Diagnostic accuracy of a 'sarcopenia index' based on serum biomarkers creatinine and cystatin C in 458,702 UK Biobank participants.

Background & Aims: There is an emerging and urgent need to identify biomarkers of sarcopenia. A novel sarcopenia index (SI), based on serum creatinine and cystatin C, has emerged as a potential biomarker for use. The SI can predict clinical outcomes and discriminate between the presence of sarcopenia in a range of chronic and acute conditions.

Skeletal Muscle Texture Assessment Using Ultrasonography: Comparison with Magnetic Resonance Imaging in Chronic Kidney Disease.

Skeletal muscle dysfunction is common in chronic kidney disease (CKD). Of interest is the concept of "muscle quality," of which measures include ultrasound-derived echo intensity (EI). Alternative parameters of muscle texture, for example, gray level of co-occurrence matrix (GCLM), are available and may circumvent limitations in EI.

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

Increasing evidence indicates that exercise has beneficial effects on chronic inflammation, cardiorespiratory function, muscle and bone strength and metabolic markers in adults with chronic kidney disease (CKD), kidney failure or kidney transplants. However, the mechanisms that underlie these benefits have received little attention, and the available clinical evidence is mainly from small, short-duration (<12 weeks) exercise intervention studies. The available data, mainly from patients with CKD or on dialysis, suggest that exercise-mediated shifts towards a less inflammatory immune cell profile, enhanced activity of the NRF2 pathway and reduced monocyte infiltration into adipose tissue may underlie improvements in inflammatory biomarkers.

Selecting Portable Ankle/Toe Brachial Pressure Index Systems for a Peripheral Arterial Disease Population Screening Programme: a Systematic Review, Clinical Evaluation Exercise, and Consensus Process.

Objective: To provide an overview of systems available for peripheral arterial disease (PAD) screening, together with respective accuracies and a clinical evaluation to identify a system suitable for use in a community screening programme.

Methods: A systematic review of the diagnostic accuracy of six ankle brachial pressure index (ABPI) and toe brachial pressure index (TBPI) devices deemed to be portable, which were Conformité Européenne (CE) marked, and were automated or semi-automated was carried out compared with gold standard handheld Doppler and duplex ultrasound. The devices were MESI-ABPI-MD, Huntleigh Dopplex Ability, Huntleigh ABPI and TBPI systems, Systoe TBPI system, and BlueDop.

The Effect of Non-Pharmacological and Pharmacological Interventions on Measures Associated with Sarcopenia in End-Stage Kidney Disease: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis provides a synthesis of the available evidence for the effects of interventions on outcome measures associated with sarcopenia in end-stage kidney disease (ESKD). Thirteen databases were searched, supplemented with internet and hand searching. Randomised controlled trials of non-pharmacological or pharmacological interventions in adults with ESKD were eligible.

Perceptions and Experiences of a Progressive Resistance Exercise Program in People with Chronic Kidney Disease.

Muscle wasting is highly prevalent in chronic conditions, such as chronic kidney disease (CKD), and can result in decreased physical functioning and strength, and impaired ability to perform daily tasks, thus impacting quality of life. Exercise, particularly resistance training, promotes a multitude of benefits, including prevention and management of muscle dysfunction; however, engagement in resistance training is poor. The aim of this study was to understand the views of people with CKD who participated in a research study evaluating a progressive resistance exercise program.

Inflammation and physical dysfunction: responses to moderate intensity exercise in chronic kidney disease.

Background: People with chronic kidney disease (CKD) experience skeletal muscle wasting, reduced levels of physical function and performance, and chronic systemic inflammation. While it is known that a relationship exists between inflammation and muscle wasting, the association between inflammation and physical function or performance in CKD has not been well studied. Exercise has anti-inflammatory effects, but little is known regarding the effect of moderate intensity exercise.

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

Background: Skeletal muscle wasting and dysfunction are common characteristics noted in people who suffer from chronic kidney disease (CKD). The mechanisms by which this occurs are complex, and although progress has been made, the key underpinning mechanisms are not yet fully elucidated. With work to date primarily conducted in nephrectomy-based animal models, translational capacity to our patient population has been challenging.

A Systematic Review of Handgrip Strength Measurement in Clinical and Epidemiological Studies of Kidney Disease: Toward a Standardized Approach.

In chronic kidney disease (CKD), handgrip strength (HGS) is recommended as a surrogate measure of protein-energy status and functional status. However, it is not routinely used because of inconsistencies such as the optimal timing of the HGS measurement and unclear guidance regarding technique. We aimed to determine the extent of variation in the protocols and methods of HGS assessment.

Muscle power and physical dysfunction: A model for tailoring rehabilitation in chronic kidney disease.

Introduction: Chronic kidney disease (CKD) is characterized by adverse physical function. Mechanical muscle power describes the product of muscular force and velocity of contraction. In CKD, the role of mechanical muscle power is poorly understood and often overlooked as a target in rehabilitation.

Association of sarcopenia with mortality and end-stage renal disease in those with chronic kidney disease: a UK Biobank study.

Background: Sarcopenia, a degenerative and generalized skeletal muscle disorder involving the loss of muscle function and mass, is an under-recognized problem in clinical practice, particularly in chronic kidney disease (CKD). We aimed to investigate the prevalence of sarcopenia in individuals with CKD, its risk factors, and its association with all-cause mortality and progression to end-stage renal disease (ESRD).

