Exercise and end-stage kidney disease: functional exercise capacity and cardiovascular outcomes

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

BACKGROUND

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

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NCT04660383.

The effect of a 9-month hybrid intradialytic exercise training program on nerve conduction velocity parameters in patients receiving hemodialysis therapy

INTRODUCTION AND AIMS

Neurological complications such as peripheral neuropathy are very common in the end-stage renal disease (ESRD) patients, occurring in 60-80% of this specific population. The aim of the present study was to examine whether a 9-month hybrid intradialytic exercise training program could alter motor and sensory nerve conduction study (NCS) parameters in hemodialysis population.

METHODS

Seventeen stable patients undergoing HD with no clinical evidence of uremic polyneuropathy were included in the study (15 M/2F, 59 ± 13.7 years). All patients completed a 9-month supervised exercise training program composed of both aerobic cycling and resistance training (hybrid) during HD. Functional capacity was assessed by a battery of tests, while pain levels and fatigue profile were assessed via validated questionnaires. Motor and sensory NCS on bilateral median, ulnar, peroneal and tibial nerves as well as F-wave were assessed using a full neurographic electromyography (EMG) assessment.

RESULTS

After the 9-month exercise training intervention, exercise capacity was increased by 65% and functional capacity by an average of 40%. The neurological assessment showed that conduction velocity from tibial and peroneal nerves was improved by 3.7% and 4.2%, respectively, while tibial F-wave latency and peroneal and sural nerve distal latency were significantly improved by 4.2%, 4.9% and 10%, respectively. Fatigue and pain were improved after the exercise intervention while fatigue score was positively correlated with conduction velocity and amplitude values.

CONCLUSIONS

The results of the current study demonstrate that 9-month hybrid exercise training induces beneficial effects on both sensory and motor NCS parameters, improving conduction velocity and F-wave latency. Improvements in neural activity were accompanied by changes in fatigue score and pain-related aspects. The parallel improvement in motor nerve conduction velocity and its correlations with functional tests supports the hypothesis that exercise could be beneficial for preventing a decline in neural function in HD patients.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

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

Effects of 12 months of detraining on health-related quality of life in patients receiving hemodialysis therapy

PURPOSE

Limited data exist regarding the effects of detraining on functional capacity and quality of life (QoL) in the hemodialysis population. The aim of the current study was to assess whether the discontinuation from a systematic intradialytic exercise training program will affect aspects of health-related QoL and functional capacity in hemodialysis patients.

METHODS

Seventeen hemodialysis patients (12 Males/5 Females, age 60.8 ± 13.6 year) participated in this study. Patients were assessed for functional capacity using various functional capacity tests while QoL, daily sleepiness, sleep quality, depression and fatigue were assessed using validated questionnaires at the end of a 12-month aerobic exercise program and after 12 months of detraining.

RESULTS

The detraining significantly reduced patients' QoL score by 20% (P = 0.01). More affected were aspects related to the physical component summary of the QoL (P < 0.001) rather than those related to the mental one (P = 0.096). In addition, the performance in the functional capacity tests was reduced (P < 0.05), while sleep quality (P = 0.020) and daily sleepiness scores (P = 0.006) were significantly worse after the detraining period. Depressive symptoms (P = 0.214) and the level of fatigue (P = 0.163) did not change significantly.

CONCLUSIONS

Detraining has a detrimental effect in patients' QoL, functional capacity and sleep quality. The affected physical health contributed significantly to the lower QoL score. It is crucial for the chronic disease patients, even during emergencies such as lockdowns and restrictions in activities to maintain a minimum level of activity to preserve some of the acquired benefits and maintain their health status.

Intradialytic exercise preconditioning: an exploratory study on the effect on myocardial stunning

BACKGROUND

Exercise preconditioning provides immediate protection against cardiac ischemia in clinical/preclinical studies in subjects without chronic kidney disease. In individuals requiring renal replacement therapy, hemodialysis (HD) results in significant circulatory stress, causing acute ischemia with resultant recurrent and cumulative cardiac injury (myocardial stunning). Intradialytic exercise (IDE) has been utilized to improve functional status in individuals receiving HD. The objective of this study was to explore the role of IDE as a preconditioning intervention and assess its effect on HD-induced myocardial stunning.

