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

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.

Accelerometer-Measured Behavior Patterns in Incident Cerebrovascular Disease: Insights for Preventative Monitoring From the UK Biobank

BACKGROUND

The goal was to compare patterns of physical activity (PA) behaviors (sedentary behavior [SB], light PA, moderate-to-vigorous PA [MVPA], and sleep) measured via accelerometers for 7 days between patients with incident cerebrovascular disease (CeVD) (n=2141) and controls (n=73 938).

METHODS AND RESULTS

In multivariate models, cases spent 3.7% less time in MVPA (incidence rate ratio [IRR], 0.963 [95% CI, 0.929-0.998]) and 1.0% more time in SB (IRR, 1.010 [95% CI, 1.001-1.018]). Between 12 and 24 months before diagnosis, cases spent more time in SB (IRR, 1.028 [95% CI, 1.001-1.057]). Within the year before diagnosis, cases spent less time in MVPA (IRR, 0.861 [95% CI, 0.771-0.964]). Although SB time was not associated with CeVD risk, MVPA time, both total min/d (hazard ratio [HR], 0.998 [95% CI, 0.997-0.999]) and guideline threshold adherence (≥150 min/wk) (HR, 0.909 [95% CI, 0.827-0.998]), was associated with decreased CeVD risk. Comorbid burden had a significant partial mediation effect on the relationship between MVPA and CeVD. Cases slept more during 12:00 to 17:59 hours (IRR, 1.091 [95% CI, 1.002-1.191]) but less during 0:00 to 5:59 hours (IRR, 0.984 [95% CI, 0.977-0.992]). No between-group differences were significant at subgroup analysis.

CONCLUSIONS

Daily behavior patterns were significantly different in patients before CeVD. Although SB was not associated with CeVD risk, the association between MVPA and CeVD risk is partially mediated by comorbid burden. This study has implications for understanding observable behavior patterns in cerebrovascular dysfunction and may help in developing remote monitoring strategies to prevent or reduce cerebrovascular decline.

Efficacy of resistance exercise during hemodialysis on improving lower limb muscle strength in patients with chronic kidney disease: a meta-analysis of randomized clinical trials

INTRODUCTION

Patients with chronic kidney disease (CKD) on hemodialysis (HD) have muscle weakness in addition to a high risk of falls, motor impairment and immobilization.

OBJECTIVE

To conduct a systematic review with meta-analysis of randomized clinical trials regarding the effectiveness of resistance exercises on muscle strengthening and lower limb endurance in patients with CKD on HD.

METHODOLOGY

The study was conducted in the PubMed, EMBASE, SciELO, LILACS and Cochrane databases, without linguistic restrictions or year of publication.

RESULTS

Of the 824 studies found, only 6 were included for analysis. Studies were allocated to some concern or high risk of bias regarding the reporting of outcomes. The low quality of outcome evidence can mainly be observed due to the severe level of inconsistency owing to the high degree of heterogeneity. A significant reduction in heterogeneity was observed after the sensitivity analysis, demonstrating an improvement in the muscle strength of the lower limbs (p = .002).

CONCLUSION

It is concluded that most studies demonstrate benefits in carrying out resistance training programs in increasing muscle strength of the lower limbs, however, it is necessary that randomized clinical trials (RCTs) with greater methodological rigor are performed to confirm these findings.

Nephrology-tailored geriatric assessment as decision-making tool in kidney failure

BACKGROUND

Dialysis might not benefit all older patients with kidney failure, particularly those with multimorbid conditions and frailty. Patients' and healthcare professionals' awareness of the presence of geriatric impairments could improve outcomes by tailoring treatment plans and decisions for individual patients.

OBJECTIVE

We aimed to explore the perspectives of patients and healthcare professionals on nephrology-tailored geriatric assessment to fuel decision-making for treatment choices in older patients with kidney failure.

DESIGN

In an exploratory qualitative study using focus groups, participants discussed perspectives on the use and value of nephrology-tailored geriatric assessment for the decision-making process to start or forego dialysis.

PARTICIPANTS AND MEASUREMENTS

Patients (n = 18) with kidney failure, caregivers (n = 4), and professionals (n = 25) were purposively sampled from 10 hospitals. Interviews were audio-recorded, transcribed verbatim and inductively analysed using thematic analysis.

RESULTS

Three main themes emerged that supported or impeded decision-making in kidney failure: (1) patient psycho-social situation; (2) patient-related factors on modality choice; (3) organisation of health care. Patients reported feeling vulnerable due to multiple chronic conditions, old age, experienced losses in life and their willingness to trade longevity for quality of life. Professionals recognised the added value of nephrology-tailored geriatric assessment in three major themes: (i) facilitating continual holistic assessment, (ii) filling the knowledge gap, and (iii) uncovering important patient characteristics.

CONCLUSIONS

nephrology-tailored geriatric assessment was perceived as a valuable tool to identify geriatric impairments in older patients with kidney failure. Integration of its outcomes can facilitate a more holistic approach to inform choices and decisions about kidney replacement therapy.

Skeletal Muscle Injury in Chronic Kidney Disease-From Histologic Changes to Molecular Mechanisms and to Novel Therapies

Chronic kidney disease (CKD) is associated with significant reductions in lean body mass and in the mass of various tissues, including skeletal muscle, which causes fatigue and contributes to high mortality rates. In CKD, the cellular protein turnover is imbalanced, with protein degradation outweighing protein synthesis, leading to a loss of protein and cell mass, which impairs tissue function. As CKD itself, skeletal muscle wasting, or sarcopenia, can have various origins and causes, and both CKD and sarcopenia share common risk factors, such as diabetes, obesity, and age. While these pathologies together with reduced physical performance and malnutrition contribute to muscle loss, they cannot explain all features of CKD-associated sarcopenia. Metabolic acidosis, systemic inflammation, insulin resistance and the accumulation of uremic toxins have been identified as additional factors that occur in CKD and that can contribute to sarcopenia. Here, we discuss the elevation of systemic phosphate levels, also called hyperphosphatemia, and the imbalance in the endocrine regulators of phosphate metabolism as another CKD-associated pathology that can directly and indirectly harm skeletal muscle tissue. To identify causes, affected cell types, and the mechanisms of sarcopenia and thereby novel targets for therapeutic interventions, it is important to first characterize the precise pathologic changes on molecular, cellular, and histologic levels, and to do so in CKD patients as well as in animal models of CKD, which we describe here in detail. We also discuss the currently known pathomechanisms and therapeutic approaches of CKD-associated sarcopenia, as well as the effects of hyperphosphatemia and the novel drug targets it could provide to protect skeletal muscle in CKD.

A tryptophan-derived uremic metabolite/Ahr/Pdk4 axis governs skeletal muscle mitochondrial energetics in chronic kidney disease

Chronic kidney disease (CKD) causes accumulation of uremic metabolites that negatively affect skeletal muscle. Tryptophan-derived uremic metabolites are agonists of the aryl hydrocarbon receptor (AHR), which has been shown to be activated in CKD. This study investigated the role of the AHR in skeletal muscle pathology of CKD. Compared with controls with normal kidney function, AHR-dependent gene expression (CYP1A1 and CYP1B1) was significantly upregulated in skeletal muscle of patients with CKD, and the magnitude of AHR activation was inversely correlated with mitochondrial respiration. In mice with CKD, muscle mitochondrial oxidative phosphorylation (OXPHOS) was markedly impaired and strongly correlated with the serum level of tryptophan-derived uremic metabolites and AHR activation. Muscle-specific deletion of the AHR substantially improved mitochondrial OXPHOS in male mice with the greatest uremic toxicity (CKD + probenecid) and abolished the relationship between uremic metabolites and OXPHOS. The uremic metabolite/AHR/mitochondrial axis in skeletal muscle was verified using muscle-specific AHR knockdown in C57BL/6J mice harboring a high-affinity AHR allele, as well as ectopic viral expression of constitutively active mutant AHR in mice with normal renal function. Notably, OXPHOS changes in AHRmKO mice were present only when mitochondria were fueled by carbohydrates. Further analyses revealed that AHR activation in mice led to significantly increased pyruvate dehydrogenase kinase 4 (Pdk4) expression and phosphorylation of pyruvate dehydrogenase enzyme. These findings establish a uremic metabolite/AHR/Pdk4 axis in skeletal muscle that governs mitochondrial deficits in carbohydrate oxidation during CKD.

