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

Body Composition and Intradialytic Exercise in Kidney Disease: A Combined Analysis of the PEDAL and CYCLE-HD Randomised Controlled Trials

BACKGROUND

Haemodialysis patients are at high risk of myopenic obesity, necessitating effective nutritional status monitoring and intervention strategies. This combined analysis of two clinical trials (PEDAL trial and CYCLE-HD study) aimed to (i) determine the clinical utility of body mass index (BMI) in comparison to fat tissue index (FTI) and lean tissue index (LTI) and (ii) assess the effect of a 6-month intradialytic exercise intervention compared to usual care on FTI and LTI.

METHODS

A priori secondary endpoints in both trials included BMI, FTI and LTI. BMI was classified by World Health Organisation definitions (underweight, healthy, overweight or obese). FTI and LTI were determined by Bioelectrical Impedance Spectroscopy and classified by previous research evidence (FTI of 4-15 kg/m2 and LTI of 15-20 kg/m2 being associated with best survival). For aim (i), BMI was compared to FTI and LTI by correlation and classification. For aim (ii), changes over 6 months in FTI and LTI were compared between exercise intervention and control groups.

RESULTS

Across both studies, 298 and 209 participants had bioelectrical impedance spectroscopy measurement at baseline and 6 months, respectively. Mean (SD) age: 58 (15) years; BMI: 28.2(6.3) kg/m2; male: 65%. At baseline, only 47 of 298 participants (16%) had an FTI and LTI associated with best survival. BMI correlated with FTI (r = 0.79; p < 0.0001). However, 34% of participants were misclassified by BMI (e.g., 9% of patients were classified as obese by BMI yet FTI revealed their body composition was healthy). BMI did not correlate with LTI (p = 0.15), and 86% of participants were misclassified by BMI (e.g., 73% of patients were classified as healthy, overweight or obese by BMI yet LTI revealed they were myopenic). There was no difference between exercise intervention and control groups in mean change (95% CI) over 6 months for LTI (-0.3 [-1.1 to 0.4] kg/m2; p = 0.4) or FTI (0.2 [-0.7 to 1.0] kg/m2; p = 0.7).

CONCLUSIONS

Worryingly, only a minority (16%) of haemodialysis patients had both LTI and FTI within the range associated with best survival. Body composition misclassification using conventional BMI cut-offs was common: despite having healthy, overweight or even obese BMI, the majority (73%) of patients had hidden myopenia according to LTI. Six months of intradialytic aerobic exercise did not improve body composition. This study identified that common measures of nutritional status in haemodialysis patients such as BMI are misleading and that interventions other than intradialytic cycling are urgently required to target myopenic obesity.

Prescribing Physical Activity and Exercise for People with CKD: A Practical Guide by the Global Renal Exercise Network

Physical activity (PA) and exercise are fundamental to optimizing and maintaining health. The evidence on the benefits of PA and exercise in people with CKD is well-established. Yet patients remain inactive, partly driven by a lack of knowledge and confidence from the healthcare providers involved in their management. A potential key element in improving PA in CKD includes better provisions around education, tools, and training resources among nephrology healthcare providers on PA recommendations, counseling, prescription, and referral to appropriate professionals for assessment, implementation, and monitoring. Much like other pharmacologic therapies, an effective prescription should be prescribed at the correct dose, strength, and frequency to the individual, titrated (and progressed) to optimize adherence and safety, and reviewed regularly to ensure maximum effectiveness. Aside from a formal prescription of exercise, many people would benefit from modest improvements in daily PA, and an emphasis on reducing sedentary behavior is likely to confer beneficial effects on outcomes. The purpose of this article is to outline the key components of successful PA and exercise prescriptions, including understanding the barriers and facilitators individuals may have, taking a PA history, and how to tailor exercise "dose" to each patient with the ultimate goal of increasing accessibility of PA for all people living with CKD. To do this, we will use worked examples to demonstrate what an exercise prescription may consist of across each of the major CKD stages.

Perceptions of healthcare providers on benefits, risks and barriers regarding intradialytic exercise among haemodialysis patients

PURPOSE

Clinical guidelines call for the inclusion of exercise interventions in every patient's dialysis session, but these recommendations are rarely adopted. Healthcare providers play a key role in this. Therefore, the aim of this study was to explore how healthcare providers perceive the benefits, risks and barriers of intradialytic exercise (IDE).

METHODS

We conducted 21 individual, semi-structured interviews with 11 nurses, 5 nephrologists, 3 training assistants and 2 managers from two dialysis centres in Slovakia. Verbatim transcripts of digitally recorded interviews were thematically analysed using MAXQDA®.

RESULTS

Participants reported the benefits of IDE as improvements in patients' physical and psychosocial functioning, independence and self-efficacy, clinical profile and quality of therapy. As risks of IDE, they most frequently reported exercise-related damage to vascular access, insufficient individualization of training and musculoskeletal injuries. The presence of psychological problems among patients was reported as a major barrier for initiating and maintaining patients' exercise. Other reported barriers included limitations in financial and personnel resources of haemodialysis care.

CONCLUSIONS

Safe and sustainable implementation of IDE, which might improve a patient's well-being, need to be prescribed in alignment with the patient's clinical profile, be delivered individually according to the patient's characteristics and requires adjustments in the available resources.

Exercise training and chronic kidney disease: characterization and bibliometrics of citation classics of clinical intervention trials

BACKGROUND

Exercise research targeting chronic kidney disease (CKD) has been conducted for more than 30 years, and the benefits of exercise for CKD patients have been progressively demonstrated. This study analyzes citation classics on clinical intervention trials on exercise training and CKD to describe the research landscape and hotspots through bibliometric analysis.

METHODS

To identify clinical trials of exercise training interventions for CKD with more than 100 citations from the Web of Science Core Collection database. Extracted bibliometric information, participant information, and study characteristics of the included articles. The total citations, annual average citations, publication of year, author keywords, and study-related data were bibliometric analyzed and described using Excel 2019 and VOSviewer software.