METHODS

We performed a single-center cross-sectional exploratory study in adults on chronic HD participating in a clinical IDE program. HD-induced cardiac stunning was evaluated over two HD sessions within the same week: a control visit (no exercise) and an exposure visit (usual intradialytic cycling). Echocardiography was performed at the same three time points for each visit. Longitudinal strain values for 12 left ventricular segments were generated using speckle-tracking software to assess the presence of HD-induced regional wall motion abnormalities (RWMAs), defined as a ≥20% reduction in strain; two or more RWMAs represent myocardial stunning.

RESULTS

A total of 19 patients were analyzed (mean age 57.2 ± 11.8 years, median dialysis vintage 3.8 years). The mean number of RWMAs during the control visit was 4.5 ± 2.6, falling to 3.6 ± 2.7 when incorporating IDE (a reduction of -0.95 ± 2.9; P = 0.17). At peak HD stress, the mean number of RWMAs was 5.8 ± 2.7 in the control visit versus 4.0 ± 1.8 during the exposure visit (a reduction of -1.8 ± 2.8; P = 0.01).

CONCLUSION

We demonstrated for the first time that IDE is associated with a significant reduction in HD-induced acute cardiac injury.

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

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

Exercise interventions for improving objective physical function in patients with end-stage kidney disease on dialysis: a systematic review and meta-analysis

Patients with end-stage kidney disease on dialysis have increased mortality and reduced physical activity, contributing to impaired physical function. Although exercise programs have demonstrated a positive effect on physiological outcomes such as cardiovascular function and strength, there is a reduced focus on physical function. The aim of this review was to determine whether exercise programs improve objective measures of physical function indicative of activities of daily living for patients with end-stage kidney disease on dialysis. A systematic search of Medline, Embase, the Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing and Allied Health Literature identified 27 randomized control trials. Only randomized control trials using an exercise intervention or significant muscular activation in the intervention, a usual care, nonexercising control group, and at least one objective measure of physical function were included. Participants were ≥18 yr of age, with end-stage kidney disease, undergoing hemo- or peritoneal dialysis. Systematic review of the literature and quality assessment of the included studies used the Cochrane Collaboration’s tool for assessing risk bias. A meta-analysis was completed for the 6-min walk test. Data from 27 studies with 1,156 participants showed that exercise, regardless of modality, generally increased 6-min walk test distance, sit-to-stand time or repetitions, and grip strength as well as step and stair climb times or repetitions, dynamic mobility, and short physical performance battery scores. From the evidence available, exercise, regardless of modality, improved objective measures of physical function for end-stage kidney disease patients undergoing dialysis. It is acknowledged that further well-designed randomized control trials are required.

"A Learned Soul to Guide Me": The Voices of Those Living with Kidney Disease Inform Physical Activity Programming

Purpose: The purpose of this study was to (a) confirm the barriers to and facilitators of physical activity (PA) among persons living with chronic kidney disease (CKD) in Ontario and (b) inform the design of a Kidney Foundation of Canada Active Living for Life programme for persons living with CKD. Method: Adults living with CKD in Ontario were invited to participate in a cross-sectional survey investigating opinions about and needs for PA programming. The 32-item survey contained four sections: programme delivery preferences, current PA behaviour, determinants of PA, and demographics. Data were summarized using descriptive statistics and thematic coding. Results: A total of 63 respondents participated. They had a mean age of 56 (SD 16) years, were 50% female, and were 54% Caucasian; 66% had some post-secondary education. The most commonly reported total weekly PA was 90 minutes (range 0-1,050 minutes). Most respondents (84%) did not regularly perform strength training, and 73% reported having an interest in participating in a PA programme. Conclusion: Individuals living with CKD require resources to support and maintain a physically active lifestyle. We identified a diversity of needs, and they require a flexible and individualized inter-professional strategy that is responsive to the episodic changes in health status common in this population.

