoing dialysis on patient-important outcomes including death, cardiovascular events, fatigue, functional capacity, pain, and depression. We also aimed to define the optimal prescription of exercise in adults undergoing dialysis.

SEARCH METHODS

In this update, we conducted a systematic search of the Cochrane Kidney and Transplant Register of Studies up to 23 December 2020. The Register includes studies identified from CENTRAL, MEDLINE, EMBASE, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov as well as kidney-related journals and the proceedings of major kidney conferences.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of any structured exercise programs of eight weeks or more in adults undergoing maintenance dialysis compared to no exercise or sham exercise.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results for eligibility, extracted the data and assessed the risk of bias using the Cochrane risk of bias tool. Whenever appropriate, we performed random-effects meta-analyses of the mean difference in outcomes. The primary outcomes were death (any cause), cardiovascular events and fatigue. Secondary outcomes were health-related quality of life (HRQoL), depression, pain, functional capacity, blood pressure, adherence to the exercise program, and intervention-related adverse events.

MAIN RESULTS

We identified 89 studies involving 4291 randomised participants, of which 77 studies (3846 participants) contributed to the meta-analyses. Seven studies included adults undergoing peritoneal dialysis. Fifty-six studies reported aerobic exercise interventions, 21 resistance exercise interventions and 19 combined aerobic and resistance training within the same study arm. The interventions lasted from eight weeks to two years and most often took place thrice weekly during dialysis treatments. A single study reported death and no study reported long-term cardiovascular events. Five studies directly assessed fatigue, 46 reported HRQoL and 16 reported fatigue or pain through their assessment of HRQoL. Thirty-five studies assessed functional capacity, and 21 reported resting peripheral blood pressure. Twelve studies reported adherence to exercise sessions, and nine reported exercise-related adverse events. Overall, the quality of the included studies was low and blinding of the participants was generally not feasible due to the nature of the intervention. Exercise had uncertain effects on death, cardiovascular events, and the mental component of HRQoL due to the very low certainty of evidence. Compared with sham or no exercise, exercise training for two to 12 months may improve fatigue in adults undergoing dialysis, however, a meta-analysis could not be conducted. Any exercise training for two to 12 months may improve the physical component of HRQoL (17 studies, 656 participants: MD 4.12, 95% CI 1.88 to 6.37 points on 100 points-scale; I² = 49%; low certainty evidence). Any exercise training for two to 12 months probably improves depressive symptoms (10 studies, 441 participants: SMD -0.65, 95% CI -1.07 to -0.22; I² = 77%; moderate certainty evidence) and the magnitude of the effect may be greater when maintaining the exercise beyond four months (6 studies, 311 participants: SMD -0.30, 95% CI 0.14 to -0.74; I² = 71%). Any exercise training for three to 12 months may improve pain (15 studies, 872 participants: MD 5.28 95% CI -0.12 to 10.69 points on 100 points-scale; I² = 63%: low certainty evidence) however, the 95% CI indicates that exercise training may make little or no difference in the level of pain. Any exercise training for two to six months probably improves functional capacity as it increased the distance reached during six minutes of walking (19 studies, 827 participants: MD 49.91 metres, 95% CI 37.22 to 62.59; I² = 34%; moderate certainty evidence) and the number of sit-to-stand cycles performed in 30 seconds (MD 2.33 cycles, 95% CI 1.71 to 2.96; moderate certainty evidence). There was insufficient evidence to assess the safety of exercise training for adults undergoing maintenance dialysis. The results were similar for aerobic exercise, resistance exercise, and a combination of both aerobic and resistance exercise.

AUTHORS' CONCLUSIONS

It is uncertain whether exercise training improves death, cardiovascular events, or the mental component of HRQoL in adults undergoing maintenance dialysis. Exercise training probably improves depressive symptoms, particularly when the intervention is maintained beyond four months. Exercise training is also likely to improve functional capacity. Low certainty evidence suggested that exercise training may improve fatigue, the physical component of quality of life, and pain. The safety of exercise training for adults undergoing dialysis remains uncertain.

Analysis of Compliance with Time under Tension and Force during Strengthening Exercises with Elastic Bands

Quantifying training variables of a physical exercise modality is essential for an appropriate dosage. In training with elastic bands, time under tension (TUT) and force represent the duration and intensity of this force-training modality. The aims of this study were to evaluate the degree of compliance to TUT prescription for three different scenarios of two exercises and the comparison of the force values obtained versus the estimate values. A total of 29 healthy volunteers were evaluated in a clinical environment under controlled conditions in 3 different scenarios (different velocities or ROMs) of both shoulder abduction and knee extension in 2 sets of 10 repetitions per scenario within a single session. Concentric and isometric phases showed a higher degree of compliance for their TUTs than the eccentric phase TUTs for all scenarios of both exercises, whereas the degree of compliance was higher for the total TUT than for the phases’ TUTs. Additionally, the eccentric phase showed a general tendency to develop for longer time periods than prescribed, whilst the fast scenario showed a higher degree of compliance for isometric phase TUTs and total TUTs than the extant two scenarios in both exercises. On the other hand, the force of the elastic bands tends to be overestimated according to the estimates of the manufacturers. These findings, both those related to the degree of compliance with TUTs and the force analysis, can be used by physiotherapists and other exercise professionals as a reference to achieve a good dosage of routine exercises with elastic bands.

Intradialytic exercise improves left ventricular mass in hemodialysis patients

Graham-Brown et al. report the results of a randomized controlled trial in patients on hemodialysis in which a 6-month intradialytic cycling program led to significant reduction in left ventricular mass as compared to the control group. However, there was no significant effect on physical function, physical activity or health-related quality of life.

