Resistance exercise: a strategy to attenuate inflammation and protein-energy wasting in hemodialysis patients?

Comparison of the effect of aerobic and resistance training on fatigue, quality of life and biochemical factors in hemodialysis patients

Although hemodialysis has been able to increase the lifespan of dialysis patients, it has also brought many problems such as fatigue, low QOL, hypertension and physical weakness to them. Therefore, the aim of this study was to compare the effect of aerobic and resistance training on fatigue, quality of life (QOL), blood Na+, hemoglobin, C-reactive protein (CRP) and urea-creatinine ratio in hemodialysis patients. This research was conducted on 51 patients in two dialysis centers in Kerman, Iran. Patients were randomly divided into resistance group (RG) (n = 17), aerobic group (AG) (n = 17) and control group (CG) (n = 17). The patients in RG and AG performed the training protocol for eight weeks. Research variables as fatigue, QOL, blood Na+, hemoglobin, CRP, and urea-creatinine ratio were measured in pre-test and post-test. Data analysis was done using one-way ANOVA and Tukey's post hoc tests in SPSS25. (p < 0.05). The mean level of fatigue in RG and AG was significantly lower than the CG (p = 0.001). The mean levels of blood Na+ in AG was significantly higher than RG and CG (p = 0.01). Also, the mean ratio of urea-creatinine in RG and AG were significantly lower than CG (p = 0.001). There was no significant difference in QOL, hemoglobin and CRP between the RG and AG compared to the CG (p > 0.05). Based on our evidence, resistance and aerobic training for 8 weeks, 3 times weekly, is likely to improve the conditions of hemodialysis patients, and might be an option to increase intradialytic exercise adherence. Future studies should determine whether the findings are generalizable and examine the long-term effects of intradialytic exercise training.

[Recommendations for the rehabilitation of patients with chronic kidney disease requiring hemodialysis (literature review)]

Chronic kidney disease (CKD) is a global health problem, CKD is widespread in the world, on average it is detected in 10-13% of the adult population. Sedentary patients with CKD on dialysis have a higher risk of mortality. Despite the significant association of physical function with mortality in patients with CKD, physical function is not routinely assessed and exercise is not a component of the routine management of patients with CKD on dialysis.

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of the influence of motor rehabilitation methods on the prognosis of patients with chronic kidney disease (CKD) using hemodialysis (HD) from the standpoint of evidence-based medicine according to a scientometric analysis of the literature.

MATERIAL AND METHODS

An analysis was carried out of systematic reviews (search depth 70 years) and network meta-analyses to assess the effectiveness of physical exercise, its intensity and duration, performed interdialytic and intradialytic in the rehabilitation of patients with CKD with renal failure requiring hemodialysis. We reviewed articles in foreign journals on the PubMed, Embase, CINAHL, Web of Science, Wan Fang data, Cochrane CENTRAL and Scopus platforms.

RESULTS

The use of different types of physical exercise with varying intensities and durations both during and outside of dialysis in CKD patients requiring hemodialysis has shown that aerobic exercise, resistance exercise and a combination of both are most effective in improving their physical condition and quality life. Meta-analyses provide evidence to support the value of intradialytic exercise compared with interdialytic exercise for dialysis patients. It is also noted that moderate-intensity exercise can be performed in various forms, both during and outside of dialysis, and the data studied demonstrate that moderate-intensity exercise best improves physical function.

CONCLUSION

Future large RCTs should pay more attention to rehabilitation and exercise programs for CKD patients requiring HD. To encourage inactive patients with CKD to engage in physical exercise, educating them about the effects of exercise is imperative. Accumulating evidence suggests that rehabilitation of patients with visceral disorders, such as renal, cardiac, and pulmonary disorders, can not only improve physical performance and quality of life, but also improve survival. Modern comprehensive rehabilitation of patients with CKD is aimed at prolonging life, which represents a new concept in renal rehabilitation.

Progress in the study of nutritional status and selenium in dialysis patients

Malnutrition is very common in patients with chronic kidney disease, especially in those on maintenance dialysis. Malnutrition is one of the major factors affecting survival and death of dialysis patients, and reducing their activity tolerance and immunity. There are numerous and interacting risk factors for malnutrition, such as reduced nutritional intake, increased energy expenditure, hormonal disorders, and inflammation. Selenium, in the form of selenoproteins, is involved in many physiological processes in the body and plays an important role in maintaining redox homeostasis. Oxidative stress and infection are very common in dialysis patients, and selenium levels in dialysis patients are significantly lower than those in the healthy population. It has been shown that there is a correlation between selenium levels in hemodialysis patients and their nutrition-related indicators, and that selenium supplementation may improve malnutrition in patients. However, further studies are needed to support this conclusion and there is a lack of basic research to further characterize the potential mechanisms by which selenium may improve malnutrition in dialysis patients. The purpose of this review is to provide a comprehensive overview of factors associated with malnutrition in dialysis patients and to describe the progress of research on nutritional status and selenium levels in dialysis patients.

Comparative efficacy of nine exercise methods on the prognosis in chronic kidney disease patients with hemodialysis: a systematic review and network meta-analysis

BACKGROUND

Several kinds of physical activities have been applied to improve the prognosis of patients with hemodialysis (HD). However, the comparative efficacy of physical activities on the outcomes in HD patients is still unknown. This study explored the effectiveness and safety of all exercise types in HD patients.

