Effects of intradialytic cycling exercise on exercise capacity, quality of life, physical function and cardiovascular measures in adult haemodialysis patients: a systematic review and meta-analysis

Frailty in patients on dialysis

Frailty is a condition that is frequently observed among patients undergoing dialysis. Frailty is characterized by a decline in both physiological state and cognitive state, leading to a combination of symptoms, such as weight loss, exhaustion, low physical activity level, weakness, and slow walking speed. Frail patients not only experience a poor quality of life, but also are at higher risk of hospitalization, infection, cardiovascular events, dialysis-associated complications, and death. Frailty occurs as a result of a combination and interaction of various medical issues in patients who are on dialysis. Unfortunately, frailty has no cure. To address frailty, a multifaceted approach is necessary, involving coordinated efforts from nephrologists, geriatricians, nurses, allied health practitioners, and family members. Strategies such as optimizing nutrition and chronic kidney disease-related complications, reducing polypharmacy by deprescription, personalizing dialysis prescription, and considering home-based or assisted dialysis may help slow the decline of physical function over time in subjects with frailty. This review discusses the underlying causes of frailty in patients on dialysis and examines the methods and difficulties involved in managing frailty among this group.

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.

Combining exercise and nutrition in chronic kidney disease and dialysis: Can we learn from the performance nutrition of athletes?

The benefits of exercise interventions in individuals with chronic kidney disease have been widely reviewed; however, exercise has not yet been incorporated into routine clinical practice. In athletic populations, the goals of exercise training are to improve a specific aspect of physical performance such as strength or endurance, to ultimately optimize physical performance. This contrasts with many chronic kidney disease exercise studies where the goals are more aligned to a minimal effect, such as prevention of decline in physical function, frailty or protein energy wasting (PEW), weight loss for cardiovascular disease risk reduction, and risk minimization for mortality. In athletic populations, there are common targeted nutrition strategies used to optimize physical performance. In this review, we consider the evidence for and potential benefits of targeted nutrition strategies to complement well-designed exercise interventions to improve physical performance in people with chronic kidney disease and dialysis. Overall, we found a small number of studies using targeted protein supplementation in combination with a variety of exercise protocols; however, results were mixed. Future studies in people with chronic kidney disease should optimize acute (pre, during, and postexercise) and chronic nutritional status, utilizing targeted nutrition interventions proven in athletes to have benefit.

Differences in the purpose of exercise between hemodialysis patients who continued or dropped out of exercise programs: a multicenter cohort study

BACKGROUND

Selecting suitable exercise goals is crucial for fostering adherence to, and maintenance of, exercise therapy. We aimed to evaluate the variance in exercise objectives between individuals who continued and those who dropped out of a 6-month intradialytic exercise program by analyzing an open-ended questionnaire administered to patients undergoing hemodialysis.

METHODS

The study consisted of outpatients (n = 541; mean age, 70 years) undergoing maintenance hemodialysis, who had been informed of an intradialytic exercise program and voluntarily agreed to participate. The primary outcome was the exercise purpose. The difference in exercise purpose was quantitatively analyzed between the exercise continuation and dropout groups. A co-occurrence network was created and concepts were constructed. The basic attributes were compared using chi-squared and independent t-tests.

RESULTS

Over 6 months, 154 patients (28.5%) dropped out of the intradialytic exercise program. Concepts related to the goals of the program were: (1) physical function and condition, (2) addressing limitations, (3) maintaining daily life activities, and (4) physical condition recognition. Co-occurrence network analysis showed that the exercise continuation group established their objectives based on the health benefits of exercise, and proactively set goals rooted in comprehending their current issues and problems. The dropout group tended to perceive treatment passively as an extension of daily clinical practice, rather than actively formulating exercise objectives.

CONCLUSION

The exercise objectives of those who continued the exercise program differed from those who dropped out. Patients in the exercise continuation group set more affirmative and specific exercise objectives, whereas those in the dropout group set more passive and abstract exercise objectives.

The impact of aerobic exercise on health-related quality of life among patients undergoing maintenance hemodialysis

To investigate the effect of exercise on cardiopulmonary function and the life quality of maintenance hemodialysis patients. Eighty-four patients who underwent maintenance hemodialysis treatment for more than 3 months were randomly divided into experimental group and control group. The general data and nutritional indexes, including hemoglobin and plasma albumin, before and after the experiment. The differences in lung function, cardiac ultrasound, cardiopulmonary function, exercise endurance between the 2 groups before and after intervention were compared. The short form 36-item health survey (SF-36) and self-rating depression scale (SDS) were assessed. In our study, the experimental group had better Force vital capacity (FVC) and peak expiratory flow (PEF) after the intervention compared to the control group (P < .05). Anaerobic threshold and 6-minute walk test (6MWT) improved significantly in the experimental group (P < .05), and SF-36 showed better physical functioning, social functioning, general health, and vitality scores in the experimental group compared to the control group (P < .05). In addition, following 24 weeks of exercise, the Depression score of the exercise group showed a statistically significant improvement when compared to the control group (P < .05). After the intervention, hemoglobin improved significantly in the experimental group (P < .05). Intradialytic exercise can improve hemoglobin, Alb, pulmonary function, aerobic capacity, and exercise endurance in maintenance hemodialysis patients, so as to improve the quality of life, which is worthy of further promotion.

Does Renal Denervation a Reasonable Treatment Option in Hemodialysis-Dependent Patient with Resistant Hypertension? A Narrative Review

PURPOSE OF REVIEW

This narrative review aims to assess the pathophysiology, diagnosis, and treatment of resistant hypertension (RH) in end-stage kidney disease (ESKD) patients on dialysis, with a specific focus on the effect of renal denervation (RDN) on short-term and long-term blood pressure (BP) control. Additionally, we share our experience with the use of RDN in an amyloidotic patient undergoing hemodialysis with RH.

RECENT FINDINGS

High BP, an important modifiable cardiovascular risk factor, is often observed in patients in ESKD, despite the administration of multiple antihypertensive medications. However, in clinical practice, it remains challenging to identify RH patients on dialysis treatment because of the absence of specific definition for RH in this context. Moreover, the use of invasive approaches, such as RDN, to treat RH is limited by the exclusion of patients with reduced renal function (eGFR < 45 mL/min/1.73 m3) in the clinical trials. Nevertheless, recent studies have reported encouraging results regarding the effectiveness of RDN in stage 3 and 4 chronic kidney disease (CKD) and ESKD patients on dialysis, with reductions in BP of nearly up to 10 mmhg. Although multiple underlying pathophysiological mechanisms contribute to RH, the overactivation of the sympathetic nervous system in ESKD patients on dialysis plays a crucial role. The diagnosis of RH requires both confirmation of adherence to antihypertensive therapy and the presence of uncontrolled BP values by ambulatory BP monitoring or home BP monitoring. Treatment involves a combination of nonpharmacological approaches (such as dry weight reduction, sodium restriction, dialysate sodium concentration reduction, and exercise) and pharmacological treatments. A promising approach for managing of RH is based on catheter-based RDN, through radiofrequency, ultrasound, or alcohol infusion, directly targeting on sympathetic overactivity.

Home-based exercise in patients on maintenance dialysis: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The impact of home-based exercise on physical performance and quality of life (QoL) in patients on maintenance dialysis has not yet been fully established.

METHODS

We searched four large electronic databases to identify randomized controlled trials (RCTs) reporting the impact of home-based exercise interventions vs. usual care or intradialytic exercise interventions, on physical performance and QoL in patients on dialysis. The meta-analysis was performed using fixed effects modeling.

