Resistance exercise: an effective strategy to reverse muscle wasting in hemodialysis patients?

Whole body resistance training on functional outcomes of patients with Stage 4 or 5 chronic kidney disease: A systematic review

Chronic kidney disease (CKD) causes skeletal muscle wasting, resulting in reduced function and inability to live independently. This systematic review critically appraised the scientific literature regarding the effects of full-body resistance training on clinically-relevant functional capacity measures in CKD. The study population included studies of people with Stage 4 or 5 CKD and a mean age of 40+ years old. Eight databases were searched for eligible studies: Pubmed, Embase, Cochrane, CINAHL, Scopus, Web of Science, MEDLINE, and AGELINE. MeSH terms and keyword combinations were used for screening following the PRISMA conduct. Inclusion criteria were based on PICO principles and no date of publication filter was applied. The intervention was training 2 days/week of structured resistance exercises using major upper and lower muscle groups. Minimum intervention period was 7 weeks. Comparison groups maintained their habitual activity without structured exercise training. Outcome measures of interest were: 6-min walk test, grip strength, timed up-and-go test, and sit-to-stand. Eight randomized controlled trials and one nonequivalent comparison-group study fulfilled the inclusion criteria and underwent data extraction. All studies were of hemodialysis patients. The evidence indicates that full-body resistance exercise significantly improved grip strength, timed up and go and sit to stand tests; metrics associated with enhanced quality and quantity of life.

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

INTRODUCTION

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

OBJECTIVE

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

Impact and safety outcomes of an intradialytic physical exercise program

INTRODUCTION

Patients undergoing hemodialysis (HD) are characterized by a poor physical condition and a substantial sedentary profile. The implementation of physical exercise programs in the hemodialysis units is usually limited by the inherent safeness and the lack of appropriate resources.

OBJECTIVES

We aimed to evaluate the impact and safety outcomes of the implementation of an intradialytic physical exercise program (IPE) by a multidisciplinary team (physiotherapist and nursing assistant) in the physical condition of the patients.

MATERIAL AND METHODS

This six months single-centre and experimental pre-post prospective study was carried out in 34 patients. A two day-week combined IPE intervention was implemented. The cardiopulmonary capacity (6MWT), muscular strength (HG, leg dynamometry and 10STS), body composition (bioimpedance) and coordination capacity (Timed Up and Go test) was assessed at the beginning and at the end of the study. Safety was evaluated by means of the number of issues regarding the vascular access, the hemodynamic stability as well as the vascular refilling profile (RBV) in each session. The adhesion to the program was also registered. Additionally, analytical parameters were recorded.

RESULTS

The adhesion to an IPE program was high (70.8%). A significant improvement of the cardiopulmonary capacity (6MWT average increase 47 m; p < 0.001), superior limbs (HG average increase of 1.6 kg; p = 0.007) as well as the lower extremities (10STS; p = 0.003; dynamometry p < 0.05). Regarding safeness, there were no incidences neither significant difference in the RBV.

CONCLUSIONS

A combined IPE may contribute to the improvement of the physical condition of the patients as well as ensures a safe development of the HD treatment. We suggest a multidisciplinary team in order to efficiently establish an IPE program.

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.

Renal Rehabilitation: Exercise Intervention and Nutritional Support in Dialysis Patients

With the growing number of dialysis patients with frailty, the concept of renal rehabilitation, including exercise intervention and nutrition programs for patients with chronic kidney disease (CKD), has become popular recently. Renal rehabilitation is a comprehensive multidisciplinary program for CKD patients that is led by doctors, rehabilitation therapists, diet nutritionists, nursing specialists, social workers, pharmacists, and therapists. Many observational studies have observed better outcomes in CKD patients with more physical activity. Furthermore, recent systematic reviews have shown the beneficial effects of exercise intervention on exercise tolerance, physical ability, and quality of life in dialysis patients, though the beneficial effect on overall mortality remains unclear. Nutritional support is also fundamental to renal rehabilitation. There are various causes of skeletal muscle loss in CKD patients. To prevent muscle protein catabolism, in addition to exercise, a sufficient supply of energy, including carbohydrates, protein, iron, and vitamins, is needed. Because of decreased digestive function and energy loss due to dialysis treatment, dialysis patients are recommended to ingest 1.2-fold more protein than the regular population. Motivating patients to join in activities is also an important part of renal rehabilitation. It is essential for us to recognize the importance of renal rehabilitation to maximize patient satisfaction.