RESULTS

A total of 30 citation classics were included, with a total citation frequency of 102 to 279 (mean ± standard deviation: 148.4 ± 49.4). The American Journal of Kidney Diseases (n = 7) published the most (n = 7) classic citations in the field of CKD exercise research, and the Journal of the American Society of Nephrology was the most cited. The hotspot of research around CKD and exercise training interventions focused on population (hemodialysis and end-stage renal disease), exercise type (resistance training, yoga, and leg-cycling), and outcomes (cardiovascular indices, physical performance, psychological status, kidney function, physical activity). Reported dropout rates ranged from 0.0% to 47.4%.

CONCLUSION

A bibliometric analysis of citation classics on exercise training and CKD highlights the potential benefits of exercise as a non-pharmacological therapy for patients with CKD, as well as developments and hotspots in the field.

Exercise and Cognitive Function in Chronic Kidney Disease: A Systematic Review and Meta-Analysis of Efficacy and Harms

Key Points

Cognitive impairment is common in CKD. Exercise targets multiple risk factors of cognitive decline. Meta-analysis found that exercise had a small but positive effect on cognitive function in CKD, albeit the quality of evidence was low. Further analyses revealed that aerobic exercise was particularly beneficial and that exercise did not substantially increase harms.

Background

People living with CKD are at higher risk of cognitive impairment. Exercise may improve cognitive function. This systematic review and meta-analysis of randomized controlled trials was completed to determine the efficacy and harms of exercise in improving cognitive function in people living with CKD.

Methods

A systematic literature review identified randomized controlled trials of people with any stage of CKD, with an intervention that exercised large-muscle groups, and with a validated outcome measure of cognitive function. First, harms were analyzed. Then a random-effects meta-analysis was completed with subsequent planned subgroup analyses to investigate heterogeneity between CKD stages and treatments; between different exercise types, durations, and intensities; and between different outcome methodologies. Finally, quality of evidence was rated.

Results

Nineteen trials randomized 1160 participants. Harms were reported on 94 occasions in intervention groups versus 83 in control. The primary analysis found that exercise had a small but statistically significant effect on cognition in CKD (effect size=0.22; 95% confidence intervals, 0.00 to 0.44; P = 0.05). However, the quality of evidence was rated as low. Subgroup analyses found that type of exercise moderated the effect on cognition (chi square=7.62; P = 0.02), with positive effects only observed following aerobic exercise (effect size=0.57; 95% confidence interval, 0.21 to 0.93; P = 0.002).

Conclusions

Across the spectrum of CKD, exercise had a small but positive and clinically meaningful effect on cognitive function and did not seem to be harmful. Aerobic exercise was particularly beneficial. However, the results must be interpreted cautiously because of the low quality of evidence. Nevertheless, care teams may choose to recommend aerobic exercise interventions to prevent cognitive decline. Researchers should design unbiased studies to clarify what intensity and duration of exercise is required to maximize efficiency of such exercise interventions.

Exercise prescriptions for patients on hemodialysis in Brazil: a scoping review

INTRODUCTION

Exercise is being incorporated into the treatment of patients on hemodialysis; however, little is known about the major characteristics of these interventions.

OBJECTIVE

To describe the exercise protocols prescribed for hemodialysis patients in Brazil.

METHODS

A scoping review was conducted following JBI and Prisma-ScR guidelines. Searches were carried out in Medline, Embase and three other databases until May 2024. Other sources (websites, books and guidelines) were also investigated. Evidence from patients on hemodialysis describing exercise protocols in all settings and designs in Brazil was included.

RESULTS

Forty-five pieces of evidence were found, resulting in 54 exercise protocols from 16 Brazilian states. Strength exercises (33.3%), followed by aerobic exercises (22.2%), were the most prescribed, mainly to be performed during dialysis (85.2%). The most prevalent professionals supervising the programs were physiotherapists and exercise physiologists (37.0% and 18.5%, respectively). All protocols implemented the principles of type and frequency training, while progression was adopted in only 53.7%. The main prescription was three times per week (88.9%). Exercise intensity was predominantly determined by subjective methods (33.3%).

CONCLUSION

Aerobic and strength exercises during dialysis were the most commonly prescribed modalities in Brazil, with the majority of programs being properly supervised by qualified professionals. However, existing protocols have not employed systematic progression throughout the intervention, which would be appropriate for providing better physiological responses and adaptations.

The Impact of Physical Exercise on microRNAs in Hemodialysis Patients: A Review and a Protocol for an Ancillary Study

Physical inactivity is considered a significant risk factor for mortality and morbidity among chronic hemodialysis (HD) patients. Therefore, physical exercise is recommended in the treatment of HD patients. Although the beneficial effects of physical exercise in HD patients are well-described in the literature, the underlying physiological mechanisms still need to be fully understood. Recently, microRNAs (miRNAs) have emerged as potential mediators of the therapeutic effects of physical exercise in healthy individuals. miRNAs are short, single-stranded, noncoding RNAs involved in gene expression regulation. Specifically, upon forming the RNA-induced silencing complex, miRNAs selectively bind to specific miRNAs within cells, reducing gene expression. miRNAs can be secreted by cells in an accessible form or enclosed within exosomes or extracellular vesicles. They can be detected in various body fluids, including serum (circulating miRNAs), facilitating the study of their diverse expression. Currently, there is no available data regarding the impact of physical exercise on the expression of miRNAs involved in osteogenic differentiation, a fundamental mechanism in the development of vascular calcification, for HD patients. Therefore, we have designed an observational and longitudinal case-control study to evaluate the expression of miR-9 and miR-30b in HD patients participating in a 3-month interdialytic physical exercise program. This paper aims to present the study protocol and review the expression of circulating miRNAs in HD patients and their modulation through physical exercise.

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.