RESULTS

We included 12 unique RCTs involving 791 patients of various ages on maintenance dialysis. Home-based exercise interventions were associated with an improvement of walking speed at the 6 Minutes Walking Test [6MWT; nine RCTs; pooled weighted mean differences (WMD): 33.7 m, 95% confidence interval (CI) 22.8-44.5; P < 0.001; I2 = 0%) and in aerobic capacity as assessed by the peak oxygen consumption (VO2 peak; 3 RCTs; pooled WMD: 2.04 ml/kg/min, 95% CI 0.25-3.83; P = 0.03; I2 = 0%). They were also associated with improved QoL, as assessed by the Short Form (36) Health (SF-36) score. Stratifying the RCTs by control groups, no significant difference was found between home-based exercise and intradialytic exercise interventions. Funnel plots did not reveal any significant publication bias.

CONCLUSIONS

Our systematic review and meta-analysis showed that home-based exercise interventions for 3-6 months were associated with significant improvements in physical performance in patients on maintenance dialysis. However, further RCTs with a longer follow-up should be conducted to assess the safety, adherence, feasibility, and effects on QoL of home-based exercise programs in dialysis patients.

Novel Approach to Intradialytic Progressive Resistance Exercise Training

Physical activity levels are typically undesirably low in chronic kidney disease patients, especially in those undergoing haemodialysis, and particularly on dialysis days. Intradialytic exercise programmes could be a solution to this issue and have been reported to be safe and relatively easily implemented in dialysis clinics. Nevertheless, such implementation has been failing in part due to barriers such as the lack of funding, qualified personnel, equipment, and patient motivation. Intradialytic aerobic exercise has been the most used type of intervention in dialysis clinics. However, resistance exercise may be superior in eliciting potential benefits on indicators of muscle strength and mass. Yet, few intradialytic exercise programmes have focused on this type of intervention, and the ones which have report inconsistent benefits, diverging on prescribed exercise intensity, absent or subjective load progression, equipment availability, or exercise supervision. Commonly, intradialytic resistance exercise interventions use free weights, ankle cuffs, or elastic bands which hinder load progression and exercise intensity monitoring. Here, we introduce a recently developed intradialytic resistance exercise device and propose an accompanying innovative resistance exercise training protocol which aims to improve the quality of resistance exercise interventions within dialysis treatment sessions.

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 Different Exercises on Physical Function, Dialysis Adequacy, and Health-Related Quality of Life in Maintenance Hemodialysis Patients: A Systematic Review and Network Meta-Analysis

BACKGROUND

Clinical guidelines recommend exercise training for patients undergoing maintenance hemodialysis (MHD). However, the effectiveness of different types of exercise remains uncertain.

OBJECTIVES

The aims of the study were to compare and rank the effect of different types of exercise on walking capacity, cardiorespiratory fitness, dialysis adequacy, and health-related quality of life (HRQOL) in patients undergoing MHD.

METHODS

Eight databases (four English and four Chinese) were searched from inception to January 1, 2022. Randomized controlled trials evaluating the efficacy of different exercises for patients undergoing MHD were included. Two independent reviewers screened the literature, extracted data, assessed the risk of bias, and evaluated the certainty of evidence. A frequentist random-effect network meta-analysis was conducted.

RESULTS

Ninety trials with 4,084 participants comparing 15 types of exercise were included, reporting on the six-minute walking test (45 trials), peak oxygen uptake (22 trials), dialysis adequacy (30 trials), and HRQOL (23 trials). Network meta-analysis showed that the most effective intervention for walking capacity was intradialytic aerobic exercise combined with blood flow restriction with a mean difference and 95% confidence interval of 97.35 (11.89-182.81), for peak oxygen uptake it was non-intradialytic combined aerobic and resistance exercise with a value of 4.35 (2.25-6.44), for dialysis adequacy it was intradialytic combined aerobic and resistance exercise with a value of 0.17 (0.06-0.28), for the physical component summary of HRQOL it was intradialytic aerobic exercise with a value of 4.93 (2.31-7.54), and for the mental component summary of HRQOL it was non-intradialytic combined aerobic and resistance exercise with a value of 6.36 (0.45-12.27). Ultimately, intradialytic combined aerobic and resistance exercise could improve all the above outcomes compared to usual care.

CONCLUSIONS

This study concluded that intradialytic combined aerobic and resistance exercise is optimal for MHD patients due to its significant positive effects on multiple outcomes. Walking capacity can be further enhanced by combining blood flow restriction with exercise. For improving dialysis adequacy, intradialytic exercise proves to be more effective than non-intradialytic exercise. Further well-designed clinical trials are needed to investigate the effects of exercise with varying durations, intensities, and frequencies.

Clinical features and molecular mechanism of muscle wasting in end stage renal disease

Muscle wasting in end-stage renal disease (ESRD) is an escalating issue due to the increasing global prevalence of ESRD and its significant clinical impact, including a close association with elevated mortality risk. The phenomenon of muscle wasting in ESRD, which exceeds the rate of muscle loss observed in the normal aging process, arises from multifactorial processes. This review paper aims to provide a comprehensive understanding of muscle wasting in ESRD, covering its epidemiology, underlying molecular mechanisms, and current and emerging therapeutic interventions. It delves into the assessment techniques for muscle mass and function, before exploring the intricate metabolic and molecular pathways that lead to muscle atrophy in ESRD patients. We further discuss various strategies to mitigate muscle wasting, including nutritional, pharmacological, exercise, and physical modalities intervention. This review seeks to provide a solid foundation for future research in this area, fostering a deeper understanding of muscle wasting in ESRD, and paving the way for the development of novel strategies to improve patient outcomes. [BMB Reports 2023; 56(8): 426-438].

A Randomized Trial Examining the Impact of Timing of Intradialytic Cycling on Intradialytic Hypotension

Introduction

Intradialytic cycling is often performed during the first half of hemodialysis because of concerns regarding increased frequency of intradialytic hypotension (IDH) late in hemodialysis. This increases exercise program resource needs and limits utility of intradialytic cycling to treat dialysis-related symptoms.

Methods

This multicenter, randomized, crossover trial compared IDH rate when cycling during the first half versus the second half of hemodialysis in 98 adults on maintenance hemodialysis. Group A cycled during the first half of hemodialysis for 2 weeks and subsequently during the second half for 2 weeks. In group B, the cycling schedule was reversed. Blood pressure (BP) was measured every 15 minutes throughout hemodialysis. Primary outcome was IDH rate (systolic BP [SBP] decrease of >20 mm Hg or SBP <90 mm Hg). Secondary outcomes included symptomatic IDH rate and time to recover post hemodialysis. Data were analyzed using negative binomial and gamma distribution mixed regression.

Results

Mean age 64.7 (SD 12.0) and 64.7 (SD 14.2) years in group A (n = 52) and group B (n = 46), respectively. Proportions of females were 33% in group A and 43% in group B. Median time on hemodialysis was 4.1 (interquartile range [IQR] 2.5, 6.1]) years in group A and 3.9 years (IQR 2.5, 6.7) in group B. IDH rate per 100 hemodialysis hours (95% confidence interval [CI]) was 34.2 (26.4, 42.0) and 36.0 (28.9, 43.1) during early and late intradialytic cycling, respectively (P = 0.53). Timing of intradialytic cycling was not associated with symptomatic IDH (relative risk [RR]: 1.07 [0.75-1.53]) or time to recover post hemodialysis (odds ratio: 0.99 [0.79-1.23]).

Conclusion

We found no association between the rate of overall or symptomatic IDH and the timing of intradialytic cycling in patients enrolled in an intradialytic cycling program. Increased use of cycling late in hemodialysis may optimize intradialytic cycling program resource use and should be studied as a possible treatment for symptoms common in late hemodialysis.

