Longitudinal study of nutritional status, body composition, and physical function in hemodialysis patients

Effects of neuromuscular electrical stimulation during hemodialysis on muscle strength, functional capacity and postural balance in patients with end-stage renal disease: a randomized controlled trial

BACKGROUND

Hemodialysis patients (HD) have a limited physical capacity and this often means low adherence to rehabilitation programs based on conventional exercise. This study investigated the effectiveness of neuromuscular electrical stimulation (NMES) during HD therapy on muscle strength, functional capacity and postural balance in HD patients.

METHODS

Twenty-two HD patients were randomly assigned to a control group (CG) or a neuromuscular electrical stimulation training group (NSTG). The NSTG underwent NMES on the quadriceps muscle during HD sessions for 12 weeks, three times per week (40 min per session. Center of pressure (COP) displacement in the mediolateral direction (COPx), in the anteroposterior direction (COPy), and the COP area (COP area) were recorded using a stabilometric platform. Timed Up and Go test (TUG) and Sit to Stand (STS30) tests, 6-minute walking test (6MWT), and the maximal voluntary contraction (MVC) were measured before and after the intervention in both groups.

RESULTS

There was a significant increase in MVC (+ 24.5%; P < 0.01), 6MWT (+ 9.8%; P < 0.05) and STS30 (+ 25.6%; P < 0.01) performance in the NSTG following the NMES intervention period. A significant reduction was observed in TUG (-11.8%; P < 0.01), COPx(-20.1%; P < 0.05) and COPy (-24.7%; P < 0.01) following the intervention period only in the NSTG. However, no significant changes were observed in the CG following the intervention period.

CONCLUSION

This study supports the effectiveness of intradialytic NMES to improve muscular strength, functional capacity and postural balance in HD patients. Given the limited implementation of exercise programs in dialysis clinical practice, NMES during HD sessions offers a novel therapeutic alternative to enhance physical condition and quality of life in these patients.

TRIAL REGISTRATION

Pan African Clinical Trial Registry Identifer: PACTR202206634181851 Registered on 21/06/2022. Registered trial name: Beneficial Effect of Intradialytic Electrical Muscle Stimulation in Hemodialysis Patients.

Exploring the Associations Between Inflammatory Biomarkers, Survival, and Cardiovascular Events in Hemodialysis Patients and the Interrelationship with Nutritional Parameters-The Experience of a Single Transylvanian Dialysis Center

Background/Objectives: In hemodialysis (HD), inflammatory biomarkers are discussed as prognostic markers for survival and cardiovascular events (CVEs). The results of the studies are not uniform and there are particularities related to population groups and comorbidities. In addition, it is known that inflammation determines protein malnutrition and less about the effect of adipose tissue on inflammation in HD. This study investigates the relationship between inflammatory molecules and nutritional biomarkers, and CVE and survival in HD patients. Methods: We included, in an observational, longitudinal study, 65 patients with chronic HD (53 without diabetes and 22 smokers), with a mean age of 60.1 ± 12.4 years. High-sensitivity C-reactive protein (hs-CRP), interleukin 1 beta, tumor necrosis factor alpha (TNF-alpha), interleukin 6, soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK), soluble CD163 (sCD163), and fibroblast growth factor 21 were determined. We recorded survival and cardiovascular events for 60 months. Univariate and multivariate analyses were performed. Results: Hs-CRP was significantly associated with survival (p = 0.014) in the total group. In smokers and former smokers, TNF-α lower than 368.34 pg/mL was associated with better survival. In multivariate analysis, hs-CRP was correlated with adipose tissue biomarkers (p = 0.006), and sCD163 was correlated with total and LDL cholesterol (p = 0.002). In addition, in univariate analysis, sTWEAK was correlated with serum albumin (p = 0.026, r = -0.30). In conclusion, in HD patients, hs-CRP was significantly associated with survival, and low TNF-alpha values in smokers and former smokers were linked to better survival. Hs-CRP was also correlated with adipose tissue biomarkers, CD163 was correlated with total and LDL cholesterol, and albumin was inversely associated with sTWEAK. The relation between inflammatory molecules and adipose tissue biomarkers was less identified in HD patients until now.

Portable bioimpedance analyzer for remote body composition monitoring: A clinical investigation under controlled conditions

OBJECTIVES

In an era when telemedicine is becoming increasingly essential, the development and validation of miniaturized Bioelectrical Impedance Analysis (BIA) devices for accurate and reliable body composition assessment is crucial. This study investigates the BIA Metadieta, a novel miniaturized BIA device, by comparing its performance with that of standard hospital BIA equipment across a diverse demographic. The aim is to enhance remote health monitoring by integrating compact and efficient technology into routine healthcare practices.

METHODS

A cross-sectional observational study was conducted with 154 participants from the Clinical Nutrition Unit. The study compared resistance (R), reactance (Xc), and phase angle (PhA) measurements obtained from the BIA Metadieta device and a traditional hospital-based BIA device.

RESULTS

Analysis revealed strong positive correlations between the BIA Metadieta and the hospital-based device for R (r = 0.988, P < 0.001), Xc (r = 0.946, P < 0.001), and PhA (r = 0.929, P < 0.001), indicating the miniaturized device's high accuracy and reliability. These correlations were consistent across different genders and BMI categories, demonstrating the device's versatility.

CONCLUSIONS

The BIA Metadieta device, with its miniaturized form factor, represents a significant step forward in the field of remote health monitoring, providing a reliable, accurate, and accessible means for assessing body composition.

Hemodynamic and neuromuscular basis of reduced exercise capacity in patients with end-stage renal disease

PURPOSE

The present study aimed to characterize the exercise-induced neuromuscular fatigue and its possible links with cerebral and muscular oxygen supply and utilization to provide mechanistic insights into the reduced exercise capacity characterizing patients with end-stage renal disease (ESRD).

METHODS

Thirteen patients with ESRD and thirteen healthy males (CTR group) performed a constant-force sustained isometric contraction at 50% of their maximal voluntary isometric contraction (MVC) until exhaustion. Quadriceps muscle activation during exercise was estimated from vastus lateralis, vastus medialis, and rectus femoris EMG. Central and peripheral fatigue were quantified via changes in pre- to postexercise quadriceps voluntary activation (ΔVA) and quadriceps twitch force (ΔQtw,pot) evoked by supramaximal electrical stimulation, respectively. To assess cerebral and muscular oxygenation, throughout exercise, near-infrared spectroscopy allowed investigation of changes in oxyhemoglobin (∆O2Hb), deoxyhemoglobin (∆HHb), and total hemoglobin (∆THb) in the prefrontal cortex and in the vastus lateralis muscle.

RESULTS

ESRD patients demonstrated lower exercise time to exhaustion than that of CTR (88.8 ± 15.3 s and 119.9 ± 14.6 s, respectively, P < 0.01). Following the exercise, MVC, Qtw,pot, and VA reduction were similar between the groups (P > 0.05). There was no significant difference in muscle oxygenation (∆O2Hb) between the two groups (P > 0.05). Cerebral and muscular blood volume (∆THb) and oxygen extraction (∆HHb) were significantly blunted in the ESRD group (P < 0.05). A significant positive correlation was observed between time to exhaustion and cerebral blood volume (∆THb) in both groups (r2 = 0.64, P < 0.01).

CONCLUSIONS

These findings support cerebral hypoperfusion as a factor contributing to the reduction in exercise capacity characterizing ESRD patients.

Effects of Laughter Yoga on Patients Receiving Hemodialysis: A Systematic Review

When it comes to end-stage renal disease patients, hemodialysing is one of the most critical treatments they can receive. Even if they received hemodialysis (HD) treatment regularly, patients would experience many complications such as cardiovascular disease, fatigue, anxiety, depression, sleep disturbances, and a declining quality of life. Laughter Yoga has been reported to have many positive effects on patients with chronic illnesses. By removing or reducing stress, Laughter Yoga (LY) helps to improve patients' quality of life, Thus, they have a longer chance of survival. However, the effect of Laughter Yoga on HD patients is generally inconclusive. Objective is to evaluate LY's impact on HD patients. We searched electronic databases that included Web of Science, Embase, PubMed, the Cochrane Library, Wanfang, China National Knowledge Infrastructure, and clinical trial registries. The search period was from their inception to January 29, 2023. The search keywords included laughter therapy, laughter yoga, laugh, hemodialysis, dialysis, and renal dialysis. The systematic review included both randomized controlled trials (RCTs) and quasi-experiments studies. Three RCTs and three non-RCTs met the inclusion criteria. Laughter Yoga showed patients having improvement in several outcomes such as life quality, pain severity, sleep quality, subjective well-being, mood, depression, blood pressure, and vital capacity. A well-designed RCT will be developed to further test the potential benefits of LY for HD patients.

