Progressive Resistance Exercise Training in CKD: A Feasibility Study

Effects of cluster set resistance training on bone mineral density and markers of bone metabolism in older hemodialysis subjects: A pilot study

Chronic kidney disease (CKD) is associated with a series of mineral bone disturbances due to increased production of parathormone which increases the activity of osteoclasts, removing calcium and phosphorous from the bones. However, the literature lacks investigations on the feasibility of different resistance training (RT) methods, such as cluster-sets, in this population. Thus, the aim of the present study was to compare traditional versus cluster-set RT protocols on bone mineral density (BMD) T-score, BMD Total, femur BMD, L3-L4 BMD, femoral neck BMD, Klotho, FGF23, Klotho - FGF23 ratio, Sclerostin, vitamin D, phosphorous and calcium in older subjects with CKD. Seventy-eight older subjects (age: 57.55 ± 4.06 years, body mass: 72.26 ± 13.96 kg, body mass index: 26.73 ± 2.97 kg/m2) with CKD undergoing maintenance hemodialysis were randomly divided into control group (CG, n = 26), traditional RT (RT, n = 26) and cluster-set RT (RT-CS, n = 26) groups. Subjects completed 24 weeks of RT three times per week, 1 h and 30 min before the hemodialysis session, and each training lasted around 60 to 80 min. There was a group×time interaction for total BMD, femur BMD, L3-L4 BMD, and femoral neck BMD, revealed by improvements for RT and RT-CS groups (pre versus post). Only femur BMD displayed differences as compared with the CG. Minimum clinically important difference (MCID) values revealed more responsive subjects in the RT-CS group for total BMD, femur BMD, klotho, FGF23, sclerostin, Vitamin D and calcium. In conclusion, RT can be used as a non-pharmacological complementary strategy for the treatment of CKD. RT-CS may be useful for these subjects as more responders were found for this type of training.

Review of Exercise Interventions to Improve Clinical Outcomes in Nondialysis CKD

Exercise interventions in chronic kidney disease (CKD) have received growing interest, with over 30 meta-analyses published in the past 5 years. The potential benefits of exercise training in CKD range from slowing disease progression to improving comorbidities and quality of life. Nevertheless, there is a lack of large, randomized control trials in diverse populations, particularly regarding exercise in nondialysis-dependent CKD (NDD). When exercise interventions are implemented, they often lack fundamental features of exercise training such as progressive overload, personalization, and specificity. Furthermore, the physiology of exercise and CKD-specific barriers appear poorly understood. This review explores the potential benefits of exercise training in NDD, draws lessons from previous interventions and other fields, and provides several basic tools that may help improve interventions in research and practice.

Treatment of chronic kidney disease in older populations

As the world population ages, an expected increase in the prevalence of chronic kidney disease (CKD) among older individuals will pose a considerable challenge for health care systems in terms of resource allocation for disease management. Treatment strategies for older patients with CKD should ideally align with those applied to the general population, focusing on minimizing cardiovascular events and reducing the risk of progression to kidney failure. Emerging therapies, such as SGLT-2 inhibitors and GLP-1 receptor agonists, hold promise for the effective management of CKD in older individuals. In addition, non-pharmacological interventions such as nutritional and exercise therapies have a crucial role. These interventions enhance the effects of pharmacotherapy and, importantly, contribute to the maintenance of cognitive function and overall quality of life. Various factors beyond age and cognitive function must be taken into account when considering kidney replacement therapy for patients with kidney failure. Importantly, all treatment options, including dialysis, transplantation and conservative management approaches, should be tailored to the individual through patient-centred decision-making. The dynamic integration of digital technologies into medical practice has the potential to transform the management of CKD in the aging population.

Feasibility of a home-based exercise intervention for patients with systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is a rare connective tissue disease causing pain, reduced mobility and decreased health-related quality of life (HRQoL). Studies suggest that exercise is a necessary adjunct to the medical treatment.

PURPOSE

To examine the feasibility of a 12-week home-based exercise program for SSc patients, and evaluate changes in physical function, HRQoL and SSc-related symptoms.

METHODS

Twenty patients were enrolled in the study. Feasibility was measured by adherence, adverse events, and exercise task self-efficacy. At baseline and follow-up patients completed the 6-minute walk test, 30-second sit-to-stand test, 30-second arm curl, SSc Impact of Disease (ScleroID) and 36-item short form survey (SF-36).

RESULTS

Median adherence to the intervention was 36 (interquartile range 27-36) out of a total of 36 exercise sessions. Fifteen patients completed the intervention, with three dropouts. Patients' exercise task self-efficacy was 98%, 93% and 78%, for one, two and three weekly exercise sessions, respectively. There were no adverse events related to the exercise sessions. Improvements were observed in all physical tests, and minor improvements in HRQoL and SSc-related symptoms.

CONCLUSION

This study suggests that a home-based exercise intervention is feasible for patients with SSc. The results suggest improvements in physical function, HRQoL and SSc-related symptoms.

The Impact of Combined Nutrition and Exercise Interventions in Patients with Chronic Kidney Disease

Combined nutrition and exercise interventions potentially improve protein-energy wasting/malnutrition-related outcomes in patients with chronic kidney disease (CKD). The aim was to systematically review the effect of combined interventions on nutritional status, muscle strength, physical performance and QoL. MEDLINE, Cochrane, Embase, Web of Science and Google Scholar were searched for studies up to the date of July 2023. Methodological quality was appraised with the Cochrane risk-of-bias tool. Ten randomized controlled trials (nine publications) were included (334 patients). No differences were observed in body mass index, lean body mass or leg strength. An improvement was found in the six-minute walk test (6-MWT) (n = 3, MD 27.2, 95%CI [7 to 48], p = 0.008), but not in the timed up-and-go test. No effect was found on QoL. A positive impact on 6-MWT was observed, but no improvements were detected in nutritional status, muscle strength or QoL. Concerns about reliability and generalizability arise due to limited statistical power and study heterogeneity of the studies included.

Association of Lower Extremity Muscle Strength and Function with Renal Resistive Index in Individuals with and without Chronic Kidney Disease

Age-related loss of lower extremity muscle strength is pronounced in individuals with chronic kidney disease (CKD). In contrast, an increase in intrarenal flow pulsatility results in initial age-related changes in renal hemodynamics, leading to the development of CKD. To date, it remains unclear whether lower extremity muscle strength determines elevated renal flow pulsatility. This study aimed to determine the association of lower extremity muscle strength and function with intrarenal hemodynamics in individuals with and without CKD. One hundred seventy-six individuals without CKD (aged 63 ± 9 years) and 101 individuals with CKD (aged 66 ± 8 years) were included in this study. Using Doppler ultrasound, the renal resistive index (RI) was measured as a parameter of renal hemodynamics. Knee extensor muscle strength (KES), gait speed (GS), and the 30 s chair stand test (30s-CST) were used to measure lower extremity muscle strength and function. Multivariate analyses showed that GS and 30s-CST scores were independent determinants of renal RI, whereas the KES score was not associated with renal RI in individuals with and without CKD. In the two-way analysis of covariance, renal RI was the highest in individuals with CKD who had lower KES, GS, and 30s-CST scores. Reduced lower extremity muscle strength and function are independent determinants of elevated renal flow pulsatility in individuals with and without CKD.

Exercise and chronic kidney disease: potential mechanisms underlying the physiological benefits

Increasing evidence indicates that exercise has beneficial effects on chronic inflammation, cardiorespiratory function, muscle and bone strength and metabolic markers in adults with chronic kidney disease (CKD), kidney failure or kidney transplants. However, the mechanisms that underlie these benefits have received little attention, and the available clinical evidence is mainly from small, short-duration (<12 weeks) exercise intervention studies. The available data, mainly from patients with CKD or on dialysis, suggest that exercise-mediated shifts towards a less inflammatory immune cell profile, enhanced activity of the NRF2 pathway and reduced monocyte infiltration into adipose tissue may underlie improvements in inflammatory biomarkers. Exercise-mediated increases in nitric oxide release and bioavailability, reduced angiotensin II accumulation in the heart, left ventricular remodelling and reductions in myocardial fibrosis may contribute to improvements in left ventricular hypertrophy. Exercise stimulates an anabolic response in skeletal muscle in CKD, but increases in mitochondrial mass and satellite cell activation seem to be impaired in this population. Exercise-mediated activation of the canonical wnt pathway may lead to bone formation and improvements in the levels of the bone-derived hormones klotho and fibroblast growth factor 23 (FGF23). Longer duration studies with larger sample sizes are needed to confirm these mechanisms in CKD, kidney failure and kidney transplant populations and provide evidence for targeted exercise interventions.