A single bout of hybrid intradialytic exercise did not affect left-ventricular function in exercise-naïve dialysis patients: a randomized, cross-over trial

INTRODUCTION

Cardiovascular diseases are the leading cause of mortality in end-stage renal disease (ESRD) patients, especially those receiving hemodialysis (HD) therapy. HD has many side effects that are related to patients' hearts, such as recurrent myocardial ischemia and global or segmental left-ventricular dysfunction, which is associated with intradialytic hypotension, long-term loss of systolic function, and high incidence of cardiovascular events and death. Systematic exercise training has a beneficial effect on measures of cardiovascular fitness and reducing cardiovascular risk factors in ESRD. Whether there is an acute benefit of exercise during HD on left-ventricular function is not well known. The current study aimed to investigate whether a single bout of hybrid (aerobic and resistance) intradialytic exercise could affect left-ventricular function during HD sessions.

METHODS

Twenty-one exercise naïve and clinically stable HD patients participated in the study. All participants completed two different HD trials on two different days, separated by 1 week: (1) standard HD and (2) HD including a single bout of hybrid intradialytic exercise. Hybrid intradialytic training included the usual intradialytic cycling followed by resistance training using elastic bands and dumbbells. Echocardiographic assessment of left-ventricular function was completed before HD, half an hour before the end of HD, and 30 min after the end of HD.

RESULTS

Cohort data for left-ventricular function indices were not different between trials and did not change across time in either the standard HD or HD plus exercise trial. Cohort data for the change in ejection fraction from baseline to during HD did mask considerable inter-individual variability (HD - 0 ± 15; HD plus exercise (- 2 ± 20). Despite this, the variability was not mediated by the addition of intradialytic hybrid exercise.

CONCLUSION

A single bout of hybrid intradialytic exercise did not affect left-ventricular function during the HD therapy. It is important to determine whether chronic exercise training could beneficially affect left-ventricular function abnormalities often observed during the HD therapy.

TRIAL REGISTRATION NUMBER

The study is registered at ClinicalTrials.gov (NCT01721551) as a clinical trial.

A randomized controlled trial to investigate the effects of intra-dialytic cycling on left ventricular mass

Cardiovascular disease is the leading cause of death for patients receiving hemodialysis. Since exercise mitigates many risk factors which drive cardiovascular disease for these patients, we assessed effects of a program of intra-dialytic cycling on left ventricular mass and other prognostically relevant measures of cardiovascular disease as evaluated by cardiac MRI (the CYCLE-HD trial). This was a prospective, open-label, single-blinded cluster-randomized controlled trial powered to detect a 15g difference in left ventricular mass measured between patients undergoing a six-month program of intra-dialytic cycling (exercise group) and patients continuing usual care (control group). Pre-specified secondary outcomes included measures of myocardial fibrosis, aortic stiffness, physical functioning, quality of life and ventricular arrhythmias. Outcomes were analyzed as intention-to-treat according to a pre-specified statistical analysis plan. Initially, 130 individuals were recruited and completed baseline assessments (65 each group). Ultimately, 101 patients completed the trial protocol (50 control group and 51 exercise group). The six-month program of intra-dialytic cycling resulted in a significant reduction in left ventricular mass between groups (-11.1g; 95% confidence interval -15.79, -6.43), which remained significant on sensitivity analysis (missing data imputed) (-9.92g; 14.68, -5.16). There were significant reductions in both native T1 mapping and aortic pulse wave velocity between groups favoring the intervention. There was no increase in either ventricular ectopic beats or complex ventricular arrhythmias as a result of exercise with no significant effect on physical function or quality of life. Thus, a six-month program of intradialytic cycling reduces left ventricular mass and is safe, deliverable and well tolerated.

Effectiveness of a resistance exercise program for lower limbs in chronic renal patients on hemodialysis: A randomized controlled trial

INTRODUCTION

Physical inactivity in hemodialysis patients is associated with increased mortality. The objective of this study was evaluated the effect of an intradialytic resistance exercise program on chronic kidney disease (CKD) patients on hemodialysis.

METHODS

One hundred seven patients were included in the study. They were aged 18-60 years, of both sexes, had undergone hemodialysis treatment for at least 1 year, sedentary. Patients were randomly divided into two groups: stretching (STG) and resistance exercise (REG). Intervention programs were performed for 8 weeks, three times a week. The evaluations were performed before and after the training programs. The primary outcome was functional capacity using the 6-minute walk test (6MWT). Secondary outcomes were peripheral muscle strength, respiratory muscle strength, spirometric respiratory function, and laboratory data.

FINDINGS

Comparisons between groups revealed the following clinically relevant results in favor of REG: lower limb muscle strength (mean difference [MD] = -1.99, 95% confidence interval [CI] = -2.77 to -1.21; d = -0.53), distance walked in the 6MWT (MD = -26.27, 95% CI = -45.40 to -7.14; d = -0.46), creatinine (MD = -1.52, 95% CI = -2.49 to -0.54; d = -0.66), and calcium (MD = -0.44, 95% CI = -0.78 to -0.10; d = -0.49).

DISCUSSION

CKD patients on hemodialysis have reduced functional capacity compared to healthy sedentary individuals. In turn, this reduction appears to be associated with a lower survival rate and affects the performance of their daily living activities. Thus, resistance exercise performed in the intradialytic phase is an effective therapeutic strategy for CKD patients, mainly because it increases functional capacity and lower limb muscle strength.