A Comprehensive Exercise (COMEX) Intervention to Optimize Exercise Participation for Improving Patient-Centered Outcomes and Physical Functioning in Patients Receiving Hemodialysis: Development and Pilot Testing

Rationale & Objective

To address the need for an intradialytic exercise program that is easily delivered in clinical setting, engaging and scalable, we developed a novel COMprehensive EXercise (COMEX) program based on input from patients receiving hemodialysis (HD), dialysis staff members and nephrologists. The objective of this study was to determine the feasibility, safety, and acceptance of COMEX during HD.

Study Design

Single-arm prospective pilot feasibility study.

Setting & Participants

Seventeen patients receiving in-center HD.

Intervention

Three-month participation in the COMEX program, which included video-based dialysis chair exercises (aerobic and resistance) integrated with educational and motivational components.

Outcomes

Data on recruitment, adherence, safety and acceptability were collected. Additional assessments were performed to evaluate changes in physical functioning, patient-reported symptoms, and objectively measured sleep and physical activity. We also examined the feasibility of obtaining skeletal muscle biopsies and blood samples to explore molecular mechanisms of muscle atrophy and to assess platelet mitochondrial function and adaptation to exercise during HD.

Results

Thirteen of the 17 (76%) participants completed the 3-month intervention. The mean participant age was 63.6 ± 15.1 years. In total, 46% of participants were males, and 55% were White. The mean body mass index was 38.7 ± 11.6 kg/m2. There were no reported adverse effects, and the adherence rate to exercise sessions was high with 88% of the sessions completed. Patient satisfaction was high, as 100% of the patients would recommend the program to other dialysis patients. It was feasible to collect data on physical functioning, patient-reported symptoms, and objective sleep and physical activity and to obtain muscle biopsies and blood samples.

Limitations

Small sample size, lack of an onsite exercise professional, and technological issues with telemedicine behavioral motivation.

Conclusions

The COMEX intradialytic exercise intervention is safe and acceptable to patients, and outcome measures were feasible to obtain. Future studies should consider including exercise professionals to facilitate progression through a personalized exercise protocol.

Funding Source

This work is supported by pilot award from P30 DK079307 (PI, Jhamb).

Trial Registration

ClinicalTrials.gov, NCT03055299.

Plain-Language Summary

We tested a new COMprehensive EXercise (COMEX) program to deliver exercise during dialysis. This 3-month program included video-based dialysis chair exercises (aerobic and resistance) integrated with educational and motivational components. Our study shows COMEX was feasible, had high satisfaction and adherence, and was safe. It was feasible to collect data on physical functioning, patient-reported symptoms, and objective sleep and physical activity and to obtain muscle biopsies and blood samples. Future studies should consider including exercise professionals to facilitate progression through a personalized exercise protocol.

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.

Sleep Quality and Its Affecting Factors among Hemodialysis Patients: A Multicenter Cross-Sectional Study

(1) Background: Sleep quality is one of the most important clinical outcomes of hemodialysis (HD) patients, as it can affect their physical and mental health. This study aimed to investigate sleep quality and its affecting factors among patients with HD. (2) Methods: A cross-sectional design was used to investigate the quality of sleep among HD patients in two cities in Saudi Arabia. The data were collected during the period from January to December 2022. A convenience sample of 250 HD patients was selected in this study. Data were collected using the Arabic version of the Pittsburgh Sleep Quality Index (PSQI). (3) Results: About two-thirds of participants (63.6%) had normal sleep, while one-third had poor sleep (36.4%). There was a significant relationship between the participants' age and the quality of sleep, where participants who were aged more than 50 had poorer sleep than those who were younger (p < 0.001). Male and married participants significantly had poor sleep more than female and single participants (p = 0.011 and 0.015, respectively). In addition, participants who were retired, had a higher number of dependents, did not adhere to exercise, and had more comorbidities had significantly poorer sleep than other groups (p = 0.002, 0.016, 0.023, and <0.001, respectively). The level of education, financial status, distance from home to dialysis center, and participants' satisfaction at the time of dialysis had no influence on the quality of sleep among HD patients. The multiple linear regression shows that exercise (p = 0.017), the number of comorbidities (p = 0.008), and the duration of dialysis (p < 0.020) were the independent factors affecting the quality of sleep among HD patients. (4) Conclusions: About one-third of HD patients in this study had poor sleep. There were significant differences between patients' age, gender, marital status, and sleep-quality levels. Moreover, participants who retired, had a higher number of dependents, did not adhere to exercise, and had more comorbidities had significantly poorer sleep than other groups. Future studies should develop appropriate interventions to address the problem of poor sleep quality among HD patients.

Intradialytic neuromuscular electrical stimulation with optional virtual reality distraction improves not only muscle strength and functional capacity but also serum albumin level in haemodialysis patients: a pilot randomized clinical trial

BACKGROUND

Sarcopenia is highly prevalent in haemodialysis (HD) patients and linked to a poor prognosis regarding comorbidities and premature mortality. Previous studies assessed the effects of neuromuscular electrical stimulation in haemodialysis patients. This study adds to the relevance of neuromuscular electrical stimulation (NMES) applications combined with a virtual reality (VR) distraction to increase intensity, dosage, and efficiency of NMES and slow sarcopenia progression in HD patients.

METHODS

We conducted a 12-week multicenter prospective randomised controlled trial. The patients were randomly assigned to one of the three groups: neuromuscular electrical stimulation with or without combined virtual reality distraction or control group.

RESULTS

The final analysis included 32 haemodialysis patients (mean age of 68 ± 10 years, 26 men). Interaction effects between groups and time (12 weeks) were significant regarding serum albumin levels (p = 0.008) and left quadriceps femoris muscle (QFM) force (p = 0.026). Both endpoints were increased in the NMES compared to the CO group at the end of the intervention. The NMES group increased serum albumin levels significantly after 12 weeks. The main effect of time was an increase in mean right QFM force between beginning and end of the intervention (p = 0.021). Functional capacity improved after 12 weeks in the NMES and NMES + VR but not in the control group, with a significant difference between the three groups (p = 0.022). Weight and body mass index increased in the NMES and NMES + VR groups, albeit not significantly. The effects of VR distraction on NMES efficiency were inconclusive.

