Beta-alanine supplementation in patients with COPD receiving non-linear periodised exercise training or neuromuscular electrical stimulation: protocol of two randomised, double-blind, placebo-controlled trials.
ABSTRACT: INTRODUCTION:Exercise intolerance is common in patients with chronic obstructive pulmonary disease (COPD) and, although multifactorial, it is largely caused by lower-limb muscle dysfunction. Research has shown that patients with severe to very severe COPD have significantly lower levels of muscle carnosine, which acts as a pH buffer and antioxidant. Beta-alanine (BA) supplementation has been shown to consistently elevate muscle carnosine in a variety of populations and may therefore improve exercise tolerance and lower-limb muscle function. The primary objective of the current studies is to assess the beneficial effects of BA supplementation in enhancing exercise tolerance on top of two types of exercise training (non-linear periodised exercise (NLPE) training or neuromuscular electrical stimulation (NMES)) in patients with COPD. METHODS AND ANALYSIS:Two randomised, double-blind, placebo-controlled trials have been designed. Patients will routinely receive either NLPE (BASE-TRAIN trial) or NMES (BASE-ELECTRIC trial) as part of standard exercise-based care during their 8-to-10 week pulmonary rehabilitation (PR) programme. A total of 222 patients with COPD (2×77 = 154 patients in the BASE-TRAIN trial and 2×34 = 68 patients in the BASE-ELECTRIC trial) will be recruited from two specialised PR centres in The Netherlands. For study purposes, patients will receive 3.2 g of oral BA supplementation or placebo per day. Exercise tolerance is the primary outcome, which will be assessed using the endurance shuttle walk test (BASE-TRAIN) or the constant work rate cycle test (BASE-ELECTRIC). Furthermore, quadriceps muscle strength and endurance, cognitive function, carnosine levels (in muscle), BA levels (in blood and muscle), markers of oxidative stress and inflammation (in blood, muscles and lungs), physical activity and quality of life will be measured. ETHICS AND DISSEMINATION:Both trials were approved by CMO Regio Arnhem-Nijmegen, The Netherlands (NL70781.091.19. and NL68757.091.19). TRIAL REGISTRATION NUMBER:NTR8427 (BASE-TRAIN) and NTR8419 (BASE-ELECTRIC).
Project description:<h4>Background</h4>Strength training and neuromuscular electrical stimulation (NMES) are effective training modalities for improving muscle function, exercise performance and health status in individuals with COPD. The aim of the present study was to analyze the metabolic load of these training modalities at baseline, half-way, and at the end of an eight-week interdisciplinary pulmonary rehabilitation program in a subgroup of individuals with COPD of the DICES trial.<h4>Methods</h4>Of 24 individuals with COPD (FEV1: 34 ± 2% predicted, men: 58%, age: 66 (61-68) years), peak oxygen uptake (VO2), peak minute ventilation (VE), heart rate, oxygen saturation and symptom scores were assessed during HF-NMES (75 Hz), LF-NMES (15 Hz) and strength training at three moments during their pulmonary rehabilitation program.<h4>Results</h4>Intervention-related peak VO2 did not change over time during HF-NMES, LF-NMES or strength training. Intervention-related peak VE did not change over time during strength training or LF-NMES and increased slightly, but significantly over time during HF-NMES. Peak VO2 and VE were significantly higher during strength training compared to HF-NMES or LF-NMES. Oxygen saturation significantly decreased after the first measurements during HF-NMES and strength training group to baseline, while no significant changes in oxygen saturation were observed during the other measurements. Heart rate significantly increased compared to baseline in all groups at all moments and was significantly higher after strength training compared to HF-NMES or LF-NMES. Median end scores (points) for dyspnea, fatigue and muscle pain ranged from 1 to 3, from 0.5 to 2 and from 0 to 6 after HF-NMES, from 2 to 3, from 2 to 5 and from 0 to 9 after LF-NMES and from 2 to 5, from 1.5 to 4 and from 0 to 28 after strength training respectively.<h4>Conclusions</h4>To conclude, the metabolic load and symptom scores remain acceptable low over time with increasing training loads during HF-NMES, LF-NMES or strength training.<h4>Trial registration</h4><h4>Trial registration</h4>NTR2322.