Impact and safety outcomes of an intradialytic physical exercise program

INTRODUCTION

Patients undergoing hemodialysis (HD) are characterized by a poor physical condition and a substantial sedentary profile. The implementation of physical exercise programs in the hemodialysis units is usually limited by the inherent safeness and the lack of appropriate resources.

OBJECTIVES

We aimed to evaluate the impact and safety outcomes of the implementation of an intradialytic physical exercise program (IPE) by a multidisciplinary team (physiotherapist and nursing assistant) in the physical condition of the patients.

MATERIAL AND METHODS

This six months single-centre and experimental pre-post prospective study was carried out in 34 patients. A two day-week combined IPE intervention was implemented. The cardiopulmonary capacity (6MWT), muscular strength (HG, leg dynamometry and 10STS), body composition (bioimpedance) and coordination capacity (Timed Up and Go test) was assessed at the beginning and at the end of the study. Safety was evaluated by means of the number of issues regarding the vascular access, the hemodynamic stability as well as the vascular refilling profile (RBV) in each session. The adhesion to the program was also registered. Additionally, analytical parameters were recorded.

RESULTS

The adhesion to an IPE program was high (70.8%). A significant improvement of the cardiopulmonary capacity (6MWT average increase 47m; p<0.001), superior limbs (HG average increase of 1.6kg; p=0.007) as well as the lower extremities (10STS; p=0.003; dynamometry p<0.05). Regarding safeness, there were no incidences neither significant difference in the RBV.

CONCLUSIONS

A combined IPE may contribute to the improvement of the physical condition of the patients as well as ensures a safe development of the HD treatment. We suggest a multidisciplinary team in order to efficiently establish an IPE program.

High Levels of Physical Activity May Promote a Reduction in Bone Mineral Density in Peritoneal Dialysis

Background and objectives: Peritoneal dialysis (PD) patients are expected to present lower levels of physical activity, unhealthy changes at the body composition level, and low levels of strength. Firstly, this study aimed to report the sex differences in physical activity, body composition and muscle strength and the relations among these variables. Secondly, we analyze the relationship between physical activity and biochemical parameters. Materials and Methods: Thirty-four patients (13 women and 21 men) participated in this study. Body composition was assessed by bioimpedance and dual-energy X-ray absorptiometry (DXA), and maximum isokinetic unilateral strength, analytical parameters and physical activity levels were evaluated. Results: The men showed higher values for weight, height, lean body mass, bone mineral content, bone mineral density (BMD) and total body water, while women showed higher values for the percentage of fat mass and hydration of lean body mass (p < 0.05). No differences between the sexes were found in different levels of physical activity; however, males registered significantly higher values for isokinetic strength variables except for knee extensor strength. BMD was positively related to sedentary activity and negatively related to moderate and vigorous activity (r = 0.383 and r = -0.404, respectively). Light physical activity was negatively correlated with albumin (r = -0.393) and total protein (r = -0.410) levels, while moderate/vigorous activity was positively correlated with urea distribution volume (r = 0.446) and creatinine clearance (r = 0.359) and negatively correlated with the triglyceride level (r = -0.455). Conclusions: PD patients with higher levels of physical activity present better results in terms of body composition and biochemical parameters. Additional studies should be conducted to clarify the relation between physical activity level and BMD.

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

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

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

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

A Systematic Review of the Acute Effects of Hemodialysis on Skeletal Muscle Perfusion, Metabolism, and Function

Introduction

The underlying mechanisms of skeletal muscle wasting in hemodialysis patients are complex. We performed a systematic review to summarize evidence on whether hemodialysis has acute effects on skeletal muscle perfusion, metabolism, and function.