CONCLUSION

Intradialytic NMES increases serum albumin level, functional capacity, muscle strength in lower limb and in tendency weight and body mass index of HD patients. Effects on VR distraction are inconclusive. Large-scaled follow-up studies on integrated sports programs with NMES and active training in combination with VR as distraction and motivation accelerator are needed.

TRIAL REGISTRATION

German Clinical Trial Register: DRKS00029276 (Retrospectively registered: 30/06/2022).

Impact of virtual reality exercises on anxiety and depression in hemodialysis

Renal replacement therapy is associated with reduced physical activity. The aim of the study was to assess the relationship between regular physical activity performed with the use of virtual reality and the occurrence of symptoms of anxiety and depression in hemodialysis patients. The study involved 85 patients from the dialysis station at the Department of Nephrology, Transplantology and Internal Medicine PUM. The examined patients were randomly divided into study group and control group. The study group consisted of patients undergoing renal replacement therapy by hemodialysis, whose task was to perform VR exercises using the prototype of the NefroVR system for 20 min during hemodialysis. The control group consisted of patients undergoing renal replacement therapy by hemodialysis who were not assigned an intervention. An intragroup analysis was performed for the Beck and GAD scales. After the end of the exercise cycle in the study group there was a decrease in the score while in the control group there was an increase in comparison to the first result. The research showed that after a 3-month exercises on a bicycle with the use of low-intensity virtual reality, a decrease in depression symptoms measured by the Beck Depression Inventory was observed. The research showed that regular physical activity using virtual reality may be associated with a reduction in the occurrence of anxiety and depression symptoms in patients included in the chronic hemodialysis program.

Intradialytic resistance training for short daily hemodialysis patients as part of the clinical routine: a quasi-experimental study

Background and purpose: Hemodialysis patients have chronic systemic inflammation, musculoskeletal impairments, and body composition changes from several factors and exercise may attenuate. We evaluated the effects of an intradialytic resistance training program on body composition, physical function, and inflammatory markers in patients under short daily hemodialysis treatment. Materials and methods: A quasi-experimental study in clinical routine was conducted over eight months. Measures of physical function (handgrip strength, five-time sit-to-stand, timed-up and go, and gait speed), body composition (by bioelectrical impedance), and inflammatory markers (interleukin [IL]-1 beta, IL-6, IL-8, IL-10, IL-12p70, and tumor necrosis factor-α) were assessed at baseline as well as at four and eight months past continued intervention. Patients underwent two intradialytic resistance training sessions per week supervised by exercise professionals. Results: A total of 18 patients (62 ± 14 years; 55.6% ≥ 60 years; 44% female) were included. Significant increases in body mass index and basal metabolic rate were found at four and eight months compared to baseline. For physical function, timed-up and go performance improved at four and eight months compared to baseline. The other body composition and physical function measures, as well as all inflammatory markers, did not significantly change over time. Conclusion: A supervised intradialytic resistance training program for patients on short daily hemodialysis treatment, as part of the clinical routine, may induce modest changes in body mass index, basal metabolic rate, and timed-up and go performance.

Nine Months of Hybrid Intradialytic Exercise Training Improves Ejection Fraction and Cardiac Autonomic Nervous System Activity

Cardiovascular disease is the most common cause of death in hemodialysis (HD) patients. Intradialytic aerobic exercise training has a beneficial effect on cardiovascular system function and reduces mortality in HD patients. However, the impact of other forms of exercise on the cardiovascular system, such as hybrid exercise, is not clear. Briefly, hybrid exercise combines aerobic and strength training in the same session. The present study examined whether hybrid intradialytic exercise has long-term benefits on left ventricular function and structure and the autonomous nervous system in HD patients. In this single-group design, efficacy-based intervention, twelve stable HD patients (10M/2F, 56 ± 19 years) participated in a nine-month-long hybrid intradialytic training program. Both echocardiographic assessments of left ventricular function and structure and heart rate variability (HRV) were assessed pre, during and after the end of the HD session at baseline and after the nine-month intervention. Ejection Fraction (EF), both assessed before and at the end of the HD session, appeared to be significantly improved after the intervention period compared to the baseline values (48.7 ± 11.1 vs. 58.8 ± 6.5, p = 0.046 and 50.0 ± 13.4 vs. 56.1 ± 3.4, p = 0.054 respectively). Regarding HRV assessment, hybrid exercise training increased LF and decreased HF (p < 0.05). Both conventional Doppler and tissue Doppler imaging indices of diastolic function did not change after the intervention period (p > 0.05). In conclusion, long-term intradialytic hybrid exercise training was an effective non-pharmacological approach to improving EF and the cardiac autonomous nervous system in HD patients. Such exercise training programs could be incorporated into HD units to improve the patients’ cardiovascular health.

Mental health and its influencing factors of maintenance hemodialysis patients: a semi-structured interview study

BACKGROUND

Maintenance hemodialysis (MHD) is a commonly used renal replacement therapy for end-stage renal disease patients. MHD patients have undergone multiple physiological stressors, which may cause physical problems and affect their mental health; however, few qualitative studies have been done on the mental health of MHD patients. Such qualitative research becomes the basis for further quantitative research and is critical to validating its results. Therefore, the current qualitative study used a semi-structured interview format, and aimed to explore the mental health and its influencing factors of MHD patients who are not receiving intervention treatment to determine how best to ameliorate their mental health.

METHODS

Based on the application of Grounded Theory, semi-structured face-to-face interviews were conducted with 35 MHD patients, following consolidated criteria for reporting qualitative studies (COREQ) guidelines. Two indicators (emotional state and well-being) were used to assess MHD patients' mental health. All interviews were recorded, after which two researchers independently performed data analyses using NVivo.

RESULTS

Acceptance of disease, complications, stress and coping styles, and social support were found to be the influencing factors of MHD patients' mental health. High acceptance of disease, healthy coping styles, and high social support were positively correlated with mental health. In contrast, low acceptance of disease, multiple complications, increased stress, and unhealthy coping styles were negatively correlated with mental health.