Project description:<h4>Rationale</h4>Neuromuscular electrical stimulation (NMES) of the lower limbs is an emerging training strategy in patients with COPD. The efficacy of this technique is related to the intensity of the stimulation that is applied during the training sessions. However, little is known about tolerance to stimulation current intensity and physiological factors that could determine it. Our goal was to find potential physiological predictors of the tolerance to increasing NMES stimulation intensity in patients with mild to severe COPD.<h4>Methods</h4>20 patients with COPD (FEV1?=?54±14% pred.) completed 2 supervised NMES sessions followed by 5 self-directed sessions at home and one final supervised session. NMES was applied simultaneously to both quadriceps for 45 minutes, at a stimulation frequency of 50 Hz. Spirometry, body composition, muscle function and aerobic capacity were assessed at baseline. Cardiorespiratory responses, leg discomfort, muscle fatigue and markers of systemic inflammation were assessed during or after the last NMES session. Tolerance to NMES was quantified as the increase in current intensity from the initial to the final NMES session (?Int).<h4>Results</h4>Mean ?Int was 12±10 mA. FEV1, fat-free-mass, quadriceps strength, aerobic capacity and leg discomfort during the last NMES session positively correlated with ?Int (r?=?0.42 to 0.64, all p?0.06) while post/pre NMES IL-6 ratio negatively correlated with ?Int (r?=?-0.57, p?=?0.001). FEV1, leg discomfort during last NMES session and post/pre IL-6 ratio to NMES were independent factors of variance in ?Int (r2?=?0.72, p?=?0.001).<h4>Conclusion</h4>Lower tolerance to NMES was associated with increasing airflow obstruction, low tolerance to leg discomfort during NMES and the magnitude of the IL-6 response after NMES.<h4>Trial registration</h4>ClinicalTrials.gov NCT00809120.
Project description:<h4>Objective</h4>The aim of this study was to compare the feasibility and effectiveness of neuromuscular electrical stimulation (NMES) with that of high-intensity volitional resistance training for improving muscle structure and function and physical function in patients with rheumatoid arthritis (RA). We also compared pre-intervention and post-intervention values of myocyte characteristics.<h4>Methods</h4>In this 2-group, single-blind, randomized pilot study, adult patients with RA were assigned to 36 sessions of NMES (n = 31 patients) or volitional training (n = 28 patients) over 16 weeks. Outcome measures included muscle structure and function (quadriceps muscle area, density, and strength), physical function (performance-based and patient-reported), feasibility (increased pain, increased disease activity, attrition, and adherence), and myocyte characteristics (area, proportion of type I or II muscle fibers, and intramyocellular lipid content). Analysis of covariance was used to compare groups.<h4>Results</h4>The intervention intensity in the NMES group was less than half that in the volitional exercise group (31% versus 77% of maximum effort). Both groups experienced significant improvements in muscle structure and function (P < 0.001 to 0.019). Improvements in muscle characteristics and physical function were not different between groups. Exercise did not result in serious adverse events or increases in pain and disease activity. Attrition was 29% in the NMES group and 7% in the volitional exercise group.<h4>Conclusion</h4>Both NMES and high-intensity volitional resistance training can be used as effective approaches to improving muscle structure and function in patients with RA. NMES may be a viable alternative for improving muscle function in patients in whom high-intensity resistance exercise may not be tolerated or is contraindicated, but attrition must be considered when using this approach.
Project description:In fresh muscle, supplementation with the rate-limiting precursor of carnosine, ?-alanine (BA), results in a decline in muscle half-relaxation time (HRT) potentially via alterations to calcium (Ca2+) handling. Accumulation of hydrogen cation (H+) has been shown to impact Ca2+ signalling during muscular contraction, carnosine has the potential to serve as a cytoplasmic regulator of Ca2+ and H+ coupling, since it binds to both ions. The present study examined the effect of BA supplementation on intrinsic in-vivo isometric knee extensor force production and muscle contractility in both fresh and fatigued human skeletal muscle assessed during voluntary and electrically evoked (nerve and superficial muscle stimulation) contractions.Twenty-three males completed two experimental sessions, pre- and post- 28 day supplementation with 6.4 g.day-1 of BA (n?=?12) or placebo (PLA; n?=?11). Isometric force was recorded during a series of voluntary and electrically evoked knee extensor contractions.BA supplementation had no effect on voluntary or electrically evoked isometric force production, or twitch electromechanical delay and time-to-peak tension. There was a significant decline in muscle HRT in fresh and fatigued muscle conditions during both resting (3?±?13%; 19?±?26%) and potentiated (1?±?15%; 2?±?20%) twitch contractions.The mechanism for reduced HRT in fresh and fatigued skeletal muscle following BA supplementation is unclear. Due to the importance of muscle relaxation on total energy consumption, especially during short, repeated contractions, BA supplementation may prove to be beneficial in minimising contractile slowing induced by fatigue.The trial is registered with Clinicaltrials.gov, ID number NCT02819505.