Methods

The protocol was registered on PROSPERO (Registration number CRD42018103682). A systematic search was performed in MEDLINE, PubMed, Cochrane, Embase, Scopus, and Web of Science. Citation, reference list, and gray literature searches were also performed. Studies were selected in 2 stages: title and abstract review, then full-text review.

Results

A total of 65 full-text articles were reviewed, and 14 studies were eligible for inclusion. No studies were identified that assessed muscle perfusion during dialysis. Two studies used near-infrared spectroscopy to indirectly measure skeletal muscle oxygen consumption, which increased during dialysis in 1 study but only in patients with diabetes in the second. Metabolism was examined in 9 studies. A number of acute metabolic changes were reported (e.g., caspase-3 activity, polyubiquitin, and interleukin-6 protein increased in response to hemodialysis) as was a net negative protein balance over the dialysis session. Three studies examining muscle function did not produce consistent findings.

Conclusion

Gaps remain in understanding the acute effects of hemodialysis on skeletal muscle, particularly for changes in perfusion and function, although there does appear to be an acute effect on muscle metabolism.

Isokinetic Strength in Peritoneal Dialysis Patients: A Reliability Study

Although there are studies assessing the effects of interventions on the knee strength of patients undergoing dialysis, there are no previous studies investigating the test–retest reliability of isokinetic measures in people undergoing peritoneal dialysis. The objective of this study was to determine the relative and absolute reliability of peak torque and work measurements for isokinetic concentric knee and elbow extension and flexion in peritoneal dialysis patients. Thirty-one patients undergoing peritoneal dialysis (19 males) participated in the current study. All isokinetic tests were performed using a Biodex System 3. Participants performed three concentric repetitions of each test (flexion or extension) with the dominant limb (knee and elbow) at 60°/s. Peak torque (Nm) and work (J) were extracted. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest real difference (SRD) were calculated. The results showed that all knee peak torque and work measures had an ICC of >0.90. On the other hand, the ICC for peak torque and work in the elbow concentric extension was <0.90, while the remaining elbow-related variables achieved an excellent reliability. Therefore, isokinetic dynamometry is a reliable technique to evaluate peak torque and work for concentric flexion and extension in both the knee and elbow joints in patients undergoing peritoneal dialysis.

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.

The association between six month intra-dialytic resistance training and muscle strength or physical performance in patients with maintenance hemodialysis: a multicenter retrospective observational study

Background

Reduced muscle strength and physical performance are prevalent in patients of maintenance hemodialysis (MHD), and deleterious changes in these parameters are associated with increased mortality.

Methods

This retrospective observational study included 306 patients, who received a 6-month resistance exercise program during hemodialysis, three times per week on an outpatient basis. The training protocol consisted of two sets of 10 repetitions of knee extension, hip abduction, and hip flexion, using an elastic band in a sitting or supine position. Primary outcome measures included muscle strength, measured by percent knee extension muscle power to dry body weight (pKEMP-dBW), and physical performance, measured by short physical performance battery (SPPB). The adjusted mean differences in these variables during the 6 months were estimated using a multivariate linear regression model.

Results

The mean age with standard deviation was 70 ± 11 years. One hundred and sixty patients (52.3%) were men and the dry weight was 55.6 ± 11.3 kg. Sarcopenia, defined as SPPB ≤8, was present in 21.4% patients. Their hemodialysis adequacy was acceptable, with a Kt/V of 1.65 ± 0.29, and their nutritional status was good, with a normalized protein catabolism rate of 0.89 ± 0.18 g/kg/day. During the 6 months, both pKEMP-dBW and SPPB showed a slight but significant increase with an adjusted mean difference of 2.8 (95% confidence interval 1.3–4.3, p <  0.001) and 0.6 (0.4–0.9, p <  0.001), respectively.

Conclusions

Six-month resistance training was associated with improved muscle strength and physical performance in patients with MHD.