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

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

Modifiable Physical Factors That Influence Physical Function for People Receiving Peritoneal Dialysis

Introduction

People receiving peritoneal dialysis experience physical function decline, impairing their ability to complete everyday activities, leading to poorer quality of life. Physical factors, including cardiorespiratory fitness, muscle strength, physical activity, and sedentary behavior are associated with physical function. However, little is known about this relationship, or temporal changes of these factors in this cohort. This study aimed to explore modifiable physical factors that are associated with physical function, identify which factor has the strongest influence, and explore temporal changes.

Methods

Adults receiving peritoneal dialysis underwent objective and self-reported physical function, cardiorespiratory fitness, muscle strength, physical activity and sedentary behavior assessments 3 times over a 12-month observation period (at baseline, 6 months, and 12 months).

Results

Eighty-two participants underwent assessments. All modifiable physical factors were predominantly moderate to strongly associated with physical function at baseline. Cardiorespiratory fitness had the strongest and most consistent influence with every meter conferring a 0.08-unit (P < 0.01) and 0.01-unit (P < 0.05) increase in self-report and objective physical function score, respectively. Temporal changes were observed for modifiable physical factors with significant mean changes in cardiorespiratory fitness (-9.8%), quadricep strength (-5%), moderate-to-vigorous (-25.9%) and total (-16.2%) physical activity, and sedentary behavior (+7.1%).

Conclusion

The results of this study indicate that cardiorespiratory fitness could be routinely monitored to detect risk of physical function decline and targeted through intervention to enhance physical function for people receiving peritoneal dialysis. Nevertheless, all factors should be considered when designing interventions to mitigate temporal changes and induce the numerous health benefits offered by being physically active.

Exercise instruction during haemodialysis treatment after changes to the insurance regime: a nationwide questionnaire survey in Japan

In April 2022, an additional medical fee for exercise instruction during haemodialysis treatment was approved for insurance claims in Japan. We conducted a questionnaire survey to investigate the current situation regarding exercise therapy during haemodialysis treatment after this change. Questionnaires were mailed to 4257 haemodialysis facilities, almost all the haemodialysis facilities in Japan, on January 31, 2023. In total, 1657 facilities responded, of which 550 (33%) provided exercise instruction during haemodialysis treatment, and 65% of these claimed the new fee. Of the 550 facilities that had claimed the fee at the time of survey, 245 (55%) started exercise instruction in April 2022 or later. Exercise instruction focused on resistance training (81%) and aerobic exercise (62%) for 20-30 min (66%) three times a week (80%). The instructors included physicians in 45% of facilities, nurses in 74%, and physical therapists in 36%. Efficacy was evaluated in 76% of the facilities providing instruction, mainly by assessing change in muscle strength (49%). Overall, 39% of facilities had experienced some adverse events, but none were life-threatening. In conclusion, after the change in the insurance regime, exercise instruction during haemodialysis treatment has become more popular, and more patients on haemodialysis are undergoing exercise therapy.

Effect of Intradialytic Exercise on Cardiovascular Outcomes in Maintenance Hemodialysis: A Systematic Review and Meta-Analysis

Key Points

Individuals receiving hemodialysis have high rates of cardiovascular disease not explained by traditional cardiovascular risk factors. Intradialytic exercise improves cardiovascular outcomes, including arterial resistance, BP, and heart rate variability. Clinicians should consider including intradialytic aerobic exercise programs in hemodialysis care to supplement broader treatment plans.

Background

Cardiovascular disease is the leading cause of death among people with kidney failure on hemodialysis, for whom improving cardiovascular health is a research priority. Intradialytic myocardial stunning is common and associated with adverse cardiovascular events. Intradialytic exercise may mitigate intradialytic myocardial stunning and improve cardiovascular structure and function. This systematic review investigated the effect of intradialytic exercise on cardiovascular outcomes in adults undergoing maintenance hemodialysis (PROSPERO CRD42018103118).

Methods

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically searched MEDLINE, Embase, Cochrane CENTRAL, SportDiscus, and PEDro databases from 1960 until June 2022, for randomized and nonrandomized studies investigating the effect of intradialytic exercise programs on objective cardiovascular outcomes, prespecified as primary or secondary outcomes. The primary outcome was arterial resistance.

Results

Of 10,837 references identified, 32 met eligibility criteria. These studies investigated the effect of intradialytic exercise on arterial resistance (eight studies), BP (20 studies), myocardial structure and function (seven studies), endothelial function (two studies), sympathetic overactivity (nine studies), biomarkers of cardiac injury (three studies), and cardiovascular hospitalization and mortality (two studies). Most studies used aerobic exercise as the intervention and usual care (no exercise) controls. Meta-analysis of intradialytic exercise versus usual care resulted in a statistically significant reduction in arterial resistance measured by pulse wave velocity with mean difference −1.63 m/s (95% confidence interval, −2.51 to −0.75). Meta-analyses for diastolic BP, left ventricular ejection fraction, and low-frequency/high-frequency ratio measure of heart rate variability also showed statistically significant improvements with exercise. There was no significant difference in change in systolic BP, augmentation index, and left ventricular mass index between groups.

Conclusions

Intradialytic exercise programming resulted in a clinically meaningful improvement to pulse wave velocity, a component of arterial resistance. Improvements in several physiologic measures of cardiovascular health, including diastolic BP, left ventricular ejection fraction, and heart rate variability measured by the low-frequency/high-frequency ratio were also observed. The effects of intradialytic exercise on major adverse cardiovascular events remains uncertain.

Evaluation of raw segmental bioelectrical impedance variables throughout anterior cruciate ligament reconstruction rehabilitation

Background.Raw bioelectrical impedance analysis (BIA) variables are related to physical function in healthy and diseased populations. Therefore, BIA may be an insightful, noninvasive method of assessment to track following anterior cruciate ligament reconstruction (ACLR).Objectives.Evaluate phase angle, reactance and impedance at 50 kHz (PhA₅₀, Xc₅₀, andZ₅₀, respectively) in the operative (OP) and non-operative (NOP) limbs during ACLR rehabilitation.Approach.Seventeen patient (12 M, 5 F; 18.8 ± 4.8 years) clinic reports were evaluated prior to ACLR (PRE), two- (2 W), six- (6 W), and twelve-weeks (12 W) post-ACLR and at return to sport testing (RTS).Setting.All observations occurred during the participant's physical therapy visits.Measurements.A multi-frequency BIA device measured segmental PhA, Xc, andZ. Linear mixed effects models were used to assess any leg and time interaction and changes over leg and time, independently. Any interactions or main effects were considered significant atp< 0.05.Main results.Significant legxtime interactions were observed for each variable. PhA₅₀and Xc₅₀of NOP were higher (p< 0.001) than OP at each time point by an average of by 0.9° and 4.9 Ω, respectively. In OP, PhA₅₀and Xc₅₀decreased from PRE to 2 W and increased from 6 to 12 W and 12 W to RTS (p< 0.01, for all). At RTS, PhA₅₀and Xc₅₀were similar to PRE in OP (p> 0.05). ForZ₅₀, the OP leg did not change over time (p> 0.05).Z₅₀was greater in NOP at 2 and 6 W (p< 0.01, for both). There were differences in PhA₅₀in NOP between PRE and 6 W and from 6 W to RTS (p< 0.05 for both). Xc₅₀did not change (p> 0.05), andZ₅₀PRE was lower than at 2 W (p< 0.05).Significance.A multi-frequency BIA device can detect changes in segmental BIA variables following ACLR.