Exosomes as Mediators of the Systemic Adaptations to Endurance Exercise

Habitual endurance exercise training is associated with multisystemic metabolic adaptations that lower the risk of inactivity-associated disorders such as obesity and type 2 diabetes mellitus (T2DM). Identification of complex systemic signaling networks responsible for these benefits are of great interest because of their therapeutic potential in metabolic diseases; however, specific signals that modulate the multisystemic benefits of exercise in multiple tissues and organs are only recently being discovered. Accumulated evidence suggests that muscle and other tissues have an endocrine function and release peptides and nucleic acids into the circulation in response to acute endurance exercise to mediate the multisystemic adaptations. Factors released from skeletal muscle have been termed myokines and we propose that the total of all factors released in response to endurance exercise (including peptides, nucleic acids, and metabolites) be termed, "exerkines." We propose that many of the exerkines are released within extracellular vesicles called exosomes, which regulate peripheral organ cross talk. Exosomes (30-140 nm) and larger microvesicles [MVs] (100-1000 nm) are subcategories of extracellular vesicles that are released into the circulation. Exosomes contain peptides and several nucleic acids (microRNA [miRNA], messenger RNA [mRNA], mitochondrial DNA [mtDNA]) and are involved in intercellular/tissue exchange of their contents. An acute bout of endurance exercise increases circulating exosomes that are hypothesized to mediate organ cross talk to promote systemic adaptation to endurance exercise. Further support for the role of exosomes (and possibly MVs) in mediating the systemic benefits of exercise comes from the fact that the majority of the previously reported myokines/exerkines are found in extracellular vesicles databases (Vesiclepedia and ExoCarta). We propose that exosomes isolated from athletes following exercise or exosomes bioengineered to incorporate one or many of known exerkines will be therapeutically useful in the treatment of obesity, T2DM, and other aging-associated metabolic disorders.

Factors Associated With Functional Capacity in Hemodialysis Patients

Hemodialysis patients have a marked decrease in functional capacity when compared to healthy individuals. We evaluated the factors associated with functional capacity in hemodialysis patients. A total of 102 hemodialysis patients were evaluated. The patients were submitted to a 6-min walk test, peripheral muscle strength tests, and an evaluation of quality of life, anxiety, and depression. The laboratory data were measured. The 6-min walk test distance correlated significantly with age, educational level, hemoglobin, creatinine, number of comorbidities, peripheral muscle strength, and some domains of SF-36 quality of life questionnaire and depression (P < 0.05). Multiple linear regression showed that educational level, hemoglobin, peripheral muscle strength, and depression significantly affected the 6-min walk test distance (P < 0.05). The multiple correlation coefficient was 0.74, and the squared multiple correlation coefficient adjusted was 0.52. In conclusion, functional capacity was significantly associated with educational level, hemoglobin, peripheral muscle strength, and depression in hemodialysis patients.

Effects of intradialytic exercise on the physical function, depression and quality of life for haemodialysis patients: a systematic review and meta-analysis of randomised controlled trials

AIMS AND OBJECTIVES

To determine the efficacy and safety of intradialytic exercises for haemodialysis patients, this study conducted a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND

Patients receiving haemodialysis have poor physical function, psychological status and quality of life than the general population. Exercise training may improve these parameters for haemodialysis patients.

DESIGN

Systemic review was performed, and a meta-analysis was conducted.

METHODS

Medline, PubMed, Cochrane Central Register of Controlled Trials, SPORTDiscus, Cumulative Index to Nursing and Allied Health Literature and Airiti Library were systematically searched for studies up to January 2015. In addition, the reference lists of eligible studies and relevant reviews were assessed.

RESULTS

Seventeen studies with a total of 651 participants were included. Compared with no resistance exercise, nonexercise and walks at home, intradialytic exercises significantly improved the peak oxygen consumption (SMD = 0·50, 95% CI: 0·26-0·74), haemoglobin (SMD = 0·34, 95% CI: 0·13-0·55), depression (SMD = -0·80, 95% CI: -1·10 to -0·50) and physical component of the quality of life (SMD = 0·46, 95% CI: 0·20-0·73). Intradialytic exercises are safe with no adverse events. However, significant improvements were not observed in the albumin level and mental component of the quality of life.

CONCLUSIONS

The study results facilitate selecting intradialytic exercise that improves and provides safety with respect to the peak oxygen consumption, haemoglobin, depression and physical component of the quality of life. Furthermore, regular exercise should be considered a crucial therapeutic modality for patients undergoing haemodialysis.

RELEVANCE TO CLINICAL PRACTICE

This study suggests that performing intradialytic exercises for 30 minutes per session three times a week for at least ≥8 weeks is beneficial. Regular exercise should be considered as a crucial therapeutic modality of managing patients undergoing haemodialysis, thus guiding in clinical practice.

