Intradialytic cycling in children and young adults on chronic hemodialysis

Cardiopulmonary fitness in children/adolescents with chronic kidney disease and the impact of exercise training: a systematic review and meta-analysis of observational study and randomized controlled trials

BACKGROUND

This systematic review and meta-analysis aimed to evaluate differences in cardiopulmonary fitness between healthy controls and children/adolescents with chronic kidney disease (CKD) and the effects of exercise training.

METHODS

PubMed, Embase, Scopus and Web of Science were searched for published studies from reception to 14 June 2023, and updated search on 15 October 2023. The included observational studies reported on cardiorespiratory fitness, included maximal oxygen uptake (VO2max), peak oxygen consumption (VO2peak) and 6-minute walk distance (6MWD), in children/adolescents with CKD and age-matched healthy controls, as well as clinical intervention trials of exercise training on cardiorespiratory fitness in samples of children and/or adolescents up to 19.

RESULTS

Fifteen observational studies and five clinical trials were included, respectively. The studies found that the mean cardiopulmonary fitness was 1.82 standardized mean differences (SMDs) units (95% confidence interval (95% CI) 1.43-2.20) lower in children/adolescents with CKD than in healthy controls or reference values. Except for pre-dialysis CKD patients, peritoneal dialysis, haemodialysis and kidney transplant recipients had significantly lower cardiorespiratory fitness than healthy controls. The results of a meta-analysis based on a pre-post single-arm trial showed that compared to baseline, exercise training improved the 6MWD by approximately 58.17 m (95% CI 16.27-100.06), with very low evidence.

CONCLUSIONS

This systematic review and meta-analysis of observational studies and clinical trials that included children/adolescents with CKD found that cardiorespiratory fitness is severely reduced in this population and that exercise training may be an effective strategy for improvement. Given the low evidence certainty, additional high-quality trials are necessary.

Effect of exercise training on functional capacity, muscle strength, exercise capacity, dialysis efficacy and quality of life in children and adolescents with chronic kidney disease: a systematic review and meta-analysis

PURPOSE

To synthesize the effect of exercise training on functional capacity, muscle strength, exercise capacity, dialysis efficacy, and quality of life (QOL) in children and adolescents with CKD.

METHODS

PubMed/Medline, Scopus, PEDro, Web of Science, CINAHL, Cochrane, and Embase were searched from inception to September 30, 2023. Randomized control trials (RCTs) and clinical trials that assessed the effect of exercise training programs on functional capacity, muscle strength, exercise capacity, dialysis efficacy, and QOL in children and adolescents with CKD were included. Random effect model and meta-regression were used for the meta-analysis.

RESULTS

Four clinical trials and three RCTs were included. The results showed that exercise training improves strength, but meta-analysis did not show a significant effect of exercise on functional capacity (WMD: 1.02; 95% CI: - 0.14 to 2.18; p = 0.083) and QOL (WMD: 8.00; 95% CI: - 3.90 to 19.91; p = 0.187). Subgroup analysis revealed that more than 25 sessions and 45 min per session of intervention, a PEDro score of more than 5, and being younger than 12 years of age had a large effect on functional capacity and QOL results. Due to the limited number of studies that reported the effect of exercise on dialysis efficacy and exercise capacity, the findings were inconclusive.

CONCLUSION

Exercise training could benefit children and adolescents with CKD by increasing their strength. Longer exercise interventions may be beneficial for improving functional capacity and QOL. Future well-designed RCTs should overcome the existing limitations using adequate sample sizes and longer exercise durations.

Physical activity and the 'pediatric inactivity triad' in children living with chronic kidney disease: a narrative review

The ‘paediatric inactivity triad’ (PIT) framework consists of three complex inter-related conditions that influence physical inactivity and related health risks. In those living with chronic kidney disease (CKD), a multi-factorial milieu of components likely confound the PIT elements, resulting in a cycle of decreased physical functioning and reduced physical activity. In this review, we explore and summarize previous research on each of the three principal PIT components (exercise deficit disorder, dynapenia, and physical illiteracy) in the pediatric CKD population. We found those living with CKD are significantly physically inactive compared to their peers. Physical inactivity occurs early in the disease process and progressively gets worse as disease burden increases. Although physical activity appears to increase post-transplantation, it remains lower compared to healthy controls. There is limited evidence on interventions to increase physical activity behaviour in this population, and those that have attempted have had negligible effects. Studies reported profound reductions in muscle strength, physical performance, and cardiorespiratory fitness. A small number of exercise-based interventions have shown favourable improvements in physical function and cardiorespiratory fitness, although small sample sizes and methodological issues preclude the generalization of findings. Physical activity must be adapted and individualized to the needs and goals of the children, particularly those with acute and chronic medical needs as is the case in CKD, and further work is needed to define optimal interventions across the life course in this population if we aim to prevent physical activity declining further.