Phase angle and cellular health: inflammation and oxidative damage

Phase angle is a composite measure that combines two raw bioelectrical impedance analysis measures: resistance and reactance. Phase angle has been considered an indicator of cellular health, integrity, and hydration. As inflammation and oxidative stress can damage cellular structures, phase angle has potential utility in early detecting inflammatory and oxidative status. Herein, we aimed to critically review the current understanding on the determinants of phase angle and its relationship with markers of inflammation and oxidative stress. We also discussed the potential role of phase angle in detecting chronic inflammation and related adverse outcomes. Several factors have been identified as predictors of phase angle, including age, sex, extracellular to intracellular water ratio, and fat-free mass. In addition to these factors, body mass index (BMI) also seems to influence phase angle. Available data also show that lower phase angle values are correlated (negligible to high correlation coefficients) with higher c-reactive protein, tumour necrosis factor-α, interleukin-6, and interleukin-10 in studies involving the general and aging populations, as well as patients with chronic conditions. Although fewer studies have evaluated the relationship between phase angle and markers of oxidative stress, available data also suggest that phase angle has potential to be used as an indicator (for screening) of oxidative damage. Future studies including diverse populations and bioelectrical impedance devices are required to confirm the validity and accuracy of phase angle as a marker of inflammation and oxidative stress for clinical use.

The effect of CKD on intertrochanteric fracture treated with proximal femoral nail anti-rotation: A 7-year study

Background

Intertrochanteric fracture is one of the most burdensome osteoporotic fractures in the elderly. Chronic kidney disease is associated with sarcopenia, especially in its advanced stages and, thus may impact functional status. Combining an intertrochanteric fracture with advanced CKD may diminish results after surgical fixation. This study aims to distinguish whether CKD affects the result of intertrochanteric fracture fixation in terms of mechanical and functional outcomes.

Methods

A retrospective study reviews all intertrochanteric fractures treated with PFNA fixation from 2012 to 2018. 445 patients were classified into 5 stages of CKD and divided by eGFR = 90 ml/min/1.73 m² into CKD and non-CKD group and by eGFR = 30 ml/min/1.73 m² into advanced CKD and non-advanced CKD group. The primary outcome was one year Harris Hip Score (HHS). Secondary outcomes were medical complications, surgical complications, and a 1-year mortality rate.

Results

Harris Hip Scores (HHS) were not different between non-CKD and CKD groups (eGFR <90 mL/min/1.73 m²). However, there was a difference between non-advanced CKD and advanced CKD groups (eGFR <30 mL/min/1.73 m²) (p < 0.001). Medical complications were not different, except for sepsis in CKD stage 5 compared with stage 1 (p = 0.023). Even though AO/OTA types were more severe in the advanced CKD group, surgical complications and 1-year mortality were not different.

Conclusion

Advanced stage CKD treated with PFNA fixation is associated with lower functional outcomes at one year. Sepsis is more prone to occur after surgery in CKD stage 5.

Level of evidence

Level III; Retrospective cohort study.

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

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

Determining factors of functioning in hemodialysis patients using the international classification of functioning, disability and health

Background

Hemodialysis (HD) treatment affects functioning, physical activity level, clinical biomarkers, and body composition. However, the association between these variables with functioning, considering International Classification of Functioning, Disability and Health (ICF) domains remains unclear. Thus, the aim of this study was to investigate the possible association between physical activity, biomarkers, and body composition with functioning in HD patients in reference to the ICF.

Methods

Eighty HD patients performed different tests grouped according to ICF domain: Body structure and function – handgrip strength (HS), 5-repetition sit-to-stand test, and 60-s sit-to-stand test (5-STS, 60-STS, respectively); Activity – short physical performance battery (SPPB); and Participation – participation scale questionnaire. Physical activity [Human Activity Profile questionnaire (HAP)], body composition (Dual-energy X-ray absorptiometry), Parathormone (PTH), and alkaline phosphatase were analyzed as possible variables associated with ICF domains. Data analyses were performed using simple and multiple regression models adjusted for age, duration of HD, and diuresis volume.

Results

In the body structure and function domain, appendicular lean mass, PTH level, and age were associated with HS (R² = 0.558); HAP and PTH were associated with 5-STS (R² = 0.263); and HAP, PTH, duration of HD, and age were associated with 60-STS (R² = 0.337). In the activity domain, HAP, PTH, alkaline phosphatase, duration of HD, age, and body fat were associated with SPPB (R² = 0.689). Finally, only HAP was associated with the participation scale (R² = 0.067).

Conclusion

Physical activity and PTH levels are determinant protagonists of functioning in all ICF domains in hemodialysis patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02719-5.

Exercise-Based Renal Rehabilitation: A Bibliometric Analysis From 1969 to 2021

Chronic kidney disease (CKD) is a growing global health challenge with an increasing incidence rate. Exercise-based renal rehabilitation is an evidence-based, multidisciplinary, and comprehensive intervention designed to improve the physical and psychological condition of patients with CKD. The knowledge structure, research hotspots, and development trends in exercise-based renal rehabilitation have not been systematically described. The aim of this study was to provide a bibliometric perspective of the progress in this field. Publications about exercise-based renal rehabilitation were retrieved from the Web of Science Core Collection, using the terms "exercise," "physical activity," and "chronic kidney disease." Annual publications, subject categories, countries, authors, references, and keywords in this field were visually analyzed using the Citespace, VOSview, and Excel software. A total of 4,610 publications were analyzed, with a steady increase in publications in the field. Overall, the United States is the major contributor to the study of exercise-based renal rehabilitation. Johansen KL and Painter P are the key researchers in this field. Keyword analysis shows that research hotspots in this field include exercise/physical activity for different stages of CKD, exercise-based renal rehabilitation for frailty, and physical activity management for CKD. These findings will make understanding exercise-based renal rehabilitation research better and inform about future research ideas.

Fatigability and the Role of Neuromuscular Impairments in Chronic Kidney Disease

BACKGROUND

The combination of neuromuscular impairments plus psychosocial aspects of chronic kidney disease (CKD) may predispose these patients to greater risk for experiencing increased levels of fatigability. There has been extensive clinical and scientific interest in the problem of fatigue in CKD and end-stage kidney disease (ESKD) patients, whereas less attention has been directed to understanding fatigability. Accordingly, the primary purposes of this review are to (1) discuss fatigue and fatigability and their potential interactions in patients with CKD and ESKD, (2) provide evidence for increased fatigability in CKD and ESKD patients, (3) examine how commonly experienced neuromuscular impairments in CKD and ESKD patients may contribute to the severity of performance fatigability, and (4) highlight preliminary evidence on the effects of exercise as a potential clinical treatment for targeting fatigability in this population.

SUMMARY

Fatigue is broadly defined as a multidimensional construct encompassing a subjective lack of physical and/or mental energy that is perceived by the individual to interfere with usual or desired activities. In contrast, fatigability is conceptualized within the context of physical activity and is quantified as the interactions between reductions in objective measures of performance (i.e., performance fatigability) and perceptual adjustments regulating activity performance (i.e., perceived fatigability). We propose herein a conceptual model to extend current understandings of fatigability by considering the interactions among fatigue, perceived fatigability, and performance fatigability. Neuromuscular impairments reported in patients with CKD and ESKD, including reductions in force capacity, skeletal muscle atrophy, mitochondrial dysfunction, abnormal skeletal muscle excitability, and neurological complications, may each contribute to the greater performance fatigability observed in these patients.

KEY MESSAGES

Considering the interactions among fatigue, perceived fatigability, and performance fatigability provides a novel conceptual framework to advance the understanding of fatigability in CKD and ESKD patients. Measures of fatigability may provide valuable clinical insights into the overall health status of CKD and ESKD patients. Existing data suggest that CKD and ESKD patients are at greater risk of experiencing increased fatigability, partly due to neuromuscular impairments associated with reduced kidney function. Further investigations are warranted to determine the potential clinical role fatigability measures can play in monitoring the health of CKD and ESKD patients, and in identifying potential treatments targeting fatigability in this patient population.

Physical activity is associated with nutritional biomarkers in hemodialysis patients: A cross-sectional study

OBJECTIVE

To explore the association between physical activity levels and nutritional biomarkers in hemodialysis patients.

METHODS

Eighty-six patients responded to the short version of the International Physical Activity Questionnaire to estimate the metabolic equivalent of tasks (MET) per week. A MET-min per week <600 was considered as sedentary. The nutritional biomarkers (i.e., albumin, globulin, and albumin/globulin ratio) were collected.

