Effects of Pulmonary Rehabilitation Including Inspiratory Muscle Training in Patients with Chronic Obstructive Pulmonary Disease after Stratification by the Degree of Static Hyperinflation.

BACKGROUND: Inspiratory muscle training (IMT) improves inspiratory muscle strength, exercise capacity and health status in patients with chronic obstructive pulmonary disease (COPD). However, there is no additional effect on top of comprehensive pulmonary rehabilitation (PR). It is unclear whether patients with different baseline degrees of static hyperinflation respond differentially to IMT as part of a PR program. Therefore, the aim was to study the effects of IMT as an add-on on PR after stratification for baseline degrees of static hyperinflation. METHODS: In this single center retrospective study data were extracted between June 2013 and October 2020 of COPD patients who participated in a comprehensive PR program including IMT. IMT was performed twice daily, one session consisted of 3 series of 10 breaths and training intensity was set initially at a load of approximately 50% of patients' maximal static inspiratory mouth pressure (MIP). The primary outcome measure was MIP. Secondary outcomes were the distance achieved on the 6-min walk test (6MWD), endurance cycling exercise capacity at 75% of the peak work rate (CWRT) and disease-specific health status using the COPD assessment test. RESULTS: 754 patients with COPD were screened for eligibility and 328 were excluded because of repeated PR programs, missing data or baseline residual volume (RV) > 350%. In total, 426 COPD patients were categorized into RV categories 50-130% (n = 84), 131-165% (n = 86), 166-197% (n = 86), 198-234% (n = 85) and 235-349% (n = 85). In the whole sample, MIP, endurance exercise capacity and health status improved significantly. The change in 6MWD was higher in the lowest baseline degree of static hyperinflation [+ 39 (9-92) m] compared with the baseline highest degree of static hyperinflation [+ 11 (- 18-54) m] (p < 0.05). CONCLUSIONS: IMT as part of a PR program in patients with COPD with different baseline degrees improved MIP irrespective of the degree of static lung hyperinflation. Improvement in functional exercise capacity was significantly higher in the group with the lowest degree of static hyperinflation compared with the patients with the highest degree of static hyperinflation.

Short Physical Performance Battery: Response to Pulmonary Rehabilitation and Minimal Important Difference Estimates in Patients With Chronic Obstructive Pulmonary Disease.

OBJECTIVE: To determine the response to a pulmonary rehabilitation (PR) program and minimal important differences (MIDs) for the Short Physical Performance Battery (SPPB) subtests and SPPB summary score in patients with chronic obstructive pulmonary disease (COPD). DESIGN: Retrospective analysis using distribution- and anchor-based methods. SETTING: PR center in the Netherlands including a comprehensive 40-session 8-week inpatient or 14-week outpatient program. PARTICIPANTS: A total of 632 patients with COPD (age, 65±8y; 50% male; forced expiratory volume in the first second=43% [interquartile range, 30%-60%] predicted). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Baseline and post-PR results of the SPPB, consisting of 3 balance standing tests, 4-meter gait speed (4MGS), and 5-repetition sit-to-stand (5STS). The chosen anchors were the 6-Minute Walk Test and COPD Assessment Test. Patients were stratified according to their SPPB summary scores into low-performance, moderate-performance, and high-performance groups. RESULTS: 5STS (∆=-1.14 [-4.20 to -0.93]s) and SPPB summary score (∆=1 [0-2] points) improved after PR in patients with COPD. In patients with a low performance at baseline, balance tandem and 4MGS significantly increased as well. Based on distribution-based calculations, the MID estimates ranged between 2.19 and 6.33 seconds for 5STS and 0.83 to 0.96 points for SPPB summary score. CONCLUSIONS: The 5STS and SPPB summary score are both responsive to PR in patients with COPD. The balance tandem test and 4MGS are only responsive to PR in patients with COPD with a low performance at baseline. Based on distribution-based calculations, an MID estimate of 1 point for the SPPB summary score is recommended in patients with COPD. Future research is needed to confirm MID estimates for SPPB in different centers.

Phenotypic Characteristics of Patients With Chronic Obstructive Pulmonary Disease After Stratification for the Short Physical Performance Battery Summary Score.