Exercise in the Prevention and Treatment of Type 2 Diabetes

Type 2 diabetes is a systemic, multifactorial disease that is a leading cause of morbidity and mortality globally. Despite a rise in the number of available medications and treatments available for management, exercise remains a first-line prevention and intervention strategy due to established safety, efficacy, and tolerability in the general population. Herein we review the predisposing risk factors for, prevention, pathophysiology, and treatment of type 2 diabetes. We emphasize key cellular and molecular adaptive processes that provide insight into our evolving understanding of how, when, and what types of exercise may improve glycemic control. © 2023 American Physiological Society. Compr Physiol 13:1-27, 2023.

Effect of Long-term Exercise Training on Physical Performance and Cardiorespiratory Function in Adults With CKD: A Randomized Controlled Trial

RATIONALE & OBJECTIVE

The safety and efficacy of long-term exercise training in reducing physical functional loss in older adults with advanced CKD and comorbidity is uncertain.

STUDY DESIGN

Multicenter, parallel group, randomized controlled trial.

SETTINGS & PARTICIPANTS

Adults 55 years and older with estimated glomerular filtration rate (eGFR) of 15 to <45 mL/min/1.73 m2 enrolled from centers in Baltimore and Boston.

INTERVENTION

Twelve months of in-center supervised exercise training incorporating majority aerobic but also muscle strengthening activities or a group health education control intervention, randomly assigned in 1:1 ratio.

OUTCOME

Primary outcomes were cardiorespiratory fitness and submaximal gait at 6 and 12 months quantified by peak oxygen consumption (Vo2peak) on graded exercise treadmill test and distance walked on the 6-minute walk test, respectively. Secondary outcomes were changes in lower extremity function, eGFR, albuminuria, glycemia, blood pressure, and body mass index.

RESULTS

Among 99 participants, the mean age was 68 years, 62% were African American, and the mean eGFR was 33 mL/min/1.73 m2; 59% had diabetes, and 29% had coronary artery disease. Among those randomized to exercise, 59% of exercise sessions were attended in the initial 6 months. Exercise was well tolerated without excess occurrence of adverse events. At 6 months, aerobic capacity was higher among exercise participants (17.9 ± 5.5 vs 15.9 ± 7.0 mL/kg/min, P = 0.03), but the differences were not sustained at 12 months. The 6-minute walk distance improved more in the exercise group (adjusted difference: 98 feet [P = 0.02; P = 0.03 for treatment-by-time interaction]). The exercise group had greater improvements on the Timed Up and Go Test (P = 0.04) but not the Short Physical Performance Battery (P = 0.8).

LIMITATIONS

Planned sample size was not reached. Loss to follow-up and dropout were greater than anticipated.

CONCLUSIONS

Among adults aged ≥55 years with CKD stages 3b-4 and a high level of medical comorbidity, a 12-month program of in-center aerobic and resistance exercise training was safe and associated with improvements in physical functioning.

FUNDING

Government grants (National Institutes of Health).

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT01462097.

Serum cystatin C to creatinine ratio is associated with sarcopenia in non-dialysis-dependent chronic kidney disease

Background

Methods

Results

Conclusion

Resistance Exercise in People With Stage-3 Chronic Kidney Disease: Effects of Training Frequency (Weekly Volume) on Measures of Muscle Wasting and Function

Background: Resistance training (RT) is a proven anabolic intervention in people living with and without chronic kidney disease (CKD). To date, there is a dearth of knowledge regarding the dose-response relationship of RT in the non-dialysis dependent CKD population. Therefore, we aimed to explore the effects of RT frequency (weekly volume) on established measures of muscle wasting and function in CKD.

Methods: Twenty people with stage-3 CKD (CKD-3) were allocated to either a low frequency (one-session per week, RT1) or higher frequency (three-sessions per week, RT3) 12-week RT programme consisting of lower extremity strengthening exercises. The two RT programmes were not volume matched. Assessment outcomes before and after the intervention included measures of total and regional body composition, muscle size and architecture, strength, physical function, and uraemic symptoms.

Results: Significant improvements over time in muscle size and architecture, strength, physical function, and uraemic symptoms were observed for both RT1 and RT3. Compared to RT1, participants who performed RT3 showed greater increases in vastus lateralis (VL) anatomical cross-sectional area (30.8% vs. 13.2%, p < 0.001) and pennation angle (36.3% vs. 17.5%, p = 0.008) after 12 weeks. In either group, there were no significant changes over time in mid-VL fascicle length, nor in measures of total body composition and upper arm muscle strength.

Conclusion: Despite the group differences observed in the VL physiological adaptations, the strength and physical function responses, as well as the reductions of uraemic symptoms, were similar whether training once or thrice weekly. Therefore, performing RT just once per week may be an effective pre-habilitation strategy for people with CKD-3.

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.

Primary skeletal muscle cells from chronic kidney disease patients retain hallmarks of cachexia in vitro

BACKGROUND

Skeletal muscle wasting and dysfunction are common characteristics noted in people who suffer from chronic kidney disease (CKD). The mechanisms by which this occurs are complex, and although progress has been made, the key underpinning mechanisms are not yet fully elucidated. With work to date primarily conducted in nephrectomy-based animal models, translational capacity to our patient population has been challenging. This could be overcome if rationale developing work could be conducted in human based models with greater translational capacity. This could be achieved using cells derived from patient biopsies, if they retain phenotypic traits noted in vivo.

METHODS

Here, we performed a systematic characterization of CKD derived muscle cells (CKD; n = 10; age: 54.40 ± 15.53 years; eGFR: 22.25 ± 13.22 ml/min/1.73 m² ) in comparison with matched controls (CON; n = 10; age: 58.66 ± 14.74 years; eGFR: 85.81 ± 8.09 ml/min/1.73 m² ). Harvested human derived muscle cells (HDMCs) were taken through proliferative and differentiation phases and investigated in the context of myogenic progression, inflammation, protein synthesis, and protein breakdown. Follow up investigations exposed HDMC myotubes from each donor type to 0, 0.4, and 100 nM of IGF-1 in order to investigate any differences in anabolic resistance.

RESULTS

Harvested human derived muscle cells isolated from CKD patients displayed higher rates of protein degradation (P = 0.044) alongside elevated expression of both TRIM63 (2.28-fold higher, P = 0.054) and fbox32 (6.4-fold higher, P < 0.001) in comparison with CONs. No differences were noted in rates of protein synthesis under basal conditions (P > 0.05); however, CKD derived cells displayed a significant degree of anabolic resistance in response to IGF-1 stimulation (both doses) in comparison with matched CONs (0.4 nm: P < 0.001; 100 nM: P < 0.001).

CONCLUSIONS

In summary, we report for the first time that HDMCs isolated from people suffering from CKD display key hallmarks of the well documented in vivo phenotype. Not only do these findings provide further mechanistic insight into CKD specific cachexia, but they also demonstrate this is a reliable and suitable model in which to perform targeted experiments to begin to develop novel therapeutic strategies targeting the CKD associated decline in skeletal muscle mass and function.

Human skeletal muscle size with ultrasound imaging: a comprehensive review

Skeletal muscle size is an important factor in assessing adaptation to exercise training and detraining, athletic performance, age-associated atrophy and mobility decline, clinical conditions associated with cachexia, and overall skeletal muscle health. Magnetic resonance (MR) imaging and computed tomography (CT) are widely accepted as the gold standard methods for skeletal muscle size quantification. However, it is not always feasible to use these methods (e.g., field studies, bedside studies, large cohort studies). Ultrasound has been available for skeletal muscle examination for more than 50 years and the development, utility, and validity of ultrasound imaging are underappreciated. It is now possible to use ultrasound in situations where MR and CT imaging are not suitable. This review provides a comprehensive summary of ultrasound imaging and human skeletal muscle size assessment. Since the first study in 1968, more than 600 articles have used ultrasound to examine the cross-sectional area and/or volume of 107 different skeletal muscles in more than 27,500 subjects of various ages, health status, and fitness conditions. Data from these studies, supported by decades of technological developments, collectively show that ultrasonography is a valid tool for skeletal muscle size quantification. Considering the wide-ranging connections between human health and function and skeletal muscle mass, the utility of ultrasound imaging will allow it to be employed in research investigations and clinical practice in ways not previously appreciated or considered.

Effects of Different Types of Exercise on Kidney Diseases

The effects of exercise on kidney function have been studied for more than three decades. One of the most common health issues among patients with chronic kidney disease (CKD) is a lack of physical activity, which leads to a low exercise capacity in these patients. The majority of maintenance hemodialysis (MHD) patients do not exercise at all. At each stage of dialysis, patients lose 10–12 g of their amino acids through blood sampling. Dialysis also leads to increased cortisol and circadian rhythm sleep disorders in hemodialysis (HD) patients. Studies have also reported higher C-reactive protein levels in HD patients, which causes arterial stiffness. Exercise has a variety of health benefits in these patients, including improved blood pressure control, better sleep, higher physical function, and reduced anxiety and depression. On the other hand, it should be noted that intense exercise has the potential to progress KD, especially when conducted in hot weather with dehydration. This review aimed to investigate the effects of different types of exercise on kidney disease and provide exercise guidelines. In conclusion, moderate-intensity and long-term exercise (for at least a 6-month period), with consideration of the principles of exercise (individualization, intensity, time, etc.), can be used as an adjunctive treatment strategy in patients undergoing dialysis or kidney transplantation.