Assessment and management of obesity and metabolic syndrome in children with CKD stages 2-5 on dialysis and after kidney transplantation-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Obesity and metabolic syndrome (O&MS) due to the worldwide obesity epidemic affects children at all stages of chronic kidney disease (CKD) including dialysis and after kidney transplantation. The presence of O&MS in the pediatric CKD population may augment the already increased cardiovascular risk and contribute to the loss of kidney function. The Pediatric Renal Nutrition Taskforce (PRNT) is an international team of pediatric renal dietitians and pediatric nephrologists who develop clinical practice recommendations (CPRs) for the nutritional management of children with kidney diseases. We present CPRs for the assessment and management of O&MS in children with CKD stages 2-5, on dialysis and after kidney transplantation. We address the risk factors and diagnostic criteria for O&MS and discuss their management focusing on non-pharmacological treatment management, including diet, physical activity, and behavior modification in the context of age and CKD stage. The statements have been graded using the American Academy of Pediatrics grading matrix. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs based on the clinical judgment of the treating physician and dietitian. Research recommendations are provided. The CPRs will be periodically audited and updated by the PRNT.

Muscle-bone axis in children with chronic kidney disease: current knowledge and future perspectives

Bone and muscle tissue are developed hand-in-hand during childhood and adolescence and interact through mechanical loads and biochemical pathways forming the musculoskeletal system. Chronic kidney disease (CKD) is widely considered as both a bone and muscle-weakening disease, eventually leading to frailty phenotype, with detrimental effects on overall morbidity. CKD also interferes in the biomechanical communication between two tissues. Pathogenetic mechanisms including systemic inflammation, anorexia, physical inactivity, vitamin D deficiency and secondary hyperparathyroidism, metabolic acidosis, impaired growth hormone/insulin growth factor 1 axis, insulin resistance, and activation of renin-angiotensin system are incriminated for longitudinal uncoordinated loss of bone mineral content, bone strength, muscle mass, and muscle strength, leading to mechanical impairment of the functional muscle-bone unit. At the same time, CKD may also interfere in the biochemical crosstalk between the two organs, through inhibiting or stimulating the expression of certain osteokines and myokines. This review focuses on presenting current knowledge, according to in vitro, in vivo, and clinical studies, concerning the pathogenetic pathways involved in the muscle-bone axis, and suggests approaches aimed at preventing bone loss and muscle wasting in the pediatric population. Novel therapeutic targets for preserving musculoskeletal health in the context of CKD are also discussed.

Endurance-oriented training program with children and adolescents on maintenance hemodialysis to enhance dialysis efficacy-DiaSport

OBJECTIVE

Pediatric patients spend significant time on maintenance hemodialysis (HD) and traveling. They are often not capable of participating in sports activities. To assess the effects of exercise training during HD on dialysis efficacy in children and adolescents, we set up a multi-center randomized controlled trial (RCT).

METHODS

Patients on HD, age 6 to 18 years, were randomized either to 3× weekly bicycle ergometer training or to no training during HD for 12 weeks. Change in single-pool Kt/V (spKt/V) was the primary outcome parameter.

RESULTS

We randomized 54 patients of whom 45 qualified (23 in the intervention and 22 in the waiting control group, 14.5 ± 3.01 years, 32 male and 13 female) for the intention-to-treat (ITT) population. Only 26 patients finished study per-protocol (PP). Training was performed for an average of 11.96 weeks (0.14-13.14) at 2.08 ± 0.76 times per week and for a weekly mean of 55.52 ± 27.26 min. Single-pool Kt/V was similar in the intervention compared to the control group (1.70 [0.33] vs. 1.79 [0.55]) at V0 and (1.70 [0.36] vs. 1.71 [0.51]) at V1; secondary endpoints also showed no difference in both ITT and PP analysis. No significant adverse events were reported. No bleeding or needle dislocation occurred in 1670 training sessions.

CONCLUSIONS

Intradialytic bicycle training is safe, but does not improve dialysis efficacy and physical fitness. However, the study can be considered underpowered, particularly because of high dropout rates. Future studies need better strategies to increase motivation and compliance and other more effective/intensive exercise measures should be evaluated.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.Gov ( Clinicaltrials.gov identifier: NCT01561118) on March 22, 2012.

