The 6-min walk distance: change over time and value as a predictor of survival in severe COPD

Effect of Rebound Exercises and Circuit Training on Complications Associated with Type 2 Diabetes: Protocol for a Randomized Controlled Trial

BACKGROUND

The incidence of type 2 diabetes mellitus, a chronic lifestyle disease, and its complications are on the rise. Exercise has been documented as being effective in the management of musculoskeletal pain, depression, and reduction of hyperglycemia in diabetic patients. However, there is no consensus regarding the types of exercise that reduce musculoskeletal pain and depression and improve quality of life as well as respiratory function among individuals with type 2 diabetes.

OBJECTIVE

The objective of this study is to determine the effects of rebound and circuit training on musculoskeletal pain, blood glucose level, cholesterol level, quality of life, depression, and respiratory parameters in patients with type 2 diabetes mellitus.

METHODS

A total of 70 participants are expected to be recruited in this single blind randomized controlled trial. Computer-generated random numbers will be used to randomize the participants into 3 groups, namely, the rebound exercise group, the circuit exercise group, and the control group. Measurements will be taken at baseline and at the end of the 8 weeks of the study. Participants' musculoskeletal pain will be assessed using the visual analog scale, quality of life will be assessed using the SF 12 Health Survey Questionnaire, depression using the Beck Depression Inventory, respiratory parameters using the spirometer, and biochemical parameters such as glucose level and cholesterol level using the glucometer. Data will be analyzed using descriptive statistics and inferential statistics of multivariate analysis of variance between the groups and paired t test within the group. Alpha will be set at .05.

RESULTS

The results of this study will identify the effectiveness of rebound exercise and circuit training, compared with the control, in the management of type 2 diabetes mellitus and on quality of life, musculoskeletal pain, depression, glycemic control, cholesterol level, as well as improvement in respiratory function.

CONCLUSIONS

Though different additional strategies such as exercise and dietary and lifestyle modifications exist for the control of type 2 diabetes, they are mostly applied for the control of glucose level. No strategies have been identified for the control of complications associated with diabetes such as musculoskeletal pain, depression, and reduction in quality of life.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03200795; https://clinicaltrials.gov/ct2/show/NCT03200795 (Archived by WebCite at http://www.webcitation.org/6mBgcj6z7).

Determinants of Peripheral Muscle Strength and Activity in Daily Life in People With Bronchiectasis

BACKGROUND

Bronchiectasis is characterized by a progressive structural lung damage, recurrent infections and chronic inflammation which compromise the exertion tolerance, and may have an impact on skeletal muscle function and physical function.

OBJECTIVE

The purpose of this study was to compare peripheral muscle strength, exercise capacity, and physical activity in daily life between participants with bronchiectasis and controls and to investigate the determinants of the peripheral muscle strength and physical activity in daily life in bronchiectasis.

DESIGN

This study used a cross-sectional design.

METHODS

The participants' quadriceps femoris and biceps brachii muscle strength was measured. They performed the incremental shuttle walk test (ISWT) and cardiopulmonary exercise testing, and the number of steps/day was measured by a pedometer.

RESULTS

Participants had reduced quadriceps femoris muscle strength (mean difference to control group = 7 kg, 95% CI = 3.8-10.1 kg), biceps brachii muscle strength (2.1 kg, 95% CI = 0.7-3.4 kg), ISWT (227 m, 95% CI = 174-281 m), peak VO2 (6.4 ml/Kg/min, 95% CI = 4.0-8.7 ml/Kg/min), and number of steps/day (3,332 steps/day, 95% CI = 1,758-4,890 steps/day). A lower quadriceps femoris strength is independently associated to an older age, female sex, lower body mass index (BMI), higher score on the modified Medical Research Council scale, and shorter distance on the ISWT (R2 = 0.449). Biceps brachii strength is independently associated with sex, BMI, and dyspnea (R2 = 0.447). The determinants of number of daily steps were dyspnea and distance walked in ISWT, explaining only 27.7% of its variance.

LIMITATIONS

Number of steps per day was evaluated by a pedometer.

CONCLUSIONS

People with bronchiectasis have reduced peripheral muscle strength, and reduced aerobic and functional capacities, and they also are less active in daily life. Modifiable variables such as BMI, dyspnea, and distance walked on the ISWT are associated with peripheral muscle strength and physical activity in daily life.

Relationship of CT-quantified emphysema, small airways disease and bronchial wall dimensions with physiological, inflammatory and infective measures in COPD

BACKGROUND

COPD is a complex, heterogeneous disease characterised by progressive development of airflow limitation. Spirometry provides little information about key aspects of pathology and is poorly related to clinical outcome, so other tools are required to investigate the disease. We sought to explore the relationships between quantitative CT analysis with functional, inflammatory and infective assessments of disease to identify the utility of imaging to stratify disease to better predict outcomes and disease response.

METHODS

Patients from the AERIS study with moderate-very severe COPD underwent HRCT, with image analysis determining the quantity of emphysema (%LAA_<- 950), small airways disease (E/I MLD) and bronchial wall thickening (Pi10). At enrolment subjects underwent lung function testing, six-minute walk testing (6MWT), blood sampling for inflammatory markers and sputum sampling for white cell differential and microbiological culture and PCR.

RESULTS

122 subjects were included in this analysis. Emphysema and small airways disease had independent associations with airflow obstruction (β = - 0.34, p < 0.001 and β = - 0.56, p < 0.001). %LAA_<- 950 had independent associations with gas transfer (β = - 0.37, p < 0.001) and E/I MLD with RV/TLC (β = 0.30, p =0.003). The distance walked during the 6MWT was not associated with CT parameters, but exertional desaturation was independently associated with emphysema (β = 0.73, p < 0.001). Pi10 did not show any independent associations with lung function or functional parameters. No CT parameters had any associations with sputum inflammatory cells. Greater emphysema was associated with lower levels of systemic inflammation (CRP β = - 0.34, p < 0.001 and fibrinogen β = - 0.28, p =0.003). There was no significant difference in any of the CT parameters between subjects where potentially pathogenic bacteria were detected in sputum and those where it was not.

CONCLUSIONS

This study provides further validation for the use of quantitative CT measures of emphysema and small airways disease in COPD as they showed strong associations with pulmonary physiology and functional status. In contrast to this quantitative CT measures showed few convincing associations with biological measures of disease, suggesting it is not an effective tool at measuring disease activity.

