Rationale and design of a randomized controlled clinical trial of functional electrical stimulation cycling in persons with severe multiple sclerosis

AbstractBackgroundThis randomized controlled trial (RCT) will examine the efficacy of supervised functional electrical stimulation (FES) cycling on walking performance and physiological function among persons with multiple sclerosis (MS) with severe mobility disability.Methods/designThis RCT will recruit 16 persons with MS that require unilateral or bilateral assistance for ambulation (i.e., Expanded Disability Status Scale (EDSS) score = 6.0–6.5). Participants will be randomized to one of two conditions: supervised FES cycling or passive cycling. The FES cycling condition will involve mild electrical stimulation that will generate an activation pattern that results in cycling the leg ergometer. The passive cycling condition will not provide any electrical stimulation, rather the movement of the pedals will be controlled by the electrical motor. Both conditions will be delivered 3 days/week for the same duration, over 6 months. Primary outcomes will include walking performance assessed as walking speed, endurance, and agility. Secondary outcomes will include physiological function assessed as cardiorespiratory fitness, muscular strength, and balance. Assessments will take place at baseline, mid-point (3-months), and immediately following the intervention (6-months).DiscussionThis study will lay the foundation for the design of a future RCT by: (1) providing effect sizes that can be included in a power analysis for optimal sample size estimation; and (2) identifying cardiorespiratory fitness, muscular strength, and balance (i.e., physiological function) as mechanisms for the beneficial effects of FES cycling on walking performance. This trial will provide important information on a novel exercise rehabilitation therapy for managing walking impairment in persons with severe MS

a systematic review of observational studies

Funding: Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, is supported by the Portuguese Foundation of Science and Technology (UID/04045/2020)Background: End-stage Kidney Disease patients have a high mortality and hospitalization risk. The association of these outcomes with physical activity is described in the general population and in other chronic diseases. However, few studies examining this association have been completed in end-stage Kidney Disease patients, raising the need to systematically review the evidence on the association of physical activity with mortality and hospitalization in this population. Methods: Electronic databases (EBSCO, Scopus and Web of Science) and hand search were performed until March 2020 for observational studies reporting the association of physical activity with mortality or hospitalization in adult end-stage Kidney Disease patients on renal replacement therapy (hemodialysis, peritoneal dialysis and kidney transplant). Methodological quality of the included studies was assessed using the Quality in Prognosis Studies tool. The review protocol was registered in PROSPERO (CRD42020155591). Results: Eleven studies were included: six in hemodialysis, three in kidney transplant, and two in hemodialysis and peritoneal dialysis patients. Physical activity was self-reported, except in one study that used accelerometers. All-cause mortality was addressed in all studies and cardiovascular mortality in three studies. Nine studies reported a significant reduction in all-cause mortality with increased levels of physical activity. Evidence of a dose-response relationship was found. For cardiovascular mortality, a significant reduction was observed in two of the three studies. Only one study investigated the association of physical activity with hospitalization. Conclusions: Higher physical activity was associated with reduced mortality in end-stage Kidney Disease patients. Future studies using objective physical activity measures could strengthen these findings. The association of physical activity with hospitalization should be explored in future investigations.publishersversionpublishe

Anabolic resistance of muscle protein turnover comes in various shapes and sizes

Anabolic resistance is defined by a blunted stimulation of muscle protein synthesis rates (MPS) to common anabolic stimuli in skeletal muscle tissue such as dietary protein and exercise. Generally, MPS is the target of most exercise and feeding interventions as muscle protein breakdown rates seem to be less responsive to these stimuli. Ultimately, the blunted responsiveness of MPS to dietary protein and exercise underpins the loss of the amount and quality of skeletal muscle mass leading to decrements in physical performance in these populations. The increase of both habitual physical activity (including structured exercise that targets general fitness characteristics) and protein dense food ingestion are frontline strategies utilized to support muscle mass, performance, and health. In this paper, we discuss anabolic resistance as a common denominator underpinning muscle mass loss with aging, obesity, and other disease states. Namely, we discuss the fact that anabolic resistance exists as a dimmer switch, capable of varying from higher to lower levels of resistance, to the main anabolic stimuli of feeding and exercise depending on the population. Moreover, we review the evidence on whether increased physical activity and targeted exercise can be leveraged to restore the sensitivity of skeletal muscle tissue to dietary amino acids regardless of the population

Integrin-associated ILK and PINCH1 protein content are reduced in skeletal muscle of maintenance haemodialysis patients