OBJECTIVE: To assess the phenotypic characteristics of patients with chronic obstructive pulmonary disease (COPD) after stratification for Short Physical Performance Battery (SPPB) summary scores and to determine phenotypic characteristics of the SPPB summary score at the start of pulmonary rehabilitation (PR). DESIGN: Retrospective, cross-sectional. SETTING: Baseline assessment for PR program. PARTICIPANTS: Patients with COPD (n=900; age 65±8y, 52% male, forced expiratory volume in the first second of expiration, 43% [interquartile range, 31%-62%] predicted). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients were stratified according to their SPPB summary scores into low-performance (LP), moderate-performance (MP), or high-performance (HP) groups. Furthermore, lung function, arterial blood gases, body composition, physical capacity, lower limb muscle strength and endurance, and symptoms of anxiety and depression were assessed. RESULTS: Generally, physical capacity and muscle function were lower and scores for symptoms of anxiety and depression were higher in LP patients than MP and HP patients (all values, P<.01). However, 25% of HP patients with COPD scored high on symptoms of anxiety and/or depression (≥10 points), and HP patients still had on average an impaired physical capacity (median, 6-minute walk test [6MWT] distance of 69% predicted). Furthermore, age and 6MWT distance (m) were the only independent predictors in a multivariate regression model, explaining 29% of the variance in SPPB summary score. CONCLUSIONS: In COPD, LP patients have the worst physical and emotional functioning. However, HP patients can still exhibit physical and emotional impairments. Because the explained variance in SPPB summary score is low, SPPB should not be considered as a test to discriminate between patients with COPD with a low or preserved physical capacity and emotional status.

Efficacy of lower-limb muscle training modalities in severely dyspnoeic individuals with COPD and quadriceps muscle weakness: results from the DICES trial.

RATIONALE: Strength training and neuromuscular electrical stimulation (NMES) improve lower-limb muscle function in dyspnoeic individuals with chronic obstructive pulmonary disease (COPD). However, high-frequency NMES (HF-NMES) and strength training have never been compared head-to-head; and effects of low-frequency NMES (LF-NMES) have never been studied in COPD. Therefore, the optimal training modality to improve lower-limb muscle function, exercise performance and other patient-related outcomes in individuals with severe COPD remains unknown. OBJECTIVES: To study prospectively the efficacy of HF-NMES (75 Hz), LF-NMES (15 Hz) or strength training in severely dyspnoeic individuals with COPD with quadriceps muscle weakness at baseline. METHODS: 120 individuals with COPD (FEV1: 33±1% predicted, men: 52%, age: 64.8±0.8 years) were randomised to HF-NMES, LF-NMES or strength training as part of a comprehensive inpatient pulmonary rehabilitation programme. No treadmill walking or stationary cycling was provided. MEASUREMENTS AND MAIN RESULTS: Groups were comparable at baseline. Quadriceps muscle strength increased after HF-NMES (+10.8 Newton-metre (Nm)) or strength training (+6.1 Nm; both p<0.01), but not after LF-NMES (+1.4 Nm; p=0.43). Quadriceps muscle endurance, exercise performance, lower-limb fat-free mass, exercise-induced symptoms of dyspnoea and fatigue improved significantly compared with baseline after HF-NMES, LF-NMES or strength training. The increase in quadriceps muscle strength and muscle endurance was greater after HF-NMES than after LF-NMES. CONCLUSIONS: HF-NMES is equally effective as strength training in severely dyspnoeic individuals with COPD and muscle weakness in strengthening the quadriceps muscles and thus may be a good alternative in this particular group of patients. HF-NMES, LF-NMES and strength training were effective in improving exercise performance in severely dyspnoeic individuals with COPD and quadriceps weakness. TRIAL REGISTRATION: NTR2322.

Metabolic load during strength training or NMES in individuals with COPD: results from the DICES trial.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. TRIAL REGISTRATION: NTR2322.

Inaccuracy of estimating peak work rate from six-minute walk distance in patients with COPD.

INTRODUCTION: The cardiopulmonary exercise test (CPET) and the 6-minute walk test (6MWT) are used to prescribe the appropriate training load for cycling and walking exercise in patients with chronic obstructive pulmonary disease (COPD). The primary aims were: (i) to compare estimated peak work rate (Wpeak(estimated)) derived from six existing Wpeak regression equations with actual peak work rate (Wpeak(actual)); and (ii) to derive a new Wpeak regression equation using six-minute walk distance (6MWD) and conventional outcome measures in COPD patients. METHODS: In 2906 patients with COPD, existing Wpeak regression equations were used to estimate Wpeak using 6MWD and a new equation was derived after a stepwise multiple regression analysis. RESULTS: The 6 existing Wpeak regression equations were inaccurate to predict Wpeak(actual) in 82% of the COPD patients. The new Wpeak regression equation differed less between Wpeak(estimated) and Wpeak(actual) compared to existing models. Still, in 74% of COPD patients Wpeak(estimated) and Wpeak(actual) differed more than (±) 5 watts. CONCLUSION: In conclusion, estimating peak work load from 6MWD in COPD is inaccurate. We recommend assessment of Wpeak using CPET during pre-rehabilitation assessment in addition to 6MWT.