The phase angle cut-off point capable of discriminating hemodialysis patients with reduced exercise tolerance: a cross-sectional study

BACKGROUND

Phase angle (PhA) is a prognostic marker of all-cause mortality in chronic kidney disease. However, no study has investigated this marker as a predictor of exercise intolerance in hemodialysis (HD) patients. The aim of this study was to determine a cut-off point for the PhA capable of discriminating HD patients with reduced exercise tolerance.

METHODS

Thirty-one patients (80.6% men, median age 69 years) were included. The evaluations were performed on three different days, before the HD session. The outcomes evaluated were: biochemical markers, inflammatory and nutritional status, body composition, peripheral muscle strength and exercise tolerance. Performance ≤50% of the predicted value in the six-minute step test (6MST) was defined as reduced exercise tolerance.

RESULTS

Patients presented an average of 67.6 steps (50.5% of predicted) in the 6MST. Fifteen patients (48.4%) were classified with reduced exercise tolerance. The receiver operating characteristic curve indicated a cut-off point of 3.73° for the PhA (sensitivity = 87%, specificity = 81%, and area under the curve = 0.88 [95% CI: 0.76-1.00]; p < 0.001). Patients with reduced exercise tolerance had worse inflammatory and nutritional status, lower PhA and greater impairment of peripheral muscle strength.

CONCLUSION

The cut-off point of 3.73° for the PhA is sensitive and specific to discriminate HD patients with reduced exercise tolerance.

TRIAL REGISTRATION

This study was registered in the Clinical Trials database (no. NCT03779126, date of first registration 19/12/2018).

The prevalence and influencing factors of frailty in patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

To investigate the prevalence and influencing factors of frailty and pre-frailty in chronic kidney disease (CKD) patients and thereby provide a scientific basis for effective avoidance of frailty in patients with CKD.

METHODS

PubMed, EMBASE, Web of Science, EBSCO, Cochrane Library, CNKI, VIP, CBMdisc, and Wanfang databases were searched for relevant studies published till December 31, 2021. The summary results were described as odds ratios (ORs) or standardized mean differences (SMDs) with 95% confidence intervals (CIs). A meta-analysis was performed using StataSE12.0.

RESULTS

Fifteen published studies, which enrolled a total of 3294 CKD patients, met the inclusion criteria. The combined prevalence of frailty in CKD patients was 38.1% (95% CI 29.7-46.5%) and pre-frailty was 37.9% (95% CI 32.7-43.1%). The main factors influencing frailty in CKD patients were age (SMD 0.524, 95% CI 0.326-0.723), diastolic blood pressure (SMD - 0.294, 95% CI - 0.518 to - 0.071), body mass index (BMI) (SMD - 0.267, 95% CI - 0.471 to - 0.064), grip strength (SMD - 0.929, 95% CI - 1.233 to - 0.626), hemoglobin level (SMD - 0.346, 95% CI - 0.448 to - 0.243), serum albumin level (SMD - 0.533, 95% CI - 0.655 to - 0.411), Charlson Comorbidity Index (SMD 0.421, 95% CI 0.150-0.692), multiple medications (SMD 0.625, 95% CI 0.354-0.895), Mini-Mental State Examination (MMSE) score (SMD - 0.563, 95% CI - 0.846 to - 0.280), and female (OR 2.391, 95% CI 1.236-4.627).

CONCLUSION

Frailty is common in CKD patients. The prevalence of frailty among CKD patients was related to age, diastolic blood pressure, BMI, grip strength, hemoglobin and serum albumin levels, Charlson Comorbidity Index, multiple medications, MMSE score, and female.

Objectively measured daily steps as an outcome in a clinical trial of chronic kidney disease: a systematic review

BACKGROUND

Physical inactivity is prevalent among individuals with chronic kidney disease (CKD) and is linked to unfavorable outcomes. In recent years, daily steps have emerged as a prominent target for interventions in clinical trials. The present study endeavors to scrutinize the effectiveness and/or efficacy of various interventions on daily steps in patients with full-spectrum CKD.

METHODS

In December 2022, a systematic search was conducted across three databases, namely PubMed, Embase, and Web of Science, and subsequently updated in June 2023. The inclusion criteria included randomized controlled studies, quasi-experimental studies, and single-arm trials that assessed an intervention's impact on objectively measured daily steps in patients with chronic kidney disease. The Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) tool was used to assess the risk of bias in non-randomized controlled trials (RCT), while the Cochrane revised tool (ROB-2) was utilized for RCTs.

RESULTS

Seventeen studies were deemed eligible for inclusion in this review, with a focus on examining the efficacy and/or effectiveness of exercise training-based interventions (n = 10), daily step goal-oriented interventions (n = 4), mobile health (mHealth) interventions (n = 1), different dialysis modalities (n = 1), and a "Sit Less, Interact, Move More" intervention (n = 1). The studies exhibit variability in their characteristics and assessment tools, reflecting the findings' heterogeneity. The results indicate that increasing physical activity levels remain challenging, as only a limited number of studies demonstrated significant improvements in participants' daily step counts from baseline to endpoint.

CONCLUSION

Clinical trials with daily steps as an outcome are still lacking in the CKD population. Well-designed clinical trials that objectively assess the physical activity of CKD patients are needed.

Muscle oxygen supply impairment during maximal exercise in patients undergoing dialysis therapy

This study aimed to investigate whether Chronic Kidney Disease (CKD) influences O2 supply including O2 delivery and release to the active muscles during maximal physical exercise. Twelve CKD patients undergoing dialysis therapy (HD group) and twelve healthy adults (CTR group) performed an incremental exercise test to determine maximal oxygen uptake (VO2peak). Throughout the exercise, near-infrared spectroscopy allowed the investigation of changes in oxyhemoglobin (∆O2Hb), deoxyhemoglobin (∆HHb), and total hemoglobin (∆THb) in the vastus lateralis muscle. VO2peak was significantly lower in HD group. In addition, HD patients had impaired changes in muscular oxygenation (∆HHb and ∆O2Hb) and blood volume (∆THb) during the exercise (p < 0.05). Moreover, a positive correlation was observed between VO2peak and muscle blood volume (∆THb) in both groups (p < 0.05). This study provides the first evidence that HD patients displayed lower VO2peak and blunted muscular deoxyhemoglobin increase during exercise. This result supports the hypothesis of an increase in oxygen affinity and/or mitochondrial dysfunction in this population.

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.

The potential of traditional herbal active ingredients in the treatment of sarcopenia animal models: focus on therapeutic effects and mechanisms

Sarcopenia is a major global public health problem that harms individual physical function. In 2018, the European Working Group on Sarcopenia in the Elderly 2 classified sarcopenia into primary and secondary sarcopenia. However, information on the pathogenesis and effective treatment of primary and secondary sarcopenia is limited. Traditional herbal active ingredients have biological activities that promote skeletal muscle health, showing potential preventive and therapeutic effects on sarcopenia. Therefore, this narrative review aims to provide a comprehensive overview of global traditional herbal active ingredients' beneficial therapeutic effects and molecular mechanisms on sarcopenia-related animal models. For this purpose, we conducted a literature search in three databases, PubMed, Web of Science, and Embase, consistent with the review objectives. After the screening, 12 animal studies met the review themes. The review results showed that the pathological mechanisms in sarcopenia-related animal models include imbalanced protein metabolism, oxidative stress, inflammation, apoptosis, insulin resistance, endoplasmic reticulum stress, impaired mitochondrial biogenesis, and autophagy-lysosome system aggravation. Eleven traditional herbal active ingredients exerted positive anti-sarcopenic effects by ameliorating these pathological mechanisms. This narrative review will provide meaningful insight into future studies regarding traditional herbal active ingredients for treating sarcopenia.

Regular exercise attenuates alcoholic myopathy in zebrafish by modulating mitochondrial homeostasis

Alcoholic myopathy is caused by chronic consumption of alcohol (ethanol) and is characterized by weakness and atrophy of skeletal muscle. Regular exercise is one of the important ways to prevent or alleviate skeletal muscle myopathy. However, the beneficial effects and the exact mechanisms underlying regular exercise on alcohol myopathy remain unclear. In this study, a model of alcoholic myopathy was established using zebrafish soaked in 0.5% ethanol. Additionally, these zebrafish were intervened to swim for 8 weeks at an exercise intensity of 30% of the absolute critical swimming speed (Ucrit), aiming to explore the beneficial effects and underlying mechanisms of regular exercise on alcoholic myopathy. This study found that regular exercise inhibited protein degradation, improved locomotion ability, and increased muscle fiber cross-sectional area (CSA) in ethanol-treated zebrafish. In addition, regular exercise increases the functional activity of mitochondrial respiratory chain (MRC) complexes and upregulates the expression levels of MRC complexes. Regular exercise can also improve oxidative stress and mitochondrial dynamics in zebrafish skeletal muscle induced by ethanol. Additionally, regular exercise can activate mitochondrial biogenesis and inhibit mitochondrial unfolded protein response (UPRmt). Together, our results suggest regular exercise is an effective intervention strategy to improve mitochondrial homeostasis to attenuate alcoholic myopathy.