The Role of Lifestyle Intervention, in Addition to Drugs, for Diabetic Kidney Disease with Sarcopenic Obesity

Diabetic kidney disease is the leading cause of end-stage renal disease in developing and developed countries. The growing prevalence and clinical challenges of sarcopenic obesity have been associated with the frailty and disability of diabetic kidney disease. It has been reported that insulin resistance, chronic inflammation, enhanced oxidative stress and lipotoxicity contribute to the pathophysiology of muscle loss and visceral fat accumulation. Sarcopenic obesity, which is diagnosed with dual-energy X-ray absorptiometry, is associated with worse outcomes in kidney disease. Growing evidence indicates that adherence to healthy lifestyles, including low protein diet, proper carbohydrate control, vitamin D supplement, and regular physical training, has been shown to improve clinical prognosis. Based on the higher risk of sarcopenic-obesity-related renal function decline, it has led to the exploration and investigation of the pathophysiology, clinical aspects, and novel approach of these controversial issues in daily practice.

Results From a Physical Activity Intervention Feasibility Study With Kidney Inpatients

Background:

Individuals with end-stage kidney disease requiring dialysis are often physically inactive, resulting in reduced physical functioning, increased frailty, and reduced quality of life. Furthermore, extended hospital stays and frequent readmissions are common, exacerbating health care costs. Physical activity may improve physical functioning, disability, and frailty but is not part of standard care of patients requiring dialysis. Research is required to determine the feasibility of implementing physical function assessments and physical activity programs in kidney inpatients requiring dialysis.

Objective:

To assess the feasibility and preliminary efficacy of an early-physical activity intervention (Move More study) in the care of kidney inpatients requiring dialysis. It was hypothesized that the intervention would be feasible with regards to administration and participation, meeting a priori feasibility criteria, and that kidney inpatients would benefit from participating.

Design:

Pilot study.

Setting:

Patient Unit 37, Foothills Medical Center, Calgary, AB, Canada.

Patients:

Kidney in-patients receiving dialysis.

Measurements:

Feasibility data were collected for recruitment, participation, assessment completion, physical activity completion, and adverse events. Participant and healthcare practitioner (HCP) satisfaction with the intervention was assessed using a questionnaire. Frailty and physical function were assessed by the kinesiologist at baseline and postintervention prior to hospital discharge.

Methods:

The study was a single-arm pilot intervention examining feasibility and preliminary efficacy. Kidney inpatients requiring dialysis were recruited to an individualized in-hospital physical activity intervention for the duration of their hospital stay. The intervention was led by a kinesiologist and supported by the clinical care team, including physiotherapists and nurse clinicians. Individualized exercise programs were created for patients to perform daily during their stay. These programs focused on strength, mobility, balance, and general movement and were tailored to each patient’s needs.

Results:

Thirty-six percent of eligible patients (n = 23/64) consented to participate in the Move More study, of whom 78% (n = 18/23) completed the intervention. The a priori level for consent to participate in the intervention was set at 60%. In addition, the a priori level for completion of assessments pre and postintervention was 50%. Ninety-five percent (n = 22/23) of preintervention assessments were completed compared to 65% of postintervention assessments. All participants who completed the survey (100%, n = 14/14) and most of the staff (77%, n = 24/31) reported being satisfied or very satisfied with the program. There were no adverse events related to the intervention. On average, Move More patients demonstrated improvements in frailty status and specific subsets of quality of life.

Limitations:

Firstly, as a feasibility study, the research was not powered to address the effectiveness of the intervention and lacked a comparison group to definitively link observed changes to the intervention itself. The voluntary nature of recruitment may have been biased toward ESKD inpatients with above-average motivation and baseline function. Furthermore, the small sample size from a single site limits the generalizability of findings. An additional limitation was the fact that postassessments were missed on a large number of patients, due to them being discharged prior to research staff knowing and being able to complete the assessments. Finally, studying the length of stay across the institution, as opposed to just the individual ward, would provide insight into hospitalization impact for these patients.

Conclusions:

The administration of and participation in a physical activity intervention for kidney inpatients requiring dialysis was initially not feasible primarily due to low recruitment and adherence challenges. The study was modified by including a research team member on the unit to increase recruitment efforts and support exercise adherence. The intervention impact includes potentially benefits on frailty and quality of life.

Group-Based Exercise in CKD Stage 3b to 4: A Randomized Clinical Trial

Rationale & Objective

We aimed to test interventions to improve physical activity in persons with advanced chronic kidney disease not yet receiving dialysis.

Study Design

Randomized controlled trial with parallel-group design.

Setting & Participants

We embedded a pragmatic referral to exercise programming in high-volume kidney clinics servicing diverse populations in San Jose, CA, and Atlanta, GA. We recruited 56 participants with estimated glomerular filtration rates < 45 mL/min/1.73 m².

Interventions

We randomly assigned participants to a mobile health (mHealth) group—wearable activity trackers and fitness professional counseling, or an Exercise is Medicine intervention framework (EIM) group—mHealth components plus twice-weekly small-group directed exercise sessions customized to persons with kidney disease. We performed assessments at baseline, 8 weeks at the end of active intervention, and 16 weeks after passive follow-up and used multilevel mixed models to assess between-group differences.

Outcomes

Activity tracker total daily step count.

Results

Of 56 participants, 86% belonged to a racial/ethnic minority group; randomly assigned groups were well balanced on baseline step count. In intention-to-treat analyses, the EIM and mHealth groups both experienced declines in daily step counts, but there was an attenuated reduction in light intensity physical activity (standard error 0.2 [5.8] vs −8.5 [5.4] min/d; P = 0.08) in the EIM compared with the mHealth group at 8 weeks. In as-treated analyses, total daily step count, distance covered, and light and moderate-vigorous activity minutes per day improved in the EIM group and declined in the mHealth group at 8 weeks (standard error +335 [506] vs −884 [340] steps per day; P = 0.05; P < 0.05 for secondary measures), but group differences faded at 16 weeks. There were no differences in quality-of-life and mental health measures during the study.

Limitations

Small sample size, limited duration of study, assessment of intermediate outcomes (steps per day).

Conclusions

A clinic-integrated referral to small-group exercise sessions is feasible, safe, and moderately effective in improving physical activity in an underserved population with high comorbid conditions.

Funding

Normon S Coplon Applied Pragmatic Clinical Research program.

Trial Registration

NCT03311763

Physical Exercise Improves Cognitive Function in Older Adults with Stage 3-4 Chronic Kidney Disease: A Randomized Controlled Trial

INTRODUCTION

Patients with chronic kidney disease (CKD) exhibit a higher probability of having cognitive impairment or dementia than those without CKD. The beneficial effects of physical exercise on cognitive function are known in the general older population, but more research is required in older adults with CKD.

METHODS

Eighty-one outpatients (aged ≥65 years) with CKD stage G3-G4 were assessed for eligibility. Among them, 60 were randomized (single-center, unblinded, and stratified) and 53 received the allocated intervention (exercise n = 27, control n = 26). Patients in the exercise group undertook group-exercise training at our facility once weekly and independent exercises at home twice weekly or more, for 24 weeks. Patients in the control group received general care. General and specific cognitive functions (memory, attention, executive, and verbal) were measured, and differences in their scores at baseline and at the 24-week follow-up visit were assessed between the 2 groups.

RESULTS

Forty-four patients completed the follow-up at 24 weeks (exercise n = 23, control n = 21). Patients in the exercise group showed significantly greater changes in Wechsler Memory Scale-Revised Logical Memory delayed recall (exercise effect: 2.82, 95% CI: 0.46-5.19, p = 0.03), and immediate and delayed recall (exercise effect: 5.97, 95% CI: 1.13-10.81, p = 0.02) scores than those in the control group.

CONCLUSIONS

The 24-week exercise intervention significantly improved the memory function in older adults with pre-dialysis CKD. This randomized controlled trial suggests that physical exercise is a useful nonpharmacological strategy for preventing cognitive decline in these patients.