METHODS

We searched randomized clinical trials from the PubMed, EMBASE, and Cochrane Library databases. Physical exercises interventions included resistance exercise (RE), aerobic exercise (AE), electrical muscle stimulation (EMS), range of motion (ROM), resistance exercise + aerobic exercise (RE + AE), stretching exercise (STE), respiratory muscle training (RMT), peripheral muscle training (PMT), walking exercise (WE), or usual care/sham exercise (UC/SE). Primary outcomes were six-minute walk test (6-mwt) and quality of life (QOL). Secondary outcomes were Kt/V, VO2max, hemoglobin (Hb), C-reactive protein (CRP), interleukin-6 (IL-6), and systolic and diastolic blood pressure (sbp and dbp). Frequentist network meta-analysis with multivariate random effects models provided mean with 95% confidence intervals (95%CI).

RESULTS

A total of 58 eligible studies were included. AE, RMT, and RE + AE significantly improved 6-mwt compared with UC/SE. SE was the worst intervention and reduced QOL much more than the UC/SE and other exercise types. AE and RE + AE were associated with higher VO2max, while ROM and RE + AE induced higher Hb levels. All physical activities did not elevate blood pressure, CRP and IL-6. Only ROM decreased sbp/dbp. CRP is significantly lower in RE.

CONCLUSION

Physical activities play a crucial role in the different outcomes of HD patients. They can be applied to specific area for their specific efficacy.

Does Exercising with the Use of Virtual Reality during Haemodialysis Have an Impact on Plasma Levels of Interleukin 1β, Interleukin 6, and Interleukin 8?

Cytokines are a group of fine proteins which play a key role in the regulation of various biological processes, including inflammatory reactions. Proinflammatory cytokines, such as interleukin 1β (IL-1β), interleukin 6 (IL-6), and interleukin 8 (IL-8), are produced in response to various stimuli, including infections, tissue damage, and oxidative stress. Virtual reality (VR) use during intradialytic exercises improves physical activity. The purpose of the study was to evaluate the relationship between exercising regularly with the use of virtual reality during haemodialysis and the levels of selected cytokines (Il-1, Il-6, Il-8). The study and the control groups consisted of end-stage renal disease patients who underwent haemodialysis as a renal replacement treatment. The study group comprised patients subject to haemodialysis as a renal replacement therapy who were to work out with the use of a prototype of the NefroVR system for 20 min when undergoing haemodialysis (HD). Statistical analyses utilised Statistica 13. The conducted research demonstrated that regular exercises with the use of virtual reality might be related to a decrease in inflammation in patients included in the chronic haemodialysis programme. It is key to encourage patients with end-stage renal disease treated with haemodialysis to exercise regularly because of the possibility of their proinflammatory parameters becoming reduced.

The Relation of Serum Dehydroepiandrosterone Sulfate Level to Protein Energy Wasting in Hemodialysis Patients

Protein-energy wasting (PEW) is a major risk for morbidity and mortality in hemodialysis (HD) patients. The change in the concentration of dehydroepiandrosterone sulfate (DHEA-S) may play a role in PEW. The aim of this work was to study the possible relationship between serum DHEA-S levels and various nutritional and inflammatory parameters in a cohort of HD patients. In total, 78 HD patients (47 males and 31 females) were included in this crosssectional observational study. In addition to taking their history, clinical examinations, and routine laboratory investigations, the nutritional status was assessed, and their serum DHEA-S was measured. Nutritional status was assessed by anthropometric measures, bioelectrical impedance analysis, malnutrition inflammation scores, and subjective global assessments. A diagnosis of malnutrition was made based on the recommendations of the International Society of Renal Nutrition and Metabolism. The relationship between DHEA-S and various nutritional parameters was analyzed. Eighteen patients (23.1%) suffered from PEW. Those with PEW had a longer duration of HD (P = 0.04), and lower serum levels of creatinine (P = 0.003), hemoglobin (P = 0.01), albumin (P <0.0001), cholesterol (P = 0.02), and DHEA-S (P = 0.01). Among the variables, serum DHEA-S levels were significant predictors of PEW in this cohort (odds ratio: 0.976; 95% confidence interval: 0.954-1.0; P = 0.04). PEW is frequently encountered in HD patients. Decreased serum DHEA-S levels were associated with PEW in male HD patients. Further studies are needed to assess the effect of hormone supplementation on this serious disorder in HD patients.

Effect of Exercise on Inflammation in Hemodialysis Patients: A Systematic Review

BACKGROUND

In recent years, physical exercise has been investigated for its potential as a therapeutic tool in patients with end-stage renal disease (ESRD) undergoing hemodialysis maintenance treatment (HD). It has been shown that regular practice of moderate-intensity exercise can improve certain aspects of immune function and exert anti-inflammatory effects, having been associated with low levels of pro-inflammatory cytokines and high levels of anti-inflammatory cytokines.

PURPOSE

The aim of this review is to examine the studies carried out in this population that analyzed the effect of intradialytic exercise on the inflammatory state and evaluate which exercise modality is most effective.

METHODS

The search was carried out in the MEDLINE, CINAHL Web of Science and Cochrane Central Register of Controlled Trials databases from inception to June 2022. The PEDro scale was used to assess methodological quality, and the Cochrane Risk of Bias Tool and MINORS were used to evaluate the risk of bias. The quality of evidence was assessed with GRADE scale. The outcome measures were systemic inflammation biomarkers.