Project description:This study investigated the effectiveness of adding neuromuscular electrical stimulation (NMES) to endurance training (ET) and resistance training (RT) on exercise tolerance and balance in COPD patients. 42 patients were assigned randomly to the ET?+?RT?+?NMES group (n?=?22) or ET?+?RT group (n?=?20). Two training programs were performed including 72 sessions. The center of pressure (CoP) displacement in the mediolateral direction (CoPML), in the anteroposterior direction (CoPAP), and the center of pressure velocity (CoPV) were recorded using a stabilometric platform with eyes open (EO) and eyes closed (EC). Time up and go and Berg Balance Scale tests, 6-minute walking test (6MWT), and the maximal voluntary contraction (MVC) were measured before and after the intervention. The walking distance, the dyspnea, and the heart rate were improved after the training period (p < 0.001) for both groups (p < 0.05). The ET?+?RT?+?NMES group showed better improvement than the ET?+?RT group in terms of 6MWD. CoPML, CoPAP, and CoPV were significantly (p < 0.001; p < 0.05; p < 0.001, respectively) more improved in EO and EC conditions in the ET?+?RT?+?NMES group than the ET?+?RT group. BBS, TUG, and MVC values improved in both groups after the training (p < 0.001). The performances in TUG and MVC tests were significantly greater in the ET?+?RT?+?NMES group than those in the ET?+?RT group (p < 0.01; p < 0.001, respectively). Combining NMES, RT, and ET improves balance in patients with COPD.
Project description:<h4>Background</h4>Transcutaneous neuromuscular electrical stimulation (NMES) can be applied as a complementary intervention to regular exercise training programs. A distinction can be made between high-frequency (HF) NMES and low-frequency (LF) NMES. In order to increase understanding of the mechanisms of functional improvements following NMES, the purpose of this study was to systematically review changes in enzyme activity, muscle fiber type composition and muscle fiber size in human lower-limb skeletal muscles following only NMES.<h4>Methods</h4>Trials were collected up to march 2012 and were identified by searching the Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL and The Physical Therapy Evidence Database (PEDro) databases and reference lists. 18 trials were reviewed in detail: 8 trials studied changes in enzyme activities, 7 trials studied changes in muscle fiber type composition and 14 trials studied changes in muscle fiber size following NMES.<h4>Results</h4>The methodological quality generally was poor, and the heterogeneity in study design, study population, NMES features and outcome parameters prohibited the use of meta-analysis. Most of the LF-NMES studies reported significant increases in oxidative enzyme activity, while the results concerning changes in muscle fiber composition and muscle size were conflicting. HF-NMES significantly increased muscle size in 50% of the studies.<h4>Conclusion</h4>NMES seems to be a training modality resulting in changes in oxidative enzyme activity, skeletal muscle fiber type and skeletal muscle fiber size. However, considering the small sample sizes, the variance in study populations, the non-randomized controlled study designs, the variance in primary outcomes, and the large heterogeneity in NMES protocols, it is difficult to draw definitive conclusions about the effects of stimulation frequencies on muscular changes.
Project description:Beta-alanine (BA) supplementation increases muscle carnosine content (MCarn), and has many proven, and purported, ergogenic, and therapeutic benefits. Currently, many questions on the nature of the MCarn response to supplementation are open, and the response to these has considerable potential to enhance the efficacy and application of this supplementation strategy. To address these questions, we conducted a systematic review with Bayesian-based meta-analysis of all published aggregate data using a dose response (Emax) model. Meta-regression was used to consider the influence of potential moderators (including dose, sex, age, baseline MCarn, and analysis method used) on the primary outcome. The protocol was designed according to PRISMA guidelines and a three-step screening strategy was undertaken to identify studies that measured the MCarn response to BA supplementation. Additionally, we conducted an original analysis of all available individual data on the MCarn response to BA supplementation from studies conducted within our lab (n = 99). The Emax model indicated that human skeletal muscle has large capacity for non-linear MCarn accumulation, and that commonly used BA supplementation protocols may not come close to saturating muscle carnosine content. Neither baseline values, nor sex, appeared to influence subsequent response to supplementation. Analysis of individual data indicated that MCarn is relatively stable in the absence of intervention, and effectually all participants respond to BA supplementation (99.3% response [95%CrI: 96.2-100]).