The Association of Short Physical Performance Battery With Mortality and Hospitalization in Patients Receiving Hemodialysis

OBJECTIVE

The Short Physical Performance Battery (SPPB) is recommended for evaluating physical performance in patients on hemodialysis (HD). However, the association between SPPB score and long-term health outcomes in these patients remains unclear. We examined the association of SPPB score with all-cause mortality, all-cause hospitalization, and cardiovascular hospitalization in patients on HD.

DESIGN AND METHODS

This retrospective cohort study included 326 patients (median age, 68 years; 62% men) who received outpatient HD therapy. These patients were divided into 2 SPPB groups: low (SPPB ≤9) and high (SPPB >9). We investigated the association of SPPB score and their change over time with health outcomes using Cox regression analysis.

RESULTS

Low SPPB score was associated with a higher risk for all-cause mortality (hazard ratio [HR]: 3.19, 95% confidence interval [95% CI]: 1.89-5.38), all-cause hospitalization (HR: 2.01, 95% CI: 1.44-2.82), and cardiovascular hospitalization (HR: 2.20, 95% CI: 1.45-3.35). Additionally, change in SPPB score over 1 year was associated with health outcomes.

CONCLUSIONS

Lower SPPB score was significantly associated with a higher risk for all-cause mortality, all-cause hospitalization, and cardiovascular hospitalization. The SPPB may be a valuable indicator for risk stratification in patients on HD. Additionally, preventive treatments may be an effective management strategy in limiting the high mortality and hospitalization rates in patients with decreased SPPB score.

Benefits of Cardiac Rehabilitation in Cardio-Renal Patients With Heart Failure With Reduced Ejection Fraction

PURPOSE

Chronic kidney disease (CKD) is common in heart failure (HF). Chronic kidney disease often worsens the prognosis and impairs the management of patients with HF. Chronic kidney disease is frequently accompanied by sarcopenia, which limits the benefits of cardiac rehabilitation (CR). The aim of this study was to evaluate the impact of CR on cardiorespiratory fitness in HF patients with reduced ejection fraction (HFrEF) according to the CKD stage.

METHODS

We conducted a retrospective study including 567 consecutive patients with HFrEF, who underwent a 4-wk CR program, and who were evaluated by cardiorespiratory exercise test before and after the program. Patients were stratified according to their estimated glomerular filtration rate (eGFR). We performed multivariate analysis looking for factors associated with an improvement of 10% in peak oxygen uptake (V˙ o2peak ).

RESULTS

Thirty-eight percent of patients had eGFR <60 mL/min/1.73m². With decreasing eGFR, we observed deterioration in V˙ o2peak , first ventilatory threshold (VT1) and workload and an increase in brain natriuretic peptide levels at baseline. After CR, there was an improvement in V˙ O2peak (15.3 vs 17.8 mL/kg/min, P < .001), VT1 (10.5 vs 12.4 mL/kg/min, P < .001), workload (77 vs 94 W, P < .001), and brain natriuretic peptide (688 vs 488 pg/mL, P < .001). These improvements were statistically significant for all stages of CKD. In a multivariate analysis predicting factors associated with V˙ o2peak improvement, renal function did not interfere with results.

CONCLUSIONS

Cardiac rehabilitation is beneficial in patients with HFrEF with CKD regardless of CKD stage. The presence of CKD should not prevent the prescription of CR in patients with HFrEF.

Handgrip strength and all-cause mortality in patients with chronic kidney disease: an updated systematic review and meta-analysis of cohort studies

OBJECTIVES

In observational studies, handgrip strength (HGS), a prognostic marker for healthy aging, has been associated with several chronic disease outcomes. The present systematic review and meta-analysis aimed to determine the quantitative relationship between HGS and the risk of all-cause mortality in patients with chronic kidney disease (CKD).

METHODS

Search PubMed, Embase, and Web of Science databases. The search was performed from inception to July 20, 2022, and the search was updated in February 2023. Cohort studies were included exploring the relationship between handgrip strength and the risk of all-cause mortality in patients with chronic kidney disease. Effect estimates and 95% confidence intervals (95% CI) were extracted from the studies to perform pooling. The quality of included studies was assessed using the Newcastle-Ottawa scale. We evaluated the overall certainty of evidence using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

RESULTS

This systematic review included 28 articles. A random-effects meta-analysis that included 16,106 patients with CKD showed that participants with lower HGS had an increased mortality risk of 96.1% compared to higher HGS (HR: 1.961; 95% CI 1.591-2.415) (GRADE: very low). Moreover, this association was independent of baseline mean age and follow-up time. In 2,967 patients with CKD, a random-effects model-based meta-analysis showed that for each 1-unit increase in HGS, the risk of death in patients with CKD was reduced by 3.9% (HR: 0.961; 95% CI 0.949-0.974) (GRADE: moderate).

CONCLUSIONS

In patients with CKD, better HGS is associated with a lower risk of all-cause mortality. This study supports using HGS as a strong predictor of mortality in this population.

The Potential Influence of Uremic Toxins on the Homeostasis of Bones and Muscles in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) often experience a high accumulation of protein-bound uremic toxins (PBUTs), specifically indoxyl sulfate (IS) and p-cresyl sulfate (pCS). In the early stages of CKD, the buildup of PBUTs inhibits bone and muscle function. As CKD progresses, elevated PBUT levels further hinder bone turnover and exacerbate muscle wasting. In the late stage of CKD, hyperparathyroidism worsens PBUT-induced muscle damage but can improve low bone turnover. PBUTs play a significant role in reducing both the quantity and quality of bone by affecting osteoblast and osteoclast lineage. IS, in particular, interferes with osteoblastogenesis by activating aryl hydrocarbon receptor (AhR) signaling, which reduces the expression of Runx2 and impedes osteoblast differentiation. High PBUT levels can also reduce calcitriol production, increase the expression of Wnt antagonists (SOST, DKK1), and decrease klotho expression, all of which contribute to low bone turnover disorders. Furthermore, PBUT accumulation leads to continuous muscle protein breakdown through the excessive production of reactive oxygen species (ROS) and inflammatory cytokines. Interactions between muscles and bones, mediated by various factors released from individual tissues, play a crucial role in the mutual modulation of bone and muscle in CKD. Exercise and nutritional therapy have the potential to yield favorable outcomes. Understanding the underlying mechanisms of bone and muscle loss in CKD can aid in developing new therapies for musculoskeletal diseases, particularly those related to bone loss and muscle wasting.

Randomized crossover clinical trial of coenzyme Q10 and nicotinamide riboside in chronic kidney disease

BackgroundCurrent studies suggest mitochondrial dysfunction is a major contributor to impaired physical performance and exercise intolerance in chronic kidney disease (CKD). We conducted a clinical trial of coenzyme Q10 (CoQ10) and nicotinamide riboside (NR) to determine their impact on exercise tolerance and metabolic profile in patients with CKD.MethodsWe conducted a randomized, placebo-controlled, double-blind, crossover trial comparing CoQ10, NR, and placebo in 25 patients with an estimated glomerular filtration rate (eGFR) of less than 60mL/min/1.73 m2. Participants received NR (1,000 mg/day), CoQ10 (1,200 mg/day), or placebo for 6 weeks each. The primary outcomes were aerobic capacity measured by peak rate of oxygen consumption (VO2 peak) and work efficiency measured using graded cycle ergometry testing. We performed semitargeted plasma metabolomics and lipidomics.ResultsParticipant mean age was 61.0 ± 11.6 years and mean eGFR was 36.9 ± 9.2 mL/min/1.73 m2. Compared with placebo, we found no differences in VO2 peak (P = 0.30, 0.17), total work (P = 0.47, 0.77), and total work efficiency (P = 0.46, 0.55) after NR or CoQ10 supplementation. NR decreased submaximal VO2 at 30 W (P = 0.03) and VO2 at 60 W (P = 0.07) compared with placebo. No changes in eGFR were observed after NR or CoQ10 treatment (P = 0.14, 0.88). CoQ10 increased free fatty acids and decreased complex medium- and long-chain triglycerides. NR supplementation significantly altered TCA cycle intermediates and glutamate that were involved in reactions that exclusively use NAD+ and NADP+ as cofactors. NR decreased a broad range of lipid groups including triglycerides and ceramides.ConclusionsSix weeks of treatment with NR or CoQ10 improved markers of systemic mitochondrial metabolism and lipid profiles but did not improve VO2 peak or total work efficiency.Trial registrationClinicalTrials.gov NCT03579693.FundingNational Institutes of Diabetes and Digestive and Kidney Diseases (grants R01 DK101509, R03 DK114502, R01 DK125794, and R01 DK101509).