Oxygen uptake, ventilation, and symptoms during low-frequency versus high-frequency NMES in COPD: a pilot study.

Transcutaneous neuromuscular electrical stimulation (NMES) involves the application of an electrical current through electrodes placed on the skin over the targeted muscles. During high-frequency NMES (HF-NMES), oxygen uptake, minute ventilation, and the degree of symptom perception (dyspnea and fatigue) have been shown to be acceptable in chronic obstructive pulmonary disease (COPD). Currently, oxygen uptake and ventilation load have never been assessed during low-frequency NMES (LF-NMES) of the lower-limb muscles. The purpose of this study was to compare prospectively oxygen uptake, ventilation, and symptom perception during a single session of LF-NMES versus a single session of HF-NMES of quadriceps muscles in patients with COPD. In 17 COPD patients (mean FEV(1) = 45% predicted, mean body mass index = 26.2 kg/m(2)), peak exercise capacity, functional exercise capacity, and the Medical Research Council dyspnea grade were evaluated. In addition, oxygen uptake, minute ventilation, heart rate, and Borg symptom scores were assessed during one session of LF-NMES (15 Hz) and one session of HF-NMES (75 Hz) and compared with peak values. Mean oxygen uptake (LF-NMES: 327 ml/min vs. HF-NMES: 315 ml/min), minute ventilation (LF-NMES: 14 L vs. HF-NMES: 15 L), and heart rate (LF-NMES: 86 BPM vs. HF-NMES: 83 BPM) were similar during both NMES frequencies. Patients used a relatively low proportion of their peak aerobic capacity during both NMES sessions (LF-NMES: 34% vs. HF-NMES: 33%; P = 0.397). In addition, symptom Borg scores for dyspnea and leg fatigue were also comparable. Oxygen uptake, ventilation, and symptoms of dyspnea and fatigue were comparable and tolerable during LF-NMES and HF-NMES in patients with COPD. Therefore, LF-NMES and HF-NMES may both be suitable rehabilitative modalities to be used in severely dyspneic patients with lower-limb muscle dysfunction.

Effects of Exercise-Based Interventions on Fall Risk and Balance in Patients With Chronic Obstructive Pulmonary Disease: A SYSTEMATIC REVIEW.

PURPOSE: Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease characterized by airflow limitation and is associated with decreased balance and increased fall risk. Since falls are related to increased mortality, interventions targeting balance and fall risk could reduce morbidity and mortality. The objective of this review was to systematically assess the effects of exercise-based interventions on fall risk and balance in patients with COPD. METHODS: PubMed, Web of Science, EMBASE, and CINAHL were screened for randomized controlled trails and within-group studies evaluating effects of exercise-based interventions on fall risk or balance in patients with COPD. Data were presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. RESULTS: Fifteen studies were identified, 6 randomized controlled trails and 9 within-group studies. All interventions reported positive effects on balance outcomes. No studies reported fall risk. Taking current recommendations of balance outcome measures in patients with COPD into account, pulmonary rehabilitation combined with balance training had the highest effect size. Nine papers had concerns regarding bias, mostly due to the lack of blinding outcome assessors. CONCLUSIONS: Exercise-based interventions have a positive effect on balance in patients with COPD. Pulmonary rehabilitation with balance training seems to have the most beneficial effect on balance. The effects on fall risk, as well as the long-term intervention effects remain unclear. A standardized balance assessment and research on long-term effects and fall risk are recommended.

An update on pulmonary rehabilitation techniques for patients with chronic obstructive pulmonary disease.

Introduction: Pulmonary rehabilitation (PR) is one of the core components in the management of patients with chronic obstructive pulmonary disease (COPD). In order to achieve the maximal level of independence, autonomy, and functioning of the patient, targeted therapies and interventions based on the identification of physical, emotional and social traits need to be provided by a dedicated, interdisciplinary PR team.Areas covered: The review discusses cardiopulmonary exercise testing in the selection of different modes of training modalities. Neuromuscular electrical stimulation as well as gait assessment and training are discussed as well as add-on therapies as oxygen, noninvasive ventilator support or endoscopic lung volume reduction in selected patients. The potentials of pulsed inhaled nitric oxide in patients with underlying pulmonary hypertension is explored as well as nutritional support. The impact of sleep quality on outcomes of PR is reviewed.Expert opinion: Individualized, comprehensive intervention based on thorough assessment of physical, emotional, and social traits in COPD patients forms a continuous challenge for health-care professionals and PR organizations in order to dynamically implement and adapt these strategies based on dynamic, more optimal understanding of underlying pathophysiological mechanisms.