Effects of intradialytic resistance training on physical activity in daily life, muscle strength, physical capacity and quality of life in hemodialysis patients: a randomized clinical trial

Purpose: We evaluated the effects of supervised intradialytic resistance training on physical activity in daily life (PADL), muscle strength, physical capacity and quality of life (QoL) in hemodialysis patients.Methods: Twenty-four hemodialysis patients were randomly assigned to either a 12-weeks moderate-intensity resistance training or a control period. An accelerometer evaluated PADL for seven consecutive days, measuring the time spent in different activities and positions of daily routine and the number of steps taken. Muscle strength, physical capacity and QoL were evaluated.Results: After 12 weeks of training, we did not find significant difference (post-pre values) in walking time (-1.2 ± 18.3 vs. -9.2 ± 13.1 min/day); standing time (-10.2 ± 28.6 vs. 3.2 ± 20.1 min/day); sitting time (20.8 ± 58.9 vs. -30.0 ± 53.0 min/day); lying down time (-9.3 ± 57.9 vs. 34.6 ± 54.0 min/day); number of steps taken [-147 (1834) vs. -454 (2066)] and muscle strength in training and control group, respectively. There was a significant increase in the six-minute walking test distance (48.8 ± 35.9 vs. 6.9 ± 45.9 m, p < 0.05) and some domains of QoL in the training compared to the control group.Conclusions: PADL was not modified after 12 weeks of intradialytic resistance training in hemodialysis patients. However, the exercise program was able to increase the physical capacity and some domains of QoL.Implications for rehabilitationPhysical activity in daily life was not modified after 12 weeks of intradialytic resistance training in hemodialysis patients.The exercise program was able to increase the physical capacity, efficacy of dialysis and some domains of quality of life in hemodialysis patients.The protocol used in this study was safe since no complications were observed during and after resistance training.These results should be interpreted with caution because we applied a moderate resistance training in both lower limbs and in the contralateral arteriovenous fistula upper limb, using perceived exertion by Borg scale to exercise prescription. Moreover, the safety protocol evaluation was not conducted.

Intradialytic resistance training: an effective and easy-to-execute strategy

Chronic kidney disease (CKD) alters the morphology and function of skeletal muscles, thereby decreasing patient physical capacity (PC) and quality of life (QoL). Intradialytic resistance training (IRT) is a pragmatic tool used to attenuate these complications. However, IRT has not been strongly adopted in nephrology care centers. This study aimed to assess the efficacy and safety of a low-cost, easy-to-use IRT protocol.

METHODS

The study enrolled 43 patients (52.8 ± 13.85 years) on HD for five to 300 months followed from April 2014 to July 2017. The efficacy of IRT was assessed based on PC - derived from muscle strength (MS) and preferred walking speed (PWS) - and QoL. The occurrence of adverse events was used as a measure of safety. The IRT protocol consisted of exercises of moderate to high intensity for the main muscle groups performed three times a week.

RESULTS

The mean follow-up time was 9.3 ± 3.24 months, for a total of 4,374 sessions of IRT. Compliance to the protocol was 96.5 ± 2.90%, and patients presented significant improvements in MS (from 27.3 ± 11.58 Kgf to 34.8 ± 10.77 Kgf) and PWS (from 0.99 ± 0.29 m/s to 1.26 ± 0.22 m/s). Physical and emotional components of QoL also increased significantly.

CONCLUSION

IRT led to significant increases in PC and higher scores in all domains of QoL. Important adverse events were not observed during intradialytic resistance training.

Effect of continuous progressive resistance training during hemodialysis on body composition, physical function and quality of life in end-stage renal disease patients: a randomized controlled trial

Objective:

This study aimed to investigate the effect of continuous progressive resistance training on body composition, functional capacity and self-reported quality of life in end-stage renal disease patients.

Design:

A randomized controlled trial.

Subjects:

The study included 52 hemodialysis patients (aged 55.7 ± 14.03 years) randomized into exercise (progressive resistance training (PRT), n = 28) or control (CON, n = 24) groups.

Intervention:

Patients randomized into the PRT group received prescribed strength exercises in two sets of 15–20 repetitions, in a repetition maximum training zone regime, thrice a week for 12 weeks, during hemodialysis. Patients randomized into the CON group received a sham-exercise with active mobilization of the arms and legs without load and progression.

Main outcome measure:

Body composition using dual-energy X-ray absorptiometry (DXA), strength using handgrip dynamometry (HGS), repeated sit-to-stand test (STT), 6-minute walk test, flexibility and the SF-36 questionnaire (quality of life (QoL)) were assessed at baseline and at 12 weeks.