Molecules of Damage-Associated Patterns in Bronchoalveolar Lavage Fluid and Serum in Chronic Obstructive Pulmonary Disease

Chronic exposure to detrimental environmental factors may induce immunogenic cell death of structural airway cells in chronic obstructive pulmonary disease (COPD). Damage-associated molecular patterns (DAMPs) is a family of heterogeneous molecules released from injured or dead cells, which activate innate and adaptive immune responses on binding to the pattern recognition receptors on cells. This study seeks to define the content of DAMPs in the bronchoalveolar lavage fluid (BALF) and serum of COPD patients, and the possible association of these molecules with clinical disease features. Thirty COPD in advanced disease stages were enrolled into the study. Pulmonary function tests, arterial blood gas content, 6-minute walk test, and BODE index were assessed. The content of DAMPs was estimated using the commercial sandwich-ELISA kits. We found differential alterations in the content of various DAMP molecules. In the main, BALF DAMPs positively associated with age, forced expiratory volume in one second (FEV1), and residual volume (RV); and inversely with PaO₂, residual volume/total lung capacity (RV/TLC) ratio, and the disease severity staging. In serum, DAMPS positively associated with the intensity of smoking and inversely with age, PaO₂, and TLC. In conclusion, DAMPs are present in both BALF and serum of COPD patients, which points to enhanced both local in the lung environment as well as systemic pro-inflammatory vein in this disease. These molecules appear involved with the lung damage and clinical variables featuring COPD. However, since the involvement of various DAMPs in COPD is variable, the exact role they play is by far unsettled and is open to further exploration.

Survival following pulmonary rehabilitation in patients with COPD: the effect of program completion and change in incremental shuttle walking test distance

Rationale

Pulmonary rehabilitation (PR) in patients with COPD has consistently been shown to produce benefits in exercise capacity, symptoms, and health status. The data surrounding survival following PR are less clear. Our aims were to compare the long-term survival in two cohorts of patients referred for PR; those who successfully completed PR, and a comparator group constructed from patients who either did not complete PR or did not start the program. Additionally, we compared survival between those people who were able to achieve a clinically meaningful improvement in exercise capacity (incremental shuttle walking test) following PR with those who were not.

Methods

A retrospective longitudinal analysis of clinical service outcomes was conducted to compare the long-term survival in "completers" and "non-completers" of rehabilitation at two hospitals within the University Hospitals of Leicester NHS Trust from January 1, 2000 to February 23, 2012. For "completers", we also analyzed survival in those meeting (and not meeting) the desired level of change in the incremental shuttle walking test (≥50 m vs <50 m).

Results

We present to you the largest dataset on this topic (n=1,515). Survival data were ascertained for 823 (54.3%) patients with COPD who had completed a course of PR and for 692 (45.7%) patients who dropped out. Survival time was significantly greater in "completers" compared to "non-completers" of PR (p<0.001). In addition, PR success (≥50 m change in walking distance) was also associated with improved survival (p<0.05).

Conclusion

The data show an association between completion of PR and survival. In addition, PR success (>50 m change in walking distance) was also associated with improved survival.

Hand grip endurance test relates to clinical state and prognosis in COPD patients better than 6-minute walk test distance

Purpose

Patients with COPD present peripheral muscle dysfunction and atrophy, expressed as muscle strength and endurance reduction. The goal of this study was direct dynamometric assessment of hand grip endurance and strength in relation to the stage of disease, multidimensional predictors of mortality, and 6-minute walk test (6MWT). To the best of our knowledge, there has been no previous study determining these parameters.

Patients and methods

In this observational study, 58 consecutive outpatients with stable COPD and 25 volunteers without respiratory problems were compared. All COPD subjects underwent a comprehensive examination to determine COPD severity, prognostic scales, and 6MWT. Body composition, basic spirometric parameters, and hand grip strength and endurance were determined in all study participants.

Results

Patients in the COPD group had a 15% decrease in maximum strength (P=0.012) and a 28% decrease in area under the force/time curve (AUC) of the endurance test (P<0.001) compared to the control group. Dynamometric parameters were significantly negatively associated with the stage of disease and values of multivariable prediction indexes, and positively associated with the results of 6MWT. In most cases, closer associations were found with AUC than with 6MWT and in the gender-specific groups.

Conclusion

Both hand grip strength and endurance are impaired in COPD patients in comparison with the control group. In particular, AUC could be considered as an attractive option not only to assess exercise capacity but also as a predictive marker with a better prognostic value than 6MWT in COPD patients. This is the first study to observe the dependence of hand grip endurance on combined COPD assessment.

Capturing complexity in pulmonary system modelling

Respiratory disease is a significant problem worldwide, and it is a problem with increasing prevalence. Pathology in the upper airways and lung is very difficult to diagnose and treat, as response to disease is often heterogeneous across patients. Computational models have long been used to help understand respiratory function, and these models have evolved alongside increases in the resolution of medical imaging and increased capability of functional imaging, advances in biological knowledge, mathematical techniques and computational power. The benefits of increasingly complex and realistic geometric and biophysical models of the respiratory system are that they are able to capture heterogeneity in patient response to disease and predict emergent function across spatial scales from the delicate alveolar structures to the whole organ level. However, with increasing complexity, models become harder to solve and in some cases harder to validate, which can reduce their impact clinically. Here, we review the evolution of complexity in computational models of the respiratory system, including successes in translation of models into the clinical arena. We also highlight major challenges in modelling the respiratory system, while making use of the evolving functional data that are available for model parameterisation and testing.

Joint statement for the diagnosis, management, and prevention of chronic obstructive pulmonary disease for Gulf Cooperation Council countries and Middle East-North Africa region, 2017

Smoking and subsequent development of COPD is an ever-increasing epidemic in Arabian Gulf and Middle East countries, with no signs of decline. The important fact to be highlighted is that this COPD epidemic of increasing incidence and prevalence is mostly unrecognized by patients, due to the common attribution of symptoms to "smoker's cough", and the underdiagnosis and undertreatment by physicians because the common signs and symptoms masquerade as asthma. Consequently, there are long-term adverse effects of missing the diagnosis. The purpose of this review article is to focus upon the status of COPD in Arabian Gulf and Middle East countries, stressing the increasing burden of smoking and COPD, to emphasize the specific factors leading to rise in prevalence of COPD, to bring to light the underdiagnosis and undermanagement of COPD, and to treat COPD in conformity with standard guidelines with local and regional modifications. This review ends with suggestions and recommendations to the health department to formulate policies and to generate awareness among the general public about the side effects of smoking and consequences of COPD.

Reference equations for the six-minute walk distance in the healthy Chinese population aged 18-59 years

BACKGROUND

The six-minute walk test (6MWT) is a safe, simple, inexpensive tool for evaluating the functional exercise capacity of patients with chronic respiratory disease. However, there is a lack of standard reference equations for the six-minute walk distance (6MWD) in the healthy Chinese population aged 18-59 years.

AIMS

The purposes of the present study were as follows: 1) to measure the anthropometric data and walking distance of a sample of healthy Chinese Han people aged 18-59 years; 2) to construct reference equations for the 6MWD; 3) to compare the measured 6MWD with previously published equations.