Muscle fat infiltration in chronic kidney disease: a marker related to muscle quality, muscle strength and sarcopenia

Muscle fat infiltration (MFI) also known as myosteatosis refers to any deposit of lipids found in the skeletal muscle. MFI is preferably assessed by image-based methods like computed tomography (CT), magnetic resonance image (MRI) and ultrasound, normally from muscle groups located in the legs, arms and in the trunk. MFI is understood as a marker of muscle quality, where a muscle with higher fat deposition has lower contraction power and capacity to produce force per unit of muscle mass. This concept supports the hypothesis that a decrease in muscle strength is not always explained by a decrease in muscle mass, but also by other factors, including lipid deposition in the muscle. In the general population, MFI is associated with older age, physical inactivity and with insulin resistance and inflammation. In chronic kidney disease (CKD), MFI has been associated with a decrease in muscle strength and impaired muscle quality as well as with metabolic abnormalities, cardiovascular disease and increased mortality. Interventions aimed at reducing MFI in CKD are incipient, but it seems that guided exercise can ameliorate muscle quality in patients on hemodialysis. The aim of this narrative review about MFI in CKD is to draw attention to a still not often addressed complication in CKD. We conclude that more studies are warranted to investigate mechanisms and factors promoting MFI in CKD. Thus, clinical trials aimed at understanding the type, frequency and intensity of exercise that can diminish MFI and improve the clinical condition of the patients are needed.

Nutritional status and the risk of malnutrition in older adults with chronic kidney disease - implications for low protein intake and nutritional care: A critical review endorsed by ERN-ERA and ESPEN

Increased life expectancy is posing unprecedented challenges to healthcare systems worldwide. These include a sharp increase in the prevalence of chronic kidney disease (CKD) and of impaired nutritional status with malnutrition-protein-energy wasting (PEW) that portends worse clinical outcomes, including reduced survival. In older adults with CKD, a nutritional dilemma occurs when indications from geriatric nutritional guidelines to maintain the protein intake above 1.0 g/kg/day to prevent malnutrition need to be adapted to the indications from nephrology guidelines, to reduce protein intake in order to prevent or slow CKD progression and improve metabolic abnormalities. To address these issues, the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Renal Nutrition group of the European Renal Association (ERN-ERA) have prepared this conjoint critical review paper, whose objective is to summarize key concepts related to prevention and treatment of both CKD progression and impaired nutritional status using dietary approaches, and to provide guidance on how to define optimal protein and energy intake in older adults with differing severity of CKD. Overall, the authors support careful assessment to identify the most urgent clinical challenge and the consequent treatment priority. The presence of malnutrition-protein-energy wasting (PEW) suggests the need to avoid or postpone protein restriction, particularly in the presence of stable kidney function and considering the patient's preferences and quality of life. CKD progression and advanced CKD stage support prioritization of protein restriction in the presence of a good nutritional status. Individual risk-benefit assessment and appropriate nutritional monitoring should guide the decision-making process. Higher awareness of the challenges of nutritional care in older adult patients with CKD is needed to improve care and outcomes. Research is advocated to support evidence-based recommendations, which we still lack for this increasingly large patient subgroup.

Youth-onset type 2 diabetes mellitus: an urgent challenge

The incidence and prevalence of youth-onset type 2 diabetes mellitus (T2DM) and its complications are increasing worldwide. Youth-onset T2DM has been reported in all racial and ethnic groups, but Indigenous peoples and people of colour are disproportionately affected. People with youth-onset T2DM often have a more aggressive clinical course than those with adult-onset T2DM or those with type 1 diabetes mellitus. Moreover, the available treatment options for children and adolescents with T2DM are more limited than for adult patients. Intermediate complications of youth-onset T2DM, such as increased albuminuria, often develop in late childhood or early adulthood, and end-stage complications, including kidney failure, develop in mid-life. The increasing frequency, earlier onset and greater severity of childhood obesity in the past 50 years together with increasingly sedentary lifestyles and an increasing frequency of intrauterine exposure to diabetes are important drivers of the epidemic of youth-onset T2DM. The particularly high risk of the disease in historically disadvantaged populations suggests an important contribution of social and environmental factors, including limited access to high-quality health care, healthy food choices and opportunities for physical activity as well as exposure to stressors including systemic racism and environmental pollutants. Understanding the mechanisms that underlie the development and aggressive clinical course of youth-onset T2DM is key to identifying successful prevention and management strategies.

Association Between Protocols of the Sit-to-Stand Test and Lower Limb Muscle Force Output in Patients on Hemodialysis and Subjects Without Chronic Kidney Disease

OBJECTIVE

To evaluate the association of three protocols of the sit-to-stand (STS) test with muscle force output of knee extension (KE) and knee flexion (KF) in patients on hemodialysis and subjects without chronic kidney disease.

METHODS

This cross-sectional study included a hemodialysis group [n = 60, 59.5 (16.8) years, 55% female] and a control group [n = 60, 43.0 (11.8) years, 50% female]. The assessments were performed in 2 days, and the participants were submitted to three protocols of STS test (5-repetition STS, 10-repetition STS and 30-s STS) or muscle force output of the KE and KF evaluation by handheld dynamometer based on randomization.

RESULTS

The hemodialysis group presented reduced muscle force output of the KE and KF, a longer time to perform the 5 STS and 10 STS tests, and a lower number of repetitions in the 30-s STS test. The three STS tests were associated with muscle force output of the KE in the hemodialysis group, in which the 10-repetition STS test showed the best association (R² = 0.47; adjusted R² = 0.42). However, the only association between the STS test and muscle force output of the KE in the control group was found in the 10-repetition STS test (R² = 0.20; adjusted R² = 0.13).

CONCLUSIONS

The three protocols of STS tests were associated with muscle force output of the KE in patients on hemodialysis. However, the 10-repetition STS test was the best protocol to estimate the quadriceps muscle torque in these patients.

Inspiratory-Expiratory Muscle Training Improved Respiratory Muscle Strength in Dialysis Patients: A Pilot Randomised Trial

End-stage kidney disease (ESKD) exposes patients to progressive physical deconditioning involving the respiratory muscles. The aim of this pilot randomized controlled trial was to determine the feasibility and effectiveness of low-intensity respiratory muscle training (RMT) learned at the hospital and performed at home. A group of ESKD patients (n = 22) were randomized into RMT or usual care (control group, CON) in a 1:1 ratio. The respiratory training was performed at home with an inspiratory-expiratory system for a total of 5 min of breathing exercises in a precise rhythm (8 breaths per minute) interspersed with 1 min of rest, two times per day on nondialysis days for a total of 4 weeks, with the air resistance progressively increasing. Outcome measures were carried out every 4 weeks for 3 consecutive months, with the training executed from the 5th to the 8th week. Primary outcomes were maximal inspiratory and expiratory pressure (MIP, MEP), while secondary outcomes were lung capacity (FEV1, FVC, MVV). Nineteen patients without baseline between-group differences completed the trial (T: n = 10; Age: 63 ± 10; Males: n = 12). Both MIP and MEP significantly improved at the end of training in the T group only, with a significant difference of MEP of 23 cmH₂O in favor of the RMT group (p = 0.008). No significant variations were obtained for FVC, FEV1 or MVV in either group, but there was a greater decreasing trend over time for the CON group, particularly for FVC (t = -2.00; p = 0.046). Low-fatiguing home-based RMT, with a simple device involving both inspiratory and expiratory muscles, may significantly increase respiratory muscle strength.