RESULTS

Sixty-five patients (75.6%) were sedentary. Binary logistic regression showed that patients with low albumin levels had an 89% lower chance to be physically active (p = 0.037), but it was not significant in the adjusted analysis (p = 0.052). Albumin and albumin/globulin ratio levels were correlated with MET-min per week (r = 0.34 and 0.30; both p < 0.05). Additionally, lower median albumin and albumin/globulin ratio levels were found in the sedentary patients (p = 0.021 and p = 0.031), respectively.

CONCLUSION

The physical activity levels were associated with albumin and albumin/globulin ratio, surrogates of nutritional status in hemodialysis patients. These nutritional biomarkers were lower in sedentary patients.

Comparison of Body Composition, Strength, and Physical Performance Measurements Between Healthy Participants and Hemodialysis Patients

Purpose

This study evaluated the difference in physical performance tests, strength, and total and regional mass using a comprehensive dataset between maintenance hemodialysis (HD) patients and a healthy population.

Patients and Methods

A total of 84 HD patients were enrolled. We selected 42 healthy participants (HPs) age- and sex-matched to the 84 HD patients as controls. Collected data were sex, age, body mass index (BMI), laboratory findings, total and regional measurements for lean mass or fat mass, thigh muscle area (TMA), handgrip strength, and physical performance measurements.

Results

There were no significant differences in BMI, total lean mass, or total fat mass including regional fat mass between the two groups. Lean leg mass and TMA were greater in HPs than in HD patients. All measurements of physical performance, including handgrip strength, were better in HPs than in HD patients. A multivariate analysis of lean leg mass, TMA, and physical performance measures had similar results to the same data studied with a univariate analysis.

Conclusion

We demonstrated that HD patients had decreased physical performance and strength compared to HPs. The difference in leg muscle mass was most prominent among the total and regional body compositions between HPs and HD patients.

Multicomponent Home-Based Training Program for Chronic Kidney Disease Patients during Movement Restriction

Both intradialytic and out-of-clinic exercise programs (EP) have been proven to be a safe and effective way to increase fitness levels in end-stage chronic kidney disease (CKD) patients. The actual COVID-19 pandemic situation has forced the suspension of EP offered in hemodialysis centers in many countries; as well as all activities considered as "non-essential" (i.e., sport facilities and fitness centers). Therefore, there is a high risk that movement restrictions would promote physical inactivity and its associated diseases in CKD patients; especially those undergoing domiciliary confinement situations. Given the importance for CKD patients' overall health to maintain exercise levels and reach physical activity recommendations, the aim of this Protocol was to design a personalized, well-structured, multicomponent physical EP that CKD patients can safely follow at home. We also aimed to provide an initial fitness evaluation tool that allows patients to adapt the EP to their fitness level. Current general exercise recommendations for people living with chronic conditions have been analyzed to develop the present home-based EP proposal.

Longitudinal study of physical activity with various methods in maintenance hemodialysis patients

INTRODUCTION

The purpose was to make longitudinal measurements of physical activity and study whether physical activity decreases over time in maintenance hemodialysis (MHD) patients.

METHODS

This was an observational study, where MHD patients were considered in a 12-month follow-up. Laboratory variables and physical activity were tested three times over 12-months in 124 hemodialysis patients. Physical activity was measured using the Human Activity Profile (HAP), the Stanford 7-day Physical Activity Recall Questionnaire (PAR), and walking speed. Repeated measure variance analysis was used to analyze changes of physical activity. The Bonferroni method was used to do pairwise comparisons.

FINDINGS

The proportion of decreased physical activity increased (P < 0.05). The maximal activity score (MAS), adjusted activity score (AAS), HAP dimension scores, and walking speed all decreased at the three time points studied (P < 0.001). At the same time, moderate physical activities and PAR values changed at three time points (P < 0.05). Pairwise comparisons showed that between the baseline and the 6-month follow-up, MAS, AAS, the scores of personal/household work, entertainment/social, independent exercise, leg effort, and back effort, all decreased(P < 0.05). Between the baseline and the 12-month follow-up, and between the 6-month follow-up and the 12-month follow-up, all the scores of HAP and walking speed decreased significantly (P < 0.001). Between the baseline and the 6-month follow-up, moderate physical activities and PAR values increased (P < 0.05). However, between the baseline and the 12-month follow-up, and between the 6-month follow-up and the 12-month follow-up, moderate physical activities and PAR did not change statistically.

CONCLUSION

Physical activity decreased in hemodialysis patients in the 12-month follow-up.

The Effects of Chronic Dialysis on Physical Status, Quality of Life, and Arterial Stiffness: A Longitudinal Study in Prevalent Dialysis Patients

INTRODUCTION

It is widely known that dialysis patients have significantly impaired functional outcomes and arterial stiffness, but still few studies have investigated the effects of dialysis longitudinally by a multidimensional approach. We aimed to assess longitudinal patterns of physical activity (PA), physical functioning (PF), health-related quality of life (HrQoL), body composition (BC), and arterial stiffness in prevalent dialysis patients.

MATERIALS AND METHODS

Thirty-nine prevalent dialysis patients (23 conventional hemodialysis [CHD] and 16 peritoneal dialysis) with a mean vintage of 25.7 (±22.1) months were included in this observational prospective study with a 2-year follow-up, and at baseline 20 healthy controls were included. Measurements were performed every 6 months. HrQoL was assessed using the Short Form-36 (SF-36) questionnaire. PA was assessed using the SenseWear™ Pro3 accelerometer. PF was assessed by walking speed, the PF subscale of the SF-36, and handgrip strength (HGS). BC was assessed using the Body Composition Monitor® and arterial stiffness by measuring carotid-femoral pulse wave velocity (PWV). The longitudinal trend was assessed using linear mixed models, correcting for sex, age, and dialysis vintage. For PWV, the trend was additionally corrected for diabetes and systolic blood pressure.

RESULTS

After correction, no statistically significant changes over time were observed for the parameters of PA, PF, HrQoL, and BC. In the combined group and in the group of CHD patients only, a significant change was observed for PWV (overall trend: p = 0.007 and p = 0.008, respectively). A statistically significant difference at baseline was observed between dialysis patients and healthy controls in all parameters, except for HGS and PWV.

DISCUSSION/CONCLUSION

We observed no statistically significant changes in functional outcomes during a 2-year follow-up period, but a significant increase was observed for arterial stiffness. These results might suggest that after a certain period in time, a relatively stable course is present in functional outcomes, but an ongoing deterioration in arterial stiffness occurs, which might increase the risk of cardiovascular disease and all-cause mortality in these patients.

A longitudinal study of the effects of age, sex and race on body composition in chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is characterized by accelerated aging, but the age-related changes in body composition and its modification by sex and race are unclear.

METHODS

We assembled a cohort of 516 patients with CKD and 45 healthy controls and serially measured body composition using air-displacement plethysmography for up to 6 years. Mixed models were used to evaluate simultaneously the baseline and longitudinal changes in body composition as influenced by age, sex and race.

RESULTS

Compared with healthy controls, patients with CKD had a greater weight, body mass index (BMI), fat mass (FM) and percent body fat (BF%), but the changes over time in body composition were similar. Older age (>60 years) was a strong determinant of loss of weight, BMI, FM and fat-free mass (FFM), but not BF%. Compared with non-blacks, blacks had a higher FFM at baseline, but they lost FFM more rapidly. Compared with women, men had an accelerated loss of FFM and accumulation of FM. Taking interactions into account, we found that young black men had no significant change in weight due to the loss of FFM and the accumulation of FM, thereby masking obesity by conventional measurements.

CONCLUSION

Among patients with CKD, the changes in body composition are influenced by age, sex and race. Young black men have changes in body composition that may remain undetectable by conventional methods thus masking the occurrence of obesity.