CONCLUSION

One's acceptance of the disease played a more significant role than other factors in affecting MHD patients' mental health.

Age and sex differences in the effectiveness of intradialytic resistance training on muscle function

Previous research shows the beneficial effects of an intradialytic resistance training (IRT) on muscle function in haemodialysis patients. However, patients vary highly in their functional responses to IRT, may be due to effects of age and sex heterogeneities in adaptation. Therefore, the aim of this study was to investigate the degree to which the effects of IRT on the muscle function of haemodialysis patients vary by age and sex. We included 57 patients who completed a 12-week IRT (EXG) and 33 patients who received no IRT (CNG) during haemodialysis. Muscle function (MF) was assessed using dynamometry before and after a 12-week intervention and after a 12-week follow-up. After the 12-week intervention, we found a moderation effect of age in the relative (%) change (p = 0.011) and absolute (Δ) change (p = 0.027) of MF, and a moderation effect of sex in %MF (p = 0.001), but not in ΔMF (p = 0.069). Regarding patients' age, the change of MF was only significantly different between EXG and CNG patients aged 60-70 years (%MF, EXG: + 34.6%, CNG: - 20.1%, p < 0.001; ΔMF, EXG: + 44.4 N, CNG: - 22.1 N, p < 0.001). Regarding patients' sex, the change of MF was only significantly different between EXG and CNG female patients (%MF, EXG: + 23.9%, CNG: - 23.6%, p < 0.001). Age and sex did not significantly moderate changes in MF measures after 12 weeks of follow-up. We conclude that both age and sex of haemodialysis patients affect their functional response to IRT in the short term.Trial Registration: Intradialytic Resistance Training in Haemodialysis Patients (IRTHEP)-#NCT03511924, 30/04/2018, https://clinicaltrials.gov/ct2/show/NCT03511924 .

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

OBJECTIVE

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

DESIGN

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

DATA SOURCES

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

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

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

RESULTS

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

CONCLUSION

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

PROSPERO REGISTRATION NUMBER

CRD42020223591.

Effect of Intradialytic Oral Nutritional Supplementation with or without Exercise Improves Muscle Mass Quality and Physical Function in Hemodialysis Patients: A Pilot Study

Background: Oral nutritional supplementation (ONS) with or without exercise (EX) could improve muscle mass (MM) in chronic kidney disease. Methods: Patients were randomized into two groups: (1) ONS and (2) ONS + EX. Thigh muscle area (cm²) and intramuscular lipid content via attenuation were evaluated at baseline and 6 months with computed tomography (CT) to measure MM quantity and quality. Physical function was measured by six-minute walk test (6 MWT), gait speed, handgrip strength (HGS), and Time Up and Go test (TUG) at baseline and 3 and 6 months. Results: The ONS group (n= 14) showed statistically significant improvement in gait speed and HGS; ONS + EX group (n = 10) showed differences in gait speed, in 6 MWT, and HGS. In the ANOVA (3 times × 2 groups), no differences were observed between groups. Greater effect sizes in favor to ONS + EX group were observed in the 6 MWT (d = 1.02) and TUG test (d = 0.63). Muscle quality at six months revealed a significant trend in favor of the EX-group (p = 0.054). Conclusions: Both groups had improved physical function, and greater effect sizes were seen in the ONS + EX group for the 6 MWT and TUG test. Neither MM quantity or quality was improved in either group.

Near-Infrared Spectroscopy Used to Assess Physiological Muscle Adaptations in Exercise Clinical Trials: A Systematic Review

Simple Summary

In recent years, physical exercise has been used as a therapeutic strategy in various clinical conditions, with pleiotropic benefits. Near-infrared spectroscopy (NIRS) has been positioned as a tool to analyze effects on muscle oxygenation, also allowing knowledge of adaptations on microvascular levels and muscle metabolism in subjects with central and peripheral vascular alterations, as well as cardiovascular, metabolic, and/or musculoskeletal diseases. This knowledge can help to guide therapeutic exercise specialists in decision making regarding the prescription and follow up of physical exercise as a therapeutic tool in the observation of acute or chronic adaptations to improve efficiency in the treatment and recovery of these patients. This review presents an overview of the effects of exercise clinical trials on muscle oxygenation in different pathologies and the technical characteristics related to the equipment used.

Abstract

Using muscle oxygenation to evaluate the therapeutic effects of physical exercise in pathologies through near-infrared spectroscopy (NIRS) is of great interest. The aim of this review was to highlight the use of muscle oxygenation in exercise interventions in clinical trials and to present the technological characteristics related to the equipment used in these studies. PubMed, WOS, and Scopus databases were reviewed up to December 2021. Scientific articles that evaluated muscle oxygenation after exercise interventions in the sick adult population were selected. The PEDro scale was used to analyze the risk of bias (internal validity). The results were presented grouped in tables considering the risk of bias scores, characteristics of the devices, and the effects of exercise on muscle oxygenation. All the stages were carried out using preferred reporting items for systematic reviews and meta-analyses (PRISMA). The search strategy yielded 820 clinical studies, of which 18 met the eligibility criteria. This review detailed the characteristics of 11 NIRS devices used in clinical trials that used physical exercise as an intervention. The use of this technology made it possible to observe changes in muscle oxygenation/deoxygenation parameters such as tissue saturation, oxyhemoglobin, total hemoglobin, and deoxyhemoglobin in clinical trials of patients with chronic disease. It was concluded that NIRS is a non-invasive method that can be used in clinical studies to detect the effects of physical exercise training on muscle oxygenation, hemodynamics, and metabolism. It will be necessary to unify criteria such as the measurement site, frequency, wavelength, and variables for analysis. This will make it possible to compare different models of exercise/training in terms of time, intensity, frequency, and type to obtain more precise conclusions about their benefits for patients.