Longitudinal study of physical activity with various methods in maintenance hemodialysis patients

INTRODUCTION

The purpose was to make longitudinal measurements of physical activity and study whether physical activity decreases over time in maintenance hemodialysis (MHD) patients.

METHODS

This was an observational study, where MHD patients were considered in a 12-month follow-up. Laboratory variables and physical activity were tested three times over 12-months in 124 hemodialysis patients. Physical activity was measured using the Human Activity Profile (HAP), the Stanford 7-day Physical Activity Recall Questionnaire (PAR), and walking speed. Repeated measure variance analysis was used to analyze changes of physical activity. The Bonferroni method was used to do pairwise comparisons.

FINDINGS

The proportion of decreased physical activity increased (P < 0.05). The maximal activity score (MAS), adjusted activity score (AAS), HAP dimension scores, and walking speed all decreased at the three time points studied (P < 0.001). At the same time, moderate physical activities and PAR values changed at three time points (P < 0.05). Pairwise comparisons showed that between the baseline and the 6-month follow-up, MAS, AAS, the scores of personal/household work, entertainment/social, independent exercise, leg effort, and back effort, all decreased(P < 0.05). Between the baseline and the 12-month follow-up, and between the 6-month follow-up and the 12-month follow-up, all the scores of HAP and walking speed decreased significantly (P < 0.001). Between the baseline and the 6-month follow-up, moderate physical activities and PAR values increased (P < 0.05). However, between the baseline and the 12-month follow-up, and between the 6-month follow-up and the 12-month follow-up, moderate physical activities and PAR did not change statistically.

CONCLUSION

Physical activity decreased in hemodialysis patients in the 12-month follow-up.

Low-Intensity Intradialytic Exercise Attenuates the Relative Blood Volume Drop Due to Intravascular Volume Loss during Hemodiafiltration

INTRODUCTION

Patients in hemodiafiltration (HDF) eliminate volume overload by ultrafiltration. Vascular volume loss is among the main mechanisms contributing to adverse events such as intradialytic hypotension. Here, we hypothesize that the intradialytic exercise (IDEX) is an intervention that could improve the acute response of physiological mechanisms involved during vascular volume loss. To test this hypothesis, we evaluated the hemodynamic response to mild aerobic exercise during HDF.

METHODS

Nineteen end-stage renal disease (ESRD) patients (11 women: 40 ± 10.8 years old, and 8 men: 42 ± 21 years old) receiving HDF thrice a week, with 6 months of previous physical conditioning, participated in this study. Three HDF sessions were scheduled for each patient: 1 resting in supine position, 1 resting in sitting position, and 1 doing aerobic exercise. The first 2 sessions were taken as control. The ultrafiltration rate was set to 800 mL/h in each session. The hemodynamic response was monitored through the relative blood volume (RBV), and cardiovascular variables measured noninvasively by photoplethysmography. Adequacy variables such as Kt/V and percentage reduction of urate, urea, creatinine (Cr), and phosphate were also monitored.

FINDINGS

The decrease rate of the RBV was smaller in the session with IDEX compared to the sessions with no exercise. No differences were found neither in the cardiovascular variables nor in the adequacy variables among the 3 sessions. There were no hypotension events during the session with exercise, and 8 events during the sessions without exercise (p = 0.002).

DISCUSSION

Mild exercise during HDF decreased the RBV drop and was associated with less hypotension events. The lack of differences in the hemodynamic variables suggests an adequate acute response of cardiovascular compensation variables to intradialytic hypovolemia.

Exercise training in dialysis patients: impact on cardiovascular and skeletal muscle health

Dialysis patients show a high rate of reduced functional capacity, morbidity and mortality. Cardiovascular disorders, muscle atrophy and malnutrition play an essential role among the aetiological factors. Sedentary lifestyle characterizes them and contributes to the aggravation of the disorders. On the contrary, exercise training is an important preventive and therapeutic tool both for cardiovascular problems and for the appearance of muscle atrophy in dialysis patients. Regular exercise causes both central (cardiac) and peripheral (muscular) adaptations, improving functional capacity. In particular, circulatory system clinical trials in haemodialysis (HD) patients documented that exercise has favourable effects on heart function, promotes balance on the cardiac autonomic nervous system and contributes to the management of arterial hypertension. In the muscular system, it prevents muscle atrophy or contributes significantly to its treatment. The main preventive mechanisms of the beneficial effect of exercise on the muscles constitute the inhibition of the apoptotic processes and protein degradation. Exercise training in HD patients leads to an increase of muscle fibers, mitochondria and capillaries, and the combination of regular exercise and dietary strategies is even more effective in preventing or treating muscle atrophy. Finally, an improvement in functional capacity and quality of life was found also in peritoneal dialysis patients following exercise training.

How to Overcome Anabolic Resistance in Dialysis-Treated Patients?

A current hypothesis is that dialysis-treated patients are "anabolic resistant" i. e., their muscle protein synthesis (MPS) response to anabolic stimuli is blunted, an effect which leads to muscle wasting and poor physical performance in aging and in several chronic diseases. The importance of maintaining muscle mass and MPS is often neglected in dialysis-treated patients; better than to describe mechanisms leading to energy-protein wasting, the aim of this narrative review is to suggest possible strategies to overcome anabolic resistance in this patient's category. Food intake, in particular dietary protein, and physical activity, are the two major anabolic stimuli. Unfortunately, dialysis patients are often aged and have a sedentary behavior, all conditions which per se may induce a state of "anabolic resistance." In addition, patients on dialysis are exposed to amino acid or protein deprivation during the dialysis sessions. Unfortunately, the optimal amount and formula of protein/amino acid composition in supplements to maximixe MPS is still unknown in dialysis patients. In young healthy subjects, 20 g whey protein maximally stimulate MPS. However, recent observations suggest that dialysis patients need greater amounts of proteins than healthy subjects to maximally stimulate MPS. Since unneccesary amounts of amino acids could stimulate ureagenesis, toxins and acid production, it is urgent to obtain information on the optimal dose of proteins or amino acids/ketoacids to maximize MPS in this patients' population. In the meantime, the issue of maintaining muscle mass and function in dialysis-treated CKD patients needs not to be overlooked by the kidney community.