The Role of Mitochondrial and Redox Alterations in the Skeletal Myopathy Associated with Chronic Kidney Disease

Significance: An estimated 700 million people globally suffer from chronic kidney disease (CKD). In addition to increasing cardiovascular disease risk, CKD is a catabolic disease that results in a loss of muscle mass and function, which are strongly associated with mortality and a reduced quality of life. Despite the importance of muscle health and function, there are no treatments available to prevent or attenuate the myopathy associated with CKD. Recent Advances: Recent studies have begun to unravel the changes in mitochondrial and redox homeostasis within skeletal muscle during CKD. Impairments in mitochondrial metabolism, characterized by reduced oxidative phosphorylation, are found in both rodents and patients with CKD. Associated with aberrant mitochondrial function, clinical and preclinical findings have documented signs of oxidative stress, although the molecular source and species are ill-defined. Critical Issues: First, we review the pathobiology of CKD and its associated myopathy, and we review muscle cell bioenergetics and redox biology. Second, we discuss evidence from clinical and preclinical studies that have implicated the involvement of mitochondrial and redox alterations in CKD-associated myopathy and review the underlying mechanisms reported. Third, we discuss gaps in knowledge related to mitochondrial and redox alterations on muscle health and function in CKD. Future Directions: Despite what has been learned, effective treatments to improve muscle health in CKD remain elusive. Further studies are needed to uncover the complex mitochondrial and redox alterations, including post-transcriptional protein alterations, in patients with CKD and how these changes interact with known or unknown catabolic pathways contributing to poor muscle health and function. Antioxid. Redox Signal. 38, 318-337.

MG53: A potential therapeutic target for kidney disease

Ensuring cell survival and tissue regeneration by maintaining cellular integrity is important to the pathophysiology of many human diseases, including kidney disease. Mitsugumin 53 (MG53) is a member of the tripartite motif-containing (TRIM) protein family that plays an essential role in repairing cell membrane injury and improving tissue regeneration. In recent years, an increasing number of studies have demonstrated that MG53 plays a renoprotective role in kidney diseases. Moreover, with the beneficial effects of the recombinant human MG53 (rhMG53) protein in the treatment of kidney diseases in different animal models, rhMG53 shows significant therapeutic potential in kidney disease. In this review, we elucidate the role of MG53 and its molecular mechanism in kidney disease to provide new approaches to the treatment of kidney disease.

Prognostic impact of the coexistence of hepato-renal dysfunction and frailty in patients with heart failure

BACKGROUND

Complex multi-organ interactions such as coexistence of hepato-renal dysfunction in heart failure (HF) adversely affects patient prognosis. However, the association between liver/kidney dysfunction and frailty and effects of their coexistence on HF prognosis remain unclear.

METHODS

This retrospective cohort study included 922 patients with HF (median age, 72 years; interquartile range: 62-79 years). All patients underwent hepato-renal function testing using the model for end-stage liver disease, excluding international normalized ratio (MELD-XI) score and frailty score. Frailty was measured using a composite of four markers: handgrip strength, gait speed, serum albumin, and activities of daily living status, combined into a total frailty score (range 0-12). Patients were assigned to a frailty score <5 (without frailty) or ≥5 (frailty) group. The multivariable logistic regression model was used to analyze the association between MELD-XI score and frailty; the prognostic value of high MELD-XI score and frailty coexistence was investigated. The endpoint was all-cause mortality.

RESULTS

After adjusting for covariates and dividing by the median MELD-XI score, the high MELD-XI score group [odds ratio: 1.663, 95 % confidence interval (CI): 1.200-2.304, p = 0.002] was significantly associated with frailty, compared with the low MELD-XI score group. One hundred and fifty deaths occurred during follow-up (median, 2.13 years; interquartile range, 0.93-4.09 years). Patients in the high MELD-XI score/frailty group had a significantly higher mortality risk, even after adjusting for HF severity (hazard ratio: 4.326, 95 % CI: 2.527-7.403, p < 0.001).

CONCLUSIONS

Hepato-renal dysfunction is associated with frailty in patients with HF, which affects patient prognosis.

BRIEF SUMMARY

This study showed that hepato-renal dysfunction in patients with HF, as assessed by the model for end-stage liver disease excluding international normalized ratio (MELD-XI) score, is associated with frailty, even after adjusting for factors involved in the frailty or severity of HF. Additionally, high MELD-XI score combined with frailty is associated with a poorer prognosis. These results suggest that hepato-renal dysfunction and frailty can be used for risk stratification in patients with HF.

Impact of Exercise on Fatigue in Patients Undergoing Dialysis in a Tertiary Care Hospital

Background Chronic kidney disease (CKD) is a current public health problem associated with progression to end-stage renal disease (ESRD), cardiovascular disease, and increased mortality rates. The disease is progressive. It is estimated that there are about 20-25 patients with milder kidney damage for every patient on renal replacement therapy. Physical activity is one of the critical elements for the prevention of chronic diseases and exercises in CKD help to improve muscular strength, cardiorespiratory endurance, overall function, and quality of life. Fatigue can cause an inability to perform exercises and can affect physiological and psychological function. There is a need to analyze the effects of exercises on fatigue in outpatients undergoing dialysis in the Indian rural population. Methods This study was a randomized, controlled, interventional, single-center trial. The participants diagnosed with ESRD and who were on hemodialysis were randomly assigned to group A, the exercise group (EG), which had exercise training during dialysis, and group B, the control group (CG), which had no added exercises during dialysis or at home and followed a standard routine method. The outcome measure of fatigue was evaluated through the total Fatigue Assessment Scale (FAS) score at 0, 12, 24, and 36 weeks. The exercise was pilot tested and planned based on the guidelines and carried out during hemodialysis two days a week. It was followed up with a five-day home exercise program when the patients did not undergo dialysis. Results A total of 48 participants were chosen for the study, of which 30 participants completed 36 weeks of training, with exercise adherence of more than 60%. There was a statistically significant difference in FAS between the two groups (F (3, 84) = 10.513, P < 0.001) at a 95% confidence interval (P < 0.05). Post hoc comparisons between groups at baseline and at 12 weeks indicated that there was no significant difference in FAS (P = 0.271 and P = 0.08), but recorded a significant difference (P = 0.001) at 24 and 36 weeks, respectively, between the EG and CG. Conclusions The results indicate that the intradialytic exercise intervention was effective in reducing the level of fatigue in outpatients undergoing dialysis on a long-term exercise program.

Effect of frailty, physical performance, and chronic kidney disease on mortality in older patients with diabetes : a retrospective longitudinal cohort study

BACKGROUND

Declined renal function is associated with physical function impairment and frailty in a graded fashion. This study aimed to examine the relationship between renal function, frailty and physical performance with mortality in older patients with diabetes, while also determining their combined effects on patient outcome.

METHODS

A retrospective longitudinal study was conducted in elderly patients with diabetes. Kidney disease staging was based on clinical practice guidelines of the International Society of Nephrology, and chronic kiney disease (CKD) was defined as urinary albumin to creatinine ratio (UACR) > 30 mg/g, persistent reduction in estimated glomerular filtration rate (eGFR) below 60 mL/min per 1.73 m² or both. The modified Rockwood frailty index (RFI) was composed of cumulative health deficits, and physical function was determined by handgrip strength (HGS). Additionally, a timed up and go (TUG) test was assessed at baseline. Kaplan-Meier survival and Cox proportional hazard analyses were used to analyze the association between CKD, frailty, physical function and mortality.

RESULTS

For the 921 enrolled patients, their mean age was 82.0 ± 6.7 years. After a median 2.92 (interquartile range [IQR] 1.06-4.43) year follow-up, the survival rate was 67.6% and 85.5% in patients with and without CKD, respectively. The mortality hazard ratio (crude HR) with CKD was 5.92 for those with an RFI higher than 0.313 (95% CI 3.44-10.18), 2.50 for a TUG time longer than 21 s (95% CI 1.22-5.13), and 2.67 for an HGS lower than 10.57 kg in females or 20.4 kg in males (95% CI 1.12-6.37). After multivariate adjustment, the mortality hazard ratio for an RFI ≥ 0.313 was 5.34 (95% CI 2.23-12.80) in CKD patients, but not in patients without CKD. In subgroup analysis, patients experiencing CKD and frailty, or physical function impairment, had the lowest survival proportion followed by only frailty/declined physical function, only CKD, without CKD, and non-frailty/non-physical impairment.

CONCLUSION

CKD, frailty and physical function impairment were all associated with an increased mortality risk in older patients with diabetes, while the combined effects of these 3 factors were seen on patient outcome.