RESULTS

Mixed results were found in terms of improving inflammation biomarkers, such as CRP, IL-6 or TNFα, after exercise. Aerobic exercise seems to improve systemic inflammation when performed at medium intensity while resistance training produced better outcomes when performed at high intensity. However, some studies reported no differences after exercise and these results should be taken with caution.

CONCLUSIONS

The low quality of the evidence suggests that aerobic and resistance exercise during HD treatment improves systemic inflammation biomarkers in patients with ESRD. In any case, interventions that increase physical activity in patients with ESRD are of vital importance as sedentary behaviors are associated with mortality. More studies are needed to affirm solid conclusions and to make intervention parameters, such as modality, dose, intensity or duration, sufficiently clear.

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

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

Effect of an aerobic and strength exercise combined program on oxidative stress and inflammatory biomarkers in patients undergoing hemodialysis: a single blind randomized controlled trial

BACKGROUND

Chronic kidney disease patients on hemodialysis treatment are characterized by increased levels of inflammatory markers and oxidative stress, in addition to a significant deterioration in physical function. The benefits of physical exercise on the functional capacity of this patients are well known; however, it can also improve the endogenous antioxidant defense system and the inflammatory state, but still very few studies have been carried out. This is the first study to analyze the effect of a 4-month exercise program with combined aerobic and strength training in patients undergoing hemodialysis, under two modalities.

METHODS

Seventy-one patients undergoing hemodialysis were enrolled and randomized in two groups, one of them performing an intra-dialysis exercise program (n = 36), and the other carrying out a home-based exercise program (n = 35). Serum levels of oxidative stress and inflammation biomarkers were determined before and after the intervention.

RESULTS

IL-6 plasma levels showed a significant decrease in the intra-dialysis group after exercise (42.61 ± 9.21 to 26.40 ± 7.84, p = 0.03), while CRP levels decreased significantly in the home-based group (16.12 ± 24.18 to 8.50 ± 11.28, p = 0.03). MCP-1, TNF-α, ICAM-1 and the oxidative stress markers MDA, GSH and GSSG, did not undergo significant changes after the intervention.

CONCLUSION

Four months of combined strength and aerobic endurance exercise improve the inflammatory status of hemodialysis patients by significantly reducing IL-6 levels in those subjects who perform intra-dialysis exercise and CRP levels in those who do it at home.

Comparison of intradialytic neuromuscular electrical stimulation and oral nutritional supplements in hemodialysis patients: study protocol for a multicenter, parallel-group, randomized controlled trial in Korea

Background

The prevalence of sarcopenia increases as renal function decreases, and a considerable number of hemodialysis (HD) patients have sarcopenia. Exercise and nutritional support are established interventions to prevent and treat sarcopenia. Recently, many studies evaluating intradialytic neuromuscular electrical stimulation (NMES) showed improvement of muscular strength and mass, functional capacity, and quality of life (QOL). However, there has been no research about the effect of simultaneous nutritional support and NMES in HD patients.

Methods

This is a 12-week, randomized controlled, parallel-group, multicenter trial of intradialytic NMES and protein supplementation for HD patients. Seventy-two patients receiving HD will be randomly assigned in a 1:1:1:1 ratio to control, intradialytic NMES only, protein supplementation only, and intradialytic NMES combined with protein supplementation groups. NMES will be delivered to a total of four areas of the bilateral vastus medialis and vastus lateralis using a 4-channel NMES instrument. A total of 25 g of protein supplements will be provided at the beginning of every dialysis session or after the NMES. The primary endpoint is the difference of hand grip and leg muscle strength at 12 weeks among 4 treatment groups. Secondary endpoints include muscle mass, physical performances, and questionnaires about QOL and physical activity.

Discussion

In this study, we will evaluate the differential effectiveness of nutritional support and NMES during HD on muscle strength, muscle mass, physical function, and QOL. We expect that this study can provide guidelines for a new therapeutic option for HD patients who are unable or hesitant to exercise. Furthermore, this option can offer an opportunity to improve the physical function, QOL, and prognosis of HD patients.

Trial registration

Clinical Research Information Service (CRIS), Korea, KCT0005573. Retrospectively registered on 03 November 2020

Steady exercise improves hand grip and leg muscle strength in hemodialysis patients

Sarcopenia due to chronic inflammation and biochemical disturbances in chronic kidney disease is severer and more prevalent in hemodialysis (HD) patients. We longitudinally evaluated the hand grip strength (HGS) and leg muscle strength (LMS) and evaluated the role of exercise in muscle strength in HD patients. We screened (January, n=127) and followed up (June, n=110 and December 2020, n=104). HGS and LMS at single center by using digital hand and leg dynamometer. HGS (24.2 kg vs. 15.5 kg) and LMS (32.8 kg vs. 22.5 kg) were better in men (P<0.001 and P<0.001, respectively). Older patients (≥60 years) showed decreased LMS than others in women (P=0.01). Patients who performed steady home- or hospital-based exercise showed marginally higher HGS (23.1 kg vs. 19.8 kg, P=0.07) and significantly higher LMS (33.7 kg vs. 25.9 kg, P=0.004). Steady exercise improved LMS throughout the study period (30.3 kg vs. 33.2 kg from Jan to Jun 2020, P=0.004; 30.3 kg vs. 34.2 kg from Jan to Dec 2020, P=0.014). Multiple linear regression analysis proved steady exercise was independently associated with better HGS and LMS. Steady exercise showed greater impact on LMS in male patients with longer HD vintage (≥44 months) and on HGS in younger male patients with shorter HD vintage (<44 months). Steady exercise was an important determinant of muscle strength in HD patients. We need to encourage patients to steadily perform regular home- or group-exercise before sarcopenia develops.