Comparison of muscle strength between hemodialysis patients and non-dialysis patients with chronic kidney disease

[Purpose] Muscle weakness in patients with chronic kidney disease is associated with several disease-related factors, and this study aimed to examine whether hemodialysis is one of risk factors for muscle weakness in patients with chronic kidney disease. [Participants and Methods] We conducted a cross-sectional study with 74 non-dialysis and 84 hemodialysis patients. Muscle strength evaluations were performed by measuring isometric knee extensor muscle strength and grip strength. Each evaluation item was compared between the hemodialysis and non-dialysis groups, and multiple regression analysis was performed to determine the factors associated with muscle strength. In addition, the correlation between lower-extremity muscle strength and grip strength was examined in each group. [Results] Isometric knee extensor muscle strength was significantly lower in the hemodialysis group than in the non-dialysis group. Grip strength was also significantly lower in the hemodialysis group than in the non-dialysis group. Hemodialysis was determined to be an independent risk factor associated with lower limb muscle strength as well as grip strength. The positive correlation between isometric knee extensor muscle strength and grip strength was almost the same in the groups. [Conclusion] Hemodialysis treatment was an independent risk factor for muscle weakness. Regular monitoring of grip strength may facilitate better management with physical therapy in hemodialysis patients.

Dietary Intake, Body Composition, and Clinical Parameters: Associations Between the Level and Type of Physical Activity in Hemodialysis Patients

BACKGROUND

Physical inactivity and muscle wasting potentiate each other and are highly prevalent among hemodialysis (HD) patients. The authors evaluated the association between physical activity (PA), clinical, nutritional, and body composition parameters in HD patients.

METHODS

Multicenter cross-sectional study with 581 HD patients. Clinical, body composition, dietary intake, and PA data were recorded. For the analysis, patients were divided into active (follow World Health Organization recommendations) and inactive groups.

RESULTS

A total of 20% of the patients followed World Health Organization recommendations on PA. Differences between physically active and physically inactive patients were observed in age, biochemical parameters and total body water, intracellular water, lean tissue index (LTI), body cell mass, energy, and protein intake. PA was a predictor of higher LTI, body cell mass, and energy intake independently of age, gender, presence of diabetes, dialysis adequacy, and dialysis vintage. Controlling for the effect of age, walking and vigorous PA were positively correlated with energy and protein intake. Vigorous PA was also positively correlated with LTI.

CONCLUSION

The PA is a predictor of higher LTI, body cell mass, and energy intake. Vigorous PA is associated with an improved body composition and dietary pattern, whereas walking seems to be also associated with a favorable nutritional status.

Association Between Muscle Strength and Cystatin C-Based Estimated Glomerular Filtration Rate Among Middle-Aged and Elderly Population: Findings Based on the China Health and Retirement Longitudinal Study (CHARLS), 2015

Background

Patients with chronic kidney disease (CKD) are prone to muscle strength degeneration. However, the relationship between mild-to-moderate renal insufficiency and low muscle strength remains unclear. As cystatin C is not subject to muscular conditions and is a sensitive serum marker in preclinical renal disease, we aimed to investigate the association between estimated glomerular filtration rate (eGFR) based on cystatin C and muscle strength in the Chinese population.

Methods

This was a cross-sectional study enrolling 12,398 Chinese participants aged above 45 years (5762 men and 6636 women) from the 2015 China Health and Retirement Longitudinal Study. Handgrip strength (HGS) was used to assess muscle strength. Locally weighted scatterplot smoothing (LOWESS) curves were employed to visualize the relationships between eGFR and HGS. Multivariable logistic regression was conducted to analyze the correlation between kidney function and low muscle strength.

Results

Significant differences in HGS by CKD stage were observed in both sexes after adjusting for age and body mass index. LOWESS curves demonstrated concomitant decreases in HGS and kidney function at eGFR levels below 120 mL/min/1.73 m² in both sexes. According to multivariate logistic regression, participants with CKD stages 2 (odds ratio [OR]: 1.256, 95% confidence interval [CI]: 1.120–1.409), 3 (OR: 2.725, 95% CI: 2.2585–3.288), and 4–5 (OR: 3.069, 95% CI 1.747–5.392) had higher risk of low muscle strength than those who were normal or had CKD stage 1 after adjusting for demographic and clinical variables.

Conclusion

Our study illustrated that CKD stage was independently associated with low muscle strength in Chinese middle-aged and elderly populations.

Association between vitamin D deficiency and exercise capacity in patients with CKD, a cross-sectional analysis

BACKGROUND

Evidence is growing for a role of vitamin D in regulating skeletal muscle mass, strength and functional capacity. Given the role the kidneys play in activating total vitamin D, and the high prevalence of vitamin D deficiency in Chronic Kidney Disease (CKD), it is possible that deficiency contributes to the low levels of physical function and muscle mass in these patients.

METHODS

This is a secondary cross-sectional analysis of previously published interventional study, with in vitro follow up work. 34 CKD patients at stages G3b-5 (eGFR 25.5 ± 8.3 mL/min/1.73m2; age 61 ± 12 years) were recruited, with a sub-group (n = 20) also donating a muscle biopsy. Vitamin D and associated metabolites were analysed in plasma by liquid chromatography tandem-mass spectroscopy and correlated to a range of physiological tests of muscle size, function, exercise capacity and body composition. The effects of 1α,25(OH)2D3 supplementation on myogenesis and myotube size was investigated in primary skeletal muscle cells from vitamin D deficient donors.

RESULTS

In vivo, there was no association between total or active vitamin D and muscle size or strength, but a significant correlation with V̇O_2Peak was seen with total vitamin D (25OHD). in vitro, 1α,25(OH)₂D3 supplementation reduced IL-6 mRNA expression, but had no effect upon proliferation, differentiation or myotube diameter.

CONCLUSIONS

Vitamin D deficiency is not a prominent factor driving the loss of muscle mass in CKD, but may play a role in reduced exercise capacity.

Optimal Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients with Sarcopenia: An Overview

Multi-factors, such as anorexia, activation of renin-angiotensin system, inflammation, and metabolic acidosis, contribute to malnutrition in chronic kidney disease (CKD) patients. Most of these factors, contributing to the progression of malnutrition, worsen as CKD progresses. Protein restriction, used as a treatment for CKD, can reduce the risk of CKD progression, but may worsen the sarcopenia, a syndrome characterized by a progressive and systemic loss of muscle mass and strength. The concomitant rate of sarcopenia is higher in CKD patients than in the general population. Sarcopenia is also associated with mortality risk in CKD patients. Thus, it is important to determine whether protein restriction should be continued or loosened in CKD patients with sarcopenia. We may prioritize protein restriction in CKD patients with a high risk of end-stage kidney disease (ESKD), classified to stage G4 to G5, but may loosen protein restriction in ESKD-low risk CKD stage G3 patients with proteinuria <0.5 g/day, and rate of eGFR decline <3.0 mL/min/1.73 m²/year. However, the effect of increasing protein intake alone without exercise therapy may be limited in CKD patients with sarcopenia. The combination of exercise therapy and increased protein intake is effective in improving muscle mass and strength in CKD patients with sarcopenia. In the case of loosening protein restriction, it is safe to avoid protein intake of more than 1.5 g/kgBW/day. In CKD patients with high risk in ESKD, 0.8 g/kgBW/day may be a critical point of protein intake.

Exercise training in chronic kidney disease-effects, expectations and adherence

There is increasing evidence showing the health benefits of physical activity, such as better survival and possibly even a slower decline in kidney function, in people with chronic kidney disease (CKD). There is convincing evidence that exercise training improves physical function measured as aerobic capacity, muscle endurance strength and balance at all ages and all stages of CKD. In fact, long-term adherence to well-designed and adequately monitored exercise training programmes is high. In general, patients express interest in exercise training and are motivated to improve their physical function and health. A growing number of nephrologists regard physical activity and exercise training as beneficial to patients with CKD. However, many feel that they do not have the knowledge to prescribe exercise training and suppose that patients are not interested. Patients state that support from healthcare professionals is crucial to motivate them to participate in exercise training programmes and overcome medical, physical and psychological barriers such as frailty, fatigue, anxiety and fear. Equally important is the provision of funding by healthcare providers to ensure adequate prescription and follow-up by trained exercise physiologists for this important non-pharmacological treatment.

The reliability and validity of the 30-seconds sit-to-stand test and its capacity for assessment of the functional status of hemodialysis patients

PURPOSE

To investigate the validity of the 30-seconds sit-to-stand test (STS-30) and its reliability in hemodialysis patients.

METHODS

Patients receiving hemodialysis treatment three times a week for at least six months were evaluated using STS-30, Incremental Shuttle Walking Test, and health-related quality of life by KDQOL-SF questionnaire. The data obtained from the Incremental Shuttle Walking Test were divided into tertiles, and the STS-30 results were compared among tertiles. The accuracy of the STS-30 to identify low exercise capacity was evaluated. A second STS-30 was performed after 6 to 8-weeks for the reliability analyses using Intraclass Correlation Coefficient (ICC). Minimal detectable change scores were calculated.