Interventions to Preserve Cognitive Functioning Among Older Kidney Transplant Recipients

PURPOSE OF REVIEW

To summarize the research on effective interventions for preserving cognitive function and prevent cognitive decline in patients with end-stage kidney disease (ESKD) who are undergoing dialysis and/or kidney transplantation (KT).

RECENT FINDINGS

Among ESKD patients undergoing hemodialysis, exercise training has been administered through home-based and intradialytic interventions. Additionally, one pilot study identified intradialytic cognitive training, electronic brain games, as an intervention to preserve cognitive function among patients undergoing hemodialysis. Fewer studies have investigated interventions to preserver cognitive function among KT recipients. To date, the only randomized controlled trial in this population identified B-vitamin supplements as an intervention to preserve cognitive function. The evidence from these trials support a short-term benefit of cognitive and exercise training as well as B-vitamin supplementation among patients with ESKD. Future studies should: 1) replicate these findings, 2) identify interventions specific to KT candidates, and 3) investigate the synergistic impact of both cognitive and exercise training.

SUMMARY

Cognitive prehabilitation, with cognitive and/or exercise training, may be novel interventions for KT candidates that not only reduces delirium risk and long-term post-KT cognitive decline but also prevents dementia.

Uremic Sarcopenia: Clinical Evidence and Basic Experimental Approach

Sustained physical activity extends healthy life years while a lower activity due to sarcopenia can reduce them. Sarcopenia is defined as a decrease in skeletal muscle mass and strength due not only to aging, but also from a variety of debilitating chronic illnesses such as cancer and heart failure. Patients with chronic kidney disease (CKD), who tend to be cachexic and in frail health, may develop uremic sarcopenia or uremic myopathy due to an imbalance between muscle protein synthesis and catabolism. Here, we review clinical evidence indicating reduced physical activity as renal function deteriorates and explore evidence-supported therapeutic options focusing on nutrition and physical training. In addition, although sarcopenia is a clinical concept and difficult to recapitulate in basic research, several in vivo approaches have been attempted, such as rodent subtotal nephrectomy representing both renal dysfunction and muscle weakness. This review highlights molecular mechanisms and promising interventions for uremic sarcopenia that were revealed through basic research. Extensive study is still needed to cast light on the many aspects of locomotive organ impairments in CKD and explore the ways that diet and exercise therapies can improve both outcomes and quality of life at every level.

An Exercise Program for Peritoneal Dialysis Patients in the United States: A Feasibility Study

BACKGROUND

People with end-stage kidney disease receiving peritoneal dialysis (PD) are generally physically inactive and frail. Exercise studies in PD are scarce and currently there are no PD exercise programs in the United States. The primary objective of this study was to test the feasibility of a combined resistance and cardiovascular exercise program for PD patients under the care of a dedicated home dialysis center in the United States.

STUDY DESIGN

Parallel randomized controlled feasibility study.

SETTING & PARTICIPANTS

PD patients were recruited from a single center and randomly assigned to the intervention (exercise; n = 18) or control (nonexercise; n = 18) group.

INTERVENTION

The intervention group received monthly exercise physiologist consultation, exercise prescription (resistance and aerobic exercise program using exercise bands), and 4 exercise support telephone calls over 12 weeks. The control group received standard care.

OUTCOMES

The primary outcome was study feasibility as measured by eligibility rates, recruitment rates, retention rates, adherence rates, adverse events, and sustained exercise rates. Secondary outcome measures were changes in physical function (sit-to-stand test, timed-up-and-go test, and pinch-strength tests) and patient-reported outcome measures.

RESULTS

From a single center with 75 PD patients, 57 (76%) were deemed eligible, resulting in a recruitment rate of 36 (63%) patients. Participants were randomly assigned into 2 groups of 18 (1:1). 10 patients discontinued the study (5 in each arm), resulting in 26 (72%) patients, 13 in each arm, completing the study. 10 of 13 (77%) intervention patients were adherent to the exercise program. A t test analysis of covariance found a difference between the treatment groups for the timed-up-and-go test (P = 0.04) and appetite (P = 0.04). No serious adverse events caused by the exercise program were reported.

LIMITATIONS

Single center, no blinded assessors.

CONCLUSIONS

A resistance and cardiovascular exercise program appears feasible and safe for PD patients. We recommend that providers of PD therapy consider including exercise programs coordinated by exercise professionals to reduce the physical deterioration of PD patients.

FUNDING

None.

TRIAL REGISTRATION

NCT03980795.