METHOD

The anthropometric data, demographic information, lung function, and walking distance of Chinese adults aged 18-59 years were prospectively measured using a standardized protocol. We obtained verbal consent from all the subjects before the test, and the study design was approved by the ethics committee of Wenzhou People's Hospital. The 6MWT was performed twice, and the longer distance was used for further analysis.

RESULTS

A total of 643 subjects (319 females and 324 males) completed the 6MWT, and average walking distance was 601.6±55.51 m. The walking distance was compared between females and males (578±49.85 m vs. 623±52.53 m; p < 0.0001) and between physically active subjects and sedentary subjects (609.3±56.17 m vs. 592±53.23 m; p < 0.0001). Pearson's correlation indicated that the 6MWD was significantly correlated with various demographic and the 6MWT variables, such as age, height, weight, body mass index (BMI), heart rate after the test and the difference in the heart rate before and after the test. Stepwise multiple regression analysis showed that age and height were independent predictors associated with the 6MWD. The reference equations from white, Canadian and Chilean populations tended to overestimate the walking distance in our subjects, while Brazilian and Arabian equations tended to underestimate the walking distance. There was no significant difference in the walking distance between Korean reference equations and the results of the current study.

CONCLUSION

In summary, age and height were the most significant predictors of the 6MWD, and regression equations could explain approximately 34% and 28% of the distance variance in the female and male groups, respectively.

Chronic Obstructive Pulmonary Disease in Elderly Patients

Chronic obstructive pulmonary disease (COPD) is prevalent in the elderly population, with high impact on quality of life, morbidity, and mortality. The diagnosis is usually made based on symptoms and spirometry values that support the presence of airflow obstruction. However, the condition is frequently underdiagnosed. COPD is associated with premature aging and several other medical conditions that can partially explain its underdiagnosis and management. There are several pharmacologic and nonpharmacologic interventions proven to be effective in ameliorating the symptoms of COPD. Appropriate drug delivery and reduction of side effects is also pivotal in the management of patients with COPD.

Hand grip strength in patients with chronic obstructive pulmonary disease

PURPOSE

Hand grip strength (HGS) is a simple way of predicting the risk of cardiovascular disease and all-cause mortality in the general population. However, the practical significance of grip strength in patients with COPD is uncertain. The aim of this study was to compare HGS between subjects with and without COPD and to evaluate its clinical relevance in patients with COPD by using a national survey.

METHODS

Data were collected from the Korean National Health and Nutrition Examination Survey. The study included 421 adults with COPD and 2,542 controls who completed questionnaires, spirometry, and a HGS test. HGS was compared between subjects with and without COPD, and the association between grip strength, lung function, and quality of life (QoL) was evaluated.

RESULTS

The mean HGS was 33.3±9.1 kg in the COPD group and 29.9±9.5 kg in the non-COPD group; adjusted HGS was 30.9±0.33 kg and 30.9±0.11 kg, respectively (P=0.99). HGS was not related to forced vital capacity (β=0.04, P=0.70) or forced expiratory volume in 1 second (β=0.11, P=0.24) in multivariable analysis. HGS was independently associated with the EQ-5D index, but the relationship was stronger in the COPD group (β=0.30, P<0.001) than in the non-COPD group (β=0.21, P<0.001). The results were similar for each component of the EQ-5D, including mobility (β=-0.25, P<0.001), daily activity (β=-0.19, P=0.01), pain/discomfort (β=-0.32, P<0.001), and anxiety/depression (β=-0.16, P=0.01).

CONCLUSION

HGS was not different between subjects with and without COPD, but was associated with QoL - including mobility, daily activity, pain/discomfort, and anxiety/depression - in patients with COPD. The HGS test could be used as a marker of QoL in patients with COPD and could assist risk stratification in clinical practice.

Different prevalence and clinical characteristics of asthma-chronic obstructive pulmonary disease overlap syndrome according to accepted criteria

BACKGROUND

A unified definition of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is not available, which makes it difficult to evaluate the prevalence and clinical features of patients with ACOS.

OBJECTIVE

To investigate the prevalence and clinical characteristics of ACOS according to the updated widely accepted diagnostic criteria.

METHODS

Participants were enrolled from a prospective cohort study conducted between April 2013 and November 2016 in South Korea. We adopted 4 criteria of ACOS: modified Spanish, American Thoracic Society (ATS) Roundtable criteria, the Latin American Project for the Investigation of Obstructive Lung Disease (PLATINO), and the Global Initiative for Asthma/Global Initiative for Chronic Obstructive Lung Disease (GINA/GOLD) criteria. The prevalence, clinical characteristics, and exacerbations of ACOS were investigated.

RESULTS

Among 301 patients with chronic obstructive pulmonary disease, 31.3%, 11.9%, 48.3%, and 46.15% were diagnosed with ACOS according to the modified Spanish, ATS Roundtable criteria, PLATINO, and GINA/GOLD criteria, respectively. Compared with other criteria, patients with ACOS diagnosed according to the modified Spanish criteria had better exercise capacity and lung function at baseline but higher risk of moderate to severe (adjusted hazard ratio, 1.97; 95% confidence interval, 1.14-3.41; P = .01) and total (adjusted odds ratio, 2.10; 95% confidence interval, 1.33-3.31; P < .01) exacerbations during at least a 1-year follow-up period than patients without ACOS.

CONCLUSION

The prevalence of ACOS varied according to the diagnostic criteria. Among the different criteria, the modified Spanish criteria could identify patients with more asthmatic features and higher risk of exacerbation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02527486.

Are heart rate dynamics in the transition from rest to submaximal exercise related to maximal cardiorespiratory responses in COPD?

BACKGROUND

Poor exercise capacity is an important negative prognostic marker in patients with chronic obstructive pulmonary disease (COPD). Heart rate variability (HRV) responses can indicate alterations in cardiac autonomic control. Nevertheless, it remains unclear whether these abnormalities are related to cardiorespiratory responses to exercise in these patients.

OBJECTIVE

To evaluate whether HRV at rest and submaximal exercise are related to impaired cardiopulmonary responses to exercise in COPD patients.

METHODS

Fifteen men (66.2±8.7 years) with COPD (FEV1: 55.1±19.2%) were assessed. The R-R interval (RRi) data collection was performed at rest (stand position) and during the six-minute walk test (6MWT). All patients performed a symptom-limited cardiopulmonary exercise test on a cycle ergometer. The HRV changes from rest to submaximal exercise (Δ rest-6MWT) were calculated.

RESULTS

We found significant correlations between low frequency (LF) and high frequency (HF) Δ rest-6MWT with Δ oxyhemoglobin saturation by pulse oximetry (r=-0.64 and r=0.65, respectively; p<0.05), minute ventilation/carbon dioxide output relationship from beginning to peak exercise (r=-0.52 and r=0.53, p<0.05), and exercise ventilatory power (r=0.52 and r=-0.53, p<0.05). Interestingly, there was a strong positive correlation (r=0.82, p<0.05) between six-minute walk distance (6MWD) and Δ LF/HF from rest to exercise.