RESULTS

Sixty-three individuals (66.7% men) aged 48.3 years (95%CI 44.6-51.9) were evaluated. There were significant correlations between STS-30, exercise capacity (r = 0.72), and physical domains of health-related quality of life (0.30 ≤ r ≤ 0.51). Tertile 1 of the Incremental Shuttle Walking Test was different from tertiles 2 and 3 for STS-30 [difference of 3.4 repetitions (95%CI 1.5-5.4) and 4.7 repetitions (95%CI 2.8-6.7), respectively]. The value of 12 repetitions was the cut-off points for stratification of individuals with low exercise capacity. The STS-30 had a high test-retest reliability (ICC = 0.93) and the minimal detectable change was 2.1 repetitions.

CONCLUSION

The STS-30 is a reliable test, associated with exercise capacity and physical domains of health-related quality of life. Thus, is a valid method for functional evaluation in hemodialysis patients.

Improving the prognosis of renal patients: The effects of blood flow-restricted resistance training on redox balance and cardiac autonomic function

NEW FINDINGS

What is the central question of this study? Can resistance training with and without blood flow restriction improve redox balance and positively impact the autonomic cardiac modulation in chronic kidney disease patients? What is the main finding and its importance? Resistance training with and without blood flow restriction improved antioxidant defence (paraoxonase 1), decreased the pro-oxidative myeloperoxidase, improved cardiac autonomic function and slowed the decrease in renal function. We draw attention to the important clinical implications for the management of redox balance and autonomic cardiac function in chronic kidney disease patients.

ABSTRACT

Patients with chronic kidney disease (CKD) are prone to cardiovascular diseases secondary to abnormalities in both autonomic cardiac function and redox balance [myeloperoxidase (MPO) to paraoxonase 1 (PON1) ratio]. Although aerobic training improves both autonomic balance and redox balance in patients with CKD, the cardioprotective effects of resistance training (RT), with and without blood flow restriction (BFR), remain unknown. We aimed to compare the effects of RT and RT+BFR on antioxidant defence (PON1), pro-oxidative status (MPO), cardiac autonomic function (quantified by heart rate variability analysis) and renal function. Conservative CKD (stages 1 to 5 who do not need hemodialysis) patients (n = 105, 33 female) of both sexes were randomized into three groups: control (CTL; 57.6 ± 5.2 years; body mass index, 33.23 ± 1.62 kg/m² ), RT (58.09 ± 6.26 years; body mass index 33.63 ± 2.05 kg/m² ) and RT+BFR (58.06 ± 6.47 years; body mass index, 33.32 ± 1.87 kg/m² ). Patients completed 6 months of RT or RT+BFR on three non-consecutive days per week under the supervision of strength and conditioning professionals. Training loads were adjusted every 2 months. Heart rate variability was recorded with a Polar-RS800 and data were analysed for time and frequency domains using Kubios software. The redox balance markers were PON1 and MPO, which were analysed in plasma samples. Renal function was estimated as estimated glomerular filtration rate. The RT and RT+BFR decreased pro-oxidative MPO (RT, ∼34 ng/ml and RT+BFR, ∼27 ng/ml), improved both antioxidant defence (PON1: RT, ∼23 U/L and RT+BFR, ∼31 U/L) and cardiac autonomic function (R-R interval: RT, ∼120.4 ms and RT+BFR, ∼117.7 ms), and slowed the deterioration of renal function (P < 0.0001). Redox balance markers were inversely correlated with heart rate variability time-domain indices. Our data indicated that both training models were effective as non-pharmacological tools to increase the antioxidant defences, decrease oxidative stress and improve the cardiac autonomic function of CKD patients.

Effects of exercise on kidney and physical function in patients with non-dialysis chronic kidney disease: a systematic review and meta-analysis

Patients with non-dialysis chronic kidney disease (CKD) are at greater risk of early mortality and decreased physical function with an advance in the stage of CKD. However, the effect of exercise in these patients is unclear. This meta-analysis aimed to determine the effects of physical exercise training on the risk of mortality, kidney and physical functions, and adverse events in patients with non-dialysis CKD. The meta-analysis conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement and the Cochrane Handbook recommendations. On 16 August 2019, the PubMed, CINAHL, Cochrane Library databases, and Embase were electronically searched, with no restrictions for date/time, language, document type, or publication status, for eligible randomized controlled trials (RCTs) investigating the effects of exercise on mortality and kidney and physical function in patients with non-dialysis CKD. Eighteen trials (28 records), including 848 patients, were analyzed. The effects of exercise on all-cause mortality and estimated glomerular filtration rate were not significantly different from that of usual care. Exercise training improved peak/maximum oxygen consumption compared to usual care. Regular exercise improves physical and walking capacity for patients with non-dialysis CKD. Effect on leg muscle strength was unclear.

Effect of intradialytic progressive resistance exercise on physical fitness and quality of life in maintenance haemodialysis patients

Purpose

To investigate the impact of intradialytic progressive resistance exercise (IPRE) on physical fitness and quality of life in maintenance haemodialysis (MHD) patients.

Methods

Subjects were allocated randomly to the exercise group received IPRE and the control group underwent a haemodialysis session alone. Outcomes measured were including physical fitness ascertained by 6‐min walk test, sit‐to‐stand 10 test and handgrip strength. Kidney Disease Quality of Life Instrument was used to assess the quality of life, and also recorded the adverse event at each exercise session.

Results

A total of 87 patients were analysed: 43 in the exercise group and 44 in the control group. After 12 weeks, there were significant improvements in physical fitness and past of the dimension of the scale in the exercise group.

Conclusions

IPRE can improve the physical fitness and quality of life in patients underwent MHD with no serious adverse events or safety issues.

The association of muscle size, strength and exercise capacity with all-cause mortality in non-dialysis-dependent CKD patients

BACKGROUND/OBJECTIVE

Patients with chronic kidney disease (CKD) are commonly reported to exhibit skeletal muscle wasting, reduced strength and exercise capacity. Evidence from patients with end-stage renal disease (ESRD) demonstrates these factors are associated with mortality, but it is unclear whether this relationship exists earlier in the illness. Our objective was to determine whether muscle size, strength or exercise capacity was associated with all-cause mortality, unscheduled hospital admissions or time to ESRD in patients not requiring dialysis.

METHODS

This is a prospective cohort study of 89 patients with CKD stages 3b-5 not requiring renal replacement therapy with a mean follow-up period of 3.3 years in which the contribution of predictors of rectus femoris muscle size, muscle strength, exercise capacity to all-cause mortality rates, progression to ESRD and time to first hospitalization were investigated.

RESULTS

Unadjusted analysis suggested each 1 cm² increase in quadriceps muscle size (measured by ultrasonography cross-sectional area) was associated with a 38% reduced risk for death (p = .006), and a 10 m improvement on the incremental shuttle walk test was associated with a 3% reduced risk for death (p = .04). However, this relationship was not present in analysis adjusted for age, gender and eGFR. No association was seen between any factor for the development of ESRD or time to first hospitalization.

CONCLUSION

These results suggest that in this small cohort, muscle size and exercise capacity are associated with mortality when considered alone, but this relationship was not present in adjusted analyses. Further investigation in a larger patient group is warranted.

Uremic Sarcopenia: Clinical Evidence and Basic Experimental Approach

Sustained physical activity extends healthy life years while a lower activity due to sarcopenia can reduce them. Sarcopenia is defined as a decrease in skeletal muscle mass and strength due not only to aging, but also from a variety of debilitating chronic illnesses such as cancer and heart failure. Patients with chronic kidney disease (CKD), who tend to be cachexic and in frail health, may develop uremic sarcopenia or uremic myopathy due to an imbalance between muscle protein synthesis and catabolism. Here, we review clinical evidence indicating reduced physical activity as renal function deteriorates and explore evidence-supported therapeutic options focusing on nutrition and physical training. In addition, although sarcopenia is a clinical concept and difficult to recapitulate in basic research, several in vivo approaches have been attempted, such as rodent subtotal nephrectomy representing both renal dysfunction and muscle weakness. This review highlights molecular mechanisms and promising interventions for uremic sarcopenia that were revealed through basic research. Extensive study is still needed to cast light on the many aspects of locomotive organ impairments in CKD and explore the ways that diet and exercise therapies can improve both outcomes and quality of life at every level.

The "Minimum Clinically Important Difference" in Frequently Reported Objective Physical Function Tests After a 12-Week Renal Rehabilitation Exercise Intervention in Nondialysis Chronic Kidney Disease

OBJECTIVE

Chronic kidney disease patients are characterized by impaired physical function. The goal of exercise-based interventions is an improvement in functional performance. However, improvements are often determined by "statistically significant" changes. We investigated the "minimum clinically important difference," "the smallest change that is important to the patient," for commonly reported physical function tests.