A Protocol of Intradialytic Exercise for Improvements in Inflammatory Status, Body Composition, and Functional Capacity

Skeletal muscle wasting has been well-documented among hemodialysis patients. This catabolic condition can be induced by numerous factors, including low-grade inflammation, and is associated with impairments in functional capacity and quality of life, as well as an increased mortality risk. We previously showed that 12 weeks of intradialytic resistance training increases lean mass, functional capacity, and the quality of life of hemodialysis patients. This chapter provides the details of a protocol of intradialytic exercise that leads to improvements in inflammatory status, body composition, and functional capacity.

Hand Grip and Leg Muscle Strength in Hemodialysis Patients and Its Determinants

BACKGROUND

Chronic kidney disease is associated with chronic inflammation and progressive loss of peripheral muscle strength and the ability to exercise, and these changes are highly pronounced in patients receiving hemodialysis (HD). We evaluated hand grip strength (HGS) and leg muscle strength (LMS) in patients receiving HD and attempted to identify factors associated with muscle strength.

METHODS

We screened HGS (opposite the fistula side) and LMS (both sides) in HD patients at a single center (n = 112) by using digital hand and leg dynamometers (T.K.K. 5401 and 5710e/5715, Takei Scientific Instruments Co. Ltd., Niigata, Japan).

RESULTS

The mean age of patients was 62.6 years, and 73.2% of the patients were male. Diabetes was the cause of kidney failure in 50% of the patients, and the median HD vintage was 34 months. A total of 77.7% of patients reported that they participated in regular home-based exercise, and 29.5% of patients regularly participated in hospital-based resistance exercise. HGS and LMS showed good correlation (r = 0.715, P < 0.001). HGS (25.1 vs. 17.0 kg) and LMS (30.1 vs. 20.4 kg) were greater in males (P < 0.001 and P < 0.001, respectively) than in females. Older patients (≥ 60 years) showed less LMS than younger patients in both males and females (P = 0.012 and P = 0.037, respectively), but HGS did not differ according to age. Patients performing regular home- or hospital-based exercise showed higher HGS than those who did not exercise (24.2 vs. 18.6 kg, P = 0.011), but LMS was not significantly different (29.3 vs. 23.6 kg, P = 0.185). Multiple linear regression analysis proved that male sex, younger age, and any type of exercise were factors associated with improved HGS and LMS. Groups of older age (≥ 60 years), male sex, and shorter duration of HD (< median) benefitted more from exercise.

CONCLUSION

Sex, age, and exercise were the most important determinants of muscle strength in HD patients. We need to encourage patients to engage in regular home or group exercise from the beginning of dialysis and introduce new feasible forms of exercise for HD patients.

Effects of dynamic and isometric resistance training protocols on metabolic profile in hemodialysis patients: a randomized controlled trial

The aim of this study was to compare the effect of dynamic (DRT) and isometric (IRT) resistance training on glycemic homeostasis, lipid profile, and nitric oxide (NO) in hemodialysis (HD) patients. Patients were randomly distributed into 3 groups: control (n = 65), DRT (n = 65), and IRT (n = 67). Patients assessed before and after the intervention period were tested for fasting blood glucose, glycated hemoglobin, oral glucose tolerance test, insulin resistance, lipid profile, leptin, insulin, adiponectin, C-reactive protein, and NO . Patients underwent to strength and body composition assessments. Subjects allocated in both DRT and IRT groups took part in a 24-week resistance training program, 3 times per week. Each training session was approximately 1 hour before dialysis and consisted of 3 sets of 8-12 repetitions at low intensity. Total workload was higher in the DRT as compared with the IRT. This heightened workload related to better glycemic homeostasis in HD patients as measured by regulation of insulin, adiponectin, and leptin, while improveing triglycerides, free-fat mass, and muscle strength. Additionally, NO levels were increased in the DRT group. NO was significantly correlated with glucose intolerance (r = -0.42, p = 0.0155) and workload (r = 0.46, p = 0.0022). The IRT group only improved strength (p < 0.05). Twenty-four weeks of DRT improved glycemic homeostasis, lipid profile, and NO in HD patients. Although IRT seems to play an important role in increasing strength, DRT might be a better choice to promote metabolic adjustments in HD patients. Clinical trial: http://www.ensaiosclinicos.gov.br/rg/RBR-3gpg5w. Novelty: DRT might be a better choice for metabolic improvements in patients with chronic kidney disease (CKD). Exercise-training might treat metabolic imbalance in CKD patients.

The cut-off values of handgrip strength and lean mass index for sarcopenia among patients on peritoneal dialysis

Background

Sarcopenia is common and contributes to a high risk of mortality among general population. There is no consensus regarding the cut-off values for sarcopenia in terms of mortality among chronic kidney disease patients. This study aimed to explore and validate cut-off points of handgrip strength (HGS) and lean mass index (LMI) for estimating the risk of mortality in peritoneal dialysis (PD) patients.

Methods

This single-center prospective cohort study enrolled 1089 incident PD patients between October 2002 and July 2019. All patients were followed until death, transfer to hemodialysis, receiving renal transplantation or the end date of study (December 2019). All participants were randomly sampled to development cohort (70% participants) and validation cohort (30% participants), matched by gender and diabetes. Lean body mass was calculated by using the equation published by our center. Cubic spline regression analysis was used to examine the relationship between HGS or LMI values and mortality, and explore the cut-off points after adjusting for age, diabetes, cardiovascular disease and serum albumin in the development cohort. The derived cut-off values were verified by the agreement rate for predicting mortality and then compared with cut-off values from various clinical guidelines in the validation cohort.