Results:

Leg lean mass ( P = 0.04, effect size (ES) of 0.56), bone mineral content ( P = 0.02, ES of 0.65), leg strength in STT repetitions ( P = 0.01, ES of 0.66) and flexibility ( P < 0.01, ES of 1.03) were significantly improved in the PRT group compared to the CON group. Walking capacity, HGS and QoL were not different between the groups.

Conclusion:

12 weeks of PRT with a repetition maximum training zone regime provided significant load to increase leg lean mass and STT performance as well as bone mineral content, compared to the CON, which continued to deteriorate. There was lack of efficacy on walking test, HGS and QoL.

Physical Activity in End-Stage Renal Disease Patients: The Effects of Starting Dialysis in the First 6 Months after the Transition Period

OBJECTIVES

Physical inactivity in end-stage renal disease (ESRD) patients is associated with increased mortality, and might be related to abnormalities in body composition (BC) and physical performance. It is uncertain to what extent starting dialysis influences the effects of ESRD on physical activity (PA). This study aimed to compare PA and physical performance between stage 5 chronic kidney disease (CKD-5) non-dialysis and dialysis patients, and healthy controls, to assess alterations in PA during the transition from CKD-5 non-dialysis to dialysis, and to relate PA to BC.

METHODS

For the cross-sectional analyses 44 CKD-5 non-dialysis patients, 29 dialysis patients, and 20 healthy controls were included. PA was measured by the SenseWear™ pro3. Also, the walking speed and handgrip strength (HGS) were measured. BC was measured by the Body Composition Monitor©. Longitudinally, these parameters were assessed in 42 CKD-5 non-dialysis patients (who were also part of the cross-sectional analysis), before the start of dialysis and 6 months thereafter.

RESULTS

PA was significantly lower in CKD-5 non-dialysis patients as compared to that in healthy controls but not as compared to that in dialysis patients. HGS was significantly lower in dialysis patients as compared to that in healthy controls. Walking speed was significantly lower in CKD-5 non-dialysis patients as compared to that in healthy controls but not as compared to that in dialysis patients. Six months after starting dialysis, activity related energy expenditure (AEE) and walking speed significantly increased.

CONCLUSIONS

PA is already lower in CKD-5 non-dialysis patients as compared to that in healthy controls and does not differ from that of dialysis patients. However, the transition phase from CKD-5 non-dialysis to dialysis is associated only with a modest improvement in AEE.

Cardiac cachexia: hic et nunc

Cardiac cachexia (CC) is the clinical entity at the end of the chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely, the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. A better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia, and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Effect of Angiotensin-Converting Enzyme Inhibitors on Physical Function in Elderly Subjects: A Systematic Review and Meta-Analysis

BACKGROUND

Sarcopenia has been accepted as a new geriatric syndrome, which will become a common and important public health challenge. And angiotensin-converting enzyme inhibitors (ACEIs) have been shown to improve exercise capacity in elderly without heart failure.

OBJECTIVES

To evaluate the effect of angiotensin-converting enzyme inhibitors (ACEIs) on physical function in elderly.

DATA SOURCES

The Cochrane Library, PubMed, EMBASE and Web of Science were searched.

ELIGIBILITY CRITERIA

All researches included were randomized controlled trials (RCTs) which compared any kind of ACEIs with placebo or other anti-hypertensives in elderly, and provided empirical data of grip strength and 6-min walk distance change from baseline.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias was systematically assessed by using the Cochrane risk of bias tool. Data of grip strength and 6-min walk distance change from baseline were collected and mean differences (MDs) were calculated along with 95% CI (confidence interval) by using a random effects model.

RESULTS

In 3 RCTs including 337 elderly participants, ACEIs (n = 178) did not significantly improved 6-min walk distance (13.45, 95% CI: -16.71 to 43.61; P = 0.38) versus placebo or other antihypertensives (n = 159). In 3 RCTs including 499 elderly participants, grip strength was not significantly different (-0.67, 95% CI: -1.53 to 0.19; P = 0.12) between ACEIs (n = 260) and placebo or other antihypertensives (n = 239).