DESIGN

Nondialysis chronic kidney disease patients completed 12-wks of a combined aerobic (plus resistance training). The incremental shuttle walking test, sit-to-stand 5 and 60, estimated 1-repetition maximum for the knee extensors, and VO2peak were assessed. After the intervention, patients rated their perceived change in health. Both anchor- and distribution-based minimum clinically important difference approaches were calculated.

RESULTS

The minimum clinically important difference was calculated as follows: incremental shuttle walking test, +45 m; sit-to-stand 5, -4.2 secs; VO2peak, +1.5 ml/kg per min. Because of comparable increases in "anchor" groups, no minimum clinically important difference was estimated for the sit-to-stand 60 or estimated 1-repetition maximum.

CONCLUSIONS

We have established the minimum clinically important difference in chronic kidney disease for common tests of physical function. These values represent the minimum change required for patients to perceive noticeable and beneficial change to their health. These scores will help interpret changes after exercise interventions where these tests are used. These minimum clinically important differences can be used to power future studies to detect clinically important changes.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Define the "minimum clinically important difference"; (2) Distinguish between concepts of minimum clinically important difference, "minimal detectable change,", and "statistically significant change"; and (3) Interpret other study findings and their own results in the context of the minimum clinically important difference rather than statistically significant changes.

LEVEL

Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Psychosocial interventions for preventing and treating depression in dialysis patients

BACKGROUND

People with end-stage kidney disease (ESKD) treated with dialysis are frequently affected by major depression. Dialysis patients have prioritised depression as a critically important clinical outcome in nephrology trials. Psychological and social support are potential treatments for depression, although a Cochrane review in 2005 identified zero eligible studies. This is an update of the Cochrane review first published in 2005.

OBJECTIVES

To assess the effect of using psychosocial interventions versus usual care or a second psychosocial intervention for preventing and treating depression in patients with ESKD treated with dialysis.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Register of Studies up to 21 June 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of psychosocial interventions for prevention and treatment of depression among adults treated with long-term dialysis. We assessed effects of interventions on changes in mental state (depression, anxiety, cognition), suicide, health-related quality of life (HRQoL), withdrawal from dialysis treatment, withdrawal from intervention, death (any cause), hospitalisation and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion and extracted study data. We applied the Cochrane 'Risk of Bias' tool and used the GRADE process to assess evidence certainty. We estimated treatment effects using random-effects meta-analysis. Results for continuous outcomes were expressed as a mean difference (MD) or as a standardised mean difference (SMD) when investigators used different scales. Dichotomous outcomes were expressed as risk ratios. All estimates were reported together with 95% confidence intervals (CI).

MAIN RESULTS

We included 33 studies enrolling 2056 participants. Twenty-six new studies were added to this 2019 update. Seven studies originally excluded from the 2005 review were included as they met the updated review eligibility criteria, which have been expanded to include RCTs in which participants did not meet criteria for depression as an inclusion criterion. Psychosocial interventions included acupressure, cognitive-behavioural therapy, counselling, education, exercise, meditation, motivational interviewing, relaxation techniques, social activity, spiritual practices, support groups, telephone support, visualisation, and voice-recording of a psychological intervention. The duration of study follow-up ranged between three weeks and one year. Studies included between nine and 235 participants. The mean study age ranged between 36.1 and 73.9 years. Random sequence generation and allocation concealment were at low risk of bias in eight and one studies respectively. One study reported low risk methods for blinding of participants and investigators, and outcome assessment was blinded in seven studies. Twelve studies were at low risk of attrition bias, eight studies were at low risk of selective reporting bias, and 21 studies were at low risk of other potential sources of bias. Cognitive behavioural therapy probably improves depressive symptoms measured using the Beck Depression Inventory (4 studies, 230 participants: MD -6.10, 95% CI -8.63 to -3.57), based on moderate certainty evidence. Cognitive behavioural therapy compared to usual care probably improves HRQoL measured either with the Kidney Disease Quality of Life Instrument Short Form or the Quality of Life Scale, with a 0.5 standardised mean difference representing a moderate effect size (4 studies, 230 participants: SMD 0.51, 95% CI 0.19 to 0.83) , based on moderate certainty evidence. Cognitive behavioural therapy may reduce major depression symptoms (one study) and anxiety, and increase self-efficacy (one study). Cognitive behavioural therapy studies did not report hospitalisation. We found low-certainty evidence that counselling may slightly reduce depressive symptoms measured with the Beck Depression Inventory (3 studies, 99 participants: MD -3.84, 95% CI -6.14 to -1.53) compared to usual care. Counselling reported no difference in HRQoL (one study). Counselling studies did not measure risk of major depression, suicide, or hospitalisation. Exercise may reduce or prevent major depression (3 studies, 108 participants: RR 0.47, 95% CI 0.27 to 0.81), depression of any severity (3 studies, 108 participants: RR 0.69, 95% CI 0.54 to 0.87) and improve HRQoL measured with Quality of Life Index score (2 studies, 64 participants: MD 3.06, 95% CI 2.29 to 3.83) compared to usual care with low certainty. With moderate certainty, exercise probably improves depression symptoms measured with the Beck Depression Inventory (3 studies, 108 participants: MD -7.61, 95% CI -9.59 to -5.63). Exercise may reduce anxiety (one study). No exercise studies measured suicide risk or withdrawal from dialysis. We found moderate-certainty evidence that relaxation techniques probably reduce depressive symptoms measured with the Beck Depression Inventory (2 studies, 122 participants: MD -5.77, 95% CI -8.76 to -2.78). Relaxation techniques reported no difference in HRQoL (one study). Relaxation studies did not measure risk of major depression or suicide. Spiritual practices have uncertain effects on depressive symptoms measured either with the Beck Depression Inventory or the Brief Symptom Inventory (2 studies, 116 participants: SMD -1.00, 95% CI -3.52 to 1.53; very low certainty evidence). No differences between spiritual practices and usual care were reported on anxiety (one study), and HRQoL (one study). No study of spiritual practices evaluated effects on suicide risk, withdrawal from dialysis or hospitalisation. There were few or no data on acupressure, telephone support, meditation and adverse events related to psychosocial interventions.

AUTHORS' CONCLUSIONS

Cognitive behavioural therapy, exercise or relaxation techniques probably reduce depressive symptoms (moderate-certainty evidence) for adults with ESKD treated with dialysis. Cognitive behavioural therapy probably increases health-related quality of life. Evidence for spiritual practices, acupressure, telephone support, and meditation is of low certainty . Similarly, evidence for effects of psychosocial interventions on suicide risk, major depression, hospitalisation, withdrawal from dialysis, and adverse events is of low or very low certainty.

The effect of aerobic and resistance exercise training on the health related quality of life, physical function, and muscle strength among hemodialysis patients with Type 2 diabetes

INTRODUCTION

Diabetic patients who undergo hemodialysis commonly suffer from reduction of both exercise capacity and muscle strength. These factors may have a negative effect on health related quality of life (HRQoL) and physical function. We investigated the effect of aerobic and resistance exercise training on the HRQoL, physical function, and muscle strength among hemodialysis patients with Type 2 diabetes.

METHODS

Twenty-eight diabetic patients who were on hemodialysis in the Milad Hospital (Tehran, Iran) were recruited for the study. Subjects were randomized into control (n = 13) and exercise training groups (n = 15). The exercise training group performed combined aerobic and resistance exercise training at moderate intensity (11-15/20 on the Borg scale) during hemodialysis treatment, 3 times a week for 8 weeks. The primary outcomes consisted of physical function measured by a 6-min walk test (6MWT), HR-QoL measured by the Short Form Health Survey (SF-36), and lower limb muscle strength measured using a hand-held Digital Dynamometer.

RESULTS

The 6MWT distance increased significantly in the exercise training group (36%). Bilateral hip flexor strength (right, 24.5%; left, 30.4%) and abductor strength (right, 27.6%; left, 25.2%) decreased significantly in the non-exercising control group but no significant change was found in the exercise group (P > 0.05). There were no significant changes in any of the 8 generic subscales of HR-QoL neither in the exercise training group nor controls following an 8- week study.

CONCLUSIONS

8 weeks of combined aerobic-resistance exercise training among diabetic hemodialysis patients seem to be effective in improvement of physical function and lower limb muscle strength.