Prehabilitation for the Frail Patient Approaching ESRD

Frailty is a distinct phenotype that is highly prevalent in chronic kidney disease (CKD) and appears to be more prevalent with decreasing glomerular filtration rate. Exercise training or intervention to increase physical activity may ameliorate poor physical functioning and frailty, and even may improve survival in patients with CKD. Although exercise interventions improve outcomes across the spectrum of CKD, including patients treated with dialysis, patients treated with dialysis face barriers to exercise that patients with predialysis CKD do not. Rehabilitation at earlier stages of CKD (or prehabilitation before dialysis) might be more beneficial than not addressing the decreasing physical functioning and low physical activity until patients are receiving dialysis. This review summarizes available literature on frailty in the CKD and end-stage renal disease population, including exercise interventions and the limited evidence for prehabilitation as a strategy.

Intradialytic Exercise is Medicine for Hemodialysis Patients

When a person's kidneys fail, hemodialysis (HD) is the most common treatment modality. With a growing number of patients requiring this life-sustaining treatment, and with evidence illustrating the significant physical dysfunction of this population, encouraging exercise is essential. The use of intradialytic exercise, as a novel and efficient use of time during HD, is well established in Australia and some European nations; however, it is slower to start in North America. While a large number of small studies have demonstrated numerous benefits and safe delivery of intradialytic exercise training for patients with end-stage kidney disease, intradialytic exercise is rarely delivered as standard of care. It is of utmost importance for health care staff to overcome barriers and bring theory into practice. Included in this report are current recommendations from governing bodies, expert opinion, as well as established policies and procedures from a successful intradialytic exercise program in Canada.

[The Experience of Fluid Management in Hemodialysis Patients]

PURPOSE

The purpose of this study was to explore the experience of fluid management in hemodialysis patients by describing how they manage fluid intake and what affects fluid management.

METHODS

Purposive sampling yielded 11 patients who have received hemodialysis for one year or longer in one general hospital. Data were collected through in-depth interviews and analysed using Giorgi's phenomenological method. Data collection and analysis were performed concurrently.

RESULTS

The findings regarding how hemodialysis patients manage fluid intake were classified into four constituents: 'recognizing the need for fluid control', 'observing the status of fluid accumulation', 'controlling fluid intake and output', 'getting used to fluid management'. The factors that affect fluid management of hemodialysis patients were revealed as 'willpower', 'change in the mindset', 'support system', and 'emotional state'.

CONCLUSION

The study results show that hemodialysis patients manage fluid intake through food and exercise as well as interpersonal relationships. These findings suggest that strategies in the development of nursing interventions for hemodialysis patients should be directed at assisting them in familiarization with fluid management based on an understanding of their sociocultural contexts.

The association between intradialytic exercise and hospital usage among hemodialysis patients

Hemodialysis (HD) patients have high hospitalization rates. Benefits of intradialytic exercise have been proven in numerous studies yet exercise programs are still rarely used in the treatment of end-stage kidney disease (ESKD). Our objective was to determine if there was an association between a 6-month intradialytic bicycling program and hospitalization rates and length of stay (LOS) in ESKD patients. This was a retrospective cohort study that took place 6 months prior to and 6 months during an intradialtyic exercise program at an outpatient HD unit in Calgary, Alberta, Canada. Participants comprised 102 patients who had commenced HD <6 months (incident) or >6 months (prevalent) prior to starting exercise. The intervention comprised a 6-month intradialytic bicycling program. Main outcome measures were hospitalization rate, cause of hospitalization, and LOS. Patients were predominantly male (67.6%) aged 65.6 ± 13.5 years and median HD vintage 1 year (range: 0–12). Comorbidities included diabetes mellitus (50%) and cardiac disease (38.2%). The hospitalization incidence rate ratio (IRR) was 0.48 (0.23–0.98; P = 0.04) in incident and 0.89 (0.56–1.42; P = 0.64) in prevalent patients. The LOS decreased from 7.8 (95% confidence interval (CI): 7.3–8.4) to 3.1 (95% CI: 2.8–3.4) days and LOS IRR was 0.39 (0.35–0.45; P < 0.001). The main predictors of hospitalization were lower albumin levels (P = 0.007) and lack of intradialytic exercise program participation (P < 0.001). In conclusion, 6 months of intradialytic exercise was associated with decreased LOS in both incident and prevalent HD patients.

Intra-dialytic training accelerates oxygen uptake kinetics in hemodialysis patients

BACKGROUND

End-stage renal disease is associated with several hemodynamic and peripheral muscle abnormalities that could slow the rate of change in oxygen uptake ([Formula: see text]O2) at the onset and at the end of exercise. This study was performed to determine whether an intra-dialytic aerobic training program would speed [Formula: see text]O2 kinetics at the transition to and from moderate and high-intensity exercise.