The Effect of Nutrition and Exercise on Body Composition, Exercise Capacity, and Physical Functioning in Advanced CKD Patients

Patients with stages 4 and 5 chronic kidney disease (CKD), and particularly chronic dialysis patients, commonly are found to have substantially reduced daily physical activity in comparison to age- and sex-matched normal adults. This reduction in physical activity is associated with a major decrease in physical exercise capacity and physical performance. The CKD patients are often physically deconditioned, and protein energy wasting (PEW) and frailty are commonly present. These disorders are of major concern because physical dysfunction, muscle atrophy, and reduced muscle strength are associated with poor quality of life and increased morbidity and mortality in CKD and chronic dialysis patients. Many randomized controlled clinical trials indicate that when CKD and chronic dialysis are provided nutritional supplements or undergo exercise training their skeletal muscle mass and exercise capacity often increase. It is not known whether the rise in skeletal muscle mass and exercise capacity associated with nutritional support or exercise training will reduce morbidity or mortality rates. A limitation of these clinical trials is that the sample sizes of the different treatment groups were small. The aim of this review is to discuss the effects of nutrition and exercise on body composition, exercise capacity, and physical functioning in advanced CKD patients.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

A prospective longitudinal study.

PARTICIPANTS

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

MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

Functional Status and Engagement in Physical Activity Among Maintenance Dialysis Patients: A Mixed Methods Study

Rationale & Objective

People receiving maintenance hemodialysis (HD) experience significant activity barriers but desire the ability to do more and remain independent. To learn about how to help people who require dialysis stay active, a mixed methods study was designed to assess functional status and explore participants’ lived activity experiences.

Study Design

A concurrent mixed methods design was chosen to increase understanding of the real-life activity experiences of people who require dialysis through in-depth interviews paired with functional status measures. The qualitative findings were fully integrated with the quantitative results to link characteristics associated with different physical activity levels.

Setting & Participants

A purposive sample of 15 adult patients receiving maintenance HD for at least 3 months was recruited from 7 dialysis centers in Newark, New Jersey.

Analytical Approach

Thematic analysis using principles of interpretive phenomenology. Fully integrated quantitative and qualitative data with joint displays and conversion mixed methods.

Results

Participants had a median age of 58 years and were predominantly African American (83%) and men (67%). Three descriptive categories were generated about the participants. They described physical activity as a routine daily activity rather than structured exercise. All participants experienced substantial hardship in addition to chronic kidney disease and expressed that family, friends, and faith were essential to their ability to be active. An overarching theme was generated for participants’ mindsets about physical activity. Within the mindset theme, we discerned 3 subthemes comprising characteristics of participants’ mindsets by levels of engagement in physical activity.

Limitations

While code saturation and trends in functional status measures were achieved with 15 participants, a larger sample size would allow for deeper meaning saturation and statistical inference.

Conclusions

Patients receiving maintenance HD with an engaged mindset exhibited more adaptive coping skills, moved more, wanted to help others, and had a normal body weight habitus. These participants employed adaptive coping skills to carry out daily life activities of importance, highlighting the value of adaptive coping to help overcome the challenges of being physically active.

Pathophysiological mechanisms leading to muscle loss in chronic kidney disease

Loss of muscle proteins is a deleterious consequence of chronic kidney disease (CKD) that causes a decrease in muscle strength and function, and can lead to a reduction in quality of life and increased risk of morbidity and mortality. The effectiveness of current treatment strategies in preventing or reversing muscle protein losses is limited. The limitations largely stem from the systemic nature of diseases such as CKD, which stimulate skeletal muscle protein degradation pathways while simultaneously activating mechanisms that impair muscle protein synthesis and repair. Stimuli that initiate muscle protein loss include metabolic acidosis, insulin and IGF1 resistance, changes in hormones, cytokines, inflammatory processes and decreased appetite. A growing body of evidence suggests that signalling molecules secreted from muscle can enter the circulation and subsequently interact with recipient organs, including the kidneys, while conversely, pathological events in the kidney can adversely influence protein metabolism in skeletal muscle, demonstrating the existence of crosstalk between kidney and muscle. Together, these signals, whether direct or indirect, induce changes in the levels of regulatory and effector proteins via alterations in mRNAs, microRNAs and chromatin epigenetic responses. Advances in our understanding of the signals and processes that mediate muscle loss in CKD and other muscle wasting conditions will support the future development of therapeutic strategies to reduce muscle loss.

Can conditions of skeletal muscle loss be improved by combining exercise with anabolic-androgenic steroids? A systematic review and meta-analysis of testosterone-based interventions

Sarcopenia, cachexia, and atrophy due to inactivity and disease states are characterized by a loss of skeletal muscle mass, often accompanied by reduced levels of anabolic hormones (e.g. testosterone). These conditions are associated with an increase in mortality, hospitalization and worsening in quality of life. Both physical exercise (EX) and anabolic-androgenic steroid (AAS) administration can improve the prognosis of patients as they increase physical functionality. However, there is a gap in the literature as to the impact of these therapies on the gains in strength and muscle mass and their implications for patient safety. Accordingly, we performed a random-effects meta-analysis to elucidate the effects of AAS and/or EX interventions on lean body mass (LBM) and muscle strength in conditions involving muscle loss. A systematic search for relevant clinical trials was conducted in MEDLINE, EMBASE, SCOPUS, Web of Science, and SPORTDiscus. Comparisons included AAS vs. Control, EX vs. Control, AAS vs. EX, AAS + EX vs. AAS and AAS + EX vs. EX. A total of 1114 individuals were analyzed. AAS increased LBM (effect size [ES]: 0.46; 95% CI: 0.25, 0.68, P = 0.00) and muscle strength (ES: 0.31; 95% CI: 0.08, 0.53, P = 0.01) when compared to a control group. EX promoted an increase in muscular strength (ES: 0.89; 95% CI: 0.53, 1.25, P = 0.00), with no effect on LBM when compared to the control group (ES: 0.15; 95% CI: -0.07, 0.38, P = 0.17). AAS did not demonstrate statistically significant differences when compared to EX for LBM and muscle strength. The combination of EX + AAS promoted a greater increase in LBM and muscular strength when compared to AAS or EX in isolation. Qualitatively, AAS administration had relatively few side effects. Significant heterogeneity was found in some analyses, which may be explained by the use of different AAS types and EX protocols. Our findings suggest that AAS administration in cachectic and sarcopenic conditions may be a viable interventional strategy to enhance muscle function when exercise is not a possible approach. Moreover, combining AAS with exercise may enhance positive outcomes in this population.