From MIA to FIFA: The vicious matrix of frailty, inflammation, fluid overload and atherosclerosis in peritoneal dialysis

Cardiovascular disease (CVD) is a major cause of mortality and morbidity in peritoneal dialysis (PD) patients. Two decades ago, the common co-existence of malnutrition and systemic inflammation PD patients with atherosclerosis and CVD led to the proposed terminology of 'malnutrition-inflammation-atherosclerosis (MIA) syndrome'. Although the importance of malnutrition is well accepted, frailty represents a more comprehensive assessment of the physical and functional capability of the patient and encompasses the contributions of sarcopenia (a key component of malnutrition), obesity, cardiopulmonary as well as neuropsychiatric impairment. In recent years, it is also increasingly recognized that fluid overload is not only the consequence but also play an important role in the pathogenesis of CVD. Moreover, fluid overload is closely linked with the systemic inflammatory status, presumably by gut oedema, gastrointestinal epithelial barrier dysfunction and leakage of bacterial fragments to the systemic circulation. There are now a wealth of published evidence to show intricate relations between frailty, inflammation, fluid overload and atherosclerotic disease in patients with chronic kidney disease (CKD) and those on PD, a phenomenon that we propose the term 'FIFA complex'. In this system, frailty and atherosclerotic disease may be regarded as two patient-oriented outcomes, while inflammation and fluid overload are two inter-connected pathogenic processes. However, there remain limited data on how the treatment of one component affect the others. It is also important to define how treatment of fluid overload affect the systemic inflammatory status and to develop effective anti-inflammatory strategies that could alleviate atherosclerotic disease and frailty.

Feasibility of randomized controlled trials and long-term implementation of interventions: Insights from a qualitative process evaluation of the PEDAL trial

Introduction

A multi-site randomized controlled trial was carried out between 2015 and 2019 to evaluate the impacts on quality of life of an intradialytic exercise programme for people living with chronic kidney disease. This included a qualitative process evaluation which gave valuable insights in relation to feasibility of the trial and of the intervention in the long-term. These can inform future clinical Trial design and evaluation studies.

Methods

A constructivist phenomenological approach underpinned face-to-face, semi-structured interviews. Purposive recruitment ensured inclusion of participants in different arms of the PEDAL Trial, providers with different roles and trial team members from seven Renal Units in five study regions. Following ethical review, those willing took part in one interview in the Renal Unit. Audio-recorded interviews were transcribed (intelligent verbatim) and inductively thematically analyzed.

Results

Participants (n = 65) (Intervention arm: 26% completed; 13% who did not; Usual care arm: 13%; 46% women; 54% men; mean age 60 year) and providers (n = 39) were interviewed (23% PEDAL Trial team members). Three themes emerged: (1) Implementing the Intervention; (2) Implementing the trial; and (3) Engagement of the clinical team. Explanatory theory named "the Ideal Scenario" was developed, illustrating complex interactions between different aspects of intervention and trial implementation with the clinical context. This describes characteristics likely to optimize trial feasibility and intervention sustainability in the long-term. Key aspects of this relate to careful integration of the trial within the clinical context to optimize promotion of the trial in the short-term and engagement and ownership in the long-term. Strong leadership in both the clinical and trial teams is crucial to ensure a proactive and empowering culture.

Conclusion

Novel explanatory theory is proposed with relevance for Implementation Science. The "Ideal Scenario" is provided to guide trialists in pre-emptive and ongoing risk analysis relating to trial feasibility and long-term intervention implementation. Alternative study designs should be explored to minimize the research-to-practice gap and optimize the likelihood of informative findings and long-term implementation. These might include Realist Randomized Controlled Trials and Hybrid Effectiveness-Implementation studies.

Effect of intradialytic exercises (IDE) on maximal oxygen consumption and quality of life undergoing hemodialysis in Indian population—a pilot study

Background

End stage renal disease (ESRD) is emerging as a major health issues across developing countries with limited access and awareness about the importance of exercises in daily life. People on prolong hemodialysis has difficulty in performing their activities of daily living (ADL). Loss of muscle mass is inevitable among patients on hemodialysis that leads to morbidity and mortality. Exercise is feasible during dialysis and can enhance quality of life. Increase in aerobic endurance by various combined protocol of aerobic and resistive exercises can improve compliance to regular exercise that underlines the theme of present study.

Methods

A total of 31 participants were recruited during November 2019 to February 2020, after screening of 65 participants for selection criteria from Indraprastha Apollo Hospital’s dialysis unit. The average age of the participants was 52.36 ± 11.56 years. A single-blinded, pre-test–post-test quasi-experimental clinical trial for intradialytic exercise program involving lower limb ergometer and resistance training for lower limbs and non-fistula hand for 24 sessions, in 3 months, twice a week was conducted.

Results

The exercise program was well tolerated and all patients completed it. Aerobic and resistance intradialytic exercises (IDE) had a positive effect on maximal oxygen consumption (VO2 Max), quality of life (SF 36), and sleep quality (PSQI). IDE showed statistically significant difference from pre- to post-intervention for maximal oxygen consumption, quality of life boosting their sleep quality.

Conclusions

IDE found to benefit the patient and results showed a significant improvement in maximal oxygen consumption, sleep quality, quality of life and fatigue over a span of 12 weeks.

Trial registration

CTRI, CTRI/2019/08/020848. Registered on 22 August 2019.

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.

An equation to predict peak heart rate for prescribing exercise intensity in middle-aged to older patients requiring hemodialysis

PURPOSE

Exercise prescription based on a population-specific physiological response can help ensure safe and effective physical interventions. However, as a facile approach for exercise prescription in hemodialysis population that is based on their exercise capacity has not yet been established, the aim of our study was to develop a unique prediction formula for peak heart rate (HR) that can be used in this population.

METHODS

This cross-sectional study measured physical function and HR at peak exercise and anaerobic threshold (AT) during cardiopulmonary exercise tests in 126 individuals. Participants were randomly assigned to the development group (n = 78), whose data were used to calculate the prediction equation, or the validation group (n = 48).

RESULTS

The HR reserve in this population was significantly lower (0.44 ± 0.20%) and there was a large discrepancy between conventional age-predicted maximal HR and measured peak-HR values (R = 0.36). The average of the ratio between HR at AT point and peak HR was 85% (95% CI, 83.5%-86.4%). The peak-HR prediction equation was based on resting HR, presence of diabetes, physical dysfunction (gait speed < 1.0 m/s), and hypoalbuminemia (< 3.5 g/dL). It showed high prediction accuracy (R² [95%CI] = 0.71 [0.70-0.71]) with similar correlation coefficients between the development and validation groups (R = 0.82).

CONCLUSION

Aerobic exercise based on estimated peak HR < 85% obtained from the equation in this study may enable safe and effective physical intervention in this population.

Renal rehabilitation as a management strategy for physical frailty in CKD

An aging population and the increasing prevalence of lifestyle-related diseases have led to a worldwide increase in the rate of chronic kidney disease requiring renal replacement therapy. The mean age of individuals requiring dialysis therapy has been increasing, and Japanese patients are aging more rapidly than those in the USA and Europe. Patients undergoing renal replacement therapy are at increased risk of sarcopenia/frailty compared with people with normal kidney function due to comorbid burden, long-standing malnutrition, chronic inflammation, metabolic acidosis, anabolic resistance, hormonal changes, physical inactivity and amino acid loss via dialysis treatment in addition to aging. Sarcopenia and frailty are serious global health problems that can decrease access to kidney transplantation and lead to various adverse health outcomes, including functional dependence, hospitalizations and deaths in patients on dialysis treatment. However, sarcopenia/frailty fortunately is potentially modifiable by early identification of poor physical functioning, sustainment and enhancement of daily physical activity, and participation in exercise treatments. The Japanese Society of Renal Rehabilitation was established in 2011 and published a clinical practice guideline for “Renal Rehabilitation” targeting nondialysis-dependent and dialysis-dependent patients and renal transplant recipients, in 2019. The guideline emphasized the importance of physical management for patients with kidney diseases in addition to nutritional supports and anemia management. Kidney health professionals should manage sarcopenia and physical frailty as a part of routine clinical care for patients undergoing hemodialysis to improve poor physical functioning, functional dependence, decreased quality of life and poor prognosis.

Intradialytic hypotension and objectively measured physical activity among patients on hemodialysis

BACKGROUND

Intradialytic hypotension is related to patient-reported outcomes such as post-dialysis fatigue, but its impact on physical activity has not been fully studied. We aimed to examine the relationship between intradialytic blood pressure (BP) and objectively measured physical activity.