Reduction of functional cardiovascular reserve in the stages of chronic kidney disease

SUMMARY OBJECTIVE Patients with chronic kidney disease (CKD) present reduced oxygen consumption at peak exercise (VO2 peak). No studies have evaluated objective measures of the cardiovascular reserve, besides VO2 peak and VO2 at the anaerobic threshold (VO2 AT), and compared these measures among ckd patients at different stages of the disease. METHODS Fifty-eight patients [pre-dialysis group (PD)=26, hemodialysis group (HD)=20, and post-kidney transplant group (KT)=12] were included. The following measures of cardiovascular reserve were obtained: 1) peak heart rate (HR); 2) peak systolic blood pressure (SBP); 3) VO2 peak and % predicted; 4) VO2 AT and % of predicted VO2; 5) peak circulatory power; 6) ventilatory efficiency for the production of carbon dioxide (VE/VCO2 slope); 7) oxygen uptake efficiency slope (OUES); and 8) recovery of gas exchange. RESULTS The VO2 peak and VO2 AT in the PD, HD, and KT groups were reduced to 86% and 69%, 70% and 57%, and 79% and 64% of the predicted value, respectively. Patients in the HD group had lower VO2 peak (17.5±5.9 vs. 23.2±8.2 [p-value=0.036]) and VO2 AT (14.0±5.2 vs. 18.3±4.7 [p-value=0.039]) compared to patients in the KT group. OUES was significantly lower in the HD group compared to the KT group (p-value=0.034). Age in the PD, HD, and KT groups and sedentary lifestyle in the KT group were predictors of VO2 peak. CONCLUSIONS CKD patients presented a reduction in cardiovascular reserve regardless of the stage of the disease. However, hemodialysis patients presented a greater reduction of cardiovascular reserve when compared to post-kidney transplant patients.

Exercise-Based Interventions in Hemodialysis Patients: A Systematic Review with a Meta-Analysis of Randomized Controlled Trials

There is a lack of agreement on the efficacy of different exercise interventions in hemodialysis patients. We analyzed which exercise type is the most beneficial in terms of functional fitness and inflammation. A literature search of seven databases yielded 33 studies that met the inclusion criteria. Compared with an inactive control, the intervention group showed moderate effects (ES = 0.74; 95% CI 0.35 to 1.14; p < 0.001; and ES = 0.70; 95% CI 0.39 to 1.01; p < 0.001; respectively) on functional capacity (six-minute walk test) and oxygen consumption. Small nonsignificant effects were observed for aerobic (ES = -0.36; 95% CI -0.85 to 0.13; p = 0.154) and resistance (ES = -0.44; 95% CI -1.07 to 0.19; p = 0.169) training types, whereas moderate effects were found for combined (ES = -0.69; 95% CI -1.47 to 0.10; p = 0.088) training type based on a 10-repetition sit-to-stand test. Further, large and small effects were observed for aerobic (ES = -1.21; 95% CI -1.94 to -0.49; p = 0.001) and resistance training (ES = -0.54; 95% CI -0.90 to -0.17; p = 0.004) types on C-reactive protein. Overall, the results showed the numerically largest effect sizes for combined types compared to solely aerobic or resistance training types, with the differences between training types not reaching statistical significance. There was a significant modifying impact of age, training frequency, and session duration on performance and inflammatory outcomes.

Intradialytic training in patients with end-stage renal disease: a systematic review and meta-analysis of randomized clinical trials assessing the effects of five different training interventions

OBJECTIVE

Patients with end-stage renal disease (ESRD) undergoing hemodialysis may have reduced dialysis adequacy (Kt/V), low cardiorespiratory fitness, and worse prognosis. Different types of intradialytic training (IDT) may serve as an adjunct therapy for the management of the ESRD. This systematic review and meta-analysis aimed to assess the impact of different types of IDT on clinical outcomes and functional parameters in ESRD.

METHODS

PubMed, Embase, CINAHL, Cochrane CENTRAL, Scopus, SPORTDiscus, and Google Scholar were searched for randomized clinical trials in adult patients with ESRD which compared IDT with usual care (UC), without language restrictions and published up to July 2019; a handsearch of references was also performed. Certainty of evidence was assessed using GRADE, and risk of bias in primary studies with the RoB 1.0 tool.

RESULTS

Fifty studies were included (n = 1757). Compared to UC, aerobic IDT improved Kt/V (WMD = 0.08), VO₂peak (WMD = 2.07 mL/kg/min), 6-minute walk test (6MWT) distance (64.98 m), reduced systolic blood pressure (- 10.07 mmHg) and C-reactive protein (- 3.28 mg/L). Resistance training increased 6MWT distance (68.50 m). Combined training increased VO₂peak (5.41 mL/kg/min) and reduced diastolic blood pressure (- 5.76 mmHg). Functional electrostimulation (FES) and inspiratory muscle training (IMT) improved 6MWT distance (54.14 m and 117.62 m, respectively). There was no impact on total cholesterol, interleukin-6, or hemoglobin levels. There was no difference in incidence of adverse events between the IDT and control groups. The certainty of evidence was variable according to the GRADE scale, with most outcomes rated very low certainty. The risk of bias assessment of primary studies showed unclear risk in most.

CONCLUSIONS

Aerobic, resistance, and combined training during hemodialysis, as well as FES and IMT, demonstrated to be effective for the treatment of the patient with ESRD. Our data should be interpreted in light of the unclear risk of bias of most evaluated articles and the low to very low certainty of evidence for evaluated outcomes.

PROSPERO REGISTRATION ID

CRD42017081338. DATA SHARING REPOSITORY: https://osf.io/fpj54/.