Risk Factors for Muscle Loss in Hemodialysis Patients with High Comorbidity

With expanding kidney transplantation programs, remaining hemodialysis patients are more likely to have a high comorbidity burden and may therefore be more prone to lose muscle mass. Our aim was to analyze risk factors for muscle loss in hemodialysis patients with high comorbidity. Fifty-four chronic hemodialysis patients (Charlson Comorbidity Index 9.0 ± 3.4) were followed for 20 weeks using 4-weekly measurements of lean tissue mass, intracellular water, and body cell mass (proxies for muscle mass), handgrip strength (HGS), and biochemical parameters. Mixed models were used to analyze covariate effects on LTM. LTM (-6.4 kg, interquartile range [IQR] -8.1 to -4.8), HGS (-1.9 kg, IQR -3.1 to -0.7), intracellular water (-2.11 L, IQR -2.9 to -1.4) and body cell mass (-4.30 kg, IQR -5.9 to -2.9) decreased in all patients. Conversely, adipose tissue mass increased (4.5 kg, IQR 2.7 to 6.2), resulting in no significant change in body weight (-0.5 kg, IQR -1.0 to 0.1). Independent risk factors for LTM loss over time were male sex (-0.26 kg/week, 95% CI -0.33 to -0.19), C-reactive protein above median (-0.1 kg/week, 95% CI -0.2 to -0.001), and baseline lean tissue index ³10th percentile (-1.6 kg/week, 95% CI -2.1 to -1.0). Age, dialysis vintage, serum albumin, comorbidity index, and diabetes did not significantly affect LTM loss over time. In this cohort with high comorbidity, we found universal and prominent muscle loss, which was further accelerated by male sex and inflammation. Stable body weight may mask muscle loss because of concurrent fat gain. Our data emphasize the need to assess body composition in all hemodialysis patients and call for studies to analyze whether intervention with nutrition or exercise may curtail muscle loss in the most vulnerable hemodialysis patients.

PhysIOpathology of NEuromuscular function rElated to fatigue in chronic Renal disease in the elderly (PIONEER): study protocol

BACKGROUND

Chronic Kidney Disease (CKD) is associated with reduced muscular strength resulting in profound fatigue. The physiopathology of these changes, their prevalence and evolution are still debated. Moreover, we have little data on elderly CKD patients. The present study protocol aims to 1) quantify the prevalence of low muscle strength (dynapenia) in a cohort of elderly patients with advanced CKD and to 2) characterize their force production coupled with electromyographic features and the symptoms of fatigue compared to a matched control group.

METHODS

This is a case-control, prospective, interventional study.

INCLUSION CRITERIA

age ≥ 60 years; CKD Stage 3b-5; clinical stability (i.e. no hospitalization and ≤ 25% in creatinine increase in the previous 3 months). Controls with normal kidney function will be matched in terms of age, gender and diabetes mellitus (requisite: estimated glomerular filtration rate ≥ 60 ml/min/1.73m² available in the last 6 months). Exclusion criteria for cases and controls: neuromuscular disease, life expectancy < 3 months. The handgrip strength protocol is an intermittent test consisting in 6 series of 9 repetitions of 3-s sub-maximum contractions at 40% of the maximum voluntary contraction (MVC) and 2 s of resting time between contractions. Each series is separated by one fast sub-maximum contraction and one MVC. Strength is assessed with a high-frequency handgrip dynamometer paired with surface electromyography. Symptoms of fatigue are assessed using MFI-20 and FACIT-F questionnaires. In order to reach a statistical power of 96%, we plan to enroll 110 subjects in each group.

DISCUSSION

The novelty of this study resides in the application of an already validated set of tests in a population in which this combination (dynamometer, electromyography and questionnaires) has not previously been explored. We expect a high prevalence of dynapenia and a higher fatigability in CKD patients. A positive correlation is expected between reported fatigue and fatigability. Better appreciation of the prevalence and the relationship between fatigability and a sensation of fatigue can help us target interventions in CKD patients to improve quality of life and survival.

TRIAL REGISTRATION

The study was approved by Ethical Committee EST III n°20.03.01 and was recorded as a Clinical Trial (NCT04330807) on April 2, 2020.

Exercise Capacity in Pediatric Patients with End-Stage Renal Disease

Objective

To evaluate the correlation between exercise capacity and hemoglobin in pediatric patients with end-stage renal disease (ESRD) treated with automated peritoneal dialysis (APD) and hemodialysis.

Design

Prospective case-control study and retrospective review.

Setting

Dialysis summer camp and Children's Mercy Hospital exercise laboratory.

Participants

Prospective evaluation conducted with 14 patients (9 males, mean age 14.5 ± 2.5 years) who received either home APD (5 patients) or in-center hemodialysis (9 patients), and 8 healthy age-matched controls. Retrospective data derived from 10 children (7 males, mean age 12.3 ± 3.3 years), all of whom received APD.

Intervention

Maximal treadmill evaluation conducted with each patient and control. The hemoglobin value of each patient was also assessed.

Main Outcome Measures

Comparison of the following data generated during treadmill protocol: peak heart rate, blood pressure, oxygen saturation, treadmill time, oxygen consumption (VO2), ventilation (Ve), oxygen consumption at anaerobic threshold (VO2 AT), and respiratory exchange ratio.

Results

The hemoglobin value of the current patient group (12.8 ± 1.6 g/dL) was significantly greater than the previously studied patients (10.5 ± 1.1 g/dL) ( p = 0.001). Treadmill time, VO2, and VO2 AT were significantly lower in both groups of dialysis patients compared to the control subjects ( p < 0.05). No differences were noted in any of these variables when comparing these two groups of dialysis patients only.

Conclusion

The exercise capacity of pediatric dialysis patients is significantly poorer than that of healthy children, an outcome apparently related to factors other than normalization of the hemoglobin value.

Improved Outcomes in Hemodialysis/Hemodiafiltration Treatments Applying Exercise and Physiological Monitoring Techniques: Preliminary Results

End-stage renal disease affects millions of people worldwide, and the only definitive solutions are renal transplants that are not widely available. Temporary solutions are renal replacement therapies such as peritoneal dialysis, hemodialysis and hemodiafiltration. These therapies as they are applied today are just partial measures and have many drawbacks and complications such as high mortality rates and high costs due to the use of supplemental drugs and emergency room visits. Many enhancements to the therapies have been published, but they are not applied consistently in real world practice. Our work presents the results from the systematic application of several techniques to provide individualized therapies that can minimize the drawbacks and improve patient outcomes. This approach is based on the use of exercise, analysis of cardiovascular parameters, such as heart-rate variability, body composition and dry weight measurements through the use of bioimpedance and real-time monitoring of energy expenditure and nutrition intradialytically in order to provide individualized and dynamically variable therapies. Results show that patients can lead long, productive lives while maintaining a quality of life equivalent to that of a renal transplant.

Adherence to the Mediterranean Diet, Dietary Patterns and Body Composition in Women with Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common female endocrine disorder and is characterized by chronic anovulation, hyperandrogenism, and polycystic ovaries. Obesity, low-grade chronic inflammatory status, and insulin-resistance (IR) often coexist in PCOS. The Mediterranean diet (MD) is an anti-inflammatory dietary pattern, which is rich in complex carbohydrates and fiber, and high in monounsaturated fat. There is a close association among obesity, low-grade chronic inflammation, IR, and hormonal derangements in PCOS. The main aim of the present study was to evaluate the adherence to MD, the dietary intake, and the body composition and their association with PCOS clinical severity in a cohort of treatment-naïve women with PCOS when compared with a control group of healthy women matched for age and body mass index (BMI). In this case-controlled, cross-sectional study, we enrolled 112 patients with PCOS and 112 controls. PREvención con DIetaMEDiterránea (PREDIMED) and seven-day food records were used to evaluate the degree of adherence to the MD and dietary pattern, respectively. Body composition was evaluated by bioelectrical impedance analysis (BIA) phase-sensitive system. Testosterone levels and Ferriman-Gallwey score assessed the clinical severity of PCOS. C-reactive protein (CRP) levels were determined with a nephelometric assay with CardioPhase high sensitivity. PCOS women showed higher testosterone levels, Ferriman-Gallwey score, fasting insulin and glucose levels, and Homeostatic Model Assessment (HoMA)-IR when compared with the control group (p < 0.001). In addition, we found that the PCOS women consumed less extra-virgin olive oil, legumes, fish/seafood, and nuts compared with control group. Despite no differences in energy intake between the two groups, the PCOS women consumed a lower quantity of complex carbohydrate, fiber, monounsaturated fatty acids (MUFA), and n-3 polyunsaturated fatty acid (PUFA), and higher quantity of simple carbohydrate, total fat, saturated fatty acid (SFA), PUFA and n-6 PUFA than the control group. The PCOS women have an adverse body composition when compared with controls, with the lowest values of phase angle (PhA) and fat-free mass (p < 0.001). Additionally, after adjusting for BMI and total energy intake, testosterone levels showed significant negative correlations with PREDIMED score (p < 0.001) and consumption of protein (p = 0.005), complex carbohydrate (p < 0.001), fiber (p < 0.001), MUFA (p < 0.001), n-3 PUFA (p = 0.001), and positive associations with CRP levels, simple carbohydrate, SFA, n-6 PUFA (p < 0.001, respectively), and PUFA (p = 0.002). The cut-off for PREDIMED score ≤ 6 (p < 0.001, area under the curve (AUC) 0.848, standard error 0.036, 95% confidence interval (CI) 0.768 to 0.909) could serve as a threshold for significantly increased risk of high value of testosterone levels. In conclusion, a novel direct association between the adherence to MD and the clinical severity of the disease was reported in women with PCOS. This association could support a therapeutic role of foods and nutrients of the Mediterranean dietary pattern in the PCOS pathogenesis likely involving their inflammatory status, IR, and hyperandrogenemia. In addition, we reported a different body composition that is characterized by lower PhA and fat-free mass than controls. These data suggested a role of PhA as a useful marker of the clinical severity of this syndrome and provided strong evidence regarding the strategic relevance of the nutritional assessment in the management of women with PCOS.