Results

All 1089 patients were followed up with the median of 36.0 (18.0, 71.0) months. In the development cohort, cut-off points for predicting the higher mortality were derived as 24.5 kg and 14 kg of HGS for males and females, 16.7 kg/m² and 13.8 kg/m² of LMI for males and females respectively. In the validation cohort, these cut-off values significantly predicted worse outcomes, with HR 1.96 (1.35, 2.84) of HGS and HR 1.76 (1.26, 2.47) of LMI for all-cause mortality after multivariate adjustment. The newly derived cut-off points of HGS have numerically higher prognostic values in all-cause mortality compared with those from current clinical guidelines, and agreement rates of HGS were 65.2 versus 62.5–64.6 respectively.

Conclusions

The derived cut-off values of HGS and LMI have sufficient and better prognostic value in predicting all-cause mortality in PD patients compared with the cut-off values in the existing guidelines. These cut-off values are only validated in a single population, thus limiting the generalizability.

Influence of exercise training on diabetic kidney disease: A brief physiological approach

IMPACT STATEMENT

Diabetic kidney disease (DKD) is associated with increased mortality in diabetic patients and has a negative impact on public health. The identification of potential therapies that help the management of DKD can contribute to the improvement of health and quality of life of patients. Thus, this paper is timely and relevant because, in addition to presenting a concise review of the pathogenesis and major pathophysiological mechanisms of DKD, it addresses the most recent findings on the impact of exercise training on this disease. Thus, since non-pharmacological interventions have gained increasing attention in the fight against chronic diseases, this paper appears as an important tool to increase knowledge and stimulate innovative research on the impact of exercise on kidney disease.

Comparative Performance of Body Composition Parameters in Prediction of Death in Hospitalized Patients on Maintenance Hemodialysis: A Cohort Study

We compared the prognostic value of nutritional or volumetric parameters measured by body composition in hospitalized patients on maintenance hemodialysis. We conducted a cohort study to assess the association of different parameters of body composition with all-cause mortality in inpatients admitted to our nephrology department from January 2014 to December 2016. Of the 704 study patients, 160 (22.7%) died during a median follow-up of 33 months. In multivariate adjusted Cox models, higher ratio of extracellular water to body cell mass (ECW/BCM) (adjusted HR per 1-SD, 1.49; 95% CI, 1.19 to 1.85), lower lean tissue index (LTI) (adjusted HR per 1-SD, 0.70; 95% CI, 0.57 to 0.86) and lower body cell mass index (BCMI) (adjusted HR per 1-SD, 0.70; 95% CI, 0.58 to 0.85) were associated with a significantly greater risk of death. When these parameters were added to the fully adjusted model, BCMI performed best in improving the predictability for all-cause mortality (integrated discrimination improvement = 0.02, P = 0.04; net reclassification index = 0.11, P = 0.04). Among body composition indexes, ECW/BCM was the most relevant fluid volume indices to mortality and BCMI and LTI were the most relevant nutritional status indices to mortality in maintenance hemodialysis patients.

Aerobic Exercise Training and Nontraditional Cardiovascular Risk Factors in Hemodialysis Patients: Results from a Prospective Randomized Trial

Introduction: Chronic kidney disease (CKD) patients have a high incidence of cardiovascular diseases (CVD) which increases their morbidity and mortality. A sedentary lifestyle in CKD is directly linked to the onset of CVD. Physical activity can bring beneficial effects to CKD patients. Aims: The aim of this study was assess the impact of aerobic training on nontraditional cardiovascular risk factors in CKD patients on hemodialysis. Materials and Methods: This is a prospective, controlled, and randomized clinical trial with analysis of intention to treat. Thirty patients underwent an exercise treadmill test, an arterial stiffness evaluation, echocardiography and analysis of endothelial reactivity, and carotid ultrasound and laboratorial tests, including analysis of serum aldosterone. The intervention group (IG) (n =15) underwent aerobic exercise during hemodialysis 3 times a week for 4 months. The control group (CG) (n =15) had no intervention. All of the patients were reassessed after 4 months. Results: In the IG, there was a statistically significant improvement in flow-mediated vasodilation (FMV; p = 0.002) and a reduction in left ventricular hypertrophy (p = 0.006) and serum aldosterone (p = 0.016). There was an increase in C-reactive protein in the CG (p = 0.002). Conclusion: This aerobic training protocol was able to improve endothelial function with enhanced FMV and reduce left ventricular hypertrophy and serum aldosterone, which could have a positive impact on the reduction of nontraditional cardiovascular risk factors in CKD patients on hemodialysis.

Effects of intradialytic resistance exercise on systemic inflammation in maintenance hemodialysis patients with sarcopenia: a randomized controlled trial

PURPOSE

To investigate the effect of intradialytic resistance exercise on inflammation markers and sarcopenia indices in maintenance hemodialysis (MHD) patients with sarcopenia.

METHODS

Forty-one MHD patients with sarcopenia were divided into an intervention group (group E, n = 21) and a control group (group C, n = 20). Group C patients only received routine hemodialysis care, whereas group E patients received progressive intradialytic resistance exercise with high or moderate intensity for 12 weeks at three times per week (using the weight of the lower limbs and elastic ball movement of the upper limb) on the basis of routine hemodialysis care.