METHODS

In this cross-sectional study, 192 hemodialysis patients underwent 4 weeks of physical activity measurement using triaxial accelerometers to measure step counts and moderate-to-vigorous physical activity (MVPA). Intradialytic BP parameters (pre-dialysis BP, post-dialysis BP, nadir BP, and fall in BP) were measured during all dialysis sessions. Mixed-effects linear regression models were used to analyze associations between intradialytic BP parameters and physical activity (1) after dialysis sessions on dialysis days and (2) on the following non-dialysis days.

RESULTS

The mean age of the patients was 71 years, and 47% had diabetes mellitus. Valid physical activity data were obtained in a total of 1938 dialysis days and 2629 non dialysis days. Lower nadir diastolic BP was significantly associated with lower step counts and shorter moderate-to-vigorous physical activity not only on dialysis days but also on the following non-dialysis days. Nadir diastolic BP showed a higher discrimination capacity for physical inactivity, defined as a step count < 4000 on non-dialysis days, than the other BP parameters. The optimal cutoff point of nadir diastolic BP for discriminating physical inactivity was 68 mmHg; its sensitivity and specificity were 66% and 67%, respectively.

CONCLUSIONS

Lower nadir diastolic BP was strongly associated with lower physical activity on both dialysis and non-dialysis days. Nadir diastolic BP may be a predictor for physical inactivity.

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.

Cardiopulmonary reserve examined with cardiopulmonary exercise testing in individuals with chronic kidney disease: A systematic review and meta-analysis

BACKGROUND

Patients with chronic kidney disease (CKD) often present reduced physical activity and exercise tolerance due to factors relevant to co-existing disturbances of the cardiac, nervous and muscular systems. Cardiopulmonary exercise testing (CPET) is used for clinical evaluation of exercise limitation and related symptoms (i.e., dyspnea, fatigue) in several medical fields.

OBJECTIVES

This is a systematic review and meta-analysis of studies using CPET technology to examine cardiopulmonary reserve in individuals with versus without CKD.

METHODS

Literature search involved PubMed, Web of Science and Scopus databases; manual search of article references and of gray literature was also performed. Observational studies and randomized trials that used CPET for patients with CKD stage 1-5 versus controls were eligible. The primary outcome was peak oxygen uptake (VO₂peak). The Newcastle-Ottawa Scale was used to evaluate the quality of retrieved studies.

RESULTS

From an initial 4944 literature records, we identified 29 studies fulfilling the inclusion criteria; of these, 25 studies (2,213 participants) with complete data were included in the final meta-analysis. VO₂peak was significantly lower in CKD patients than controls without CKD [standardized mean difference (SMD) -1.40, 95% confidence interval (CI) -1.68; -1.13)]. Values were lower for CKD than non-CKD individuals for oxygen consumption at anaerobic threshold (SMD -1.06, 95% CI -1.34; -0.79) and maximum workload [weighted mean difference (WMD) -58.26, 95% CI 74.14; -42.38]. In 3 studies, CKD patients had higher VO₂peak than controls with heart failure without CKD (WMD 6.60, 95% CI 3.02; 10.18). Sensitivity analyses confirmed the robustness of these findings.

CONCLUSIONS

VO₂peak and other commonly analyzed CPET variables were lower in patients with CKD than controls, which indicates reduced functional cardiopulmonary reserve in CKD. In contrast, patients with CKD performed better than controls with heart failure without CKD. Overall, rehabilitation programs should be more widely applied to individuals with CKD.

PROSPERO REGISTRATION NUMBER

CRD42021227805.

Feasibility of Intradialytic Cycling Program in a Remote Community Hemodialysis Unit: Mixed-Methods Analysis of Implementation

BACKGROUND

There is growing evidence demonstrating the benefits of intradialytic cycling. However, there are relatively few centers where this practice has been adopted with no reports from hemodialysis units in rural, remote, and northern locations. Maintaining mobility and quality of life for patients on kidney replacement therapy living in remote northern communities is inhibited by inclement weather and lack of access to resources and infrastructure that support physical activity. The integration of intradialytic cycling during hemodialysis offers patients a form of safe physical activity year-round.

OBJECTIVE

This study focuses on better understanding the feasibility and acceptability of implementing intradialytic cycling in a remote northern geographical context.

DESIGN

A feasibility study using a mixed-methods explanatory design was adopted for this study.

SETTING

The research is conducted in Prince George, British Columbia.

PARTICIPANTS

The participants are patients attending a community-based dialysis unit in remote northern British Columbia and health professionals working in the same facility.

METHODS

Quantitative measures were captured through cycling logbooks and quality of life measure, and qualitative data were obtained through semi-structured interviews and analyzed using thematic analysis.

RESULTS

Six (43%) eligible patients used leg ergometers more than once for a median of 2.5 (interquartile range: 1-4) months and 87% of hemodialysis sessions. Participants cycled for a median of 65 (interquartile range: 39-76) minutes per session, with frequent variability noted between participants and different hemodialysis sessions for the same participant. Nine patients completed the European Quality of Life Health Questionnaire prestudy, with 5 (56%) also completing it poststudy. Interviews with 9 patients, 4 nurses, and 1 physiotherapist led to the identification of themes instrumental to implementation: a supportive community dialysis unit, shared responsibility, knowledge of patients/providers, and benefits associated with engagement. Themes that were identified as being key to acceptability in this remote dialysis unit were trust, connection, and engagement through common values.

LIMITATIONS

Due to dialysis unit size, we had a small number of participants.

CONCLUSIONS

This study demonstrates the feasibility of implementing best practice in a remote community and provides insight into the elements of context and participation that contribute to acceptability in the implementation of intradialytic cycling.

Does the interference phenomenon affect strength development during same-session combined rehabilitation program in hemodialysis patients?

INTRODUCTION

This study aimed to assess if an interference effect could blunt the neuromuscular gains induced by a same-session combined rehabilitation in hemodialysis (HD) patients.

METHODS

Patients exercised twice a week, for 16 weeks, over their HD sessions. They were either always trained with resistance and endurance exercises (continuous training, "CONT") or alternatively with 1 week of resistance alternated with 1 week of endurance (discontinuous training, "DISC"). Adherence and workload were continuously recorded. Short Physical Performance Battery (SPPB) score, one-leg balance test, and handgrip and quadriceps strength were evaluated before and after training intervention.

RESULTS

Adherence to both programs was high (>90%). SPPB score had significantly improved (CONT: +1.5 point, DISC: +1.2 pt, p < 0.001), like one-leg balance test (CONT: +3.7 s, DISC: +5.5 s, p < 0.05), handgrip strength of exercised (CONT: +5.5 kg, DISC: +5.6 kg, p < 0.001) and of nonexercised arm (CONT: +4.4 kg, DISC: +2.8 kg, p < 0.01) as well as maximal quadriceps strength (+22 N·m for dominant and +29 N·m for nondominant leg in both groups, p < 0.001) bearing no difference between the trainings.

CONCLUSION

Same-session combined training does not induce an interference effect in HD patients and temporal separation of exercises does not optimize strength gains. These practical data may be relevant for clinicians and practitioners to alternate endurance and resistance exercises.

Effects of intradialytic exercise on health-related quality of life in patients undergoing maintenance haemodialysis: a systematic review and meta-analysis

PURPOSE

To summarize the current evidence regarding the effectiveness of intradialytic exercise (IDE) on the health-related quality of life (HRQOL) of patients undergoing maintenance haemodialysis.

METHODS

Five English databases (PubMed, EMBASE, Cochrane Library, Web of Science, and ScienceDirect) and four Chinese databases (VIP, WAN FANG, CNKI, CBM) were comprehensively searched from their inception to 18 March 2021. This study was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Two independent reviewers selected the papers and extracted the details of each study therein. Only randomized controlled trials were included. The risk of bias tool version 2.0 was used to evaluate the risk of bias of the included studies. A random-effects meta-analysis was conducted to pool the effect size.