Leucine-enriched amino acid supplementation and exercise to prevent sarcopenia in patients on hemodialysis: a single-arm pilot study

Background

Sarcopenia, which is strongly associated with mortality and quality of life, occurs in up to 40% of hemodialysis patients. Here, we investigated the preventive effects of leucine-enriched amino acid supplementation and resistance exercise in non-sarcopenic hemodialysis patients, and characterized the biochemical and immunophenotypic profiles of those who benefited from the intervention.

Methods

Twenty-two patients on maintenance hemodialysis at our hospital were enrolled in this single center, prospective, single-arm pilot trial. For the first 12 weeks, the subjects were administered a total of 6 g of leucine per day. Three grams were supplied via capsules, and the remaining three grams were provided via beverages containing macro- and micro- nutrients, such as 10 μg of vitamin D and 290 mg of calcium. The supplements were not provided for the next 12 weeks. Muscle mass, grip strength, and physical performance were measured using the bioimpedance analyzer (BIA), handgrip strength (HGS), and short physical performance battery (SPPB) protocols, respectively, at baseline, 12 weeks, and 24 weeks. In addition, serum biochemistry, immunophenotype of peripheral blood mononuclear cells, and nutritional status was assessed at the three time points. Those who showed 5% or more improvement in parameters were defined as responders, otherwise, as non-responders (ClinicalTrials.gov identification number: NCT04927208).

Results

Twenty-one out of twenty-two patients (95.4%) showed improvement in at least one or more parameters among muscle mass, grip strength, and physical performance. After 12 weeks of intervention, skeletal muscle index was increased in 14 patients (63.6%), and grip strength was improved in 7 patients (31.8%). Baseline grip strength lower than 35.0 kg was the strongest predictor of improvement in grip strength (AUC 0.933 from ROC curve). Grip strength showed a significant increase in females than males (7.6 ± 8.2 vs. -1.6 ± 7.2%, p = 0.03), in age over 60 than under 60 (5.3 ± 6.2 vs. -1.4 ± 9.1%, p = 0.04), and in higher (≥95%) than lower (<95%) exercise compliance (6.8 ± 7.7 vs. -3.2 ± 6.4%, p = 0.004). In SPPB study, gait speed and sit-to-stand time was improved in 13 patients (59.1%) and 14 patients (63.6%), respectively. Baseline hemoglobin lower than 10.5 g/dl and hematocrit lower than 30.8% were predictor of improvement in the sit-to-stand time (AUC 0.862 and 0.848, respectively). Serum biochemistry results showed that, compared to non-responders, responders in muscle mass had lower baseline monocyte fraction (8.4 ± 1.9 vs. 6.9 ± 1.1%, p = 0.03), and responders in grip strength had lower baseline total protein (6.7 ± 0.4 vs. 6.4 ± 0.3 g/dL, p = 0.04). Immunophenotypic analysis found that the intervention tended to increase the naïve/memory CD8+ T cell ratio (from 1.2 ± 0.8 to 1.4 ± 1.1, p = 0.07).

Conclusion

Leucine-enriched amino acid supplementation and resistance exercise induced significant improvement in muscle mass, strength, and physical function in subpopulation of the non-sarcopenic hemodialysis patients. Those who benefited from the intervention were old-age females with lower baseline grip strength or lower hemoglobin or hematocrit, and who have good exercise compliance. Therefore, we propose that the intervention will help to prevent sarcopenia in selected patients on maintenance hemodialysis.

A Causal-Pathway Phenotype of Chronic Fatigue Syndrome due to Hemodialysis in Patients with End-Stage Renal Disease

BACKGROUND

End-stage renal disease (ESRD) is associated with fatigue and physiosomatic symptoms.

OBJECTIVE

The objective of this study is to delineate the associations between severity of fatigue and physio-somatic symptoms and glomerular filtration rate, inflammatory biomarkers, and Wnt/cateninpathway proteins.

METHODS

The Wnt-pathway related proteins β-catenin, Dickkopf-related protein 1 (DKK1), R-spondin- 1, and sclerostin were measured by ELISA technique in 60 ESRD patients and 30 controls. The Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale was used to assess the severity of FF symptoms.

RESULTS

ESRD is characterized by a significant increase in the total FF score, muscle tension, fatigue, sadness, sleep disorders, gastro-intestinal (GI) symptoms, and a flu-like malaise. The total-FF score was significantly correlated with serum levels of urea, creatinine, and copper (positively), and β-catenin, eGFR, hemoglobin, albumin, and zinc (inversely). The total-FF score was associated with the number of total dialysis and weekly dialysis sessions, and these dialysis characteristics were more important in predicting FF scores than eGFR measurements. Partial Least Squares analysis showed that the FF score comprised two factors that are differently associated with biomarkers: a) 43.0% of the variance in fatigue, GI symptoms, muscle tension, sadness, and insomnia is explained by hemoglobin, albumin, zinc, β-catenin, and R-spondin-1; and b) 22.3% of the variance in irritability, concentration and memory impairments by increased copper and cations/chloride ratio, and male sex.

CONCLUSION

ESRD patients show high levels of fatigue and physio-somatic symptoms associated with hemodialysis and mediated by dialysis-induced changes in inflammatory pathways, the Wnt/catenin pathway, and copper.

The Association of Sarcopenia and Central Obesity with Mortality Risk in Patients with Chronic Kidney Disease - a 2-Year Observational Study

Background

Patients with chronic kidney disease (CKD) face numerous challenges regarding their nutritional status, including undernutrition, wasting, overweight, and obesity. However, there is a gap in the knowledge on the importance of nutritional status on the survival of CKD in patients along the spectrum of progression of CKD.

Objectives

This study aimed to investigate the association of several nutritional measures with all-cause mortality. The hypothesis was that indicators of nutritional status exceeding BMI are associated with increased mortality risk.

Methods

One-hundred seventy adult patients with predialysis CKD (n = 82), receiving hemodialysis (n = 42) or kidney transplantation (n = 46) were recruited from 2014 to 2019. At baseline, nutritional status was assessed by anthropometry, body composition, and muscle function by handgrip strength. Patient survival was assessed after a 2-y follow-up by Cox regression models adjusted for age, sex, and renal function and generalized additive models.

Results

Thirty-one patients (18%) died during the 2-y follow-up. Sarcopenia (n = 30) was associated with an increased risk of death (HR: 2.92; 95% CI: 1.24, 6.89), whereas central obesity (n = 82) was not associated with mortality (1.05; 0.51, 2.15) in the Cox regression analyses. An association between BMI and mortality risk per unit increase (0.97; 0.90, 1.05) was not observed. Other markers of nutritional status were inversely associated with mortality risk, including handgrip strength (0.89; 0.83, 0.95), mid-upper arm circumference (0.86; 0.78, 0.95), and phase angle (per 0.1 degree increase 0.86; 0.81, 0.92). In the generalized additive models, U-shaped relationships were observed between mortality risk and waist circumference and mid-upper arm muscle circumference, while BMI < 22 kg/m2 was associated with increased mortality risk.

Conclusions

Sarcopenia, but not central obesity was associated with total mortality in patients with CKD. The inclusion of muscle strength and mass measures in clinical practice should be considered.

Skeletal Muscle Complications in Chronic Kidney Disease

PURPOSE OF REVIEW

To provide an overview of the recent literature investigating the pathophysiology of skeletal muscle changes, interventions for skeletal muscle, and effects of exercise in chronic kidney disease (CKD).

RECENT FINDINGS

There are multiple CKD-related changes that negatively impact muscle size and function. However, the variability in the assessment of muscle size, in particular, hinders the ability to truly understand the impact it may have in CKD. Exercise interventions to improve muscle size and function demonstrate inconsistent responses that warrant further investigation to optimize exercise prescription. Despite progress in the field, there are many gaps in the knowledge of the pathophysiology of sarcopenia of CKD. Identifying these gaps will help in the design of interventions that can be tested to target muscle loss and its consequences such as impaired mobility, falls, and poor quality of life in patients with CKD.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

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

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

Background

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

Methods

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

Result

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

Conclusion

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

Systematic review registration

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

Efficacy of neuromuscular electrical stimulation with combined low and high frequencies on body composition, peripheral muscle function and exercise tolerance in patients with chronic kidney disease undergoing haemodialysis: a protocol for a randomised, double-blind clinical trial

INTRODUCTION

Neuromuscular electrical stimulation (NMES) as an adjunctive strategy to increase isolated muscular strength or endurance has been widely investigated in patients with chronic kidney disease (CKD) undergoing haemodialysis (HD). However, the efficacy of combined low and high frequencies, to improve both muscular strength and endurance, is unknown. This trial aims to evaluate the efficacy of this combined NMES strategy in this population.