Key points: Patients with renal failure undergoing maintenance haemodialysis are associated with insulin resistance and protein metabolism dysfunction. Novel research suggests that disruption to the transmembrane protein linkage between the cytoskeleton and the extracellular matrix in skeletal muscle may contribute to reduced amino acid metabolism and insulin resistance in haemodialysis. ILK, PINCH1 and pFAKTyr397 were significantly decreased in haemodialysis compared to controls, whereas Rac1 and Akt2 showed no different between groups. Rac1 deletion in the Rac1 knockout model did not alter the expression of integrin-associated proteins. Phenylalanine kinetics were reduced in the haemodialysis group at 30 and 60 min post meal ingestion compared to controls; both groups showed similar levels of insulin sensitivity and β-cell function. Key proteins in the integrin–cytoskeleton linkage are reduced in haemodialysis patients, suggesting for the first time that integrin-associated proteins dysfunction may contribute to reduced phenylalanine flux without affecting insulin resistance in haemodialysis patients. Abstract: Muscle atrophy, insulin resistance and reduced muscle phosphoinositide 3-kinase-Akt signalling are common characteristics of patients undergoing maintenance haemodialysis (MHD). Disruption to the transmembrane protein linkage between the cytoskeleton and the extracellular matrix in skeletal muscle may contribute to reduced amino acid metabolism and insulin resistance in MHD patients. Eight MHD patients (age: 56 ± 5 years: body mass index: 32 ± 2 kg m–2) and non-diseased controls (age: 50 ± 2 years: body mass index: 31 ± 1 kg m–2) received primed continuous l-[ring-2H5]phenylalanine before consuming a mixed meal. Phenylalanine metabolism was determined using two-compartment modelling. Muscle biopsies were collected prior to the meal and at 300 min postprandially. In a separate experiment, skeletal muscle tissue from muscle-specific Rac1 knockout (Rac1 mKO) was harvested to investigate whether Rac1 depletion disrupted the cytoskeleton-integrin linkage, allowing for cross-model examination of proteins of interest. ILK, PINCH1 and pFAKTyr397 were significantly lower in MHD (P

Differential Post-Exercise Blood Pressure Responses between Blacks and Caucasians

Post-exercise hypotension (PEH) is widely observed in Caucasians (CA) and is associated with histamine receptors 1- and 2- (H1R and H2R) mediated post-exercise vasodilation. However, it appears that blacks (BL) may not exhibit PEH following aerobic exercise. Hence, this study sought to determine the extent to which BL develop PEH, and the contri- bution of histamine receptors to PEH (or lack thereof) in this population. Forty-nine (22 BL, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either a combined H1R and H2R antagonist (fexofenadine and ranitidine) or a con- trol placebo. Supine blood pressure (BP), cardiac output and peripheral vascular resistance measurements were obtained at baseline, as well as at 30 min, 60 min and 90 min after 45 min of treadmill exercise at 70% heart rate reserve. Exercise increased diastolic BP in young BL but not in CA. Post-exercise diastolic BP was also elevated in BL after exercise with histamine receptor blockade. Moreover, H1R and H2R blockade elicited differential responses in stroke volume between BL and CA at rest, and the difference remained follow- ing exercise. Our findings show differential BP responses following exercise in BL and CA, and a potential role of histamine receptors in mediating basal and post-exercise stroke vol- ume in BL. The heightened BP and vascular responses to exercise stimulus is consistent with the greater CVD risk in BL

Sex differences in autonomic function following maximal exercise

Background: Heart rate variability (HRV), blood pressure variability, (BPV) and heart rate recovery (HRR) are measures that provide insight regarding autonomic function. Maximal exercise can affect autonomic function, and it is unknown if there are sex differences in autonomic recovery following exercise. Therefore, the purpose of this study was to determine sex differences in several measures of autonomic function and the response following maximal exercise. Methods: Seventy-one (31 males and 40 females) healthy, nonsmoking, sedentary normotensive subjects between the ages of 18 and 35 underwent measurements of HRV and BPV at rest and following a maximal exercise bout. HRR was measured at minute one and two following maximal exercise. Results: Males have significantly greater HRR following maximal exercise at both minute one and two; however, the significance between sexes was eliminated when controlling for VO2 peak. Males had significantly higher resting BPV-low-frequency (LF) values compared to females and did not significantly change following exercise, whereas females had significantly increased BPV-LF values following acute maximal exercise. Although males and females exhibited a significant decrease in both HRV-LF and HRV-high frequency (HF) with exercise, females had significantly higher HRV-HF values following exercise. Males had a significantly higher HRV-LF/HF ratio at rest; however, both males and females significantly increased their HRV-LF/HF ratio following exercise. Conclusions: Pre-menopausal females exhibit a cardioprotective autonomic profile compared to age-matched males due to lower resting sympathetic activity and faster vagal reactivation following maximal exercise. Acute maximal exercise is a sufficient autonomic stressor to demonstrate sex differences in the critical post-exercise recovery period