DESIGN

This study was a randomized controlled trial.

METHODS

Twenty-four patients with end-stage renal disease (14 females; 47.0 ± 11.9 years) were randomly assigned to either 12-week cycle ergometer-based training at moderate exertion or a similar control period. At initial and final evaluations, patients underwent 6 min moderate and high-intensity tests to exercise intolerance (Tlim).

RESULTS

Training improved Tlim by ∼90% (median (inter-quartile range) = 232 (59) s to 445 (451) s, p < 0.05); in contrast, Tlim decreased by ∼30% in controls (291 (134) s to 202 (131) s). [Formula: see text]O2 kinetics at the onset of moderate-intensity exercise were significantly accelerated with training leading to lower oxygen (O2) deficit (mean ± standard deviation (SD) = 3.2 ± 1.3 l vs 2.3 ± 1.2 l). Similar positive effects were found at the high-intensity test either at the onset of, or recovery from, exercise (p < 0.05). "Excess" [Formula: see text]O2 at the high-intensity test was also lessened with training. Changes in Tlim correlated with faster [Formula: see text]O2 kinetics and lower "excess" [Formula: see text]O2 (Spearman's ρ = -0.56 and -0.75, respectively; p < 0.01).

CONCLUSIONS

A symptom-targeted intra-dialytic training program improved sub-maximal aerobic metabolism and endurance exercise capacity. [Formula: see text]O2 kinetics are valuable in providing relatively effort-independent information on the efficacy of exercise interventions in this patient population.

A single-blind randomized controlled trial to evaluate the effect of 6 months of progressive aerobic exercise training in patients with uraemic restless legs syndrome

BACKGROUND

Uraemic restless legs syndrome (RLS) affects a significant proportion of patients receiving haemodialysis (HD) therapy. Exercise training has been shown to improve RLS symptoms in uraemic RLS patients; however, the mechanism of exercise-induced changes in RLS severity is still unknown. The aim of the current randomized controlled exercise trial was to investigate whether the reduction of RLS severity, often seen after training, is due to expected systemic exercise adaptations or it is mainly due to the relief that leg movements confer during exercise training on a cycle ergometer. This is the first randomized controlled exercise study in uraemic RLS patients.

METHODS

Twenty-four RLS HD patients were randomly assigned to two groups: the progressive exercise training group (n = 12) and the control exercise with no resistance group (n = 12). The exercise session in both groups included intradialytic cycling for 45 min at 50 rpm. However, only in the progressive exercise training group was resistance applied, at 60-65% of maximum exercise capacity, which was reassessed every 4 weeks to account for the patients' improvement. The severity of RLS symptoms was evaluated using the IRLSSG severity scale, functional capacity by a battery of tests, while sleep quality, depression levels and daily sleepiness status were assessed via validated questionnaires, before and after the intervention period.

RESULTS

All patients completed the exercise programme with no adverse effects. RLS symptom severity declined by 58% (P = 0.003) in the progressive exercise training group, while a no statistically significant decline was observed in the control group (17% change, P = 0.124). Exercise training was also effective in terms of improving functional capacity (P = 0.04), sleep quality (P = 0.038) and depression score (P = 0.000) in HD patients, while no significant changes were observed in the control group. After 6 months of the intervention, RLS severity (P = 0.017), depression score (P = 0.002) and daily sleepiness status (P = 0.05) appeared to be significantly better in the progressive exercise group compared with the control group.

CONCLUSION

A 6-month intradialytic progressive exercise training programme appears to be a safe and effective approach in reducing RLS symptom severity in HD patients. It seems that exercise-induced adaptations to the whole body are mostly responsible for the reduction in RLS severity score, since the exercise with no applied resistance protocol failed to improve the RLS severity status of the patients.

Exercise in kidney disease and diabetes: time for action

Physical inactivity is well recognised as a major health issue in today's society. Regular exercise is important in maintaining health and preventing chronic disease, it is increasingly accepted as a valuable therapeutic intervention in many long-term conditions. Unfortunately the role of physical activity in renal disease has been largely overlooked and provision of exercise advice and rehabilitation programmes for kidney patients lags well behind that of cardiology and pulmonary services. Research indicates that exercise can impact positively upon many of the health issues associated with declining renal function and renal replacement therapy, as concluded by a recent Cochrane review on the topic. As exercise should be integral to the management of diabetes, the issue is particularly relevant for patients with diabetic kidney disease. This paper summarises what is known about the main effects of exercise training in chronic kidney disease and diabetic kidney disease, and suggests how adaptations in the attitudes and approaches of the multidisciplinary renal and diabetes healthcare teams can help patients to enjoy the diverse benefits of an appropriately active lifestyle.