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.

Intelligent Personalized Exercise Prescription Based on an eHealth Promotion System to Improve Health Outcomes of Middle-Aged and Older Adult Community Dwellers: Pretest-Posttest Study

BACKGROUND

A scientific, personalized, and quantitative exercise prescription that has the potential to be an important therapeutic agent for all ages in the prevention of chronic disease is highly recommended. However, it is often poorly implemented, as clinicians lack the necessary knowledge and skills while participants have low adherence due to design defects (eg, prescriptions fail to take individual willingness, the appeal of exercise, and complex physical conditions into account). Intelligent personalized prescription is thus worth exploring.

OBJECTIVE

The aim of this study was to investigate whether a year-long cloud platform-based and intelligent personalized exercise prescription intervention could improve Chinese middle-aged and older adult community dwellers' health outcomes.

METHODS

A total of 177 participants (aged 52-85 years; mean 67.93, SD 7.05) were recruited from 2 Chinese community health service centers in Anhui Province, China. The exercise intervention was delivered over 12 months with a single-group pretest-posttest design. After being assessed in terms of physical activity, health-related lifestyle, history of chronic diseases and drug use, family history of disease and cardiovascular function, body composition, bone mineral density, and physical fitness through an eHealth promotion system, participants with relative contraindications for exercise were personally prescribed the health care exercise mode by an intelligent system, while those without relative contraindication and who had a regular exercise habit were prescribed the scientific fitness mode. Paired t tests were used for the analysis.

RESULTS

A total of 97 participants were classified into the health care mode, and the remaining 80 participants were assigned to the scientific fitness mode. Significant changes in heart rate (mean difference [MD] 2.97; 95% CI 1.1-4.84; P=.002), subendocardial viability ratio (MD -0.13; CI: -1.19 to -0.63; P<.001), weight (MD 0.99; CI 0.29-1.69; P=.006), BMI (MD 0.38; CI 0.11-0.64; P=.006), body fat rate (MD 0.88; CI 0.24-1.51; P=.007), fat mass (MD 0.92; CI 0.33-1.53; P=.003), and brachial-ankle pulse wave velocity (MD: -0.72; CI -1.17 to -0.27; P=.002) were observed among participants with the health care mode exercise prescriptions at the 12-month postintervention versus the baseline assessment, while no changes in systolic blood pressure, diastolic blood pressure, muscle mass, bone mineral density, t value, z value, balance, or ability were discerned. The results showed a functional decline in the physical fitness of both groups, including in handgrip strength (healthcare mode: MD 4.41; scientific fitness mode: MD 3.11), vital capacity (healthcare mode: MD 261.99; scientific fitness mode: MD 250.78), and agility (healthcare mode MD=-0.35; scientific fitness mode: MD=-0.39) with all P values <.001, except handgrip strength in the scientific fitness mode (P=.002). There were no significant differences in other parameters among participants with scientific fitness mode exercise prescriptions.

CONCLUSIONS

The observations suggest that our exercise prescription intervention program might promote certain health outcomes in Chinese middle-aged and older adult community dwellers, yet we are unable to recommend such a program given the existing limitations. Future randomized controlled trials with diverse samples are warranted to confirm our findings.

Anabolic Resistance of Muscle Protein Turnover Comes in Various Shapes and Sizes

Anabolic resistance is defined by a blunted stimulation of muscle protein synthesis rates (MPS) to common anabolic stimuli in skeletal muscle tissue such as dietary protein and exercise. Generally, MPS is the target of most exercise and feeding interventions as muscle protein breakdown rates seem to be less responsive to these stimuli. Ultimately, the blunted responsiveness of MPS to dietary protein and exercise underpins the loss of the amount and quality of skeletal muscle mass leading to decrements in physical performance in these populations. The increase of both habitual physical activity (including structured exercise that targets general fitness characteristics) and protein dense food ingestion are frontline strategies utilized to support muscle mass, performance, and health. In this paper, we discuss anabolic resistance as a common denominator underpinning muscle mass loss with aging, obesity, and other disease states. Namely, we discuss the fact that anabolic resistance exists as a dimmer switch, capable of varying from higher to lower levels of resistance, to the main anabolic stimuli of feeding and exercise depending on the population. Moreover, we review the evidence on whether increased physical activity and targeted exercise can be leveraged to restore the sensitivity of skeletal muscle tissue to dietary amino acids regardless of the population.

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.

Comparison of Combined Hemodialysis and Hemoperfusion with Hemoperfusion Alone in 106 Patients with Diabetic Ketoacidosis and Acute Renal Failure: A Retrospective Study from a Single Center in China

Background

Acute kidney injury with acute renal failure is associated with severe diabetic ketoacidosis. This retrospective study was conducted at a single center in China and aimed to compare combined hemodialysis and hemoperfusion (hemodialysis+hemoperfusion) with hemoperfusion alone in 106 patients with diabetic ketoacidosis and acute renal failure.

Material/Methods

The 106 patients were divided into 2 groups according to different dialysis programs, with 53 cases in each group. Hemodialysis was performed using a single-pass 4008S FX8 HeLix-One hollow fiber hemodialyzer (Fresenius Medical Care, St. Wendel, Germany). Hemoperfusion was performed using HA130 resin adsorbents.