Exercise as a prescription for patients with various diseases

A growing understanding of the benefits of exercise over the past few decades has prompted researchers to take an interest in the possibilities of exercise therapy. Because each sport has its own set of characteristics and physiological complications that tend to occur during exercise training, the effects and underlying mechanisms of exercise remain unclear. Thus, the first step in probing the effects of exercise on different diseases is the selection of an optimal exercise protocol. This review summarizes the latest exercise prescription treatments for 26 different diseases: musculoskeletal system diseases (low back pain, tendon injury, osteoporosis, osteoarthritis, and hip fracture), metabolic system diseases (obesity, type 2 diabetes, type 1 diabetes, and nonalcoholic fatty liver disease), cardio-cerebral vascular system diseases (coronary artery disease, stroke, and chronic heart failure), nervous system diseases (Parkinson's disease, Huntington's disease, Alzheimer's disease, depression, and anxiety disorders), respiratory system diseases (chronic obstructive pulmonary disease, interstitial lung disease, and after lung transplantation), urinary system diseases (chronic kidney disease and after kidney transplantation), and cancers (breast cancer, colon cancer, prostate cancer, and lung cancer). Each exercise prescription is displayed in a corresponding table. The recommended type, intensity, and frequency of exercise prescriptions are summarized, and the effects of exercise therapy on the prevention and rehabilitation of different diseases are discussed.

Ultrasound assessment of muscle mass in response to exercise training in chronic kidney disease: a comparison with MRI

BACKGROUND

Chronic kidney disease (CKD) is a catabolic condition associated with muscle wasting and dysfunction, which associates with morbidity and mortality. There is a need for simple techniques capable of monitoring changes in muscle size with disease progression and in response to interventions aiming to increase muscle mass and function. Ultrasound is one such technique; however, it is unknown how well changes in muscle cross-sectional area (CSA) measured using ultrasound relate to changes in whole muscle volume measured using magnetic resonance imaging. We tested whether rectus femoris CSA (RF-CSA) could be used as a valid indication of changes in quadriceps muscle volume as a single measure of muscle size and following a 12 week exercise intervention that resulted in muscle hypertrophy.

METHODS

Secondary analysis of data was collected from the ExTra CKD study (ISRCTN 36489137). Quadriceps muscle size was assessed from 36 patients with non-dialysis CKD before and after 12 weeks of supervised exercise that resulted in muscle hypertrophy.

RESULTS

Strong positive correlations were observed between RF-CSA and quadriceps volume at baseline (r² = 0.815, CI 0.661 to 0.903; P < 0.001) and following 12 week exercise (r² = 0.845, CI 0.700 to 0.923; P < 0.001). A moderate positive association was also observed between changes in RF-CSA and quadriceps following exercise training (rho = 0.441, CI 0.085 to 0.697; P = 0.015). Bland-Altman analysis revealed a small bias (bias 0.6% ± 12.5) between the mean percentage changes in RF-CSA and quadriceps volume but wide limits of agreement from -24 to 25.

CONCLUSIONS

Rectus femoris CSA appears to be a reliable index of total quadriceps volume as a simple measure of muscle size, both as a single observation and in response to exercise training in non-dialysis CKD patients.

Randomized Controlled Trial of Exercise in CKD-The RENEXC Study

Introduction

Home-based, clinically feasible trials in non-dialysis-dependent patients with chronic kidney disease (CKD) are sparse. We compared the effects of 2 different exercise training programs on physical performance, and measured glomerular filtration rate (mGFR) and albuminuria level in patients with CKD stages 3 to 5.

Methods

This is a single-center, randomized controlled trial (RCT) comprising 151 patients (mGFR: 22 ± 8 ml/min per 1.73 m²; age 66 ± 14 years) randomized to either balance or strength training. Both groups were prescribed 30 minutes of exercise per day for 5 days per week for 12 months, comprising 60 minutes per week of endurance training and 90 minutes per week of either strength or balance exercises. The exercises were individually prescribed, and the intensity was monitored with Borg's rating of perceived exertion (RPE).

Results

There were no treatment differences for any of the primary outcomes measuring physical performance. The strength and balance groups showed significantly increased effect sizes after 12 months for the following: walking (31 m and 24 m, P < 0.001) and the 30-second sit-to-stand test (both: 1 time, P < 0.001); quadriceps strength (right/left: strength 1.2/0.8 kg*m, P < 0.003; balance 0.6/0.9, P < 0.01); functional reach (both: 2 cm, P < 0.01); and fine motor skills (open/closed eyes, right/left, both: between 0.3 and 4 seconds faster, P < 0.05). After 12 months, there was a significant treatment difference for albuminuria (P < 0.02), which decreased by 33% in the strength group. In both groups, mGFR declined by 1.8 ml/min per 1.73 m².

Conclusion

Our primary hypothesis that strength training was superior to balance training was not confirmed. Within groups, 12 months of exercise training resulted in significant improvements in most measures of physical performance. Measured GFR declined similarly in the 2 groups. The strength group showed a significant decrease in albuminuria.

Comparing effects of 4 months of two self-administered exercise training programs on physical performance in patients with chronic kidney disease: RENEXC - A randomized controlled trial

Background

Exercise training is recommended to patients with chronic kidney disease (CKD). However, the level of evidence is still low. This randomized controlled trial (RCT) compared two different and self-administered exercise training programs in a representative CKD population.

Methods

This single centre RCT included 151 non-dialysis dependent CKD patients, irrespective of age and comorbidity. Self-administered exercise training of 150 minutes per week was prescribed for 4 months and consisted of 60 minutes endurance training in combination with 90 minutes of either strength or balance training (strength versus balance group). Overall endurance (6-minute walk-test (6-MWT), stair climbing), muscular endurance (30-seconds sit-to-stand (30-STS), heel rises and toe lifts, handgrip (HGS) and isometric quadriceps (IQS) strength, balance (functional reach (FR) and Berg´s balance scale (BBS)) and fine motor skills (Moberg´s picking up test (MPUT)) were measured at baseline and after 4 months. Intention to treat analyses with mixed models was used.

Results

53 women and 98 men, mean age 66 ± 14: range 19 to 87 years, eGFR 20 ± 7: range 8 to 48 ml/min/1.73m² participated. The strength group (n = 76) improved significantly in 6-MWT, stair climbing, 30-STS, heel rises right and left, toe lifts right, IQS right and left, and MPUT with closed eyes with the right and left hand. The balance group (n = 75) improved significantly in heel rises right and left, IQS left, BBS and left-handed MPUT with open and closed eyes. A significant effect between the groups was found for IQS right.

Conclusions

Two different exercise training programs, consisting of endurance in combination with either strength or balance exercise training, improved or maintained overall endurance, muscular strength and endurance, balance and fine motor skills after 4 months of 150 minutes/week self-administered exercise training in a representative CKD population, regardless of age and comorbidity.

Satellite cell function, intramuscular inflammation and exercise in chronic kidney disease

Skeletal muscle wasting is a common feature of chronic kidney disease (CKD) and is clinically relevant due to associations with quality of life, physical functioning, mortality and a number of comorbidities. Satellite cells (SCs) are a population of skeletal muscle progenitor cells responsible for accrual and maintenance of muscle mass by providing new nuclei to myofibres. Recent evidence from animal models and human studies indicates CKD may negatively affect SC abundance and function in response to stimuli such as exercise and damage. The aim of this review is to collate recent literature on the effect of CKD on SCs, with a particular focus on the myogenic response to exercise in this population. Exercise is widely recognized as important for the maintenance of healthy skeletal muscle mass and is increasingly advocated in the care of a number of chronic conditions. Therefore a greater understanding of the impact of uraemia upon SCs and the possible altered myogenic response in CKD is required to inform strategies to prevent uraemic cachexia.

Wasting in Chronic Kidney Disease – a Complex Issue

Chronic kidney disease (CKD) has become a global health burden and is associated with increased morbidity and mortality. In particular, wasting is highly prevalent in later stages of the illness with muscle loss being a common problem. The aetiology and progression of this wasting is complex and multiple states have been identified linked to wasting in CKD. These include: ‘malnutrition’, ‘disease-related malnutrition’, ‘protein-energy wasting’, ‘cachexia’, ‘sarcopenia’, ‘frailty’ and ‘muscle wasting’. The purpose of this paper is to review these terms in the context of CKD. Common features include weight loss, loss of muscle mass and muscle function principally driven by CKD disease specific factors and inflammatory mediators. Disease-related malnutrition would appear to be a more appropriate term for CKD than malnutrition as it take in to consideration disease specific factors such as inflammation for example.  Frailty is commonly associated with age-related decline in physiological function. Development of novel screening tools measuring across multiple domains of nutritional status, muscle and physical function may be useful in CKD. Research into potential treatments are currently underway with focus on multi-modal therapies including nutrition, resistance training and anabolic drugs such as myostatin blockade and selective androgen receptor modulators. A better understanding of different states and terms may help guide assessment and treatment opportunities for patients.