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

Patients with chronic kidney disease show poorer functional and cardiorespiratory capacity than healthy individuals, and these impairments result in sedentarism. The aim of this study was to conduct a systematic review and meta-analysis of randomized clinical trials on the effects of different intradialytic exercise protocols on cardiopulmonary capacity in chronic kidney disease patients. The primary outcome was peak oxygen consumption (VO_2peak) and the secondary outcomes were exercise duration and ventilation in the cardiopulmonary test. The quality of the evidence was evaluated using the GRADE guidelines. Seven studies with a total of 124 participants met the inclusion criteria. Compared to the non-exercise group, the exercise group improved in mean VO_2peak (MD 4.06 [IC 0.81; 7.31]). In a separate analysis according to exercise modality, aerobic exercise plus strength training performed better than aerobic exercise alone (MD 5.28 [IC 3.90; 6.66]). In the exercise group, both exercise tolerance values (MD 3.10 [IC 1.70; 4.51]) and ventilation values in the cardiopulmonary test were better than those of the control group (MD 13.10 [IC 7.12; 19.09]). Thus, intradialytic exercise protocols can improve cardiopulmonary function, exercise tolerance and ventilatory efficiency in chronic kidney disease patients.

Effects of long-term aerobic training and detraining on functional capacity and quality of life in hemodialysis patients: A pilot study

Although previous studies have shown the benefits of exercise training in hemodialysis patients, little is known about the effects of long-term of exercise program on these patients. We investigated the effects and the safety of long-term aerobic training and the effects of detraining on functional capacity and quality of life in hemodialysis patients. Ten patients were allocated to two groups: training and detraining. The training group completed at least 30 months of aerobic training, and the detraining group completed at least 20 months and then discontinued the training for at least 10 months. The outcomes were analyzed at baseline, after 3 months of aerobic training and at the 30-month follow-up. The training and detraining groups performed 37 (5.5) and 24 (3.0) months of aerobic training, respectively. The detraining group discontinued the training for 11.0 (2.0) months. After 3 months of aerobic training, six-minute walking test distance increased significantly in both groups (training group = 569 (287.8) vs 635.5 (277.0) m, p = 0.04; detraining group = 454.5 (72.3) vs 515.0 (91.8) m, p = 0.04). There was no significant difference in the six-minute walking test distance in the training group (576.5 (182.5), p > 0.05) and a significant decrease (436.2 (89.6) m, p = 0.04) in the detraining group at the follow-up compared to the third month of aerobic training. No significant difference was observed in quality of life during the study. No complications were found during the protocol of the exercise. These results suggest that long-term aerobic training is safe and can maintain functional capacity in hemodialysis patients. In contrast, detraining can result in loss of functional capacity in these patients.

Exercise and cognitive function in patients with end-stage kidney disease

In this review we summarize the research pertaining to the role of exercise in preventing cognitive decline in patients with end-stage kidney disease (ESKD). Impairment in cognitive function, especially in executive function, is common in patients with ESKD, and may worsen with maintenance dialysis as a result of retention of uremic toxins, recurrent cerebral ischemia, and high burden of inactivity. Cognitive impairment may lead to long-term adverse consequences, including dementia and death. Home-based and intradialytic exercise training (ET) are among the nonpharmacologic interventions identified to preserve cognitive function in ESKD. Additionally, cognitive training (CT) is an effective approach recently identified in this population. While short-term benefits of ET and CT on cognitive function were consistently observed in patients undergoing dialysis, more studies are needed to replicate these findings in diverse populations including kidney transplant recipients with long-term follow-up to better understand the health and quality of life consequences of these promising interventions. ET as well as CT are feasible interventions that may preserve or even improve cognitive function for patients with ESKD. Whether these interventions translate to improvements in quality of life and long-term health outcomes, including dementia prevention and better survival, are yet to be determined.

Are dialysis patients too frail to exercise?

Clinical manifestations of functional and morphological muscular abnormalities in dialysis patients are muscle weakness and low exercise capacity, possibly leading to a sedentary life style with low physical activity. Low cardiorespiratory fitness and muscle atrophy and weakness contribute to the development of frailty and affect patients' ability to physically navigate their environment. While many dialysis patients may appear too frail to participate in moderate-to-vigorous aerobic exercise training, those who can complete such programs appear to derive substantial benefit. Less vigorous aerobic exercise, resistance training, and alternative forms of exercise can also be beneficial. Most patients on dialysis are not too frail to perform resistance exercise of adequate intensity to achieve increases in muscle size and strength, therefore, frailty should not be considered a contraindication to exercise.

Home-based Aerobic Exercise and Resistance Training in Peritoneal Dialysis Patients: A Randomized Controlled Trial

Potential effects of aerobic and resistance training in peritoneal dialysis (PD) patients have been partially elucidated. We investigated effects of a home-based exercise program on physical functioning and health-related quality of life (HRQOL) in PD patients. Patients were randomly assigned to exercise (n = 24) and usual care (n = 23) groups. The exercise patients performed aerobic exercise thrice weekly and resistance training twice weekly at home for 12 weeks. The usual care patients received no specific intervention. The distance in incremental shuttle walking test significantly improved in the exercise group compared with the usual care group (P = 0.02). Among the HRQOL subscales assessed using the Kidney Disease Quality of Life-Short Form questionnaire, kidney disease component summary (P = 0.03), physical role functioning (P = 0.01), emotional role functioning (P < 0.01), and role/social component summary (P < 0.01) significantly improved in the exercise group. Moreover, serum albumin was significantly maintained in the exercise group (P = 0.03). There were no reported adverse events associated with the intervention. To our knowledge, this is the first randomized controlled trial to indicate the beneficial effects of a 12-week home-based exercise program exclusively in PD patients.

Efficacy and safety of intradialytic exercise in haemodialysis patients: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of intradialytic exercise for haemodialysis patients.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Databases, including PubMed, Embase, the Cochrane Library, China Biology Medicine and China National Knowledge Infrastructure, were screened from inception to March 2017.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) aimed at comparing the efficacy and safety of intradialytic exercise versus no exercise in adult patients on haemodialysis for at least 3 months. A minimum exercise programme period of 8 weeks.