CONCLUSION

HRV analysis in the transition from rest to submaximal exercise is associated with exercise ventilatory and hemodynamic abnormalities in COPD patients. Rehabilitative strategies to improve HRV responses may provide an important tool to clinical practice in these patients.

Image-based computational fluid dynamics in the lung: virtual reality or new clinical practice?

The development and implementation of personalized medicine is paramount to improving the efficiency and efficacy of patient care. In the respiratory system, function is largely dictated by the choreographed movement of air and blood to the gas exchange surface. The passage of air begins in the upper airways, either via the mouth or nose, and terminates at the alveolar interface, while blood flows from the heart to the alveoli and back again. Computational fluid dynamics (CFD) is a well-established tool for predicting fluid flows and pressure distributions within complex systems. Traditionally CFD has been used to aid in the effective or improved design of a system or device; however, it has become increasingly exploited in biological and medical-based applications further broadening the scope of this computational technique. In this review, we discuss the advancement in application of CFD to the respiratory system and the contributions CFD is currently making toward improving precision medicine. The key areas CFD has been applied to in the pulmonary system are in predicting fluid transport and aerosol distribution within the airways. Here we focus our discussion on fluid flows and in particular on image-based clinically focused CFD in the ventilatory system. We discuss studies spanning from the paranasal sinuses through the conducting airways down to the level of the alveolar airways. The combination of imaging and CFD is enabling improved device design in aerosol transport, improved biomarkers of lung function in clinical trials, and improved predictions and assessment of surgical interventions in the nasal sinuses. WIREs Syst Biol Med 2017, 9:e1392. doi: 10.1002/wsbm.1392 For further resources related to this article, please visit the WIREs website.

Predictors and Association With Clinical Outcomes of the Changes in Exercise Capacity After Transcatheter Aortic Valve Replacement

BACKGROUND

At present, there are no objective data specifically examining the clinical impact of variations in exercise capacity post-transcatheter aortic valve replacement (TAVR). We describe the changes in exercise capacity between baseline and 6 months post-TAVR, and ascertain factors associated with and clinical implications of a lack of improvement in exercise capacity post-TAVR.

METHODS

A total of 305 patients (mean age, 79±9 years; 44% men; Society of Thoracic Surgeons predicted risk mortality score, 6.7±4.2%) undergoing TAVR completed both baseline and follow-up exercise capacity assessments at 6 months post-TAVR. Exercise capacity was evaluated by the 6-minute walk test (6MWT). Clinical outcomes were compared between patients displaying greater than (n=152; improving group) versus less than (n=153; nonimproving group) the median percentage change in distance walked between baseline and 6-month follow-up examinations. The primary outcome measure was clinical event rates, measured from the 6-month post-TAVR period onward. Further dichotomization according to baseline 6MWT distance (less than versus more than median walking distance, or slow walker versus fast walker) was also assessed.

RESULTS

The mean overall distances walked pre- and post-TAVR (6 months post-TAVR) were 204±119 and 263±116 m, respectively (Δ6MWT=60±106 m), with 219 (72%) patients demonstrating an increase in their walking distance (median percentage increase of the entire population was 20% [interquartile range, 0%-80%]). Factors independently correlated with reduced exercise capacity improvement included a range of baseline clinical characteristics (older age, female sex, chronic obstructive pulmonary disease; P<0.05 for all), periprocedural major or life-threatening bleeding (P=0.009) and new-onset anemia at 6 months post-TAVR (P=0.009). Failure to improve the 6MWT distance by at least 20% was independently associated with all-cause mortality (P=0.002) and cardiovascular death or rehospitalization for cardiovascular causes (P=0.001). Baseline slow walkers who were able to improve the 6MWT distance presented with significantly better outcomes than nonimprovers (P=0.01 for all-cause mortality; P=0.001 for cardiovascular end point).

CONCLUSIONS

Approximately one-third of patients undergoing TAVR did not improve their exercise capacity postprocedure. The lack of functional improvement post-TAVR was predicted by a mix of baseline and periprocedural factors translating into poorer clinical outcomes. These results suggest that systematically implementing exercise capacity assessment pre- and post-TAVR may help to improve patient risk stratification.

Exertional dyspnoea in COPD: the clinical utility of cardiopulmonary exercise testing

Activity-related dyspnoea is often the most distressing symptom experienced by patients with chronic obstructive pulmonary disease (COPD) and can persist despite comprehensive medical management. It is now clear that dyspnoea during physical activity occurs across the spectrum of disease severity, even in those with mild airway obstruction. Our understanding of the nature and source of dyspnoea is incomplete, but current aetiological concepts emphasise the importance of increased central neural drive to breathe in the setting of a reduced ability of the respiratory system to appropriately respond. Since dyspnoea is provoked or aggravated by physical activity, its concurrent measurement during standardised laboratory exercise testing is clearly important. Combining measurement of perceptual and physiological responses during exercise can provide valuable insights into symptom severity and its pathophysiological underpinnings. This review summarises the abnormal physiological responses to exercise in COPD, as these form the basis for modern constructs of the neurobiology of exertional dyspnoea. The main objectives are: 1) to examine the role of cardiopulmonary exercise testing (CPET) in uncovering the physiological mechanisms of exertional dyspnoea in patients with mild-to-moderate COPD; 2) to examine the escalating negative sensory consequences of progressive respiratory impairment with disease advancement; and 3) to build a physiological rationale for individualised treatment optimisation based on CPET.

Safety of early performance of the six-minute walk test following acute myocardial infarction: a cross-sectional study

•

Coronary artery disease (CAD) is one of the main causes of death.

•

The stress test is indispensable before cardiac rehabilitation.

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The 6MWT is a simple, low-cost, valid, and reliable method.

•

The 6MWT can be used safely in the hospital after an AMI.

Background

The six-minute walk test (6MWT) is a simple, low cost, reliable, and valid method for evaluating the functional capacity of cardiac patients. However, its early use and safety following acute myocardial infarction (AMI) is recent and has been little investigated.

Objective

To evaluate and to compare the safety and the cardiac behavior of early performance of the 6MWT in patients following uncomplicated AMI up to 4 days or more than 4 days after the event.

Methods

Following discharge from the Coronary Care Unit, 152 stable asymptomatic patients diagnosed with uncomplicated AMI performed the 6MWT. During the test, in addition to the distance walked, heart rate (HR), blood pressure (BP), and adverse events were also recorded. Electrocardiography was recorded using a Holter monitor in 105 patients. Patients were allocated considering two groups according to the number of days since AMI: Up to 4 Days Group and After 4 Days Group.