LIMITATIONS

There exists only 4 RCTs and the number of participants is limited. Pooling of data were from different trials including different participant characteristics. And intervention is not strictly consistent.

CONCLUSION

This study shows that ACEIs can not significantly improve walk distance or the age-related decline of muscle strength for older participants in clinical trials.

Evaluation of C-terminal Agrin Fragment as a marker of muscle wasting in patients after acute stroke during early rehabilitation

BACKGROUND

C-terminal Agrin Fragment (CAF) has been proposed as a novel biomarker for sarcopenia originating from the degeneration of the neuromuscular junctions. In patients with stroke muscle wasting is a common observation that predicts functional outcome. We aimed to evaluate agrin sub-fragment CAF22 as a marker of decreased muscle mass and physical performance in the early phase after acute stroke.

METHODS

Patients with acute ischaemic or haemorrhagic stroke (n = 123, mean age 70 ± 11 y, body mass index BMI 27.0 ± 4.9 kg/m(2)) admitted to inpatient rehabilitation were studied in comparison to 26 healthy controls of similar age and BMI. Functional assessments were performed at begin (23 ± 17 days post stroke) and at the end of the structured rehabilitation programme (49 ± 18 days post stroke) that included physical assessment, maximum hand grip strength, Rivermead motor assessment, and Barthel index. Body composition was assessed by bioelectrical impedance analysis (BIA). Serum levels of CAF22 were measured by ELISA.

RESULTS

CAF22 levels were elevated in stroke patients at admission (134.3 ± 52.3 pM) and showed incomplete recovery until discharge (118.2 ± 42.7 pM) compared to healthy controls (95.7 ± 31.8 pM, p < 0.001). Simple regression analyses revealed an association between CAF22 levels and parameters of physical performance, hand grip strength, and phase angle, a BIA derived measure of the muscle cellular integrity. Improvement of the handgrip strength of the paretic arm during rehabilitation was independently related to the recovery of CAF22 serum levels only in those patients who showed increased lean mass during the rehabilitation.

CONCLUSIONS

CAF22 serum profiles showed a dynamic elevation and recovery in the subacute phase after acute stroke. Further studies are needed to explore the potential of CAF22 as a serum marker to monitor the muscle status in patients after stroke.

Nutritional Status of Maintenance Dialysis Patients: Low Lean Body Mass Index and Obesity Are Common, Protein-Energy Wasting Is Uncommon

BACKGROUND AND AIMS

Maintenance dialysis patients are at increased risk of abnormal nutritional status due to numerous causative factors, both nutritional and non-nutritional. The present study assessed the current prevalence of protein-energy wasting, low lean body mass index and obesity in maintenance dialysis patients, and compared different methods of nutritional assessment.

METHODS

In a cross-sectional study conducted in 2014 at Roskilde Hospital, Denmark, we performed anthropometry (body weight, skinfolds, mid-arm, waist, and hip circumferences), and determined plasma albumin and normalized protein catabolic rate in order to assess the prevalence of protein-energy wasting, low lean body mass index and obesity in these patients.

RESULTS

Seventy-nine eligible maintenance dialysis patients participated. The prevalence of protein-energy wasted patients was 4% (95% CI: 2-12) as assessed by the coexistence of low lean body mass index and low fat mass index. Low lean body mass index was seen in 32% (95% CI: 22-44). Obesity prevalence as assessed from fat mass index was 43% (95% CI: 32-55). Coexistence of low lean body mass index and obesity was seen in 10% (95% CI: 5-19). The prevalence of protein-energy wasting and obesity varied considerably, depending on nutritional assessment methodology.

CONCLUSIONS

Our data indicate that protein-energy wasting is uncommon, whereas low lean body mass index and obesity are frequent conditions among patients in maintenance dialysis. A focus on how to increase and preserve lean body mass in dialysis patients is suggested in the future. In order to clearly distinguish between shortage, sufficiency and abundance of protein and/or fat deposits in maintenance dialysis patients, we suggest the simple measurements of lean body mass index and fat mass index.