Impact of mild-to-moderate exacerbations on outcomes of neuromuscular electrical stimulation (NMES) in patients with COPD.

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are common among patients attending pulmonary rehabilitation (PR) and may compromise its outcomes. Neuromuscular electrical stimulation (NMES) seems one of the few exercise modalities that can actually be continued during AECOPD, due to its low burden on the impaired respiratory and cardiovascular system. However, the quality of evidence is low. The purpose of this study was to assess the impact of mild-to-moderate AECOPD on adherence/outcomes of a high-frequency (HF) or low-frequency (LF) NMES training program, as part of inpatient PR, in severely dyspneic, weakened individuals with COPD. 62 patients who received NMES as the sole supervised muscle training modality during an 8-week PR program (HF-NMES: n = 33; LF-NMES: n = 29) were analyzed retrospectively. 48.4% experienced ≥1 AECOPD during PR and were classified as exacerbators. Exacerbators completed 75 NMES sessions (interquartile range: 73-78) and were able to increase training intensity with 24 mA (15-39), while non-exacerbators completed 76 sessions (73-79) and increased training intensity with 35 mA (22-50), with no between-group differences (p = 0.474 and p = 0.065, respectively). The median change in 6-min walking distance, cycle endurance time, and isokinetic quadriceps strength and endurance did not differ between the exacerbation and non-exacerbation group. To conclude, the occurrence of mild-to-moderate AECOPD during a PR program primarily focused on NMES, does not affect adherence, intensity, and clinical outcomes in patients with severe COPD. Continuing NMES seems a feasible way to potentially counteract exacerbation-related lower-limb muscle dysfunction and improve outcomes of PR, with HF-NMES being the preferential muscle training modality.

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.

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).

Profiling of Patients with COPD for Adequate Referral to Exercise-Based Care: The Dutch Model.

A loss of physical functioning (i.e., a low physical capacity and/or a low physical activity) is a common feature in patients with chronic obstructive pulmonary disease (COPD). To date, the primary care physiotherapy and specialized pulmonary rehabilitation are clearly underused, and limited to patients with a moderate to very severe degree of airflow limitation (GOLD stage 2 or higher). However, improved referral rates are a necessity to lower the burden for patients with COPD and for society. Therefore, a multidisciplinary group of healthcare professionals and scientists proposes a new model for referral of patients with COPD to the right type of exercise-based care, irrespective of the degree of airflow limitation. Indeed, disease instability (recent hospitalization, yes/no), the burden of disease (no/low, mild/moderate or high), physical capacity (low or preserved) and physical activity (low or preserved) need to be used to allocate patients to one of the six distinct patient profiles. Patients with profile 1 or 2 will not be referred for physiotherapy; patients with profiles 3-5 will be referred for primary care physiotherapy; and patients with profile 6 will be referred for screening for specialized pulmonary rehabilitation. The proposed Dutch model has the intention to get the right patient with COPD allocated to the right type of exercise-based care and at the right moment.

The metabolic response during resistance training and neuromuscular electrical stimulation (NMES) in patients with COPD, a pilot study.

Resistance training and transcutaneous neuromuscular electrical stimulation (NMES) are new modalities in rehabilitation of severely disabled patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to compare the metabolic response during resistance training and during NMES of the quadriceps femoris muscles in patients with COPD entering pulmonary rehabilitation. Pulmonary function, body composition, peak aerobic capacity, the Medical Research Council dyspnoea grade, the one-repetition maximum strength assessment were evaluated in 13 COPD patients. Additionally, peak oxygen uptake, peak minute ventilation and Borg symptom scores were assessed during a resistance training session and a NMES session. The median peak oxygen uptake and median peak minute ventilation during the resistance training session were significantly higher compared to the NMES session. Additionally, these higher metabolic responses were accompanied by higher symptom Borg scores for dyspnoea and leg fatigue. To conclude, the metabolic response was significantly lower during a NMES session compared to a resistance exercise training session in patients with COPD. Nevertheless, both modalities seem to result in an acceptable metabolic response accompanied by a clinically acceptable sensation of dyspnoea and leg fatigue.