Results

All patients completed the 6MWT, 66 in the Up to 4 Days Group and 86 in the After 4 Days Group. The walking distance was similar in both groups (85% of the predicted value), as well as the physiological responses (increase in systolic BP and HR), reaching 63% (median) of maximum HR. Only 3.9% of patients had major complications (angina, drop in BP, or ventricular tachycardia), with no difference between the groups. None of the complications regarded as severe led to truly significant complications or death.

Conclusion

The 6MWT was proven to be safe and feasible for early functional evaluation following uncomplicated AMI.

Six Minute Walk Test: A Tool for Predicting Mortality in Chronic Pulmonary Diseases

INTRODUCTION

Six Minute Walk Test (6MWT) is a simple test used to measure exercise capacity in Chronic Pulmonary Diseases (CPDs). Decreased exercise capacity significantly affects the quality of life. The 6MWT is a known tool to measure exercise capacity and quality of life in CPD. However, the role of change in follow up Six Minute Walk Distance (6MWD) in assessing mortality and its correlation with known prognostic factors haven't been tested to the best of our knowledge.

AIM

To study the correlation of change in 6MWD with change in spirometry and to study the role of 6MWD in predicting mortality in CPD.

SETTINGS AND DESIGN

Prospective cohort study.

MATERIALS AND METHODS

A total of 139 CPD patients were grouped into obstructive, restrictive and post Tuberculosis (TB) sequelae. Optimized treatment was given and they were followed up regularly. Spirometry and 6MWT was done at the beginning and after one year. Mean decline in FEV1, FVC was correlated with mean decline in 6MWD.

STATISTICAL ANALYSIS

With STATA 13.1 correlation between 6MWT and spirometric values were done using Wilcoxon signed rank test. Predictors of mortality were studied using multivariate analysis.

RESULTS

Overall mean decline in 6MWD was 16.07 m/year. There was no correlation between mean change in 6MWD and change in FEV1, FVC, and FEV1/FVC. On multivariate analysis, 6MWD was the better predictor of mortality than FEV1 (p<0.001), FVC (p<0.001). At cut off value of 240 meters, sensitivity and specificity of 6MWT in predicting mortality was 71.05% and 81.94% respectively.

CONCLUSION

The 6MWD changes independently and has no correlation with change in spirometry, it is an independent predictor of mortality in CPD.

Predicting Pulmonary Function from Phone Sensors

Introduction:Smartphones are ubiquitous, but it is unknown what physiological functions can be monitored at clinical quality. Pulmonary function is a standard measure of health status for cardiopulmonary patients. We have shown phone sensors can accurately measure walking patterns. Here we show that improved classification models can accurately predict pulmonary function, with sole inputs being motion sensors from carried phones.

Subjects and Methods:Twenty-five cardiopulmonary patients performed 6-minute walk tests in pulmonary rehabilitation at a regional hospital. They carried smartphones running custom software recording phone motion. Each patient's pulmonary function was measured by spirometry. A universal model, based on support vector machine, then computed the category of function with input from signal processing features and patient demographic features.

Results:All but a few of every 10-second interval for every patient was correctly predicted. The trained model perfectly computed the GOLD (Global Initiative for Chronic Obstructive Lung Disease) level 1/2/3, which is a standard classification of pulmonary function. Each level was determined to have a characteristic motion, which could be recognized from the sensor features. In addition, longitudinal changes were detected for 10 patients with multiple walk tests, except for cases with clinical instability.

Conclusions:These results are encouraging toward clinical validation of passive monitors running continuously in the background, for patients in homes during daily activities. Initial testing indicates the same high accuracy as with active monitors, for patients in hospitals during walk tests. We expect patients can simply carry their phones during everyday living, while models support automatic prediction of pulmonary function for health monitoring.

Assessing upper-extremity motion: An innovative method to quantify functional capacity in patients with chronic obstructive pulmonary disease

BACKGROUND

Assessment of functional capacity is important in directing chronic obstructive pulmonary disease (COPD) care (e.g., rehabilitation and discharge readiness), and in predicting outcomes (e.g., exacerbation, hospitalization, and mortality). The 6-minute walk distance (6MWD) test for functional capacity assessment, may be time-consuming and burdensome.

OBJECTIVE

The purpose of the current study was to evaluate an upper-extremity function (UEF) test for assessing functional capacity in older adults with COPD.

METHODS

In this cross-sectional study, 49 older adults (≥55 years) with diagnosed COPD were recruited, and pulmonary function measures and 6MWD were obtained. Participants wore wireless sensors on forearm and upper-arm and performed rapid elbow flexion for 20 seconds (the UEF test). Slowness was assessed by measuring elbow speed, and acceleration and weakness (muscle strength) were assessed by measuring power of movement and elbow moment.

RESULTS

Speed, power, and moment UEF parameters were independently associated with 6MWD, when controlling for age, gender, and body mass index (BMI) (r = 0.78, p < .001). Elbow moment showed significant Pearson correlations with all pulmonary function measures and maximal inspiratory/expiratory pressure measures (r = 0.35-0.69, p<0.02).

CONCLUSIONS

Results show promise of a quick upper-extremity measure of functional capacity in patients with COPD, and as an outcome measure in clinical COPD trials.

Advances in the Evaluation of Respiratory Pathophysiology during Exercise in Chronic Lung Diseases

Dyspnea and exercise limitation are among the most common symptoms experienced by patients with various chronic lung diseases and are linked to poor quality of life. Our understanding of the source and nature of perceived respiratory discomfort and exercise intolerance in chronic lung diseases has increased substantially in recent years. These new mechanistic insights are the primary focus of the current review. Cardiopulmonary exercise testing (CPET) provides a unique opportunity to objectively evaluate the ability of the respiratory system to respond to imposed incremental physiological stress. In addition to measuring aerobic capacity and quantifying an individual's cardiac and ventilatory reserves, we have expanded the role of CPET to include evaluation of symptom intensity, together with a simple "non-invasive" assessment of relevant ventilatory control parameters and dynamic respiratory mechanics during standardized incremental tests to tolerance. This review explores the application of the new advances in the clinical evaluation of the pathophysiology of exercise intolerance in chronic obstructive pulmonary disease (COPD), chronic asthma, interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). We hope to demonstrate how this novel approach to CPET interpretation, which includes a quantification of activity-related dyspnea and evaluation of its underlying mechanisms, enhances our ability to meaningfully intervene to improve quality of life in these pathologically-distinct conditions.