Does inflammation affect outcomes in dialysis patients?

Chronic, low-grade inflammation is a common comorbid condition in chronic kidney disease (CKD), and particularly in chronic dialysis patients. In this review, we consider the question of whether inflammation affects outcomes in dialysis patients. Levels of proinflammatory cytokines, as well as C-reactive protein, are elevated in chronic dialysis patients. Multiple factors likely contribute to chronic inflammatory activation in kidney disease patients including the uremic milieu, lifestyle and epigenetic influences, infectious and thrombotic events, the dialysis process, and dysbiosis. Increased inflammatory markers in both CKD and chronic dialysis patients are associated with adverse clinical outcomes including all-cause mortality, cardiovascular events, kidney disease progression, protein energy wasting and diminished motor function, cognitive impairment, as well as other adverse consequences including CKD-mineral and bone disorder, anemia, and insulin resistance. Strategies that have been shown to reduce chronic systemic inflammation in CKD and chronic dialysis patients include both pharmacological and nonpharmacological interventions. However, despite evidence that systemic inflammatory markers can be lowered in kidney disease patients treated with various strategies, evidence that this improves clinical outcomes is largely unavailable and represents an important future research direction. Overall, there is strong observational evidence that inflammation is high in chronic dialysis patients and that this is independently associated with numerous adverse clinical outcomes. Targeting inflammation represents a potentially novel and attractive strategy if it can indeed improve adverse outcomes common in this population.

Exploring the Clinical Relevance of Providing Increased Removal of Large Middle Molecules

Dialysis technologies have continued to advance over recent decades; however, these advancements have not always been met with improved patient outcomes. In part, the high morbidity and mortality associated with dialysis have been attributed to a group of uremic toxins, which are described as "difficult to remove." With a new generation of hemodialysis membranes now making meaningful clearance of these molecules possible, it is an apt time to review the clinical relevance of these middle molecules. Our review describes the developments in membrane technology that enable the removal of large middle molecules (molecular mass >15 kD) that is limited with high-flux dialysis membranes. Of the known 58 middle molecules, a literature search identified 27 that have molecular mass >15 kD. This group contains cytokines, adipokines, hormones, and other proteins. These molecules are implicated in chronic inflammation, atherosclerosis, structural heart disease, and secondary immunodeficiency in the literature. Single-center safety and efficacy studies have identified that use of these membranes in maintenance dialysis populations is associated with limited loss of albumin and increased clearance of large middle molecules. Larger, robustly conducted, multicenter studies are now evaluating these findings. After completion of these safety and efficacy studies, the perceived clinical benefits of providing clearance of large middle molecules must be assessed in rigorously conducted, randomized clinical studies.

A low phase angle measured with bioelectrical impedance analysis is associated with osteoporosis and is a risk factor for osteoporosis in community-dwelling people: the Yakumo study

Although the phase angle has been reported to be related to predictive factors and therapeutic effects in various diseases, its relation with osteoporosis is unclear. In our large prospective survey of community-dwelling people, a low phase angle was related with osteoporosis, and it could be a predictor of osteoporosis.

PURPOSE

The phase angle measured with bioelectrical impedance analysis (BIA) is one of the clinically important impedance parameters, and it is a predictor of prognosis and mortality for several diseases. The present cross-sectional study aimed to elucidate the association between osteoporosis and variables measured with BIA, including the phase angle.

METHODS

The study included 307 participants from an annual health checkup. All participants underwent measurement of bone status by quantitative ultrasound and body composition by BIA. Osteoporosis was diagnosed according to the WHO classification, and statistical comparisons were conducted between normal individuals and osteoporosis patients.

RESULTS

Age, proteins, minerals, and the phase angle were significantly different between normal individuals and osteoporosis patients (p < 0.001). Furthermore, after controlling for age and sex, proteins, minerals, and the phase angle were significantly lower in osteoporosis patients than those in normal individuals (p < 0.001). In multivariate logistic regression analysis, older age and a low phase angle were risk factors for osteoporosis. Additionally, multiple regression analysis showed that age, sex, proteins, minerals, and the appendicular skeletal muscle index were significantly related to the phase angle.

CONCLUSIONS

The phase angle is a predictor of osteoporosis, which is unaffected by age and sex, and a lower phase angle is associated with greater probability of osteoporosis. The phase angle can be easily measured, and osteoporosis can be confirmed even at home. This may facilitate early diagnosis and treatment, which may be useful for preventing diseases related to osteoporosis.

Muscle Atrophy in Chronic Kidney Disease

The renal damage and loss of kidney function that characterize chronic kidney disease (CKD) cause several complex systemic alterations that affect muscular homeostasis, leading to loss of muscle mass and, ultimately, to muscle atrophy. CKD-induced muscle atrophy is highly prevalent and, in association with common CKD comorbidities, is responsible for the reduction of physical capacity, functional independence, and an increase in the number of hospitalizations and mortality rates. Thus, this chapter summarizes current knowledge about the complex interactions between CKD factors and the pathophysiological mechanisms that induce muscle atrophy that, despite growing interest, are not yet fully understood. The current treatments of CKD-induced muscle atrophy are multidisciplinary, including correction of metabolic acidosis, nutritional supplementation, reducing insulin resistance, administration of androgenic steroids, resisted and aerobic exercise, neuromuscular electrical stimulation, and inspiratory muscle training. However, further studies are still needed to strengthen the comprehension of CKD-induced muscle atrophy and the better treatment strategies.

Physical performance and protein-energy wasting in patients treated with nocturnal haemodialysis compared to conventional haemodialysis: protocol of the DiapriFIT study

BACKGROUND

Poor physical performance and protein-energy wasting (PEW) are health issues of major concern in haemodialysis patients. The conventional haemodialysis (CHD) regime, three times per week 3-5 h, is subject of discussion because of high morbidity and mortality rates. When patients switch from CHD to longer dialysis sessions, i.e. nocturnal haemodialysis (NHD), improvement in protein intake and increase in body weight is seen. However, it is unclear whether physical performance and more important aspects of PEW, such as body composition, improve as well. Therefore, the aim of this study is to investigate whether physical performance improves and PEW decreases, when patients switch from CHD to NHD. A second aim is to assess the influence of NHD on the biomarkers fibroblast growth factor-23 and sclerostin which are thought to be associated with malnutrition and mortality in patients on haemodialysis.

METHODS

This study is a prospective multicentre cohort study with an inclusion aim of 50 patients: 25 patients in a control group (three times per week, 3-5 h CHD) and 25 patients in a nocturnal group (three times per week, 7-9 h NHD). Primary outcome is change in physical performance, measured by the Short Physical Performance Battery. Additional measurements are a 6-min walk test, handgrip strength, a physical activity questionnaire and physical activity monitoring. The secondary outcome of the study is PEW, which will be evaluated by body weight, dual-energy X-ray absorptiometry, bio-electrical impedance spectroscopy, mid-upper arm muscle circumference, subjective global assessment, visual analogue scale for appetite and dietary records. Laboratory measurements including fibroblast growth factor-23 and sclerostin, and quality of life assessed with the Kidney Disease Quality of Life-Short Form are also studied. In every patient, four repeated measurements will be performed during one year of follow-up.