RESULTS

Thirty-three eligible studies with 1481 participants were included. For the generic HRQOL, assessed by the Medical Outcomes Study Short-Form survey, IDE significantly improved most domains and the physical component summary compared with the control group. Furthermore, aerobic exercise alone significantly improved more domains compared to resistance exercise, combined aerobic and resistance exercise, and other types of exercise. Regarding the kidney-specific HRQOL, IDE improved three of eleven domains, including the symptom/problem list, the effect of kidney disease, and the quality of social interaction. No significant effect was found on other domains of kidney-specific HRQOL.

CONCLUSION

Intradialytic exercise could benefit patients undergoing haemodialysis in improving most domains of generic HRQOL, but the effect on most domains of kidney-specific HRQOL is insufficient.

Association between the transtheoretical model approach and sustained intradialytic pedaling exercise: A retrospective cohort study

The transtheoretical model (TTM) is a promising approach to the promotion of behavior change, but it remains to be established whether there is an association between the TTM approach and intradialytic exercise among patients on hemodialysis (HD) with low motivation to exercise in a real-world setting.This retrospective cohort study, conducted in a regional hospital in Japan, included adult outpatients receiving HD 3 times per week who had never participated in intradialytic pedaling exercise despite the encouragement of the HD personnel. Patients were divided into 2 groups according to HD weekday. Patients undergoing HD on Tuesday, Thursday, and Saturday were encouraged by the HD unit team to exercise during HD based on the TTM (exposure group) and those receiving HD on Monday, Wednesday, and Friday were encouraged to exercise as usual (control group). The primary outcome was sustained intradialytic exercise using a leg ergometer, defined as a total of 72 sessions of 30-minute pedaling exercise (duration of at least 6 months).Overall, 85 patients were included in the analysis (mean age: 67.1 ± 11.9 years, 22% female). Of 33 patients in the exposure group, 10 (30%) maintained intradialytic exercise, compared with 2 of 52 patients (4%) in the control group. Log-binomial regression models with stabilized inverse probability of treatment weighting showed a significant association between the TTM approach and sustained intradialytic exercise (adjusted risk ratio 9.23 [95% confidence interval 2.13-40.00]). There were no exercise-related cardiovascular events.Among patients with low motivation to exercise during HD, use of the TTM approach in clinical practice was associated with sustained intradialytic exercise compared with usual care.

Effect of blood volume change related to intensity of intradialytic aerobic exercise on hemodialysis adequacy: a pilot study

PURPOSE

Intradialytic exercise may improve dialysis efficiency; however, the association between changes in blood volume (BV) related to exercise intensity and solute removal kinetics remains unknown. We herein investigated the relationship between changes in BV with exercise and removal of solute molecules during hemodialysis.

METHODS

Each of the 21 hemodialysis patients underwent cardiopulmonary exercise test to measure anaerobic threshold (AT). According to the exercise intensity, patients were classified into two groups, the low group (n = 12), whose intensity was below the AT, and the high group (n = 9), whose intensity was at the AT level. Each patient completed two trial arms of resting and discontinuous exercise dialysis sessions in a randomized manner.

RESULTS

The change in BV with the exercise dialysis session in the high group decreased during exercise (p = 0.028) and remained decreased after exercise (p = 0.016), compared with the low group. In the low group, compared with routine sessions, the removal of potassium (p = 0.030), phosphate (p = 0.024), and urea nitrogen (p = 0.065) increased during exercise, but the total removal of these solutes did not change. In the high group, the removal of phosphate (p < 0.001) and urea nitrogen (p = 0.018) after exercise and even total phosphate (p = 0.027) decreased.

CONCLUSION

These findings suggest that the removal of small solute molecules is improved during exercise in intradialytic low-intensity exercise with no change in BV, and decreased after exercise in high-intensity exercise with a decrease in BV.

CLINICAL TRIALS REGISTRY

Trial retrospectively registered at the UMIN Clinical Trials Registry: study number UMIN000038629 (Registration date: September 7, 2019).

Motivation, Barriers, and Suggestions for Intradialytic Exercise-A Qualitative Study among Patients and Nurses

Background: Intradialytic exercise is an effective intervention to reduce morbidity and mortality and increase quality of life among patients with chronic kidney disease undergoing dialysis. However, implementing and sustaining it in clinical practice has proved challenging. To identify how to best design an effective and sustainable intervention in clinical practice, we aimed to explore hemodialysis patients’ and nurses’ attitudes towards intradialytic exercise, including their motivation, anticipated barriers, and suggestions for the design of a proposed exercise program. Methods: Data were collected through qualitative semistructured interviews with patients and focus group interviews with nurses and analyzed inductively with content analysis. Results: Overall, patients’ and nurses’ attitudes towards intradialytic exercise were positive. Patients were motivated by their expectations about perceived benefits, such as improved quality of life and reduced musculoskeletal pain. Their main concern was triggering dialysis machine alarms and disturbing nurses. Nurses were more skeptical of intradialytic exercise and concerned about patient safety. Patients and nurses had several ideas on how to design a safe and motivating intradialytic exercise intervention. Conclusion: The analysis of patients’ and nurses’ experiences and attitudes generated recommendations for an intradialytic exercise program. Recommendations include individually tailored programs that are safe and that patients can do independently, continuous collaboration between patients, nurses, physicians, and physiotherapists, and educating nurses about the benefits and safety of intradialytic exercise.

Cluster Randomized Controlled Trial on the Effects of 12 Months of Combined Exercise Training during Hemodialysis in Patients with Chronic Kidney Disease-Study Protocol of the Dialysis Training Therapy (DiaTT) Trial

Patients with chronic kidney disease (CKD) on hemodialysis (HD) experience treatment-related immobility and physical deconditioning, which is responsible for an increased risk of frailty and a high burden of multi-morbidity. Exercise has been shown to counteract this vicious cycle; however, its effectiveness has only been investigated in small cohorts. Therefore, the objective of the Dialysis Training Therapy (DiaTT) trial will be to assess the effects of a 12-month intradialytic exercise program on physical functioning, frailty and health economics in a large cohort of HD patients in a real-world setting. DiaTT will be a prospective, cluster-randomized (1:1), controlled, multi-center, interventional clinical trial across 28 dialysis units, aiming at the recruitment of >1100 CKD patients on HD. The intervention group will receive 12 months’ intradialytic exercise (combined aerobic and resistance training), whereas the usual care group will not receive intervention. The primary endpoint will be a change on the sit-to-stand test (STS60) result between baseline and 12 months. Secondary endpoints will include physical functioning, frailty, quality of life, 3-point MACE, hospitalizations, survival, quality of HD, health literacy and health care costs. By including almost as many patients as previously investigated in smaller trials, DiaTT will be the largest randomized, controlled trial assessing frailty, quality of life and mortality in the field of nephrology.

Association of the nutritional risk index for Japanese hemodialysis patients with long-term mortality: The Q-Cohort Study

BACKGROUND

Protein-energy wasting (PEW) is a risk factor for mortality in patients undergoing hemodialysis. Recently, a nutritional risk index for Japanese hemodialysis patients (NRI-JH) has been proposed as a surrogate index of PEW. However, no study has determined the association of the NRI-JH with long-term mortality in patients undergoing hemodialysis. Furthermore, the validity of the NRI-JH has not been confirmed.

METHODS

In total, 3046 patients undergoing hemodialysis and registered in the Q-Cohort Study were followed up for 10 years. The NRI-JH was calculated on the basis of body mass index and serum levels of albumin, total cholesterol, and creatinine. The patients were divided into four groups according to the NRI-JH scores: 0-3 (G1, n = 1343), 4-7 (G2, n = 1136), 8-10 (G3, n = 321), and 11-13 (G4, n = 246). We examined the association between the NRI-JH and the 4-year and 10-year risks of all-cause, cardiovascular, and infection-related deaths using the Cox proportional hazards model.