End-of-life prognostic indicators in patients with COPD: part 2

In the UK, chronic respiratory diseases cause 13% of adult disability. The major chronic respiratory disease is chronic obstructive pulmonary disease (COPD), a condition involving chronic airway inflammation that causes airflow obstruction and destruction of lung tissue. This leads to a progressive loss of respiratory membrane, which accounts for the clinical manifestation of COPD, which is difficulty maintaining sufficient gas exchange to meet metabolic demands. The primary cause is smoking, with the vast majority of COPD patients having a past or present history of smoking. However, exposure to industrial pollutants is also a contributing factor, as is a rare genetic predisposition to developing COPD.

The predictive value of an adjusted COPD assessment test score on the risk of respiratory-related hospitalizations in severe COPD patients

We evaluated whether a chronic obstructive pulmonary disease (COPD) assessment test (CAT) with adjusted weights for the CAT items could better predict future respiratory-related hospitalizations than the original CAT. Two focus groups (respiratory nurses and physicians) generated two adjusted CAT algorithms. Two multivariate logistic regression models for infrequent (≤1/year) versus frequent (>1/year) future respiratory-related hospitalizations were defined: one with the adjusted CAT score that correlated best with future hospitalizations and one with the original CAT score. Patient characteristics related to future hospitalizations ( p ≤ 0.2) were also entered. Eighty-two COPD patients were included. The CAT algorithm derived from the nurse focus group was a borderline significant predictor of hospitalization risk (odds ratio (OR): 1.07; 95% confidence interval (CI): 1.00-1.14; p = 0.050) in a model that also included hospitalization frequency in the previous year (OR: 3.98; 95% CI: 1.30-12.16; p = 0.016) and anticholinergic risk score (OR: 3.08; 95% CI: 0.87-10.89; p = 0.081). Presence of ischemic heart disease and/or heart failure appeared 'protective' (OR: 0.17; 95% CI: 0.05-0.62; p = 0.007). The original CAT score was not significantly associated with hospitalization risk. In conclusion, as a predictor of respiratory-related hospitalizations, an adjusted CAT score was marginally significant (although the original CAT score was not). 'Previous respiratory-related hospitalizations' was the strongest factor in this equation.

End-of-life prognostic indicators in patients with COPD: Part 1

In the UK, chronic respiratory diseases cause 13% of adult disability. The major chronic respiratory disease is chronic obstructive pulmonary disease (COPD), a condition involving chronic airway inflammation that causes airflow obstruction and destruction of lung tissue. This leads to a progressive loss of respiratory membrane, which accounts for the clinical manifestation of COPD, which is difficulty maintaining sufficient gas exchange to meet metabolic demands. The primary cause is smoking, with the vast majority of COPD patients having a past or present history of smoking. However exposure to industrial pollutants is also a contributing factor, as is a rare genetic predisposition to developing COPD.

Decreased left ventricular stroke volume is associated with low-grade exercise tolerance in patients with chronic obstructive pulmonary disease

BACKGROUND

Low-grade exercise tolerance is associated with a poor prognosis in patients with chronic obstructive pulmonary disease (COPD). The 6 min walk test (6MWT) is commonly used to evaluate exercise tolerance in patients with COPD. However, little is known regarding the relationship between cardiac function and exercise tolerance in patients with COPD. The aim of this study was to identify predictive factors in cardiac function for low-grade exercise tolerance in patients with stable COPD.

METHODS

We recruited 57 patients with stable COPD (men 54, women 3) to perform the 6MWT. Patients with underlying orthopaedic disease or heart failure were excluded. Cardiac function was evaluated by echocardiography and contrast-enhanced cardiac CT. We also measured pulmonary function and the 6MWT distance.

RESULTS

Forced expiratory volume in 1 s (FEV₁) and per cent predicted FEV, along with left ventricular end diastolic volume and left ventricular cardiac output as measured by cardiac CT, were significantly related to the 6MWT distance. On multivariate analysis, left ventricular stroke volume was the factor most closely associated with a decreased walked distance in the 6MWT.

CONCLUSIONS

Decreased left ventricular stroke volume was associated with low-grade exercise tolerance in patients with stable COPD without heart failure.

A Pilot Randomized, Controlled Trial of a Wall Climbing Intervention for Gynecologic Cancer Survivors

PURPOSE/OBJECTIVES

To examine the feasibility and preliminary efficacy of an eight-week supervised climbing intervention for gynecologic cancer survivors (GCSs).
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DESIGN

A pilot randomized, controlled trial.
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SETTING

The Wilson Climbing Center in Edmonton, Alberta, Canada.
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SAMPLE

35 GCSs who had completed cancer therapy.
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METHODS

GCSs were randomized to an eight-week (16 session) supervised wall climbing intervention (WCI) (n = 24) or usual care (UC) (n = 11).
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MAIN RESEARCH VARIABLES

Feasibility outcomes included recruitment rate, adherence rate, skill performance, and safety. Preliminary efficacy outcomes were objective health-related and functional fitness assessed before and after the eight-week intervention using the Senior Fitness Test.
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FINDINGS

Median adherence to the WCI was 13.5 of 16 sessions. Most GCSs were proficient on 16 of 24 skill assessment items. No serious adverse events were reported. Based on intention-to-treat analyses, the WCI group was superior to the UC group for the 6-minute walk, 30-second chair stand, 30-second arm curls, sit and reach, 8-foot up-and-go, grip strength-right, and grip strength-left assessments.
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CONCLUSIONS

The Gynecologic Cancer Survivors Wall Climbing for Total Health (GROWTH) Trial demonstrated that an eight-week supervised WCI was safe, feasible, and improved functional fitness in GCSs. Phase II and III trials are warranted to further establish the safety, feasibility, and efficacy of WCIs in cancer survivors.
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IMPLICATIONS FOR NURSING

Oncology nurses may consider a climbing wall as an alternative type of physical activity for improving functional fitness in GCSs.

A Modified Method for Examining the Walking Pattern and Pace of COPD Patients in a 6-min Walk Test Before and After the Inhalation of Procaterol

Objective The 6-min walk test (6MWT) is a simple test that is used to examine the exercise tolerance and outcomes in patients with chronic obstructive pulmonary disease (COPD). Although the 6MWT is useful for assessing exercise tolerance, it is difficult to evaluate time-dependent parameters such as the walking pattern. A modified 6MWT has been devised to assess the walking pattern by calculating the number of steps per second (NSPS). This study was performed to investigate walking pattern of COPD patients in the modified 6MWT before and after a single inhalation of the short-acting β₂-agonist procaterol. Methods Nine male COPD patients participated in this study. The 6MWT was performed before and after the inhalation of procaterol hydrochloride. A digital video recording of the 6MWT was made. After the 6MWT, the number of steps walked by the subject in each 5-s period was counted manually with a hand counter while viewing the walking test on the video monitor. Results After the inhalation of procaterol, the 6-min walking distance increased significantly in comparison to baseline (p<0.01). The mean NSPS was also significantly increased after the inhalation of procaterol in comparison to baseline (p<0.01). The walking pattern was displayed on a graph of time versus NSPS, and the walking pace was shown by a graph of time versus cumulative steps. Conclusion The analysis of the COPD patients' walking test performance and their walking pattern and pace in the 6MWT may help to evaluate the effects of drug treatment.