METHODS AND ANALYSIS

This is a randomised controlled trial with blinded assessments and analysis. A total of 56 patients with CKD undergoing HD will be recruited and randomised to an NMES protocol. The evaluations will be performed on three different days at baseline and after 24 sessions of follow-up. Assessments will include the background, insulin-like growth factor, lactate measurement, malnutrition and inflammation score evaluation, an electrical bioimpedance examination, global muscular evaluation by means of the Medical Research Council scale, handgrip strength evaluation, muscular isokinetic evaluation of lower limbs, 6 min step test performance and quality of life (QoL) questionnaire with emphasis on physical function. The patients will be allocated in one of the following four groups: 1) combined low and high frequencies; 2) low frequency; 3) high frequency; and 4) sham stimulation with minimal intensity to generate only sensory perception (with no visible contraction). In all groups, the intensity throughout the session will be the highest tolerated by patient (except for control group). The primary endpoint is the change of peripheral muscle function (muscular strength and endurance). The secondary endpoints will be the changes of body composition; muscle trophism; exercise tolerance; QoL; and nutritional, inflammatory, and metabolic markers. The findings of this study are expected to provide valuable knowledge on how to optimise the NMES intervention, with improvements in both muscle strength and endurance.

ETHICS AND DISSEMINATION

This protocol has been approved by the Ethics Committee on Research with Humans of Hospital Sírio-Libanês (approval no. 24337707). Written informed consent will be obtained from each participant. The results of the study will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03779126.

Continuous Long-Term Physical Activity Monitoring in Hemodialysis Patients

Background

Physical inactivity is common in patients receiving hemodialysis, but activity patterns throughout the day and in relation to dialysis are largely unknown. This knowledge gap can be addressed by long-term continuous activity monitoring, but this has not been attempted and may not be acceptable to patients receiving dialysis.

Methods

Ambulatory patients with end-stage kidney disease receiving thrice-weekly hemodialysis wore commercially available wrist-worn activity monitors for 6 months. Step counts were collected every 15 minutes and were linked to dialysis treatments. Physical function was assessed using the Short Physical Performance Battery (SPPB). Fast time to recovery from dialysis was defined as ≤2 hours. Mixed effects models were created to estimate step counts over time.

Results

Of 52 patients enrolled, 48 were included in the final cohort. The mean age was 60 years, and 75% were Black or Hispanic. Comorbidity burden was high, 38% were transported to and from dialysis by paratransit, and 79% had SPPB <10. Median accelerometer use (199 days) and adherence (95%) were high. Forty-two patients (of 43 responders) reported wearing the accelerometer every day, and few barriers to adherence were noted. Step counts were lower on dialysis days (3991 [95% CI, 3187 to 4796] versus 4561 [95% CI, 3757 to 5365]), but step-count intensity was significantly higher during the hour immediately after dialysis than during the corresponding time on nondialysis days (188 steps per hour increase [95% CI, 171 to 205]); these levels were the highest noted at any time. Postdialysis increases were more pronounced among patients with fast recovery time (225 [95% CI, 203 to 248] versus 134 [95% CI, 107 to 161] steps per hour) or those with SPPB ≥7. Estimates were unchanged after adjustment for demographics, diabetes status, and ultrafiltration rate.

Conclusions

Long-term continuous monitoring of physical activity is feasible in patients receiving hemodialysis. Highly granular data collection and analysis yielded new insights into patterns of activity after dialysis treatments.

Role of exosomes and exosomal microRNA in muscle–Kidney crosstalk in chronic kidney disease

Chronic kidney disease (CKD) is a progressive damage of kidneys that can no longer serve the blood-filtering function, and is a life-threatening condition. Skeletal muscle wasting is a common complication of CKD. Yet the relationship between kidney and skeletal muscle in CKD remains unclear. Exosomes, a type of small membrane-bound vesicles released from cells to the extracellular environment, have increasingly received attention due to their potential as mediators of crosstalk between kidneys and different organs, including skeletal muscle. This mini-review summarizes the recent findings that point to the role of exosomes in the cross-talk between kidney and skeletal muscle in CKD. Understanding of the contents and the mechanism of exosome release may prone exosomes be the potential therapeutic targets for CKD.

Frailty in end stage renal disease: Current perspectives

Frailty is common in end stage renal disease (ESRD) and is a marker of poor outcomes. Its prevalence increases as chronic kidney disease (CKD) progresses. There are different measurement tools available to assess frailty in ESRD. The pathogenesis of frailty in ESRD is multifactorial including uraemia and dialysis related factors. In this current review, we discuss the importance of frailty, its pathogenesis, screening methods, prognostic implications and management strategies in context of ESRD.

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.

Aerobic Exercise Attenuates Kidney Injury, Improves Physical Performance, and Increases Antioxidant Defenses in Lungs of Adenine-Induced Chronic Kidney Disease Mice

The association between chronic kidney disease (CKD) and pulmonary pathophysiological changes is well stablished. Nevertheless, the effects of aerobic exercise (AE) on lungs of CKD need further clarification. Thus, Swiss mice were divided in control, AE, CKD, and CKD + AE groups. CKD was induced by 0.2% adenine intake during 8 weeks (4 weeks of CKD induction and 4 weeks of AE). AE consisted in running on treadmill, at moderate intensity, 30 min/day, 5 days/week, during 4 weeks. Twenty-four hours after the last training day, functional capacity test was performed, and 48 h after the test, mice were euthanized. CKD mice showed a significant increase in urine output, serum urea, and creatinine concentrations, and decreased body weight and urine density, besides oxidative damage (p = 0.044), edema area (p < 0.001), leukocyte infiltration (p = 0.040), and collagen area in lung tissue (p = 0.004). AE resulted in an increase of distance traveled (p = 0.049) and maximum speed (p = 0.046), increased activity of catalase (p = 0.031) and glutathione peroxidase (p = 0.048) in lungs, increased levels of nitric oxide (NOx) in serum (p = 0.001) and bronchoalveolar lavage fluid (p = 0.047), and decreased kidney histological injury (p = 0.018) of CKD mice. However, AE also increased oxidative damage (p = 0.003) and did not change collagen content or perivascular edema in lungs (p > 0.05) of CKD mice. Therefore, AE attenuated kidney injury and improved antioxidants defenses in lungs. Despite no significant changes in pulmonary damage, AE significantly improved physical performance in CKD mice.

Anaesthetic Approach to Enhanced Recovery after Surgery for Kidney Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) protocols are designed to reduce medical complications, the length of hospital stays (LoS), and healthcare costs. ERAS is considered safe and effective for kidney transplant (KTx) surgery. KTx recipients are often frail with multiple comorbidities. As these patients follow an extensive diagnostic pathway preoperatively, the ERAS protocol can ideally be implemented at this stage. Small singular changes in a long perioperative pathway can result in significant positive outcomes. We have investigated the current evidence for an ERAS pathway related to anaesthetic considerations in renal transplant surgery for adult recipients.

Efficacy of power training to improve physical function in individuals diagnosed with frailty and chronic disease: A meta-analysis

Muscle power training with emphasis on high-velocity of concentric movement improves physical functionality in healthy older adults, and, maybe superior to traditional exercise programs. Power training may also be advantageous for patients with acute and chronic illnesses, as well as frail individuals. To determine the efficacy of power training compared with traditional resistance training on physical function outcomes in individuals diagnosed with frailty, acute illness or chronic disease. PubMed (MEDLINE), CINAHL, PEDro, Web of Science, and Google Scholar. (1) at least one study group receives muscle power training of randomized controlled trial (RCT) (2) study participants diagnosed as prefrail, frail or have an ongoing acute or chronic disease, condition or illness; (3) study participants over the age of 18; (4) publication in English language; (5) included physical function as the primary or secondary outcome measures. Two independent reviewers assessed articles for inclusion and graded the methodological quality using Cochrane Risk-of-Bias tool for RCTs. Fourteen RCTs met the inclusion criteria. In seven studies, muscle power training was more effective at improving physical function compared to control activities with a mean fixed effect size (ES) of 0.41 (p = 0.006; 95% CI 0.12 to 0.71). Power training and conventional resistance training had similar effectiveness in eight studies with a mean fixed ES of 0.10 (p = 0.061; 95% CI -0.01 to 0.40). Muscle power training is just as efficacious for improving physical function in individuals diagnosed with frailty and chronic disease when compared to traditional resistance training. The advantages of power training with reduced work per session may support power training as a preferential exercise modality for clinical populations. The findings should be interpreted with caution since generalizability is questioned due to the heterogeneity of patient populations enrolled and participants were relatively mobile at baseline.