RESULTS

After 12 weeks, a significant difference in physical activity status (maximum grip strength, daily pace, and physical activity level), Kt/V, and C-reactive protein was found between groups E and C. Inflammatory factors (interleukin (IL)-6, IL-10, and tumor necrosis factor(TNF)-α) increased or decreased more significantly in group E than in group C.

CONCLUSIONS

This study showed that intradialytic resistance exercise can improve physical activity effectively and reduce microinflammatory reactions even if this simple exercise does not affect the muscle mass in MHD patients with sarcopenia.

Intradialytic Resistance Training Improves Functional Capacity and Lean Mass Gain in Individuals on Hemodialysis: A Randomized Pilot Trial

OBJECTIVE

To compare the effects of high vs moderate loads of intradialytic resistance training (RT) on body composition, sarcopenia prevalence, functional capacity, inflammatory markers, and quality of life (QoL) in individuals on hemodialysis.

DESIGN

A pilot randomized clinical trial.

SETTING

Two hemodialysis centers.

PARTICIPANTS

Individuals on hemodialysis (N=80; 51% men, aged 30-75y) in treatment for at least 3 months, adequately dialyzed (Kt/V≥1.2, where K is dialyzer clearance in mL/min, t is time, and V is volume of water) with vascular access via arteriovenous fistula.

INTERVENTIONS

The 12 weeks of intradialytic RT was performed 3 times per week. The training groups were: high-load intradialytic group (HLG, 8-10 repetitions), moderate-load intradialytic group (MLG, 16-18 repetitions), and control group (CG, stretching exercise). The total training volume was equalized among training groups.

MAIN OUTCOME MEASURES

Lean leg mass was assessed by a dual-energy x-ray absorptiometry; functional capacity was assessed by Short Physical Performance Battery and Timed Up and Go test; and QoL was assessed by Kidney Disease QoL Instrument, inflammatory markers, and sarcopenia.

RESULTS

After the training period, the HLG increased lean leg mass compared with the CG. The HLG also displayed improvements in the pain and physical function domains. The skeletal muscle index and functional capacity increased in both RT protocols. The prevalence of sarcopenia was reduced 14.3% and 25% in the MLG and HLG, respectively, while there was an increase of 10% in the CG. No differences were observed in cytokines after intervention.

CONCLUSIONS

High-load intradialytic RT was associated with gains in lean leg mass and QoL while functional capacity, appendicular muscle mass, and sarcopenia status were improved regardless of the RT load.

Effect of exercise therapy on physical performance and functional balance in patients on maintenance renal hemodialysis: randomized controlled study

Physical performance (PP) and functional balance (FB) abnormalities are frequently encountered problems in patients on maintenance renal hemodialysis (MRH). Although the exercise therapy is an adjunctive to the routine medical care for patients with chronic kidney disease of various stages; but the benefits as well as the long-term effects of different exercises on the PP and FB in patients on MRH are not yet fully described. In this study; Sixty-six patients on MRH (36 males, 30 females), age 35–45 years, were randomly assigned into one of the three groups: aerobic exercise training group (AETG), resistance exercise training group (RETG), and control group (CG). The PP (evaluated using the 6-min walk test “6MWT”) and the FB (evaluated via the Berg balance scale “BBS”) were the main study outcomes evaluated prestudy (evaluation-1), after 3 months (evaluation-2) and 2 months poststudy cessation (evaluation-3). Results revealed that the PP and FB mean values and percentages of changes at evaluation-2 were 444.25±21.83 (33.1%), 413.57±28.55 (22.52%), 337±12.23 (0.33%) m, 50.05±0.89 (22.95%), 49.95±2.06 (22.52%), 41.28±1.75 (0.94%) for AETG, RETG, and CG respectively. At evaluation-3; the PP and FB mean values and the percentage of changes were 425±21.49 (27.36), 366.86±17.47 (8.5%), 336.68 (0.42%) m, 44.4±1.85 (8.06%), 42.95±2.04 (5.003%), 39.48±2.06 (−4.44%) for AETG, RETG, and CG respectively. In conclusions; both aerobic exercise training (AET) and resistance exercise training (RET) have favorable effects, with the AET has higher short and long-term favorable effects on the PP and FB than RET in patients on MRH.

The effects of intradialytic resistance training on muscle strength, psychological well-being, clinical outcomes and circulatory micro-ribonucleic acid profiles in haemodialysis patients: Protocol for a quasi-experimental study

BACKGROUND

Intradialytic resistance training (IRT) protects patients' muscle mass and functions against protein-energy wasting, malnutrition and cachexia. However, the evidence of the effects of such an intervention in haemodialysis patients is limited and not conclusive. To improve the applicability of such interventions, we need a better understanding of molecular, functional and psycho-social adaptation in dialysed patients following a physical training. Therefore, the aim of this study is to investigate the effects of IRT on lower extremity muscle functions, quality of life, and anxiety and depression, clinical outcomes and circulatory micro-ribonucleic acid (miRNA) profiles in patients on chronic haemodialysis therapy.

METHODS

We will perform a quasi-experimental study in 3 dialysis centres. Patients will be recruited via their nephrologists and will be allocated to an experimental and a control group based on the location of the patients' dialysis centre. Patients allocated to the experimental group will undergo a 12-week IRT, while the control group will remain physically inactive during dialysis. The primary outcome is the change in the maximal force produced during an isometric contraction of lower extremity muscles. Secondary outcomes regard quality of life, anxiety and depression, clinical outcomes and circulatory miRNA profiles. Patients' level of health literacy defined as the ability to get and understand health information will be also measured in the study as a potential modifier of effects.