Exercise training in chronic kidney disease patients

Chronic kidney disease (CKD) is a major public health problem that affects an estimated 1.7 million Australians. Patients with CKD commonly progress to end-stage kidney disease (ESKD) requiring dialysis and/or kidney transplantation. They are at high risk of cardiovascular disease and many die from this prior to reaching ESKD. Few therapies are available to slow CKD progression and reduce cardiovascular morbidity and mortality. The benefit of exercise training has been well demonstrated in a range of disease conditions including ESKD and was recently highlighted by a systematic review in haemodialysis patients and a recent Cochrane review of all stages of CKD. However, the effects of exercise training in patients with CKD have not been extensively investigated. Our systematic search of the literature found only ten clinical trials in this area. The aim of this review is to review these studies, and to discuss the findings, safety considerations and suggest future areas of research. Overall, the majority of the studies are small, non-randomized, non-controlled trials. They have found that exercise training can increase exercise capacity, improve muscle strength and function, decrease blood pressure, and improve inflammation and oxidative stress biomarkers. The effects of exercise training on kidney function, cardiovascular disease and quality of life are unknown. Studies are needed to answer these questions and develop evidence-based exercise training guidelines for individuals with CKD.

Patients' perspectives on the implementation of intra-dialytic cycling--a phenomenographic study

BACKGROUND

Adults undergoing haemodialysis have significantly reduced physical capacity and run a high risk of developing cardiovascular complications. Research has shown that intra-dialytic cycling has many evidence-based health effects, but implementation is rare within renal clinical practice. This may be due to several causes, and this study focuses on the patients' perspective. This perspective has seldom been taken into account when aiming to assess and improve the implementation of clinical research. The aim of this study was to describe how adults undergoing in-centre haemodialysis treatment experienced an implementation process of intra-dialytic cycling. It aimed to identify potential motivators and barriers to the implementation process from a patient perspective.

METHODS

Maximum-variation purposive sampling was used. Data were collected until saturation, through semistructured interviews, which were analysed using phenomenography.

RESULTS

The implementation of intra-dialytic cycling was experienced as positive, as it had beneficial effects on physical and psychological well-being. It was easy to perform and did not intrude on patients' spare time. These factors increased the acceptance of the implementation and supported the maintenance of intra-dialytic cycling as an evidence-based routine within their haemodialysis care. The patients did, however, experience some barriers to accepting the implementation of intra-dialytic cycling. These barriers were sometimes so strong that they outweighed the participants' knowledge of the advantages of intra-dialytic cycling and the research evidence of its benefits. The barriers sometimes also outweighed the participants' own wish to cycle. The barriers that we identified concerned not only the patients but also the work situation of the haemodialysis nurses.

CONCLUSIONS

Consideration of the motivators and barriers that we have identified can be used in direct care to improve the implementation of intra-dialytic cycling.

Exercise in individuals with CKD

There are few studies evaluating exercise in the nondialysis chronic kidney disease (CKD) population. This review covers the rationale for exercise in patients with CKD not requiring dialysis and the effects of exercise training on physical functioning, progression of kidney disease, and cardiovascular risk factors. In addition, we address the issue of the risk of exercise and make recommendations for implementation of exercise in this population. Evidence from uncontrolled studies and small randomized controlled trials shows that exercise training results in improved physical performance and functioning in patients with CKD. In addition, although there are no studies examining cardiovascular outcomes, several studies suggest that cardiovascular risk factors such as hypertension, inflammation, and oxidative stress may be improved with exercise training in this population. Although the current literature does not allow for definitive conclusions about whether exercise training slows the progression of kidney disease, no study has reported worsening of kidney function as a result of exercise training. In the absence of guidelines specific to the CKD population, recent guidelines developed for older individuals and patients with chronic disease should be applied to the CKD population. In sum, exercise appears to be safe in this patient population if begun at moderate intensity and increased gradually. The evidence suggests that the risk of remaining inactive is higher. Patients should be advised to increase their physical activity when possible and be referred to physical therapy or cardiac rehabilitation programs when appropriate.