Results

There were no significant differences in terms of sex, age, duration of diabetes, A1c, pH, and admission blood glucose between the 2 groups (P=0.54, 0.564, 0.53, 0.78, 0.82, 0.51). There were no significant differences in fasting blood glucose, blood urea nitrogen, osmotic pressure, and creatinine between the 2 groups before treatment (P=0.146, 0.978, 0.786, 0.983). After treatment, blood urea nitrogen and creatinine in the dual-treatment group were lower than in the control group, and the osmotic pressure was higher than that in the control group (P=0.000, 0.000, 0.000). The dual-treatment group experienced a lower prevalence of dizziness (5.7%), anemia (7.5%), bone pain (7.5%), hypertension (3.8%), and pruritus (5.7%) than the control group (P<0.05).

Conclusions

Compared with hemoperfusion alone, hemodialysis+hemoperfusion significantly reduced pruritus and anemia, improved renal function, and was associated with significantly fewer adverse events in patients with diabetic ketoacidosis and acute renal failure.

How to Overcome Anabolic Resistance in Dialysis-Treated Patients?

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

Effects of Individualized Aerobic Exercise Training on Physical Activity and Health-Related Physical Fitness among Middle-Aged and Older Adults with Multimorbidity: A Randomized Controlled Trial

The presence of multimorbidity in middle-aged and older adults, which reduces their physical activity and quality of life, is a global health challenge. Exercise is one of the most important health behaviors that individuals can engage in. Previous studies have revealed that aerobic exercise training is beneficial for healthy middle-aged and older adults and those with various chronic diseases, but few studies have designed individualized aerobic exercise training for individuals with multimorbidity. Although individuals with multimorbidity are considerably less adherent to physical activity interventions, telephone-based motivational interviewing may help in strengthening motivation and promoting behavioral change for increasing physical activity and health-related physical fitness. This study aimed to examine whether a 12-week individualized aerobic exercise training in a rehabilitation center combined with telephone-based motivational interviewing is effective in promoting physical activity and health-related physical fitness among middle-aged and older adults with multimorbidity. A randomized controlled trial was conducted. Forty-three participants (aged > 40) were recruited and randomly assigned to the intervention group, comparison group, or control group. The participants’ physical activity and health-related physical fitness were assessed at baseline and at 12 weeks. The results indicated that after individualized aerobic exercise training combined with telephone-based motivational interviewing, the participants reported increased total physical activity (F_in = 481.3, p = 0.011), vigorous-intensity physical activity (F_in= 298.9, p = 0.007), dominant and nondominant hand grip (kg) (F_in = 1.96, p = 0.019; F_in = 2.19, p = 0.027, respectively), FEV₁/FVC (F_in = 0.045, p = 0.043), VO₂ max (ml/kg/min) (F_in = 5.30, p = 0.001), VO₂ max predicted (%) (F_in = 21.6, p = 0.001), work (watts) (F_in = 22.5, p = 0.001), and anaerobic threshold (L/min) (F_in = 0.165, p = 0.011). Twelve weeks of individualized aerobic exercise training in the rehabilitation center combined with telephone-based motivational interviewing can increase the total physical activity, vigorous physical activity, and cardiorespiratory fitness of middle-aged and older adults with multimorbidity.

Exercise intolerance in kidney diseases: physiological contributors and therapeutic strategies

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

Advances in exercise therapy in predialysis chronic kidney disease, hemodialysis, peritoneal dialysis, and kidney transplantation

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is characterized by poor levels of physical activity which contribute to increased morbidity across the disease trajectory. The short nature, small samples, and poor methodology across most studies have failed to translate the role of exercise in CKD into its adoption as a frontline adjunct therapeutic option. This review focuses on recent advances surrounding the benefits of exercise interventions across the CKD spectrum.

RECENT FINDINGS

Key recent advances in exercise studies have focused on the efficacy of novel intervention strategies across the CKD spectrum. These include high-intensity interval training, virtual reality gaming, intradialytic yoga, electrical stimulation of muscles, blood flow restriction training, and protocols combining exercise with nutritional supplementation. Research is also beginning to explore the role of prehabilitation for patients prior to dialysis and kidney transplantation.

SUMMARY

Studies continue to demonstrate wide-ranging benefits of exercise across CKD; however, implementation of exercise remains scarce. Future research needs include evaluating the efficacy of larger and/or more comprehensive interventions on clinically important outcomes. It is hoped with increasing global evidence, high-quality clinical studies, and sustained clinician and patient engagement, exercise programs will become better prioritized in the nephrology field.

The effects of an intradialytic resistance training on lower extremity muscle functions

Purpose: The loss of muscle functions is a significant health issue among dialysis patients. Poor muscle strength negatively affects a patient's mobility, independence and quality of life. The aim of the study was to assess the effects of an intradialytic resistance training (IRT) on lower extremity muscle functions among dialysed patients.Materials and methods: Ninety patients were allocated into an experimental group (n = 57) or control group (CNG) (n = 33) according to the location of the dialysis service center. Fifty-eight patients completed the study follow-up. The intervention regarded 12-week IRT, while the controls remained physically inactive during hemodialysis. In both groups of patients, we assessed lower extremity muscle functions by a diagnostics of maximal isometric force generated during hip flexion (HF), hip extension (HE), and knee extension (KE) contractions at baseline, after the 12-weeks intervention and after a further 12-weeks follow up.Results: We found that improvements in HE between baseline and post-intervention were significantly larger for the experimental than the CNG (difference 32.0, 95% CI = 12.3-51.8, p = 0.002). For the other primary outcomes, we found no differences between the groups, and neither for the two other indices of muscle strength (HF and KE). At 12-weeks follow-up, we found no statistically significant differences between the two groups.Conclusions: Our findings indicate that exercise during dialysis not just suppresses adverse effects in muscle strength and functioning, but effectively and safely increases lower extremities muscle function in a relatively short time.Implications for RehabilitationRegular, progressive, resistance training realized during dialysis is well tolerated and safe for exercise interventions in hemodialysis patients.A 12-weeks intradialytic resistance training is effective in the prevention and clinical management of muscle function loss among hemodialysis patients.The range of improvements in muscle functions, demonstrated by the assessment of maximal isometric force, varied severely during different lower extremity movements of hemodialysis patients.