The impact of iron deficiency and anaemia on exercise capacity and outcomes in patients with chronic heart failure. Results from the Studies Investigating Co-morbidities Aggravating Heart Failure

Anaemia and iron deficiency (ID) are important co-morbidities in patients with chronic heart failure (HF) and both may lead to reduced exercise capacity.

METHODS

We enrolled 331 out-patients with stable chronic HF (mean age: 64 ± 11 years, 17% female, left ventricular ejection fraction [LVEF] 35 ± 13%, body mass index [BMI] 28.5 ± 5.2 kg/m(2), New York Heart Association [NYHA] class 2.2 ± 0.7, chronic kidney disease 35%, glomerular filtration rate 61.7 ± 20.1 mL/min). Anaemia was defined according to World Health Organization criteria (haemoglobin [Hb] < 13 g/dL in men, < 12 g/dL in women). ID was defined as serum ferritin < 100 μg/L or ferritin < 300 μg/L with transferrin saturation (TSAT) < 20%. Exercise capacity was assessed as peak oxygen consumption (peak VO2) by spiroergometry and 6-minute walk test (6MWT).

RESULTS

A total of 91 (27%) patients died from any cause during a mean follow-up of 18 months. At baseline, 98 (30%) patients presented with anaemia and 149 (45%) patients presented with ID. We observed a significant reduction in exercise capacity in parallel to decreasing Hb levels (r = 0.24, p < 0.001). In patients with anaemia and ID (n = 63, 19%), exercise capacity was significantly lower than in patients with ID or anaemia only. Cox regression analysis showed that after adjusting for NYHA, age, hsCRP and creatinine anaemia is an independent predictor of mortality in patients with HF (hazard ratio [HR]: 0.56, 95% confidence interval [CI]: 0.33-0.97, p = 0.04).

CONCLUSION

The impact of anaemia on reduced exercise capacity and on mortality is stronger than that of ID. Anaemia remained an independent predictor of death after adjusting for clinically relevant variables.

Cachexia: a nutritional syndrome?

Cachexia leads to nutritional deficits including anorexia and loss of fat and muscle mass. In persons with precachexia or early cachexia, for example, old persons with weight loss and chronic obstructive pulmonary disease, there is strong evidence that nutritional support improves outcomes. Limited evidence suggests that this may be true for heart failure and chronic kidney disease. The evidence for nutritional support in refractory cachexia is, not surprisingly, less dramatic. It would appear that early in the cachectic process, nutrition, coupled with exercise, may be an important therapeutic approach.

Cardiac cachexia: hic et nunc: "hic et nunc" - here and now

Cardiac cachexia (CC) is the clinical entity at the end of chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. Better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick-up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Uric acid and xanthine oxidase in heart failure - Emerging data and therapeutic implications

The role of hyperuricaemia as cardiovascular risk factor has exhaustingly been debated for decades. While the association of elevated uric acid (UA) levels with increased mortality risk as convincingly been shown, the question whether UA is independently predictive of just a related effect within a more complex risk factor profile (including metabolic, inflammatory and haemodynamic risk factors) is still a matter of dispute. In heart failure the independent prognostic and functional impact of elevated UA has not only been shown but also the pathophysiologic mechanism(s) and the potential of targeted therapeutic interventions have been investigated in some detail. The emerging picture suggests the increased activity of the enzyme xanthine oxidase (XO) with corresponding increased production of free oxygen radical (ROS) as a main underlying principle with the resulting increase in UA levels being mostly a marker of this up-regulated pathway. While this concept will not diminish the value of UA as a prognostic marker, it provides the basis for a novel metabolic treatment option and the means to identify those patients most eligible for this tailored therapy. This review will summarize the recent evidence on XO as a novel and promising therapeutic target in heart failure.