DATA EXTRACTION

Study characteristics and study quality domains were reviewed. Studies were selected, and data extracted by two reviewers.

DATA ANALYSIS

The pooled risk ratios and mean differences (MDs) with 95% CIs for dichotomous data and continuous data were calculated, respectively.

RESULTS

A total of 27 RCTs involving 1215 subjects were analysed. Compared with no exercise, intradialytic exercise increased dialysis adequacy (Kt/V) (MD 0.07, 95% CI 0.01 to 0.12, p=0.02) and maximum volume of oxygen that the body can use during physical exertion peak oxygen consumption (MD 4.11, 95% CI 2.94 to 5.27, p<0.0001), alleviated depression standardised mean difference (-1.16, 95% CI -1.86 to -0.45, p=0.001) and improved physical component summary-short form-36 (SF-36) level (MD 7.72, 95% CI 1.93 to 13.51, p=0.009). Also, intradialytic exercise could significantly reduce systolic blood pressure (MD -4.87, 95% CI -9.20 to -0.55, p=0.03) as well as diastolic blood pressure (MD -4.11, 95% CI -6.50 to -1.72, p=0.0007). However, intradialytic exercise could not improve mental component summary-SF-36 level (MD 3.05, 95% CI -1.47 to 7.57, p=0.19). There was no difference in the incidence of adverse events between the intradialytic exercise and control groups.

CONCLUSIONS

Intradialytic exercise resulted in benefits in terms of improving haemodialysis adequacy, exercise capacity, depression and quality of life for haemodialysis.

Combined training is the most effective training modality to improve aerobic capacity and blood pressure control in people requiring haemodialysis for end-stage renal disease: systematic review and network meta-analysis

QUESTIONS

Do aerobic, resistance and combined exercise training improve aerobic capacity, arterial blood pressure and haemodialysis efficiency in people requiring haemodialysis for end-stage renal disease? Is one exercise training modality better than the others for improving these outcomes?

DESIGN

Systematic review with network meta-analysis of randomised trials.

PARTICIPANTS

Adults requiring haemodialysis for end-stage renal disease.

INTERVENTION

Aerobic training, resistance training, combined training and control (no exercise or placebo).

OUTCOME MEASURES

Aerobic capacity, arterial blood pressure at rest, and haemodialysis efficiency.

RESULTS

Thirty-three trials involving 1254 participants were included. Direct meta-analyses were conducted first. Aerobic capacity improved significantly more with aerobic training (3.35 ml/kg/min, 95% CI 1.79 to 4.91) and combined training (5.00 ml/kg/min, 95% CI 3.50 to 6.50) than with control. Only combined training significantly reduced systolic (-9 mmHg, 95% CI -13 to -4) and diastolic (-5 mmHg, 95% CI -6 to -3) blood pressure compared to control. Only aerobic training was superior to control for haemodialysis efficiency (Kt/V 0.11, 95% CI 0.02 to 0.20). However, when network meta-analysis was conducted, there were some important different findings. Both aerobic training and combined training again elicited greater improvements in aerobic capacity than control. For systolic blood pressure, combined training was superior to control. For diastolic blood pressure, combined training was superior to aerobic training and control. No modality was superior to control for haemodialysis efficiency. Combined training was ranked as the most effective treatment for aerobic capacity and arterial blood pressure.

CONCLUSION

Combined training was the most effective modality to increase aerobic capacity and blood pressure control in people who require haemodialysis. This finding helps to fill the gap created by the lack of head-to-head comparisons of different modalities of exercise in people with end-stage renal disease.

REGISTRATION

PROSPERO CRD42015020531.

Higher Physical Activity Is Associated With Less Fatigue and Insomnia Among Patients on Hemodialysis

Introduction

Patients on hemodialysis experience a heavy burden of symptoms that may be related to the low levels of physical activity reported in this population. We hypothesized that physical activity would be inversely related to symptom severity and that depression might mediate this association.

Methods

We designed a cross-sectional study of 48 patients receiving hemodialysis at 3 San Francisco dialysis clinics. Physical activity was measured using pedometers and recorded within 1 week of symptom assessment. Symptoms were assessed using total symptom burden and severity on the Dialysis Symptom Index (DSI; burden 0–29, severity 0–145), individual symptoms on the DSI (0–5), Kidney Disease Quality of Life Vitality scores, (0–100), and the Center for Epidemiologic Study-Depression (0–60).

Results

Median daily step count was 2631 (25th, 75th percentile 1125, 5278). Seventy-three percent of patients reported fatigue. After adjustment for age, sex, diabetes, and serum albumin, physical activity was associated with 0.2 points lower fatigue severity per 1000 steps per day (95% confidence interval [CI] −0.3 to 0.0), P = 0.04. Physical activity was also associated with higher Vitality score (2.36 points per 1000 steps; 95% CI 0.07–4.65) and lower insomnia scores (−0.1 points per 1000 steps; 95% CI −0.3 to 0.0], P < 0.05) in our adjusted models. Physical activity was not associated with other symptoms.

Conclusion

Because the study was cross-sectional, we cannot determine whether physical activity lowers fatigue and insomnia or whether less insomnia and fatigue increase physical activity. However, interventions to increase physical activity should be considered alongside current strategies as a possible approach to managing fatigue and insomnia.

Intradialytic exercise training modalities on physical functioning and health-related quality of life in patients undergoing maintenance hemodialysis: systematic review and meta-analysis

OBJECTIVE

To determine the effects of different intradialytic exercise training modalities on physical functioning and health-related quality of life of maintenance hemodialysis patients.