DISCUSSION

This study will investigate whether physical performance improves and PEW decreases when patients switch from CHD to NHD, compared to a control group who continue treatment with CHD. Strengths of this study are the comparison with a conventional haemodialysis cohort, and the broad variety of objective measurements combined with patient-reported outcomes of physical performance and PEW.

TRIAL REGISTRATION

NTR4715 , Netherlands Trial Register. Registered 30 July 2014.

Predicting clinical outcomes using phase angle as assessed by bioelectrical impedance analysis in maintenance hemodialysis patients

OBJECTIVE

Protein-energy wasting is common in patients on hemodialysis and is an independent risk factor for adverse events. The aim of this study was to retrospectively investigate whether phase angle (PA), known as a nutritional marker, can predict various clinical outcomes in patients with end-stage renal disease (ESRD) who are receiving hemodialysis.

METHODS

Using bioelectrical impedance analysis (BIA), PA was obtained every 6 mo, and patients were divided into two groups according to baseline PA: group A included patients with PA ≥4.5°, and group B included patients with PA <4.5°.

RESULTS

We followed 142 patients for a median of 29 mo (12-42 mo). We found that a decrease in PA was associated with an increased risk for death that persisted after adjusting for age, sex, and comorbidities (hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.33-0.97). Cardiovascular events were not associated with PA (P = 0.685). We found that PA predicted the occurrence of infection, independent of age, sex, and comorbidities (HR, 0.65; 95% CI, 0.45-0.94). Although levels of hemoglobin did not differ between groups during the study period, patients in group B received higher doses of erythropoiesis-stimulating agents and intravenous iron than those in group A (P = 0.004 and 0.044, respectively). In longitudinal analyses, we did not find increases in PA over time in patients who had a mean dialysis adequacy ≥1.4, daily protein catabolic rate ≥1.2 g/kg, or total carbon dioxide level ≥22 mmol/L.

CONCLUSIONS

PA assessed in a simple manner using BIA provides practical information to predict clinical outcomes in ESRD patients on maintenance hemodialysis.

Longitudinal bioimpedance vector plots add little value to fluid management of peritoneal dialysis patients

Bioimpedance (BI) has the potential to enable better management of fluid balance, which can worsen over time on peritoneal dialysis (PD) due to loss of residual kidney function and progressive muscle wasting. We undertook a prospective, randomized, open-label, blinded end-point controlled trial to determine whether availability of longitudinal BI measures as vector plots helped clinicians maintain stable fluid status over 12 months in 308 peritoneal dialysis patients from the United Kingdom and Shanghai, China. Patients were recruited into 4 groups nested within a single trial design according to country and residual kidney function. Nonanuric subjects from both countries demonstrated stable fluid volumes irrespective of randomization. Hydration worsened in control anuric patients in Shanghai with increased extracellular/total body water (ECW/TBW) ratio (0.04; 95% CI: 0.01, 0.06) and reduced TBW (-1.76 L 95% CI: -2.70, -0.82), but was stable in the BI intervention group whose dialysate glucose prescription was increased. However, multilevel analysis incorporating data from both countries showed worsening ECW/TBW in active and control anuric patients. Clinicians in the United Kingdom reduced target weight in the nonanuric BI intervention group causing a reduction in TBW without beneficial effects on ECW or blood pressure. Thus, routine use of longitudinal BI vector plots to improve clinical management of fluid status is not supported.

Levocarnitine and Dialysis: A Review

Among the various metabolic abnormalities documented in dialysis patients are abnormalities related to the metabolism of fatty acids. Aberrant fatty-acid metabolism has been associated with the promotion of free-radical production, insulin resistance, and cellular apoptosis. These processes have been identified as important contributors to the morbidity experienced by dialysis patients. There is evidence that levocarnitine supplementation can modify the deleterious effects of defective fatty-acid metabolism. Patients receiving hemodialysis and, to a lesser degree, peritoneal dialysis have been shown to be carnitine deficient, as manifested by reduced levels of plasma free carnitine and an increase in the acyl:free carnitine ratio. Cardiac and skeletal muscles are particularly dependent on fatty-acid metabolism for the generation of energy. A number of clinical abnormalities have been correlated with a low plasma carnitine status in dialysis patients. Clinical trials have examined the efficacy of levocarnitine therapy in a number of conditions common in dialysis patients, including skeletal-muscle weakness and fatigue, cardiomyopathy, dialysis-related hypotension, hyperlipidemia, and anemia poorly responsive to recombinant human erythropoietin therapy (rHuEPO). This review examines the evidence for carnitine deficiency in patients requiring dialysis, and documents the results of relevant clinical trials of levocarnitine therapy in this population. Consensus recommendations by expert panels are summarized and contrasted with present guidelines for access to levocarnitine therapy by dialysis patients.

Changes in Body Composition in the Two Years after Initiation of Haemodialysis: A Retrospective Cohort Study

Malnutrition is common in haemodialysis (HD) and is linked to poor outcomes. This study aimed to describe changes in body composition after the initiation of HD and investigate whether any routinely collected parameters were associated with these changes. The study cohort came from the HD population of a single centre between 2009 and 2014. Body composition measurements were obtained from a database of bioimpedance results using the Body Composition Monitor (BCM), while demographics and laboratory values came from the renal unit database. Primary outcomes were changes in normohydration weight, lean tissue mass and adipose tissue mass over the two years after HD initiation. A total of 299 patients were included in the primary analyses, showing an increase in adipose tissue, loss of lean tissue and no significant change in normohydration weight. None of the routinely collected parameters were associated with the lean tissue changes. Loss of lean tissue over the first year of dialysis was associated with increased mortality. The results showing loss of lean tissue that is not limited to those traditionally assumed to be at high risk supports interventions to maintain or improve lean tissue as soon as possible after the initiation of HD. It highlights the importance of monitoring nutrition and the potential for routine use of bioimpedance.

Evaluation of Exercise Tolerance in Dialysis Patients Performing Tai Chi Training: Preliminary Study

Introduction. Patients with end-stage renal disease (ESRD) have poor physical performance and exercise capacity due to frequent dialysis treatments. Tai Chi exercises can be very useful in the area of rehabilitation of people with ESRD. Objectives. The aim of the study was to assess exercise capacity in ESRD patients participating in 6-month Tai Chi training. Patients and Methods. Twenty dialysis patients from Wroclaw took part in the training; at the end of the project, 14 patients remained (age 69.2 ± 8.6 years). A 6-minute walk test (6MWT) and spiroergometry were performed at the beginning and after 6 months of training. Results. After 6 months of Tai Chi, significant improvements were recorded in mean distance in the 6MWT (387.89 versus 436.36 m), rate of perceived exertion (7.4 versus 4.7), and spiroergometry (8.71 versus 10.08 min). Conclusions. In the ESRD patients taking part in Tai Chi training, a definite improvement in exercise tolerance was recorded after the 6-month training. Tai Chi exercises conducted on days without dialysis can be an effective and interesting form of rehabilitation for patients, offering them a chance for a better quality of life and fewer falls and hospitalisations that are the result of it.

Nutrition assessment and its effect on various clinical variables among patients undergoing liver transplant

BACKGROUND

Malnutrition is highly prevalent in patients undergoing liver transplantation and has been associated to various clinical variables and outcome of the surgery.

METHODS

We recruited 54 adult patients undergoing living donor liver transplant (LT) as study sample. Nutrition assessment was performed by body mass index (BMI), BMI for ascites, albumin, subjective global assessment (SGA) and anthropometry [mid upper arm circumference (MUAC), mid arm muscle circumference (MAMC), and triceps skin-fold (TSF)], Hand Grip strength, and phase angle of the body. Prevalence and comparison of malnutrition was performed with various clinical variables: aetiology, Child Turcotte Pugh scores and model for end stage liver disease (ESLD) grades, degree of ascites, blood product usage, blood loss during the surgery, mortality, days [intensive care unit (ICU), Ventilator and Hospital], and Bio-impedance analysis [weight, fat mass, fat free mass (FFM), muscle mass and body fat%].