RESULTS

During the follow-up period, 647 patients died during the first 4 years, and 1503 patients died within 10 years. The 4-year prognosis was analyzed and compared with the lowest NRI-JH score group. Multivariable-adjusted hazard ratios (95% confidence intervals) for all-cause death were 1.93 (1.57-2.38), 2.68 (2.05-3.50), and 3.16 (2.40-4.16) in the G2, G3, and G4 groups, respectively. Similarly, a higher NRI-JH score was associated with an increased risk of cardiovascular and infection-related deaths.

CONCLUSION

A higher NRI-JH score was associated with an increased risk of long-term mortality in patients undergoing maintenance hemodialysis.

TRIAL REGISTRATION

The study protocol was registered in the University Hospital Medical Information Network (UMIN) clinical trial registry (UMIN ID: 000000556).

Effects of Home-Based Exercise on Frailty in Patients With End-Stage Renal Disease: Systematic Review

BACKGROUND

New or worsening frailty is a common problem in patients with end-stage renal disease (ESRD) during the prolonged time awaiting kidney transplantation. Structured physical activity in the dialysis setting has been shown to mitigate frailty, but little is known about the benefits of home-based exercise. The purpose of this systematic review was to summarize the effects of home-based exercise interventions on indicators of frailty (weakness, slowness, low physical activity, perceived exhaustion, and shrinking) among patients diagnosed with ESRD.

METHODS

We searched PubMed, MEDLINE, Scopus, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Google Scholar using Medical Subject Heading terms and free text keywords including kidney failure, exercise, and frailty. We identified 13 relevant articles (eight randomized controlled trials, five quasi-experimental studies).

RESULTS

Our review found potential effectiveness of home-based exercise interventions on mitigating or preventing selected indicators of frailty (e.g., weakness, slowness, low physical activity, perceived exhaustion), particularly when the interventions combined aerobic walking, resistance exercise, and behavioral components and were delivered for at least 6 months. However, no published studies measured the effect of home-based exercise interventions on frailty as a whole.

CONCLUSIONS

While existing studies suggest likely benefits of home-based exercise interventions among patients with ESRD, future research is warranted to develop and test home-based physical activity interventions that address all indicators of frailty.

Cardiorespiratory fitness in kidney transplant recipients compared to patients with kidney failure: a systematic review and meta-analysis

Patients with kidney failure often present with reduced cardiovascular functional reserve and exercise tolerance. Previous studies on cardiorespiratory fitness examined with cardiopulmonary exercise testing (CPET) in kidney transplant recipients (KTR) had variable results. This is a systematic review and meta-analysis of studies examining cardiovascular functional reserve with CPET in KTR in comparison with patients with kidney failure (CKD-Stage-5 before dialysis, hemodialysis or peritoneal dialysis), as well as before and after kidney transplantation. Literature search involved PubMed, Web-of-Science and Scopus databases, manual search of article references and grey literature. From a total of 4,944 identified records, eight studies (with 461 participants) were included in quantitative analysis for the primary question. Across these studies, KTR had significantly higher oxygen consumption at peak/max exercise (VO₂ peak/VO₂ max) compared to patients with kidney failure (SMD = 0.70, 95% CI [0.31, 1.10], I²  = 70%, P = 0.002). In subgroup analyses, similar differences were evident among seven studies comparing KTR and hemodialysis patients (SMD = 0.64, 95% CI [0.16, 1.12], I²  = 65%, P = 0.009) and two studies comparing KTR with peritoneal dialysis subjects (SMD = 1.14, 95% CI [0.19, 2.09], I²  = 50%, P = 0.16). Across four studies with relevant data, oxygen consumption during peak/max exercise showed significant improvement after kidney transplantation compared to pretransplantation values (WMD = 2.43, 95% CI [0.01, 4.85], I²  = 68%, P = 0.02). In conclusion, KTR exhibit significantly higher cardiovascular functional reserve during CPET compared to patients with kidney failure. Cardiovascular reserve is significantly improved after kidney transplantation in relation to presurgery levels.

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.

Exercise programme to improve quality of life for patients with end-stage kidney disease receiving haemodialysis: the PEDAL RCT

BACKGROUND

Whether or not clinically implementable exercise interventions in haemodialysis patients improve quality of life remains unknown.

OBJECTIVES

The PEDAL (PrEscription of intraDialytic exercise to improve quAlity of Life in patients with chronic kidney disease) trial evaluated the clinical effectiveness and cost-effectiveness of a 6-month intradialytic exercise programme on quality of life compared with usual care for haemodialysis patients.

DESIGN

We conducted a prospective, multicentre randomised controlled trial of haemodialysis patients from five haemodialysis centres in the UK and randomly assigned them (1 : 1) using a web-based system to (1) intradialytic exercise training plus usual-care maintenance haemodialysis or (2) usual-care maintenance haemodialysis.

SETTING

The setting was five dialysis units across the UK from 2015 to 2019.

PARTICIPANTS

The participants were adult patients with end-stage kidney disease who had been receiving haemodialysis therapy for > 1 year.

INTERVENTIONS

Participants were randomised to receive usual-care maintenance haemodialysis or usual-care maintenance haemodialysis plus intradialytic exercise training.

MAIN OUTCOME MEASURES

The primary outcome of the study was change in Kidney Disease Quality of Life Short Form, version 1.3, physical component summary score (from baseline to 6 months). Cost-effectiveness was determined using health economic analysis and the EuroQol-5 Dimensions, five-level version. Additional secondary outcomes included quality of life (Kidney Disease Quality of Life Short Form, version 1.3, generic multi-item and burden of kidney disease scales), functional capacity (sit-to-stand 60 and 10-metre Timed Up and Go tests), physiological measures (peak oxygen uptake and arterial stiffness), habitual physical activity levels (measured by the International Physical Activity Questionnaire and Duke Activity Status Index), fear of falling (measured by the Tinetti Falls Efficacy Scale), anthropometric measures (body mass index and waist circumference), clinical measures (including medication use, resting blood pressure, routine biochemistry, hospitalisations) and harms associated with intervention. A nested qualitative study was conducted.

RESULTS

We randomised 379 participants; 335 patients completed baseline assessments and 243 patients (intervention, n = 127; control, n = 116) completed 6-month assessments. The mean difference in change in physical component summary score from baseline to 6 months between the intervention group and control group was 2.4 arbitrary units (95% confidence interval -0.1 to 4.8 arbitrary units; p = 0.055). Participants in the intervention group had poor compliance (49%) and very poor adherence (18%) to the exercise prescription. The cost of delivering the intervention ranged from £463 to £848 per participant per year. The number of participants with harms was similar in the intervention (n = 69) and control (n = 56) groups.

LIMITATIONS

Participants could not be blinded to the intervention; however, outcome assessors were blinded to group allocation.

CONCLUSIONS

On trial completion the primary outcome (Kidney Disease Quality of Life Short Form, version 1.3, physical component summary score) was not statistically improved compared with usual care. The findings suggest that implementation of an intradialytic cycling programme is not an effective intervention to enhance health-related quality of life, as delivered to this cohort of deconditioned patients receiving haemodialysis.

FUTURE WORK

The benefits of longer interventions, including progressive resistance training, should be confirmed even if extradialytic delivery is required. Future studies also need to evaluate whether or not there are subgroups of patients who may benefit from this type of intervention, and whether or not there is scope to optimise the exercise intervention to improve compliance and clinical effectiveness.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN83508514.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 40. See the NIHR Journals Library website for further project information.

Randomized Trial-PrEscription of intraDialytic exercise to improve quAlity of Life in Patients Receiving Hemodialysis

Introduction

Whether clinically implementable exercise interventions in people receiving hemodialysis (HD) therapy improve health-related quality of life (HRQoL) remains unknown. The PrEscription of intraDialytic exercise to improve quAlity of Life (PEDAL) study evaluated the clinical benefit and cost-effectiveness of a 6-month intradialytic exercise program.