Methods: UK Biobank participants were grouped according to the presence of CKD (defined as an estimated glomerular filtration rate <60 mL/min/1.

Quantitative Muscle Ultrasonography Using 2D Textural Analysis: A Novel Approach to Assess Skeletal Muscle Structure and Quality in Chronic Kidney Disease.

Chronic kidney disease (CKD) is characterized by progressive reductions in skeletal muscle function and size. The concept of muscle quality is increasingly being used to assess muscle health, although the best means of assessment remains unidentified. The use of muscle echogenicity is limited by an inability to be compared across devices.

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

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

Methods: This is a secondary cross-sectional analysis of previously published interventional study, with in vitro follow up work.

Muscle-Bone Crosstalk in Chronic Kidney Disease: The Potential Modulatory Effects of Exercise.

Chronic kidney disease (CKD) is a prevalent worldwide public burden that increasingly compromises overall health as the disease progresses. Two of the most negatively affected tissues are bone and skeletal muscle, with CKD negatively impacting their structure, function and activity, impairing the quality of life of these patients and contributing to morbidity and mortality. Whereas skeletal health in this population has conventionally been associated with bone and mineral disorders, sarcopenia has been observed to impact skeletal muscle health in CKD.

Utility of Ultrasound as a Valid and Accurate Diagnostic Tool for Sarcopenia: Sex-Specific Cutoff Values in Chronic Kidney Disease.

Objectives: Patients with chronic kidney disease (CKD) have aberrant changes in body composition, including low skeletal muscle mass, a feature of "sarcopenia." The measurement of the (quadriceps) rectus femoris (RF) cross-sectional area (CSA) is widely used as a marker of muscle size. Cutoff values are needed to help discriminate the condition of an individual's muscle (eg, presence of sarcopenia) quickly and accurately.

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

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

Response of the oxygen uptake efficiency slope to exercise training in patients with chronic kidney disease.

Background: Chronic kidney disease (CKD) patients have poor cardiorespiratory fitness. Although cardiopulmonary exercise testing (CPET) is a universal assessment of cardiorespiratory fitness, values taken at 'peak' effort are strongly influenced by motivation and the choice of test endpoint. The oxygen uptake efficiency slope (OUES) integrates cardiovascular, musculoskeletal, and respiratory function into a single index to provide a more pragmatic and safer alternative to maximal testing.

Reductions in skeletal muscle mitochondrial mass are not restored following exercise training in patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) exhibit reduced exercise capacity, poor physical function and symptoms of fatigue. The mechanisms that contribute to this are not clearly defined but may involve reductions in mitochondrial function, mass and biogenesis. Here we report on the effect of non-dialysis dependent CKD (NDD-CKD) on mitochondrial mass and basal expression of transcription factors involved in mitochondrial biogenesis compared to a healthy control cohort (HC).

Skeletal muscle wasting in chronic kidney disease: the emerging role of microRNAs.

Skeletal muscle wasting is a common complication of chronic kidney disease (CKD), characterized by the loss of muscle mass, strength and function, which significantly increases the risk of morbidity and mortality in this population. Numerous complications associated with declining renal function and lifestyle activate catabolic pathways and impair muscle regeneration, resulting in substantial protein wasting. Evidence suggests that increasing skeletal muscle mass improves outcomes in CKD, making this a clinically important research focus.

Peak aerobic capacity from incremental shuttle walk test in chronic kidney disease.

Background: Assessment of cardiorespiratory fitness is an important outcome in chronic kidney disease (CKD). We aimed to develop a predictive equation to estimate peak oxygen uptake (VO ) and power output (W ), as measured during a cardiopulmonary exercise test (CPET), from the distance walked (DW) during the incremental shuttle walk test (ISWT).

Methods: Thirty-six non-dialysing patients with CKD [17 male, age: 61 ± 12 years, eGFR: 25±7 ml/min/1.

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

Background: Chronic kidney disease (CKD) is a catabolic condition associated with muscle wasting and dysfunction, which associates with morbidity and mortality. There is a need for simple techniques capable of monitoring changes in muscle size with disease progression and in response to interventions aiming to increase muscle mass and function. Ultrasound is one such technique; however, it is unknown how well changes in muscle cross-sectional area (CSA) measured using ultrasound relate to changes in whole muscle volume measured using magnetic resonance imaging.

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

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

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

Skeletal muscle wasting is a common feature of chronic kidney disease (CKD) and is clinically relevant due to associations with quality of life, physical functioning, mortality and a number of comorbidities. Satellite cells (SCs) are a population of skeletal muscle progenitor cells responsible for accrual and maintenance of muscle mass by providing new nuclei to myofibres. Recent evidence from animal models and human studies indicates CKD may negatively affect SC abundance and function in response to stimuli such as exercise and damage.

The association of physical function and physical activity with all-cause mortality and adverse clinical outcomes in nondialysis chronic kidney disease: a systematic review.

Objective: People with nondialysis-dependent chronic kidney disease (CKD) and renal transplant recipients (RTRs) have compromised physical function and reduced physical activity (PA) levels. Whilst established in healthy older adults and other chronic diseases, this association remains underexplored in CKD. We aimed to review the existing research investigating poor physical function and PA with clinical outcome in nondialysis CKD.

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

Objective: Chronic kidney disease patients are characterized by impaired physical function. The goal of exercise-based interventions is an improvement in functional performance. However, improvements are often determined by "statistically significant" changes.