Inadequate Palliative Care in Chronic Lung Disease. An Issue of Health Care Inequality

Patients with chronic lung diseases suffer higher symptom burden, lower quality of life, and greater social isolation compared with patients with other diagnoses, such as cancer. These conditions may be alleviated by palliative care, yet palliative care is used less by patients with chronic lung disease compared with patients with cancer. Underuse is due, in part, to poor implementation of primary palliative care and inadequate referral to specialty palliative care. Lack of primary and specialty palliative care in patients with chronic lung disease falls short of the minimum standard of competent health care, and represents a disparity in health care and a social injustice. We invoke the ethical principles of justice and sufficiency to highlight the importance of this issue. We identify five barriers to implementing palliative care in patients with chronic lung disease: uncertainty in prognosis; lack of provider skill to engage in discussions about palliative care; fear of using opioids among patients with chronic lung disease; fear of diminishing hope; and perceived and implicit bias against patients with smoking-related lung diseases. We propose mechanisms for improving implementation of palliative care for patients with chronic lung disease with the goal of enhancing justice in health care.

The 6-Minute-Walk Distance Test as a Chronic Obstructive Pulmonary Disease Stratification Tool. Insights from the COPD Biomarker Qualification Consortium

RATIONALE

The 6-minute-walk distance (6MWD) test predicts mortality in chronic obstructive pulmonary disease (COPD). Whether variability in study type (observational vs. interventional) or region performed limits use of the test as a stratification tool or outcome measure for therapeutic trials is unclear.

OBJECTIVES

To analyze the original data from several large observational studies and from randomized clinical trials with bronchodilators to support the qualification of the 6MWD test as a drug development tool in COPD.

METHODS

Original data from 14,497 patients with COPD from six observational (n = 9,641) and five interventional (n = 4,856) studies larger than 100 patients and longer than 6 months in duration were included. The geographical, anthropometrics, FEV1, dyspnea, comorbidities, and health status scores were measured. Associations between 6MWD and mortality, hospitalizations, and exacerbations adjusted by study type, age, and sex were evaluated. Thresholds for outcome prediction were calculated using receiver operating curves. The change in 6MWD after inhaled bronchodilator treatment and surgical lung volume reduction were analyzed to evaluate the responsiveness of the test as an outcome measure.

MEASUREMENTS AND MAIN RESULTS

The 6MWD was significantly lower in nonsurvivors, those hospitalized, or who exacerbated compared with those without events at 6, 12, and greater than 12 months. At these time points, the 6MWD receiver operating characteristic curve-area under the curve to predict mortality was 0.71, 0.70, and 0.68 and for hospitalizations was 0.61, 0.60, and 0.59, respectively. After treatment, the 6MWD was not different between placebo and bronchodilators but increased after surgical lung volume reduction compared with medical therapy. Variation across study types (observational or therapeutic) or regions did not confound the ability of 6MWD to predict outcome.

CONCLUSIONS

The 6MWD test can be used to stratify patients with COPD for clinical trials and interventions aimed at modifying exacerbations, hospitalizations, or death.

Estimulação elétrica transcutânea diafragmática pela corrente russa em portadores de DPOC

RESUMO A doença pulmonar obstrutiva crônica (DPOC) ocasiona prejuízos na mecânica pulmonar, interferindo na atuação, mobilidade e conformidade do diafragma. A estimulação elétrica diafragmática tradicional é capaz de gerar benefícios ao pneumopata; poderia a corrente russa ser outra opção? Objetivou-se identificar as alterações após estimulação diafragmática elétrica transcutânea pela corrente russa em indivíduos portadores de DPOC. Trata-se de estudo prospectivo, quase experimental, com os seguintes critérios de inclusão: estabilidade medicamentosa, cessação tabágica, DPOC grau III e IV e manutenção do estilo de vida. Foram avaliadas medidas antropométricas, respiratórias e funcionais. A estimulação diafragmática se deu pelo Endophasys R ET 9701 por quatro meses, duas vezes por semana, com 30 sessões. O tempo de terapia e frequência para cada sessão foram: 18 min. (20 a 30 Hz) e 12 min. (70 a 100 Hz), respectivamente. Para análise dos dados foi aplicado teste “t” de Student (p<0,05). Participaram do tratamento 13 DPOC, sendo 11 (84,6%) do sexo masculino, todos brancos com idade de 68,46±11,11 anos e carga tabágica de 74,03±56,2 maços-ano. Ao final da intervenção houve mudanças no: volume minuto de 14,47±4,72 para 13,03±4,00 L/min.; índice BODE de 3,92±2,10 para 3,23±1,87; e distância no teste de caminhada de 6 minutos (TC6) de 336±76,36 para 402,76±51,29 m. Concluiu-se que a estimulação elétrica diafragmática por meio da corrente russa promove benefícios significativos ao portador de DPOC, proporcionando melhora respiratória e funcional.

Survival after pulmonary rehabilitation in patients with COPD: impact of functional exercise capacity and its changes

The impact of rehabilitation-induced changes in 6-minute walk distance (6MWD) on the survival of patients with chronic obstructive pulmonary disease (COPD) has not been fully elucidated. This study sought to determine the association of baseline 6MWD and its changes after pulmonary rehabilitation (PR) with 5-year survival in patients with COPD. Patients who were referred to a 12-week outpatient PR program were followed up for 5 years postcompletion, and survival status was verified. Survival was analyzed according to four groups based upon initial 6MWD (6MWDi) and its changes (Δ6MWD) after PR (Group 1: 6MWDi ≥350 m and Δ6MWD ≥30 m; Group 2: 6MWDi ≥350 m and Δ6MWD <30 m; Group 3: 6MWDi <350 m and Δ6MWD ≥30 m; and Group 4: 6MWDi <350 m and Δ6MWD <30 m) via Kaplan–Meier analysis and log rank test. Cox regression was performed to identify possible confounders of mortality estimates. In total, 423 patients (with mean ± standard deviation of forced expiratory volume in the first second [FEV₁] 43±16% predicted, age 65±8 years, and 6WMDi 381±134 m) underwent PR between 1999 and 2010. Survival rates decreased progressively from Group 1 to Group 4 (Group 1, 81%; Group 2, 69%; Group 3, 47%; Group 4, 27%; log rank test, P<0.05). 6MWDi ≥350 m (hazard ratio [HR] 0.39 [95% confidence interval {CI} 0.30–0.50]) and Δ6MWD ≥30 m (HR 0.66 [95% CI 0.51–0.85]) were strongly and independently associated with survival. Compared with Group 1, mortality risks progressively increased in Group 2 (HR 1.36 [95% CI 0.92–2.00]; not significant), Group 3 (HR 1.90 [95% CI 1.28–2.84]; P=0.001), and Group 4 (HR 3.28 [95% CI 2.02–5.33]; P<0.0001). Both poor 6MWD and lack of improvement >30 m after PR are associated with worse 5-year survival in patients with COPD.