Project description:A reduced exercise capacity is associated with increased morbidity and mortality in patients with advanced non-small cell lung cancer (NSCLC). Therapeutic exercise can be beneficial and neuromuscular electrical stimulation (NMES) of the quadriceps muscles may represent a practical approach. The primary aim of this study was to determine the acceptability of NMES of the quadriceps to patients with NSCLC used alongside palliative chemotherapy. Secondary aims explored aspects of safety and efficacy of NMES in this setting.Patients with advanced NSCLC due to receive first-line palliative chemotherapy were randomized to usual care with or without NMES. They were asked to undertake 30 minute sessions of NMES, ideally daily, but as a minimum, three times weekly. For NMES to be considered acceptable, it was predetermined that ?80% of patients should achieve this minimum level of adherence. Qualitative interviews were held with a subset of patients to explore factors influencing adherence. Safety was assessed according to the Common Terminology Criteria for Adverse Events. Quadriceps muscle strength, thigh lean mass, and physical activity level were assessed at baseline and after three cycles of chemotherapy.49 patients (28 male, median (IQR) age 69 (64-75) years) participated. Of 30 randomized to NMES, 18 were eligible for the primary endpoint, of whom 9 (50% [90% CI, 29 to 71]) met the minimum level of adherence. Adherence was enhanced by incorporating sessions into a daily routine and hindered by undesirable effects of chemotherapy. There were no serious adverse events related to NMES, nor significant differences in quadriceps muscle strength, thigh lean mass or physical activity level between groups.NMES is not acceptable in this setting, nor was there a suggestion of benefit. The need remains to explore NMES in patients with cancer in other settings.Current Controlled Trials ISRCTN 42944026 www.controlled-trials.com/ISRCTN42944026.
Project description:Neuromuscular electrical stimulation (NMES) has been shown to reduce quadriceps activation failure (QAF), and eccentric exercise has been shown to lessen muscle atrophy post-ACL reconstruction. Given that these are two critical components of quadriceps strength, intervention combining these therapies may be effective at reinstituting quadriceps function post-reconstruction. Thus, the aim of this study was to evaluate the effectiveness of a combined NMES and eccentric exercise intervention to improve the recovery of quadriceps activation and strength post-reconstruction.Thirty-six individuals post-injury were placed into four treatment groups (N&E, NMES and eccentrics; E-only, eccentrics only; N-only, NMES-only; and STND, standard of care) and ten healthy controls participated. N&E and N-only received the NMES protocol 2× per week for the first 6 weeks post-reconstruction. N&E and E-only received the eccentric exercise protocol 2× per week beginning 6 weeks post-reconstruction. Quadriceps activation was assessed via the superimposed burst technique and quantified via the central activation ratio. Quadriceps strength was assessed via maximal voluntary isomeric contractions (Nm/kg). Data was gathered on three occasions: pre-operative, 12-weeks-post-surgery and at return-to-play.No differences in pre-operative measures existed (P>0.05). E-only recovered quadriceps activation better than N-only or STND (P<0.05). N&E and E-only recovered strength better than N-only or the STND (P<0.05) and had strength values that were similar to healthy at return-to-play (P>0.05).Eccentric exercise was capable of restoring levels of quadriceps activation and strength that were similar to those of healthy adults and better than NMES alone.Level 3, Parallel longitudinal study.
Project description:Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD) patients is common. Neuromuscular Electrical Stimulation (NMES) is a powerful exercise training that may relieve muscle dysfunction in COPD. This study investigated whether electrical stimulation may have atypical adaptations via activation of miRNA related pathways in counteracting COPD muscle dysfunction. Forty-eight male Sprague-Dawley rats were randomly assigned to 3 groups. With the exception of the rats in the control group, the experimental rats were exposed to chronic intermittent hypoxia-hypercapnia (CIHH) (9?11%O2,5.5?6.5%CO2) for 2 or 4 weeks. Electrical stimulation was performed immediately after each CIHH session. Following assessment of the running capacity, biopsy samples were obtained from the gastrocnemius of the rats. The miR-1, miR-133a and miR-133b levels were measured, as well as their related proteins: phosphorylation of Akt (p-AKT), PGC-1alpha (PGC-1?), histone deacetylase 4 (HDAC4) and serum response factor (SRF). Myosin heavy chainIIa (MHCIIa) and myosin heavy chainIIb (MHCIIb) were also measured to assess fiber type changes. After 2 weeks, compared with the controls, only miR-1 and miR-133a were significantly increased (p<0.05) in the exposure group. After 4 weeks, the exposure group exhibited a decreased running distance (p = 0.054) and MHCIIa-to-MHCIIb shift (p<0.05). PGC-1? (p = 0.051), nuclear HDAC4 (p = 0.058), HDAC4, p-AKT, PGC-1? and SRF was also significantly decreased (p<0.05). In contrast, miR-1 and miR-133a were significantly increased (p<0.05). Four weeks of electrical stimulation can partly reversed those changes, and miR-133b exhibited a transient increase after 2 weeks electrical stimulation. Our study indicate miRNAs may have roles in the response of CIHH-impaired muscle to changes during electrical stimulation.