A Comparison of Dietary Intake Between Individuals Undergoing Maintenance Hemodialysis in the United Kingdom and China

OBJECTIVE: Protein-energy wasting is highly prevalent in people with end-stage kidney disease receiving regular hemodialysis. Currently, it is unclear what the optimal nutritional recommendations are, which is further complicated by differences in dietary patterns between countries. The aim of the study was to understand and compare dietary intake between individuals receiving hemodialysis in Leicester, UK and Nantong, China. METHODS: The study assessed 40 UK and 44 Chinese participants' dietary intake over a period of 14 days using 24-hour diet recall interviews. Nutritional blood parameters were obtained from medical records. Food consumed by participants in the UK and China was analyzed using the Nutritics and Nutrition calculator to quantify nutritional intake. RESULTS: Energy and protein intake were comparable between UK and Chinese participants, but with both below the recommended daily intake. Potassium intake was higher in UK participants compared to Chinese participants (2,115 [888] versus 1,159 [861] mg/d; P < .001), as was calcium (618 [257] versus 360 [312] mg/d; P < .001) and phosphate intake (927 [485] versus 697 [434] mg/d; P = .007). Vitamin C intake was lower in UK participants compared to their Chinese counterparts (39 [51] versus 64 [42] mg/d; P = .024). Data are reported here as median (interquartile range). CONCLUSION: Both UK and Chinese hemodialysis participants have insufficient protein and energy in their diet. New strategies are required to increase protein and energy intakes. All participants had inadequate daily intake of vitamins C and D; there may well be a role in the oral supplementation of these vitamins, and further studies are urgently needed

Global Policy Barriers and Enablers to Exercise and Physical Activity in Kidney Care

Objective: Impairment in physical function and physical performance leads to decreased independence and health-related quality of life in people living with chronic kidney disease and end-stage kidney disease. Physical activity and exercise in kidney care are not priorities in policy development. We aimed to identify global policy-related enablers, barriers, and strategies to increase exercise participation and physical activity behavior for people living with kidney disease. Design and Methods: Guided by the Behavior Change Wheel theoretical framework, 50 global renal exercise experts developed policy barriers and enablers to exercise program implementation and physical activity promotion in kidney care. The consensus process consisted of developing themes from renal experts from North America, South America, Continental Europe, United Kingdom, Asia, and Oceania. Strategies to address enablers and barriers were identified by the group, and consensus was achieved. Results: We found that policies addressing funding, service provision, legislation, regulations, guidelines, the environment, communication, and marketing are required to support people with kidney disease to be physically active, participate in exercise, and improve health-related quality of life. We provide a global perspective and highlight Japanese, Canadian, and other regional examples where policies have been developed to increase renal physical activity and rehabilitation. We present recommendations targeting multiple stakeholders including nephrologists, nurses, allied health clinicians, organizations providing renal care and education, and renal program funders. Conclusions: We strongly recommend the nephrology community and people living with kidney disease take action to change policy now, rather than idly waiting for indisputable clinical trial evidence that increasing physical activity, strength, fitness, and function improves the lives of people living with kidney disease

Next Steps for Intradialytic Cycling Research

Hemodialysis patients typically have extremely low physical activity levels, which contributes to poor physical function and quality of life (QOL). Numerous studies show that exercise, intradialytic cycling in particular, may improve physical and cardiovascular function and QOL. But there are also significant inconsistencies in the literature, and the benefits in many studies are modest. This may be due in part to methodological limitations in intradialytic cycling trials, including small sample sizes, short interventions, low volume, and intensity of exercise prescriptions, and/or low retention and protocol adherence rates. The goal of this review is twofold. First, we summarize the current literature on intradialytic cycling in HD patients, highlighting benefits and concerns noted in several recently published trials that were among the most robust and clinically relevant trials conducted to date. Second, we will consider strategies for moving forward with exercise and physical activity interventions in HD, including promoting intradialytic cycling as a core component of a more patient-centric and comprehensive strategy that helps progress patients towards standard physical activity guidelines. We urge researchers and exercise professionals to consider intradialytic cycling as a valuable component of a comprehensive patient-centered, lifestyle intervention, as opposed to a stand-alone exercise prescription

A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions Are Needed

Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity.info:eu-repo/semantics/publishedVersio