Resistance training downregulates macrophages infiltration in the kidney of 5/6 nephrectomized rats

INTRODUCTION

Chronic kidney disease (CKD) is considered a significant world health problem with elevated mortality rates. Patients with CKD are restricted to mild physical activity, present chronic inflammatory state and loss of muscle strength. Currently, the influence of resistance exercise (RE) on the progression of renal disease has not being fully elucidated.

PURPOSE

To evaluate the effects of RE on the progression of CKD in a remnant kidney model (5/6Nx) in rats.

METHODS

Eight-week-old Wistar rats were submitted to 5/6 nephrectomy and were divided into four groups: Sham sedentary (Sham SD); Sham RE (Sham RE); 5/6Nx SD and 5/6Nx RE. The animals were trained for 8 weeks in a vertical climbing ladder for 3 days per week, on non-consecutive days.

RESULTS

As expected, 5/6Nx SD group presented a markedly loss of renal function, increased plasma inflammatory cytokines and increased oxidative stress with a reduced activity of nitric oxide. The higher macrophage infiltration and fibrosis confirmed these conditions. RE attenuated systolic blood pressure and renal function decrease and also improved serum lipid parameters in 5/6 Nx animals. It was evident the increase of muscle strength and mass in the trained groups while the sedentary group showed reduced muscle weight and strength compared to Sham SD.

CONCLUSIONS

RE implemented following 5/6Nx retard the progression of chronic kidney injury while simultaneously allowed the maintenance of skeletal muscle strength.

Twelve weeks of supervised exercise improves self-reported symptom burden and fatigue in chronic kidney disease: a secondary analysis of the 'ExTra CKD' trial

Background

Chronic kidney disease (CKD) patients experience a high symptom burden including fatigue, sleep difficulties, muscle weakness and pain. These symptoms reduce levels of physical function (PF) and activity, and contribute to poor health-related quality of life (HRQoL). Despite the gathering evidence of positive physiological changes following exercise in CKD, there is limited evidence on its effect on self-reported symptom burden, fatigue, HRQoL and physical activity.

Methods

Thirty-six patients [mean ± SD 61.6 ± 11.8 years, 22 (61%) females, estimated glomerular filtration rate: 25.5 ± 7.8 mL/min/1.73 m²] not requiring renal replacement therapy underwent 12 weeks (3 times/week) of supervised aerobic exercise (AE), or a combination (CE) of AE plus resistance training. Outcomes included self-reported symptom burden, fatigue, HRQoL and physical activity.

Results

Exercise reduced the total number of symptoms reported by 17% and had favourable effects on fatigue in both groups. AE reduced the frequency of ‘itching’, ‘impotence’ and ‘shortness of breath’ symptoms, and the intrusiveness for symptoms of ‘sleep disturbance’, ‘loss of muscular strength/power’, ‘muscle spasm/stiffness’ and ‘restless legs’. The addition of resistance exercise in the CE group saw a reduction in ‘loss of muscular strength/power’. No changes were seen in subjective PF or physical activity levels. AE increased self-efficacy for physical activity.

Conclusions

Supervised exercise had favourable effects on symptom frequency and intrusiveness, including substantial improvements in fatigue. Although the intervention did not improve self-reported physical activity levels, AE increased patients’ self-efficacy for physical activity. These favourable changes in self-reported outcomes support the important role of exercise in CKD.

Physical inactivity and protein energy wasting play independent roles in muscle weakness in maintenance haemodialysis patients

Background

Muscle weakness is associated with increased mortality risk in chronic haemodialysis (CHD) patients. Protein energy wasting (PEW) and low physical activity could impair muscle quality and contribute to muscle weakness beyond muscle wasting in these patients. Aim of this study was to assess clinical and biological parameters involved in the reduction of muscle strength of CHD patients.

Methods

One hundred and twenty-three CHD patients (80 males, 43 females; 68,8 [57.9–78.8] y.o.) were included in this study. Maximal voluntary force (MVF) of quadriceps was assessed using a belt-stabilized hand-held dynamometer. Muscle quality was evaluated by muscle specific torque, defined as the strength per unit of muscle mass. Muscle mass was estimated using lean tissue index (LTI), skeletal muscle mass (SMM) assessed by bioelectrical impedance analysis and creatinine index (CI). Voorrips questionnaire was used to estimate physical activity. Criteria for the diagnosis of PEW were serum albumin, body mass index < 23 kg/m², creatinine index < 18.82 mg/kg/d and low dietary protein intake estimated by nPCR < 0.80g/kg/d.

Results

MVF was 76.1 [58.2–111.7] N.m. and was associated with CI (β = 5.3 [2.2–8.4], p = 0.001), LTI (β = 2.8 [0.6–5.1], p = 0.013), Voorrips score (β = 17.4 [2.9–31.9], p = 0.02) and serum albumin (β = 1.9 [0.5–3.2], p = 0.006). Only serum albumin (β = 0.09 [0.03–0.15], p = 0.003), Voorrips score (β = 0.8 [0.2–1.5], p = 0.005) and CI (β = 0.2 [0.1–0.3], p<0.001) remained associated with muscle specific torque. Thirty patients have dynapenia defined as impaired MVF with maintained SMM and were younger with high hs-CRP (p = 0.001), PEW criteria (p<0.001) and low Voorrips score (p = 0.001), and reduced dialysis vintage (p<0.046).

Conclusions

Beyond atrophy, physical inactivity and PEW conspire to impair muscle strength and specific torque in CHD patients and could be related to muscle quality.

Trial registration

ClinicalTrials.gov NCT02806089

Chronic kidney disease: considerations for monitoring skeletal muscle health and prescribing resistance exercise

Skeletal muscle wasting has gained interest as a primary consequence of chronic kidney disease (CKD) due to the relationship between skeletal muscle mass, mortality and major adverse cardiovascular events in this population. The combination of reductions in physical function, skeletal muscle performance and skeletal muscle mass places individuals with CKD at greater risk of sarcopenia. Therefore the monitoring of skeletal muscle composition and function may provide clinical insight into disease progression. Dual-energy X-ray absorptiometry and bioelectrical impedance analysis are frequently used to estimate body composition in people with CKD within clinical research environments, however, their translation into clinical practice has been limited. Proxy measures of skeletal muscle quality can be obtained using diagnostic ultrasound, providing a cost-effective and accessible imaging modality to aid further clinical research regarding changes in muscle composition. Clinicians and practitioners should evaluate the strengths and limitations of the available technology to determine which devices are most appropriate given their respective circumstances. Progressive resistance exercise has been shown to improve skeletal muscle hypertrophy of the lower extremities, muscular strength and health-related quality of life in end-stage renal disease, with limited evidence available in CKD predialysis. Fundamental principles (i.e. specificity, overload, variation, reversibility, individuality) can be used in the development of more advanced programs focused on improving specific neuromuscular and functional outcomes. Future research is needed to determine the applicability of skeletal muscle monitoring in clinical settings and the feasibility and efficacy of more advanced resistance exercise approaches in those with CKD predialysis.

Twelve-week combined resistance and aerobic training confers greater benefits than aerobic training alone in nondialysis CKD

There is a growing consensus that patients with chronic kidney disease (CKD) should engage in regular exercise, but there is a lack of formal guidelines. In this report, we determined whether combined aerobic and resistance exercise would elicit superior physiological gains, in particular muscular strength, compared with aerobic training alone in nondialysis CKD. Nondialysis patients with CKD stages 3b–5 were randomly allocated to aerobic exercise {AE, n = 21; 9 men; median age 63 [interquartile range (IQR) 58–71] yr; median estimated glomerular filtration rate (eGFR) 24 (IQR 20–30) ml·min−1·1.73 m−2} or combined exercise [CE, n = 20, 9 men, median age 63 (IQR 51–69) yr, median eGFR 27 (IQR 22–32) ml·min−1·1.73 m−2], preceded by a 6-wk run-in control period. Patients then underwent 12 wk of supervised AE (treadmill, rowing, or cycling exercise) or CE training (as AE plus leg extension and leg press exercise) performed three times per week. Outcome assessments of knee extensor muscle strength, quadriceps muscle volume, exercise capacity, and central hemodynamics were performed at baseline, following the 6-wk control period, and at the end of the intervention. AE and CE resulted in significant increases in knee extensor strength of 16 ± 19% (mean ± SD; P = 0.001) and 48 ± 37% ( P < 0.001), respectively, which were greater after CE ( P = 0.02). AE and CE resulted in 5 ± 7% ( P = 0.04) and 9 ± 7% ( P < 0.001) increases in quadriceps volume, respectively ( P < 0.001), which were greater after CE ( P = 0.01). Both AE and CE increased distance walked in the incremental shuttle walk test [28 ± 44 m ( P = 0.01) and 32 ± 45 m ( P = 0.01), respectively]. In nondialysis CKD, the addition of resistance exercise to aerobic exercise confers greater increases in muscle mass and strength than aerobic exercise alone.