Effect of endurance and/or strength training on muscle fiber size, oxidative capacity, and capillarity in hemodialysis patients

We previously reported reduced limb muscle fiber succinate dehydrogenase (SDH) activity and capillarity density and increased cross-sectional areas (CSAs) of all fiber types in maintenance hemodialysis (MHD) patients compared with matched controls that may contribute to their effort intolerance and muscle weakness. This study evaluated whether endurance training (ET), strength training (ST), or their combination (EST) alters these metabolic and morphometric aberrations as a mechanism for functional improvement. Five groups were evaluated: 1) controls; 2) MHD/no training; 3) MHD/ET; 4) MHD/ST; and 5) MHD/EST. Training duration was 21.5 ± 0.7 wk. Vastus lateralis muscle biopsies were obtained after HD at baseline and at study end. Muscle fibers were classified immunohistochemically, and fiber CSAs were computed. Individual fiber SDH activity was determined by a microdensitometric assay. Capillaries were identified using antibodies against endothelial cells. Type I and IIA fiber CSAs decreased significantly (10%) with EST. In the ET group, SDH activity increased 16.3% in type IIA and 19.6% in type IIX fibers. Capillary density increased significantly by 28% in the EST group and 14.3% with ET. The number of capillaries surrounding individual fiber type increased significantly in EST and ET groups. Capillary-to-fiber ratio increased significantly by 11 and 9.6% in EST and ET groups, respectively. We conclude that increments in capillarity and possibly SDH activity in part underlie improvements in endurance of MHD patients posttraining. We speculate that improved specific force and/or neural adaptations to exercise underlie improvements in limb muscle strength of MHD patients.

Muscle wasting in ageing and chronic illness

PURPOSE

As life expectancy increases, muscle wasting is becoming a more and more important public health problem. This review summarizes the current knowledge of pathophysiological mechanisms underlying muscle loss in ageing and chronic diseases such as heart failure and discusses evolving interventional strategies.

RECENT FINDINGS

Loss of skeletal muscle mass and strength is a common phenomenon in a wide variety of disorders associated with ageing and morbidity-associated catabolic conditions such as chronic heart failure. Muscle wasting in ageing but otherwise healthy human beings is referred to as sarcopenia. Unlike cachexia in advanced stages of chronic heart failure, muscle wasting per se is not necessarily associated with weight loss. In this review, we discuss pathophysiological mechanisms underlying muscle loss in sarcopenia and cachexia, highlight similarities and differences of both conditions, and discuss therapeutic targets and possible treatments, such as exercise training, nutritional support, and drugs. Candidate drugs to treat muscle wasting disease include myostatin antagonists, ghrelin agonists, selective androgen receptor molecules, megestrol acetate, activin receptor antagonists, espindolol, and fast skeletal muscle troponin inhibitors.

SUMMARY

Present approaches to muscle wasting disease include exercise training, nutritional support, and drugs, although particularly the latter remain currently restricted to clinical studies. Optimizing skeletal muscle mass and function in ageing and chronic illness including heart failure is one of the chapters that are far from finished and gains future potential for new therapeutic interventions to come.

Latest consensus and update on protein-energy wasting in chronic kidney disease

PURPOSE OF REVIEW

Protein-energy wasting (PEW) is a state of metabolic and nutritional derangements in chronic disease states including chronic kidney disease (CKD). Cumulative evidence suggests that PEW, muscle wasting and cachexia are common and strongly associated with mortality in CKD, which is reviewed here.

RECENT FINDINGS

The malnutrition-inflammation score (KALANTAR Score) is among the comprehensive and outcome-predicting nutritional scoring tools. The association of obesity with poor outcomes is attenuated across more advanced CKD stages and eventually reverses in the form of obesity paradox. Frailty is closely associated with PEW, muscle wasting and cachexia. Muscle loss shows stronger associations with unfavorable outcomes than fat loss. Adequate energy supplementation combined with low-protein diet for the management of CKD may prevent the development of PEW and can improve adherence to low-protein diet, but dietary protein requirement may increase with aging and is higher under dialysis therapy. Phosphorus burden may lead to poor outcomes. The target serum bicarbonate concentration is normal range and at least 23 mEq/l for nondialysis-dependent and dialysis-dependent CKD patients, respectively. A benefit of exercise is suggested but not yet conclusively proven.

SUMMARY

Prevention and treatment of PEW should involve individualized and integrated approaches to modulate identified risk factors and contributing comorbidities.