METHODS

We searched MEDLINE, Cochrane Trials Register and CINAHL for controlled trials that evaluated the effects of intradialytic exercise training for maintenance hemodialysis patients and published from the earliest available date to December 2017. Weighted mean difference and 95% confidence interval (CI) were calculated, and heterogeneity was assessed using the I² test.

RESULTS

Fifty-six studies met the study criteria, comprising a total of 2586 patients. Compared with no exercise, combined aerobic and resistance exercise resulted in significant improvement in peak VO₂ weighted mean difference (5.1 mL kg^-1 min^-1; 95% CI: 3.4, 6.8 mL kg^-1 min^-1), depression symptoms (-7.32; 95% CI -9.31, -5.33) and both physical function (10.67 points; 95% CI 1.08, 20.25 points) and vitality (10.01 points; 95% CI 4.30, 15.72 points) domains of health-related quality of life. Resistance exercise alone was significantly associated with improvement in the 6-minute walk test distance (30.2 m; 95% CI 24.6, 35.9 m), knee extensor strength (0.6 N; 95% CI 0.1, 1.0 N) and Physical Component Score of health-related quality of life (9.53 points; 95% CI -3.09, 22.15 points) when compared with control group. Aerobic exercise alone was not significantly associated with aerobic capacity and quality of life improvement.

CONCLUSION

The results provide support to interventions that combine intradialytic aerobic and resistance exercises to improve physical functioning and quality of life in end-stage renal disease patients undergoing hemodialysis.

Barriers to exercise for patients with renal disease: an integrative review

Renal disease is a common health condition that leads to loss of physical function, frailty, and premature loss of independence in addition to other severe comorbidities and increased mortality. Increased levels of physical activity and initiation of exercise training is recommended in the current guidelines for all patients with renal disease, but participation and adherence rates are low. The barriers to exercise and physical activity in patients with renal disease are not well defined and currently based on patient provider perception and opinion. There have been no published reviews that have synthesized published findings on patient reported barriers to exercise. This integrative literature review therefore aimed to identify the current understanding of patient reported barriers to regular exercise. This integrative review found that patient perceived barriers to exercise are not consistent with the barriers that have been identified by renal disease specialists and healthcare providers, which were disinterest, lack of motivation, and being incapable of exercise. The patient reported barriers identified through this review were complex and diverse, and the most frequently reported patient perceived barrier to exercise was low energy levels and fatigue. It is clear that additional research to identify patient perceived barriers to exercise is needed and that patient directed interventions to address these barriers should be developed. This integrative review provides information to the interdisciplinary nephrology team that can be used to tailor their assessment of barriers to exercise and provide exercise education for patients with renal disease.

Exercise Training in Elderly People Undergoing Hemodialysis: A Systematic Review and Meta-analysis

Introduction

Previous reviews have indicated the effectiveness of exercise in people undergoing hemodialysis. However, these analyses did not take into account whether the subjects were elderly. We performed a systematic review of the effects of exercise training in elderly people undergoing hemodialysis and updated the evidence of exercise for people undergoing hemodialysis by adding recent research data.

Methods

We searched 8 electronic databases up to June 2016. Inclusion criteria were as follows: randomized controlled trial, English publication, subjects aged 18 and older undergoing hemodialysis, evaluation of physical function as an outcome of exercise intervention. We defined elderly as age 60 years and older. The main outcomes were exercise tolerance (peak/maximum oxygen consumption) and walking ability (6-minute walk distance). Secondary outcomes were lower extremity muscle strength and quality of life.

Results

After screening of 10,923 references, 30 comparisons were entered into the analysis. However, because we found only 1 study in which elderly subjects were treated, we could not perform a meta-analysis for these people. For the general population undergoing hemodialysis, supervised exercise training was shown to significantly increase peak/maximum oxygen consumption (standard mean difference, 0.62; 95% confidence interval 0.38-0.87; P < 0.001), 6-minute walk distance (standard mean difference, 0.58; 95% confidence interval 0.24-0.93; P < 0.001), lower extremity muscle strength (standard mean difference, 0.94; 95% confidence interval 0.67-1.21; P < 0.001), and quality of life (standard mean difference, 0.53; 95% confidence interval 0.52-0.82; P < 0.001).

Discussion

Our analysis on the effectiveness of exercise training in elderly people undergoing hemodialysis as compared with nonelderly people was somewhat inconclusive. Future studies should be carried out for elderly people to identify the most favorable exercise program for this population.

Exercise and CKD: Skeletal Muscle Dysfunction and Practical Application of Exercise to Prevent and Treat Physical Impairments in CKD

Patients with chronic kidney disease experience substantial loss of muscle mass, weakness, and poor physical performance. As kidney disease progresses, skeletal muscle dysfunction forms a common pathway for mobility limitation, loss of functional independence, and vulnerability to disease complications. Screening for those at high risk for mobility disability by self-reported and objective measures of function is an essential first step in developing an interdisciplinary approach to treatment that includes rehabilitative therapies and counseling on physical activity. Exercise has beneficial effects on systemic inflammation, muscle, and physical performance in chronic kidney disease. Kidney health providers need to identify patient and care delivery barriers to exercise in order to effectively counsel patients on physical activity. A thorough medical evaluation and assessment of baseline function using self-reported and objective function assessment is essential to guide an effective individualized exercise prescription to prevent function decline in persons with kidney disease. This review focuses on the impact of kidney disease on skeletal muscle dysfunction in the context of the disablement process and reviews screening and treatment strategies that kidney health professionals can use in clinical practice to prevent functional decline and disability.