Methods

In a multicenter, single-blinded, randomized, controlled trial, people receiving HD were randomly assigned to (i) intradialytic exercise training (exercise intervention group [EX]) and (ii) usual care (control group [CON]). Primary outcome was change in Kidney Disease Quality of Life Short-Form Physical Component Summary (KDQOL-SF 1.3 PCS) from baseline to 6 months. Cost-effectiveness was determined using health economic analysis; physiological impairment was evaluated by peak oxygen uptake; and harms were recorded.

Results

We randomized 379 participants; 335 and 243 patients (EX n = 127; CON n = 116) completed baseline and 6-month assessments, respectively. Mean difference in change PCS from baseline to 6 months between EX and CON was 2.4 (95% confidence interval [CI]: -0.1 to 4.8) arbitrary units (P = 0.055); no improvements were observed in peak oxygen uptake or secondary outcome measures. Participants in the intervention group had poor compliance (47%) and poor adherence (18%) to the exercise prescription. Cost of delivering intervention ranged from US$598 to US$1092 per participant per year. The number of participants with harms was similar between EX (n = 69) and CON (n = 56). A primary limitation was the lack of an attention CON. Many patients also withdrew from the study or were too unwell to complete all physiological outcome assessments.

Conclusions

A 6-month intradialytic aerobic exercise program was not clinically beneficial in improving HRQoL as delivered to this cohort of deconditioned patients on HD.

Spinning the legs and blood: should intradialytic exercise be routinely offered during maintenance haemodialysis?

Patients with end-stage kidney disease on haemodialysis (HD) have an elevated risk of cardiovascular disease (CVD). These patients also experience high levels of physical deconditioning and programmes of rehabilitation have been tested in a variety of forms with variable success. It has been suggested that programmes of exercise rehabilitation have a role to play in improving the physical condition of patients on HD and in addressing the traditional and non-traditional risk factors that drive CVD for this population. Intradialytic exercise has often been suggested as a convenient way of delivering rehabilitation for patients on HD, as it makes use of otherwise dead time, but there are legitimate concerns about this group of at-risk patients undertaking exercise at a time when their myocardium is already vulnerable to the insults of demand ischaemia from the processes of dialysis and ultrafiltration. A study in this issue of Clinical Kidney Journal provides reassuring data, showing that cycling during dialysis potentially reduces evidence of demand ischaemia (episodes of myocardial stunning). Together with the safety and quality of life data, we expect from the multicentre PrEscription of Intra-Dialytic Exercise to Improve quAlity of Life in Patients With Chronic Kidney Disease study (the protocol for which is published concurrently), rehabilitation programmes that include intradialytic exercise are perhaps closer than ever for patients on HD.

Breathing-based leg exercises during hemodialysis improve quality of life: A randomized controlled trial

OBJECTIVE

To evaluate the effect of a 12-week breathing-based leg exercises program on quality of life under stabilizing heart rate variability and reducing fatigue in regular hemodialysis patients.

DESIGN

Randomized controlled trial.

SETTING

A 94-bed hemodialysis department at a medical center in northern Taiwan.

PARTICIPANTS

Eighty-six patients with end-stage renal disease undergoing hemodialysis were recruited and randomly assigned to the ExBr or control groups.

INTERVENTIONS

The breathing-based leg exercises program comprised abdominal breathing and low-intensity leg exercise, including leg lifts, quadriceps femoris contraction and knee flexion, and lasted for 15 minutes at one time, three times a week for 12 weeks.

MAIN MEASURE

Data was collected by using the World Health Organization quality of life assessment-brief, physiological signal recorder for heart rate variability and hemodialysis-related fatigue scale at baseline and on Week 4, Week 8, and Week 12.

RESULTS

Average (standard deviation) age was 53.70 (10.04) years in the ExBr group and 61.19 (10.19) years in the control group. The linear mixed model with adjusted age, creatinine, heart rate variability and fatigue revealed that the ExBr group had significantly higher quality of life than did the control group (P = 0.01), especially on Week 12 (P = 0.04). Fatigue was significantly correlated with quality of life (P < 0.001).

CONCLUSION

This study supported the benefits of the continued breathing-based leg exercises during hemodialysis for at least 12 weeks, which improved the quality of life of patients with end-stage renal disease and did not affect the stability of their vital signs.

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.

Effect of Aerobic Exercise on Dialysis-Related Symptoms in Individuals Undergoing Maintenance Hemodialysis: A Systematic Review and Meta-Analysis of Clinical Trials

BACKGROUND

Hemodialysis is associated with a high symptom burden that impairs health-related quality of life and functional status. Effective symptom management is a priority for individuals receiving hemodialysis. Aerobic exercise may be an effective, nonpharmacologic treatment for specific hemodialysis-related symptoms. This systematic review investigated the effect of aerobic exercise on hemodialysis-related symptoms in adults with kidney failure undergoing maintenance hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched MEDLINE, PubMed, Cochrane CENTRAL, CINAHL, PsycINFO, SPORTDiscus, EMBASE, PEDro, and Scopus databases from 1960 or inception until April 15, 2020 for randomized controlled trials investigating the effect of aerobic exercise on hemodialysis-related symptoms, identified as prespecified primary or secondary outcomes, as compared with controls in adults on maintenance hemodialysis. We identified restless legs syndrome as the primary outcome.

RESULTS

Of 3048 studies identified, 15 randomized controlled trials met the eligibility criteria. These studies investigated the effect of aerobic exercise on restless legs syndrome (two studies), sleep disturbance (four studies), anxiety (four studies), depression (nine studies), muscle cramping (one study), and fatigue (one study). Exercise interventions were intradialytic in ten studies and outside of hemodialysis in five studies. Heterogenous interventions and outcomes and moderate to high risk of bias precluded meta-analysis for most symptoms. Aerobic exercise demonstrated improvement in symptoms of restless legs syndrome, muscle cramping, and fatigue, as compared with nonexercise controls. Meta-analysis of depressive symptoms in studies using the Beck Depression Inventory demonstrated a greater reduction in Beck Depression Inventory score with exercise as compared with control (mean difference -7.57; 95% confidence interval, -8.25 to -6.89).

CONCLUSIONS

Our review suggests that in adults on maintenance hemodialysis, aerobic exercise improves several hemodialysis-related symptoms, including restless legs syndrome, symptoms of depression, muscle cramping, and fatigue. However, the use of validated outcome measures with demonstrated reliability and responsiveness in more diverse hemodialysis populations is required to fully characterize the effect of this intervention.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

PROSPERO #CRD42017056658.

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.

Multicomponent Home-Based Training Program for Chronic Kidney Disease Patients during Movement Restriction

Both intradialytic and out-of-clinic exercise programs (EP) have been proven to be a safe and effective way to increase fitness levels in end-stage chronic kidney disease (CKD) patients. The actual COVID-19 pandemic situation has forced the suspension of EP offered in hemodialysis centers in many countries; as well as all activities considered as "non-essential" (i.e., sport facilities and fitness centers). Therefore, there is a high risk that movement restrictions would promote physical inactivity and its associated diseases in CKD patients; especially those undergoing domiciliary confinement situations. Given the importance for CKD patients' overall health to maintain exercise levels and reach physical activity recommendations, the aim of this Protocol was to design a personalized, well-structured, multicomponent physical EP that CKD patients can safely follow at home. We also aimed to provide an initial fitness evaluation tool that allows patients to adapt the EP to their fitness level. Current general exercise recommendations for people living with chronic conditions have been analyzed to develop the present home-based EP proposal.

Reasons for Nonparticipation in a Sustained Hemodialysis Intradialytic Exercise Program

OBJECTIVE(S)

Patients with end-stage kidney disease requiring hemodialysis suffer frailty and poor physical function. Exercise can improve physical function; however, barriers exist to intradialytic exercise programs. The objective of this study was to explore patients' reasons for not exercising in an extant intradialytic exercise program.