DISCUSSION

This quasi-experimental study can add in an important way to our understanding of the effects of resistance training on dialysis patients' muscle strength, quality of life and disease-specific outcomes.

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.

Effect of intradialytic resistance training on pulse wave velocity and associated cardiovascular disease biomarkers in end stage renal disease

AIMS

Cardiovascular disease (CVD) is the leading cause of mortality in patients with end-stage renal disease (ESRD) receiving maintenance haemodialysis treatment. This study investigated the effect of a 12-week intradialytic progressive resistance training (PRT) intervention on pulse wave velocity (PWV) and associated haemodynamic, anthropometric, and hematologic outcomes in patients with ESRD.

METHODS

Twenty-two patients with ESRD (59% men, 71.3 ± 11.0 years) were recruited. Supervised PRT (three sets of 11 exercises) was prescribed three times per week during routine dialysis. The primary outcome was brachial-ankle PWV via applanation tonometry. Secondary outcomes included augmentation index, brachial and aortic blood pressures, endothelial progenitor cells, C-reactive protein, blood lipids and anthropometrics.

RESULTS

The intradialytic PRT regimen resulted in no significant change in PWV between control and intervention periods [mean difference = 0 (95% CI = -0.1 to 0.1); P = 0.58]. Similarly, no significant change was noted in any secondary outcome measures between the control and intervention periods. Post-hoc analyses limited to high adherers (≥75% attendance; n = 11) did not differ from the primary analysis, indicating no dose-response effect of our intervention.

CONCLUSION

Our 12-week PRT intervention did not change PWV or any secondary outcomes. Future studies should determine if higher dosages of intradialytic PRT (i.e. longer duration and/or higher intensity) can be applied as a method to improve arterial stiffness to potentially reduce cardiovascular disease and associated mortality this cohort.

Inflammation status of healthy young men: initial and specific responses to resistance training

Our primary aim was to study the effects of a 4-week preparatory resistance-training (RT) period followed by 12 weeks of 2 specific RT protocols (either hypertrophic-strength (HS) or strength-hypertrophy-power training) on inflammation markers and the possible relationship of the changes in abdominal fat and lean mass to the changes in inflammation status. A total of 82 healthy men were included in the study. Maximal concentric leg press strength (1-repetition maximum), total body lean mass, total body and abdominal fat mass, circulating high-sensitivity C-reactive protein, interleukin-6, interleukin-1 receptor antagonist (IL-1ra), monocyte chemoattractant protein 1 (MCP-1), and selected adipocytokines (resistin, adiponectin, and leptin) concentrations were measured before and after 4 (wk4) and 16 weeks (wk16) of RT. After the initial phase of RT, on wk4, abdominal and total fat mass as well as plasma leptin concentrations were significantly reduced (p < 0.05), whereas muscle mass, IL-1ra, resistin, and MCP-1 concentrations were significantly increased (p < 0.05). During specialized training phase, at wk16, only HS led to further reduction in abdominal and total fat mass, resistin, and leptin (p < 0.05), whereas both training modes led to lower MCP-1 concentrations (p < 0.05). Abdominal fat mass and circulating leptin were reduced already after 4 weeks of RT. Simultaneously, circulating MCP-1 and resistin concentrations increased, possibly as markers of muscle adaptation and regeneration. The present findings also suggest that RT with hypertrophic focus is beneficial for further reductions in abdominal fat mass and to decrease circulating inflammatory markers.

Does resistance exercise performed during dialysis modulate Nrf2 and NF-κB in patients with chronic kidney disease?

Studies have shown that nuclear factor erythroid 2-related factor 2 (Nrf2) can be modulated by physical exercise. However, the impact of resistance exercise has never been investigated in patients with chronic kidney disease (CKD). The aim of this study was to evaluate the effects of resistance exercise programs on the expression of transcription factors Nrf2 and nuclear factor κB (NF-κB) in CKD patients on hemodialysis (HD). Patients on an HD program were randomly assigned to an exercise group of 25 patients (54.5% women, aged 45.7±15.2years and time on dialysis=71.2±45.5months) or a control group of 19 patients who had no exercise intervention (61.5% women, aged 42.5±13.5years and time on dialysis=70.1±49.9months). A strength exercise program was performed 3 times a week during the HD sessions. Peripheral blood mononuclear cells were isolated and processed for the expression of Nrf2 and NF-κB by quantitative real-time polymerase chain reaction 3months before and after the exercise program. Using an enzyme-linked immunosorbent assay, the activity of glutathione peroxidase (GPx) as well as the products of high-sensitivity C-reactive protein and nitric oxide (NO) were assessed. Nrf2 expression (ranging from 0.86±0.4 to 1.76±0.8) and GPx activity were significantly increased after exercise intervention. In the exercise group, no difference in the levels of NO was observed; however, there was a significant reduction in the control group. In conclusion, these data suggest that resistance exercises seem to be capable of inducing Nrf2 activation in CKD patients on HD.