RESULTS

Assessment of nutrition status represents a major challenge because of complications like fluid retention, hypoalbuminemia and hypoproteinemia. Different nutrition assessment tools show great disparity in the level of malnutrition among ESLD patients. In the present study recipient nutrition status evaluation by different nutrition assessment tools used showed malnutrition ranging from 3.7% to 100%. BMI and anthropometric measurements showed lower prevalence of malnutrition than phase angle and SGA whereas hand grip strength showed 100% malnutrition. Agreement among nutrition assessment methods showed moderate agreement (κ=0.444) of SGA with phase angle of the body. Malnutrition by different assessment tools was significantly associated to various clinical variables except MELD and days (ICU, Ventilator and Hospital). SGA was significantly (P<0.05) associated to majority of the clinical variables like aetiology, child Turcotte Pugh grades, degree of ascites, blood product usage, blood loss during the surgery, BIA (fat mass, FFM, muscle mass and body fat%).

CONCLUSIONS

The different nutrition assessment tools showed great variability of results. SGA showed moderate agreement with phase angle of the body and was associated with various clinical and prognostic variables of liver transplantation.

Nutritional Status in Nocturnal Hemodialysis Patients - A Systematic Review with Meta-Analysis

Background

Hemodialysis patients experience an elevated risk of malnutrition associated with increased morbidity and mortality. Nocturnal hemodialysis (NHD) results in more effective removal of waste products and fluids. Therefore, diet and fluid restrictions are less restricted in NHD patients. However, it is ambiguous whether transition from conventional hemodialysis (CHD) to NHD leads to improved intake and nutritional status. We studied the effect of NHD on protein intake, laboratory indices of nutritional status, and body composition.

Study design

Systematic review with meta-analysis.

Population

NHD patients.

Search strategy

Systematic literature search from databases, Medline, Cinahl, EMBASE and The Cochrane Library, to identify studies reporting on nutritional status post-transition from CHD to NHD.

Intervention

Transition from CHD to NHD.

Outcomes

Albumin, normalized protein catabolic rate (nPCR), dry body weight (DBW), body mass index (BMI), phase angle, protein intake, and energy intake.

Results

Systematic literature search revealed 13 studies comprising 282 patients that made the transition from CHD to NHD. Meta-analysis included nine studies in 229 patients. In control group controlled studies (n = 4), serum albumin increased significantly from baseline to 4–6 months in NHD patients compared with patients that remained on CHD (mean difference 1.3 g/l, 95% CI 0.02; 2.58, p = 0.05). In baseline controlled studies, from baseline to 4–6 months of NHD treatment, significant increases were ascertained in serum albumin (mean difference (MD) 1.63 g/l, 95% CI 0.73–2.53, p<0.001); nPCR (MD 0.16 g/kg/day; 95% CI 0.04–0.29, p = 0.01); protein intake (MD 18.9 g, 95% CI 9.7–28.2, p<0.001); and energy intake (MD 183.2 kcal, 95% CI 16.8–349.7, p = 0.03). Homogeneity was rejected only for nPCR (baseline versus 4–6 months). DBW, BMI, and phase angle did not significantly change. Similar results were obtained for comparison between baseline and 8–12 months of NHD treatment.

Limitations

Most studies had moderate sample sizes; some had incomplete dietary records and relatively brief follow-up period. Studies markedly differed with regard to study design.

Conclusions

NHD is associated with significantly higher protein and energy intake as well as increases in serum albumin and nPCR. However, the data on body composition are inconclusive.

Bioelectrical phase angle and psoriasis: a novel association with psoriasis severity, quality of life and metabolic syndrome

BACKGROUND

Obesity, metabolic syndrome (MetS), and psoriasis, largely driven by environmental factors, show multiple bidirectional associations, with important metabolic implications in psoriatic patients. Besides body mass index (BMI) as a measure of obesity, data on phase angle (PhA), a direct measure by bioelectrical impedance analysis (BIA), used as a marker of cellular health and a predictor of morbidity and mortality in various diseases, are still lacking in psoriasis. In this case-control, cross-sectional study, we investigated the PhA in 180 pairs of adult psoriatic patients and healthy controls, evaluating also the potential use of the PhA as marker of the clinical severity, the quality of life, and the presence of the MetS in psoriatic patients.

METHODS

Anthropometric measures, metabolic profile and bioelectrical variables were evaluated. The clinical severity was assessed by standardized psoriasis area and severity index (PASI) score and c-reactive protein (CRP) levels, and the quality of life was evaluated by dermatology life quality index (DLQI). MetS was diagnosed according to Adult Treatment Panel III.

RESULTS

Psoriatic patients presented smaller PhA (p < 0.001) and higher prevalence MetS compared with controls. The PhA was significantly associated with number of parameters of MetS in both groups (p < 0.001). After adjusting for BMI, this association remained significant in psoriatic patients only (p < 0.001). Among psoriatic patients, the PhA was the major index value for the diagnosis of MetS (OR 5.87, 95 % CI 5.07-6.79) and was inversely associated with both PASI score and DLQI, independently of BMI (p < 0.001). At multiple regression analysis, the PhA well predicted the PASI score and DLQI. Based on ROC curves, the most sensitive and specific cutoffs of PhA to predict the highest PASI score and the lowest DQLI were ≤4.8° and ≤4.9°, respectively.

CONCLUSIONS

We reported that psoriatic patients presented small PhAs, with a novel association between PhA, clinical severity, quality of life in psoriatic patients, and MetS. Further studies are required to validate the PhA's prognostic ability in assessing the clinical severity and MetS in psoriatic patients.

Factors associated with leisure-time physical activity among patients undergoing hemodialysis

BACKGROUND

End-stage renal disease patients are characterized by low levels of physical activity, especially during leisure time. However, the recognition of variables associated with patterns of physical activity in this population has been little explored. Thus, the objective was to assess factors associated with levels of physical activity during leisure time among patients on haemodialysis.

METHODS

Ninety-eight patients (51.6 ± 15.7 years, 57 M/41 F) from two dialysis centres in São Paulo, Brazil participated in this cross-sectional study. Participants were divided into those who never exercised during leisure-time (inactive) and those who exercised at least once a week (active). The independent factors assessed were: socio-demographic data, comorbidities, personal barriers to exercise and physical activity records from childhood to adulthood (tracking of physical activity).

RESULTS

Only 27 % of patients were engaged in PA during their leisure time at least once a week. Patients who engaged in regular physical activity during adulthood before the initiation of the hemodialysis treatment (adjusted OR: 7.24 95 % IC: 1.99; 26.50), those who developed the renal disease through diseases other than diabetes or hypertension (adjusted OR: 4.82; 95 % IC: 1.48; 15.68), and those who had no cardiovascular diseases (adjusted OR: 11.33; 95 % IC: 1.23; 103.8) where more likely to be active during their leisure-time.

CONCLUSION

Comorbidities such as cardiovascular disease, hypertension and diabetes mellitus as well as the level of physical activity prior to end-stage renal disease could predict leisure-time physical activity among patients receiving hemodialysis therapy.

The Effects of Aquatic Exercises on Physical Fitness and Muscle Function in Dialysis Patients

Purpose. The aim of this study was to assess the impact of a 3-month physical training program, conducted in an aquatic environment with end-stage renal disease patients (ESRD), on the physical fitness and functional parameters of the knee joint muscles. Patients and Methods. The study included 20 ESDR patients with mean age 64.2 ± 13.1 y. treated with hemodialysis in Dialysis Center of the University Hospital in Wroclaw. Before and 3 months after the physical training in water, a test was performed to evaluate the physical fitness of each patient; additionally, a measurement was taken of force-velocity parameters. The 3-month training program took place on nonhemodialysis days, in the recreational pool of the University of Physical Education in Wroclaw. Results. After aquatic training cycle, an improvement was observed in all parameters measured using the Fullerton test. The value of peak torque and its relation to body mass increased in the movement of flexors and extensors of left and right lower extremities in all tested velocities. Conclusions. In assessing the physical fitness of studied women, the biggest improvement was achieved in tests assessing the strength of upper and lower extremities as well as lower body flexibility. Higher values of force-velocity parameters are conducive to women achieving better physical fitness test results.