Muscle Wasting in Chronic Kidney Disease: Mechanism and Clinical Implications—A Narrative Review

Muscle wasting, known to develop in patients with chronic kidney disease (CKD), is a deleterious consequence of numerous complications associated with deteriorated renal function. Muscle wasting in CKD mainly involves dysregulated muscle protein metabolism and impaired muscle cell regeneration. In this narrative review, we discuss the cardinal role of the insulin-like growth factor 1 and myostatin signaling pathways, which have been extensively investigated using animal and human studies, as well as the emerging concepts in microRNA- and gut microbiota-mediated regulation of muscle mass and myogenesis. To ameliorate muscle loss, therapeutic strategies, including nutritional support, exercise programs, pharmacological interventions, and physical modalities, are being increasingly developed based on advances in understanding its underlying pathophysiology.

Beneficial Effect of H2S-Releasing Molecules in an In Vitro Model of Sarcopenia: Relevance of Glucoraphanin

Sarcopenia is a gradual and generalized skeletal muscle (SKM) syndrome, characterized by the impairment of muscle components and functionality. Hydrogen sulfide (H₂S), endogenously formed within the body from the activity of cystathionine-γ-lyase (CSE), cystathionine- β-synthase (CBS), and mercaptopyruvate sulfurtransferase, is involved in SKM function. Here, in an in vitro model of sarcopenia based on damage induced by dexamethasone (DEX, 1 μM, 48 h treatment) in C2C12-derived myotubes, we investigated the protective potential of exogenous and endogenous sources of H₂S, i.e., glucoraphanin (30 μM), L-cysteine (150 μM), and 3-mercaptopyruvate (150 μM). DEX impaired the H₂S signalling in terms of a reduction in CBS and CSE expression and H₂S biosynthesis. Glucoraphanin and 3-mercaptopyruvate but not L-cysteine prevented the apoptotic process induced by DEX. In parallel, the H₂S-releasing molecules reduced the oxidative unbalance evoked by DEX, reducing catalase activity, O₂⁻ levels, and protein carbonylation. Glucoraphanin, 3-mercaptopyruvate, and L-cysteine avoided the changes in myotubes morphology and morphometrics after DEX treatment. In conclusion, in an in vitro model of sarcopenia, an impairment in CBS/CSE/H₂S signalling occurs, whereas glucoraphanin, a natural H₂S-releasing molecule, appears more effective for preventing the SKM damage. Therefore, glucoraphanin supplementation could be an innovative therapeutic approach in the management of sarcopenia.

Dietary Inflammatory Potential Is Associated With Sarcopenia Among Chronic Kidney Disease Population

Background

Sarcopenia, characterized by impaired muscle mass and function, is a common complication and the main reason for bad life quality and high mortality in chronic kidney disease (CKD). Limiting systemic inflammation is a potable intervention for sarcopenia. Dietary inflammatory potential can influence systemic inflammation. However, research about the association between dietary inflammatory potential and sarcopenia in CKD is limited.

Aim

To investigate the association between dietary inflammatory potential and sarcopenia in the CKD population.

Methods

We conducted a cross-section study based on the public database of the National Health and Nutrition Examination Survey (NHANES). In total, 2,569 adult CKD participants who had complete data for dietary inflammatory potential and sarcopenia were included. The dietary inflammatory potential was calculated by the dietary inflammation index (DII) score based on dietary recall interviews. We assessed sarcopenia via low skeletal muscle mass measured by dual-energy X-ray absorptiometry. Smooth curve fitting and a generalized linear mixed model were used to evaluate the relationship between DII and sarcopenia. Moreover, subgroup and sensitivity analyses were performed.

Results

The overall prevalence of sarcopenia among patients with CKD is 19.11%. Smooth curve fitting results displayed that the DII score is near-linear positively associated with sarcopenia. Logistic regression confirmed sarcopenia is independently related to DII scores (odds ratio [OR], 1.17; 95% CI, 1.06–1.29). Subgroup analyses revealed relatively stronger associations between DII and sarcopenia among patients with CKD with other sarcopenia risk factors, such as hypoalbuminemia, low energy intake, low protein intake, and comorbidities.

Conclusion

The dietary inflammatory potential is independently related to sarcopenia among patients with CKD. Anti-inflammatory diet patterns may be a protective intervention for CKD-associated sarcopenia.

Physical activity and exercise recommendations for people receiving dialysis: A scoping review

INTRODUCTION

Remaining physically active is important to patients undertaking dialysis, however, clinical recommendations regarding exercise type, timing, intensity, and safety precautions vary. The purpose of this scoping review was to analyse and summarise recommendations for physical activity and exercise for people undertaking dialysis and identify areas that require further research or clarification.

MATERIALS AND METHODS

A scoping review of literature from five bibliographic databases (Medline, Scopus, Web of Science, CINAHL, and SPORTDiscus) was conducted. Eligible articles included consensus guidelines, position statements, reviews, or clinical practice guidelines that included specific physical activity and exercise recommendations for people undertaking dialysis. Key search terms included "kidney disease" OR "kidney failure" OR "chronic kidney disease" OR "end stage kidney disease" AND guideline* OR consensus OR "position statement" OR prescription OR statement AND exercise OR "physical activity". Hand searching for relevant articles in all first twenty quartile 1 journals listed on SCImago under 'medicine-nephrology' and 'physical therapy, sports therapy and rehabilitation' using the terms 'exercise and dialysis' was undertaken. Finally, home pages of key societies and professional organisations in the field of sports medicine and nephrology were searched.

RESULTS

The systematic search strategy identified 19 articles met the inclusion criteria. Two were specific to pediatric dialysis and three to peritoneal dialysis. Whilst many publications provided recommendations on aerobic exercise, progressive resistance training and flexibility, few provided explicit guidance. Recommendations for the intensity, duration and frequency of aerobic and resistance training varied. Discrepancies or gaps in guidance about precautions, contraindications, termination criteria, progression, and access site precautions were also apparent.

CONCLUSION

Future guidelines should include specific guidance regarding physical activity, safety precautions, and timing and intensity of exercise for individuals who undertake dialysis. Collaborative multidisciplinary guideline development and appropriate exercise counselling may lead to increased participation in physical activity and exercise and facilitate better patient outcomes.

Potential implications of blood flow restriction exercise on patients with chronic kidney disease: a brief review

Combining blood flow restriction (BFR) with exercise is considered a relevant, helpful method in load-compromised individuals and a viable replacement for traditional heavy-load strength training. BFR exercise may be particularly useful for those unable to withstand high mechanical stresses on joints resulting in skeletal muscle dysfunction, such as patients with chronic kidney disease (CKD). Current literature suggests that BFR training displays similar positive health benefits to exercise training alone for CKD patients, including maintenance of muscle strength, glomerular filtration rate maintenance, uremic parameters, inflammatory profile, redox status, glucose homeostasis, blood pressure adjustments, and low adverse reports. In this review of nine studies in CKD patients, we clarify the potential safety and health effects of exercise training with BFR compared to exercise training alone and recommend insights for future research and practical use. Furthermore, we introduce relevant gaps in this emerging field, providing substantial guidance, critical discussion, and valuable preliminary conclusions in this demographic of patients. However, based on the limited studies in this area, more research is necessary to determine the optimal BFR exercise programming.

The effects of exercise on kidney injury: the role of SIRT1

In patients with kidney injury, muscle mass and strength decrease with altered muscle protein synthesis and degradation along with complications such as inflammation and low physical activity. A treatment strategy to maintain muscle metabolism in kidney injury is important. One of the proposed strategies in this regard is exercise, which in addition to inducing muscle hypertrophy, reducing plasma creatinine and urea and decreasing the severity of tubal injuries, can boost immune function and has anti-inflammatory effects. One of the molecules that have been considered as a target in the treatment of many diseases is silent information regulator 1 (SIRT1). Exercise increases the expression of SIRT1 and improves its activity. Therefore, studies that examined the effect of exercise on kidney injury considering the role of SIRT1 in this effect were reviewed to determine the direction of kidney injury research in future regarding to its prevalence, especially following diabetes, and lack of definitive treatment. In this review, we found that SIRT1 can be one of renoprotective target pathways of exercise. However, further studies are needed to determine the role of SIRT1 in different kidney injuries following exercise according to the type and severity of exercise, and the type of kidney injury.

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.