Intradialytic aerobic cycling exercise alleviates inflammation and improves endothelial progenitor cell count and bone density in hemodialysis patients

Inflammation, endothelial dysfunction, and mineral bone disease are critical factors contributing to morbidity and mortality in hemodialysis (HD) patients. Physical exercise alleviates inflammation and increases bone density. Here, we investigated the effects of intradialytic aerobic cycling exercise on HD patients. Forty end-stage renal disease patients undergoing HD were randomly assigned to either an exercise or control group. The patients in the exercise group performed a cycling program consisting of a 5-minute warm-up, 20 minutes of cycling at the desired workload, and a 5-minute cool down during 3 HD sessions per week for 3 months. Biochemical markers, inflammatory cytokines, nutritional status, the serum endothelial progenitor cell (EPC) count, bone mineral density, and functional capacity were analyzed. After 3 months of exercise, the patients in the exercise group showed significant improvements in serum albumin levels, the body mass index, inflammatory cytokine levels, and the number of cells positive for CD133, CD34, and kinase insert domain-conjugating receptor. Compared with the exercise group, the patients in the control group showed a loss of bone density at the femoral neck and no increases in EPCs. The patients in the exercise group also had a significantly greater 6-minute walk distance after completing the exercise program. Furthermore, the number of EPCs significantly correlated with the 6-minute walk distance both before and after the 3-month program. Intradialytic aerobic cycling exercise programs can effectively alleviate inflammation and improve nutrition, bone mineral density, and exercise tolerance in HD patients.

Could physical exercise help modulate the gut microbiota in chronic kidney disease?

Chronic kidney disease (CKD) patients have several metabolic disorders caused by chronic oxidative stress and inflammation. The imbalance of gut microbiota has been identified as a factor that may contribute to the development of these disorders, which can promote cardiovascular disease in CKD patients. Among several strategies to modulate gut microbiota, physical exercise could represent a new nonpharmacological approach. Although exercise can reduce cardiovascular risk in CKD patients through its beneficial effects on oxidative stress and inflammation, there are no available data regarding the relationship between exercise and modulation of gut microbiota in CKD patients. This review is intended to provide a brief overview of the hypothesis regarding gut microbiota modulation through physical exercise, with a particular emphasis on CKD.

Quadriceps Strength as a Predictor of Mortality in Coronary Artery Disease

BACKGROUND

The purpose of this study was to investigate the prognostic value of quadriceps isometric strength (QIS) in coronary artery disease (CAD).

METHODS

The study population consisted of 1314 patients aged >30 years (64.7 ± 10.6 years, 1051 male) with CAD who were hospitalized for acute coronary syndrome or coronary artery bypass grafting. Maximal QIS was evaluated as a marker of leg strength and expressed relative to body weight (% body weight). The primary and secondary endpoints were all-cause death and cardiovascular (CV) death, respectively.

RESULTS

During a mean follow-up of 5.0 ± 3.5 years, corresponding to 6537 person-years, there were 118 all-cause deaths and 63 CV deaths. A higher QIS remained associated with decreased all-cause mortality and CV mortality risks (hazard ratio for increasing 10% body weight of QIS 0.77, 95% confidence interval 0.67-0.89, P < .001 for all-cause death; hazard ratio 0.66, 95% confidence interval 0.54-0.82, P < .001 for CV death) after adjustment for other prognostic factors. The inclusion of QIS significantly increased both continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) for all-cause death (cNRI: 0.25, P = .009; IDI: 0.007, P = .030) and CV death (cNRI: 0.34, P = .008; IDI: 0.013, P = .008).

CONCLUSIONS

A high level of quadriceps strength was strongly associated with a lower risk of both all-cause and CV mortality in patients with CAD. Evaluation of QIS offered incremental prognostic information beyond pre-existing risk factors.

Effects of resistance exercise training on acyl-ghrelin and obestatin levels in hemodialysis patients

BACKGROUND

Patients undergoing hemodialysis (HD) present altered levels of appetite hormones such as acyl-ghrelin (orexigenic) and obestatin (anorexigenic), which may contribute to anorexia. Physical exercise may affect these hormones and improve appetite in these patients.

OBJECTIVES

The objective of this study is to evaluate the effects of a resistance exercise program in appetite hormones, body composition, and nutritional status in HD patients.

DESIGN

Intervention study with the control group.

SUBJECTS

Fifty-two patients on regular HD program were enrolled into two groups: 37 patients performed exercises (56.7% male, 45 ± 12.8 years, 57 (9-192) months on HD) and 15 patients comprised the control group (66.7% men, 50 ± 10.6 years, 57 (11-153) months on HD).

MEASUREMENTS

Exercise program (performed with elastic bands and ankle cuffs in both lower limbs) was supervised three times a week during 6 months (72 sessions). Patients had their blood drawn in a regular HD day after overnight fasting, before and after 6 months of exercise program. Obestatin, acyl-ghrelin, routine biochemical parameters, quality of life, and anthropometric data were collected and analyzed before and after 6 months.

RESULTS

After 6 months of exercise, obestatin levels reduced [from 3.0 ng/mL (2.3-3.4) to 1.9 ng/mL (0.6-3.4)] and acyl-ghrelin levels increased [from 21.5 pg/mL (1.3-77.7) to 37.2 pg/mL (16.7-94.1)] and the control group presented no significant differences in both plasma levels of hormones. Body composition and physical functional assessed by SF-36 and albumin levels (3.7 ± 0.3 to 3.9 ± 0.2, p < 0.05) improved after exercises.

CONCLUSION

Six months of resistance exercises contributed to changes in plasma appetite hormones, body composition, and nutritional status in hemodialysis patients.