Endurance training during maintenance hemodialysis in pediatric and adolescent patients-theory and best practice suggestions

Patients on maintenance hemodialysis (HD) spend significant sedentary time traveling to and receiving dialysis, which leaves little time for social or sport events. Also, chronic HD patients are not physically fit, too exhausted after HD, and are not necessarily motivated to perform sports. There is increasing evidence that endurance training during HD can both increase dialysis efficacy and improve the ability of patients to participate in social life. With limited spare time, how can we motivate patients to train? Would that training improve endurance and modify leisure activity choice? Since HD patients would be a captive audience, we would suggest that endurance training during HD would be a preferred solution, if pediatric and adolescent patients could be persuaded to participate. There are few data on how training should be organized, as well as which parameters are best markers of safety and efficacy. And, most importantly, motivational aspects for performing endurance training on a regular basis clearly have to be considered. It is therefore in any case important to assess whether training improves endurance and, thus, quality of life or also quality of care parameters.

Cardiovascular risk factors in children on dialysis: an update

Cardiovascular disease (CVD) is a life-limiting comorbidity in patients with chronic kidney disease (CKD). In childhood, imaging studies have demonstrated early phenotypic characteristics including increases in left ventricular mass, carotid artery intima-media thickness, and pulse wave velocity, which occur even in young children with early stages of CKD. Vascular calcifications are the signature of an advanced phenotype and are mainly found in adolescents and young adults treated with dialysis. Association studies have provided valuable information regarding the significance of a multitude of risk factors in promoting CVD in children with CKD by using intermediate endpoints of measurements of surrogate parameters of CVD. Dialysis aggravates pre-existing risk factors and accelerates the progression of CVD with additional dialysis-related risk factors. Coronary artery calcifications in children and young adults with CKD accumulate in a time-dependent manner on dialysis. Identification of risk factors has led to improved understanding of principal mechanisms of CKD-induced damage to the cardiovascular system. Treatment strategies include assessment and monitoring of individual risk factor load, optimization of treatment of modifiable risk factors, and intensified hemodialysis if early transplantation is not possible.

Quadriceps muscle strength after training with a cycloergometer in patients on hemodialysis

Abstract Introduction: Functional disability is common in patients with chronic kidney disease, especially in those on hemodialysis. Muscle strength can be evaluated by a dynamometer; however, no study using this technique on the quadriceps of patients undergoing hemodialysis was found in literature. Objective: To assess the effects of cycloergometer training on the quadriceps muscle strength of patients with chronic kidney disease undergoing hemodialysis. Method: This was a clinical trial including 46 patients, both men and women, over 18 years old who had been undergoing hemodialysis for more than six months and signed an informed consent form. Patients were allocated into two groups: intervention group (n = 22) and control group (n = 20). The intervention group underwent intradialytic training in a physical therapy protocol with the cycloergometer for two months, whereas the control group, in turn, was only reevaluated two months after the initial evaluation. All patients were assessed for demographic data at baseline and, two months later for quadriceps muscle strength by standardized dynamometry and with the use of a rigid belt and suction cups. Results: A significant increase was detected in quadriceps muscle strength in the right and left lower limbs in the intervention group when compared with the control group. Conclusion: Quadriceps muscle strength improved after patients with chronic kidney disease on hemodialysis underwent training with the cycloergometer.

Muscle wasting in chronic kidney disease

Loss of lean body mass is a relevant component of the cachexia, or protein energy wasting (PEW), syndrome. Reduced muscle mass seems to be the most solid criterion for the presence of cachexia/PEW in patients with chronic kidney disease (CKD), and those with greater muscle mass loss have a higher risk of death. Children with CKD have many risk factors for lean mass and muscle wasting, including poor appetite, inflammation, growth hormone resistance, and metabolic acidosis. Mortality risks in patients with CKD increases as body mass index (BMI) and weight decreases. However, data regarding cachexia/PEW and muscle wasting in children with CKD is scarce due to lack of consensus in diagnostic criteria and an appropriate investigative methodology. Further research is urgently needed to address this important complication in the pediatric CKD setting, which may have fundamental impact on clinical outcomes.

Hypertension in children with end-stage renal disease

This review summarizes current data on the epidemiology, pathophysiology, and treatment of hypertension (HTN) in children with end-stage renal disease (ESRD). Worldwide prevalence of ESRD ranges from 5.0 to 84.4 per million age-related population. HTN is present in 27-79% of children with ESRD, depending on the modality of renal replacement therapy and the exact definition of hypertension. Ambulatory BP monitoring has been recommended for the detection of HTN and evaluation of treatment effectiveness. HTN in dialyzed patients is mostly related to hypervolemia, sodium overload, activation of the renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system, impaired nitric oxide synthesis, reduced vitamin D levels, and effects of microRNA. In children undergoing chronic dialysis therapy, important factors include optimization of renal replacement therapy and preservation of residual renal function, allowing reduction of volume- and sodium-overload, along with appropriate drug treatment, particularly with calcium channel blockers, RAAS inhibitors, and loop diuretics.