DESIGN AND METHODS

We conducted a retrospective analysis reporting the reasons for not exercising in an intradialytic exercise program in two hemodialysis centers over a 4-week period. We explored whether patient characteristics and the presence of an exercise professional were associated with missed exercise sessions.

RESULTS

Seventy-five patients participating in the intradialytic exercise program completed 57% of prescribed intradialytic exercise sessions. The three most frequently reported reasons from patients not exercising were refusal (24%), followed by fatigue (19%) and symptoms (14%). Patients were more than twice as likely to exercise if a kinesiologist was present (odds ratio [OR]: 2.26, confidence interval [CI]: 1.5, 3.4 P = .03). They were less likely to exercise if they were women (OR: 0.66, CI: 0.45, 0.95 P = .002), had been on dialysis greater than 60 months (OR: 0.55, CI: 0.37, 0.80 P < .002), or had more than two comorbid conditions (OR: 0.63, CI: 0.43, 0.90, P = .01).

CONCLUSION

Patient adherence to intradialytic exercise programs is strongly associated with the presence of exercise professionals.

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.

Impact of Physical Activity on Dialysis and Nondialysis Days and Clinical Outcomes Among Patients on Hemodialysis

OBJECTIVE

Patients undergoing hemodialysis (HD) have different physical activity (PA) patterns on HD and non-HD days. Nonetheless, whether these differences are associated with clinical outcomes remains unclear. We examined the association of PA levels on HD and non-HD days with cardiovascular (CV) hospitalizations and mortality.

METHODS

Outpatients undergoing HD from 2002 to 2019 were retrospectively enrolled. The number of steps performed over 3 HD days and 4 non-HD days was recorded via accelerometry. Outcomes were all-cause mortality and a composite of CV hospitalizations and mortality. Patients were divided into two groups, each according to the median number of steps performed on HD (2371 steps/day) and non-HD days (3752 steps/day). Further, we categorized them into 4 groups according to each median values: "more active on HD/more active on non-HD (MM)," "more active on HD/less active on non-HD (ML)," "less active on HD/more active on non-HD (LM)," and "less active on HD/less active on non-HD (LL)." Cox and mixed-effects Poisson regression models were used for these outcomes.

RESULTS

We analyzed 512 patients (median follow-up, 3.4 years). Higher PA on HD (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.54-0.65), and non-HD (HR, 0.84; 95% CI, 0.80-0.88) was associated with lower mortality risk, respectively. Further, the ML group (HR, 1.20; 95% CI, 1.13-1.28), LM group (HR, 1.82; 95% CI, 1.53-2.17), and LL group (HR, 1.83; 95% CI, 1.65-2.02) had higher mortality risks than the MM group. Associations of PA with multiple CV hospitalizations and mortality were similar to those between PA and mortality.

CONCLUSIONS

Higher PA on HD and non-HD days was associated with lower risks of CV hospitalizations and mortality. However, higher PA levels on either HD or non-HD days alone did not improve clinical outcomes.

Exercise for people living with frailty and receiving haemodialysis: a mixed-methods randomised controlled feasibility study

OBJECTIVES

Frailty is highly prevalent in haemodialysis (HD) patients, leading to poor outcomes. This study aimed to determine whether a randomised controlled trial (RCT) of intradialytic exercise is feasible for frail HD patients, and explore how the intervention may be tailored to their needs.

DESIGN

Mixed-methods feasibility.

SETTING AND PARTICIPANTS

Prevalent adult HD patients of the CYCLE-HD trial with a Clinical Frailty Scale Score of 4-7 (vulnerable to severely frail) were eligible for the feasibility study.

INTERVENTIONS

Participants in the exercise group undertook 6 months of three times per week, progressive, moderate intensity intradialytic cycling (IDC).

OUTCOMES

Primary outcomes were related to feasibility. Secondary outcomes were falls incidence measured from baseline to 1 year following intervention completion, and exercise capacity, physical function, physical activity and patient-reported outcomes measured at baseline and 6 months. Acceptability of trial procedures and the intervention were explored via diaries and interviews with n=25 frail HD patients who both participated in (n=13, 52%), and declined (n=12, 48%), the trial.

RESULTS

124 (30%) patients were eligible, and of these 64 (52%) consented with 51 (80%) subsequently completing a baseline assessment. n=24 (71% male; 59±13 years) dialysed during shifts randomly assigned to exercise and n=27 (81% male; 65±11 years) shifts assigned to usual care. n=6 (12%) were lost to follow-up. The exercise group completed 74% of sessions. 27%-89% of secondary outcome data were missing. Frail HD patients outlined several ways to enhance trial procedures. Maintaining ability to undertake activities of daily living and social participation were outcomes of primary importance. Participants desired a varied exercise programme.

CONCLUSIONS

A definitive RCT is feasible, however a comprehensive exercise programme may be more efficacious than IDC in this population.

TRIAL REGISTRATION NUMBERS

ISRCTN11299707; ISRCTN12840463.

Effects of intradialytic cycling exercise on daily physical activity, physical fitness, body composition, and clinical parameters in high-volume online hemodiafiltration patients: a pilot randomized-controlled trial

PURPOSE

The mortality of dialysis patients treated with high-volume online hemodiafiltration (OL-HDF) is better than hemodialysis, but is still higher than healthy population. Low daily physical activity increases cardiovascular mortality. Addition of intradialytic exercise (IDX) program might improve physical activity and health status in OL-HDF patients. This pilot open-labeled randomized-controlled trial was conducted to evaluate the effects of IDX on physical activity and other clinical parameters in OL-HDF patients.

METHODS

Twelve OL-HDF patients were randomized into control (n = 6) or IDX (n = 6) groups. The subjects in IDX group were trained to exercise using a cycle ergometer for 60 min during each OL-HDF session. Physical activity measured as daily step count using a wrist-worn triaxial accelerometer, physical fitness, or cardiorespiratory fitness assessed by VO₂max and other physical performance tests, lean body mass determined by the Dual-energy X-ray absorptiometry (DXA), quality of life (QOL), and various parameters were compared between baseline and 6 months.

RESULTS

The baseline physical activity status was comparable. Following 6-month IDX, the physical activity was significantly improved in IDX group [+ 1048.79 (+ 741.50, + 2792.54) vs. - 362.06 (- 1626.82, - 167.47) steps/day, p = 0.01], while physical fitness and QOL were unchanged. The lean body mass parameters were preserved in the IDX group while seemed to decrease in the control group. Serum albumin was significantly increased in the IDX group (p = 0.01). The hemoglobin changes were significantly better (p = 0.01) and the erythropoietin resistance index was significantly lower in the IDX group (p = 0.03). Phosphate reduction was significantly greater in the IDX group (p = 0.04).

CONCLUSIONS

IDX could improve physical activity and other metabolic parameters in OL-HDF patients and these might contribute to further improvement in clinical and survival outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Registration: NCT03353844.

A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions Are Needed

Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity.

The Effect of Exercise on Nutritional Status and Body Composition in Hemodialysis: A Systematic Review

Chronic kidney disease (CKD) is associated with aggravating factors which can affect both body composition and nutritional status. The purpose of the present systematic review was to investigate the potential effects of any physical activity on body composition or nutritional status among patients with stage 5 CKD undergoing hemodialysis (HD). A literature search on PubMed, Scopus, Web of Science, Google Scholar, and Cochrane was conducted and 14 randomized clinical trials were included. Skeletal muscle index and mid-arm muscular circumference increased after resistance exercise, and the results on body mass index, % body fat, and lean body mass varied. Serum albumin and C-reactive protein, in most cases, showed a slight increase and decrease, respectively. An improvement was also observed in body strength and overall performance status. The results suggest that physical activity can be beneficial for both the body composition and nutritional status of patients undergoing HD and can help in the prevention of sarcopenia. However, further research is needed mainly in the field of nutritional status.