Metabolic and structural changes in lower-limb skeletal muscle following neuromuscular electrical stimulation: a systematic review.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

New normative values for handgrip strength: results from the UK Biobank.

OBJECTIVES: To develop normative values for right and left handgrip strength after stratification for confounders like gender, age, and height. DESIGN: Cross-sectional, descriptive. SETTING: General population. PARTICIPANTS: A total of 502,713 people living in the United Kingdom. INTERVENTION: None. MEASUREMENTS: Handgrip strength was measured using a Jamar hydraulic hand dynamometer, which is considered to be an accurate instrument to measure handgrip strength. In addition, self-reported chronic conditions and ethnic background were registered, and lung function was assessed using spirometry. RESULTS: After exclusion of all individuals with missing data, a nonwhite ethnic background, the presence of 1 or more self-reported conditions, and/or an obstructive lung function (defined as FEV1/FVC <0.7), new normative values for right and left handgrip strength were derived from 224,830 and 224,852 individuals (54.2% women; age: 55.0 [8.0] years; height: 169.0 [9.2] cm; body mass index: 26.9 [4.4] kg/m(2)) with a nonobstructed spirometry (FEV1: 3.0 [0.8] L). Men were stronger than women. Moreover, significant associations were found between handgrip strength and height, and between handgrip strength and age. Finally, percentiles 5, 10, 25, 50, 75, 90, and 95 were calculated for right and left handgrip strength, after stratification for gender, age, and height. CONCLUSION: The UK Biobank dataset provided the opportunity to determine new normative values for handgrip strength in men and women aged 39 to 73 years. These normative values take into consideration age, height, and measurement side. Therefore, these new normative handgrip strength values are of broad clinical interest.

Heterogeneity in clinical characteristics and co-morbidities in dyspneic individuals with COPD GOLD D: findings of the DICES trial.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous respiratory disease with important extra-pulmonary features and comorbidities. The aim of this study was to assess clinical heterogeneity in a well-defined subgroup of individuals with COPD GOLD D, including possible gender differences. METHODS: Pulmonary function, arterial blood gases, exercise performance, quadriceps muscle function, problematic activities of daily life, dyspnea, health status and comorbidities have been assessed in 117 individuals with a MRC dyspnea grade 4/5 and COPD GOLD D entering pulmonary rehabilitation. RESULTS: A broad range of values were found for diffusion capacity, exercise capacity, quadriceps muscle function and health status. Indeed, the high coefficients of variation were found for these outcomes. Problematic activities of daily life as well as objectified comorbidities also varied to a great extent. Moreover, significant gender differences were found for exercise performance, lower-limb muscle function and various comorbidities. CONCLUSION: The current findings emphasize that COPD is a heterogeneous disease whose clinical presentation varies significantly, even in individuals with very severe COPD with the same degree of dyspnea and all classified as GOLD D. TRIAL REGISTRATION: NTR2322.

Effects of neuromuscular electrical stimulation of muscles of ambulation in patients with chronic heart failure or COPD: a systematic review of the English-language literature.

INTRODUCTION: Despite optimal drug treatment, many patients with congestive heart failure (CHF) or COPD still experience disabling dyspnea, fatigue, and exercise intolerance. They also exhibit significant changes in body composition. Attempts to rehabilitate these patients are often futile because conventional exercise-training modalities are limited by the severity of exertional dyspnea. Therefore, there is substantial interest in new training modalities that do not evoke dyspnea, such as transcutaneous neuromuscular electrical stimulation (NMES). MATERIALS AND METHODS: In this article, we systematically review the literature that addresses the effects of NMES applied to the muscles of ambulation. We focused on the effects of NMES on strength, exercise capacity, and disease-specific health status in patients with CHF or COPD. We also address the methodological quality of the reported studies as well as the safety of NMES. Manuscripts published prior to December 2007 were identified by searching the Medline/PubMed, Embase, Cochrane Controlled Trials Register, CINAHL, and Physiotherapy Evidence Database (PEDro) databases. RESULTS: Fourteen trials were identified (nine trials that examined NMES in CHF patients, and five in COPD patients). PEDro scores for methodological quality of the trials were generally moderate to good. Many of the studies reported significant improvements in muscle strength, exercise capacity, and/or health status. DISCUSSION: Nonetheless, the limited number of studies, the disparity in patient populations, and the variability in NMES methodology prohibit the use of metaanalysis. Yet, from the viewpoint of a systematic review, NMES looks promising as a means of rehabilitating patients with CHF and COPD. There is at least sufficient evidence to warrant more large prospective, randomized, controlled trials.