Pulmonary rehabilitation coupled with negative pressure ventilation decreases decline in lung function, hospitalizations, and medical cost in COPD: A 5-year study

Pulmonary rehabilitation (PR) brings benefits to patients with chronic obstructive pulmonary disease (COPD). Negative pressure ventilation (NPV) increases ventilation and decreases hyperinflation as well as breathing work in COPD. We evaluated the long-term effects of a hospital-based PR program coupled with NPV support in patients with COPD on clinical outcomes.One hundred twenty-nine patients with COPD were followed up for more than 5 years, with the NPV group (n = 63) receiving the support of NPV (20-30 cm H2O delivery pressure for 60 min) and unsupervised home exercise program of 20 to 30 min daily walk, while the control group (n = 6) only received unsupervised home exercise program. Pulmonary function tests and 6 min walk tests (6MWT) were performed every 3 to 6 months. Emergency room (ER) visits and hospitalization with medical costs were recorded.A significant time-by-group interaction in the yearly decline of forced expiratory volume in 1 s in the control group analyzed by mixed-model repeated-measure analysis was found (P = 0.048). The 6MWT distance of the NPV group was significantly increased during the first 4 years, with the interaction of time and group (P = 0.003), the time alone (P = 0.014), and the quadratic time (P < 0.001) being significant between the 2 groups. ER exacerbations and hospitalizations decreased by 66% (P < 0.0001) and 54% (P < 0.0001) in the NPV group, respectively. Patients on PR program coupled with NPV had a significant reduction of annual medical costs (P = 0.022).Our hospital-based multidisciplinary PR coupled with NPV reduced yearly decline of lung function, exacerbations, and hospitalization rates, and improved walking distance and medical costs in patients with COPD during a 5-year observation.

Chronic Obstructive Pulmonary Disease Subtypes. Transitions over Time

BACKGROUND

Although subtypes of chronic obstructive pulmonary disease are recognized, it is unknown what happens to these subtypes over time. Our objectives were to assess the stability of cluster-based subtypes in patients with stable disease and explore changes in clusters over 1 year.

METHODS

Multiple correspondence and cluster analysis were used to evaluate data collected from 543 stable patients included consecutively from 5 respiratory outpatient clinics.

RESULTS

Four subtypes were identified. Three of them, A, B, and C, had marked respiratory profiles with a continuum in severity of several variables, while the fourth, subtype D, had a more systemic profile with intermediate respiratory disease severity. Subtype A was associated with less dyspnea, better health-related quality of life and lower Charlson comorbidity scores, and subtype C with the most severe dyspnea, and poorer pulmonary function and quality of life, while subtype B was between subtypes A and C. Subtype D had higher rates of hospitalization the previous year, and comorbidities. After 1 year, all clusters remained stable. Generally, patients continued in the same subtype but 28% migrated to another cluster. Together with movement across clusters, patients showed changes in certain characteristics (especially exercise capacity, some variables of pulmonary function and physical activity) and changes in outcomes (quality of life, hospitalization and mortality) depending on the new cluster they belonged to.

CONCLUSIONS

Chronic obstructive pulmonary disease clusters remained stable over 1 year. Most patients stayed in their initial subtype cluster, but some moved to another subtype and accordingly had different outcomes.

Non-invasive Assessment of Respiratory Muscle Function and its Relationship to Exercise Tolerance in Patients with Chronic Obstructive Pulmonary Disease

Most patients with chronic obstructive pulmonary disease (COPD) have impaired respiratory muscle function. Maximal oesophageal pressure correlates closely with exercise tolerance and seems to predict the distance walked during the 6-min walk test. This study assessed the non-invasive parameters of respiratory muscle function in 41 patients with COPD to investigate their relationship to pulmonary function tests and exercise tolerance. The COPD patients, who demonstrated the full range of airway obstruction severity, had a mean forced expiratory volume in 1 s of 42.5% predicted (range, 20–79% predicted). Both the maximal inspiratory muscle strength and non-invasive tension-time index were significantly correlated with the degree of lung hyperinflation, as expressed by the ratio of residual volume to total lung capacity, and the distance walked in 6 min. We conclude that respiratory muscle function was influenced mainly by lung hyperinflation and that it had an important effect on exercise tolerance in COPD patients.

Influence of weight status on physical and mental health in Moroccan perimenopausal women

Introduction

There is a lack of information about fitness and other health indicators in women from countries such as Morocco. This study aims to explore the association of weight status with physical and mental health in Moroccan perimenopausal women.

Methods

151 women (45-65 years) from the North of Morocco were analyzed by standardized field-based fitness tests to assess cardiorespiratory fitness, muscular strength, flexibility, agility and balance. Quality of life was assessed by means of the Short-Form-36 Health Survey. Resting heart rate, blood pressure and plasma fasting glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides were also measured.

Results

Blood pressure (P=0.001), plasma triglycerides (P=0.041) and the prevalence of metabolic syndrome (P<0.001) increased as weight status increased. Levels of cardiorespiratory fitness, upper-body flexibility (both, P<0.001), static balance (P<0.05) and dynamic balance (P<0.01) decreased as weight status increased. Pairwise comparisons showed differences mainly between normal-weight and overweight vs. obese groups. No differences between groups were observed on quality of life.

Conclusion

Cardiovascular and lipid profile and fitness, important indicators of cardiovascular disease risk, worsened as weight status increased, whereas quality of life appears to be independent of weight status. Exercise and nutritional programs focus on weight management may be advisable in this under studied population.

Lung perfusion and emphysema distribution affect the outcome of endobronchial valve therapy

The exclusion of collateral ventilation (CV) and other factors affect the clinical success of endoscopic lung volume reduction (ELVR). However, despite its benefits, the outcome of ELVR remains difficult to predict. We investigated whether clinical success could be predicted by emphysema distribution assessed by computed tomography scan and baseline perfusion assessed by perfusion scintigraphy. Data from 57 patients with no CV in the target lobe (TL) were retrospectively analyzed after ELVR with valves. Pulmonary function tests (PFT), St George's Respiratory Questionnaire (SGRQ), and 6-minute walk tests (6MWT) were performed on patients at baseline. The sample was grouped into high and low levels at the median of TL perfusion, ipsilateral nontarget lobe (INL) perfusion, and heterogeneity index (HI). These groups were analyzed for association with changes in outcome parameters from baseline to 3 months follow-up. Compared to baseline, patients showed significant improvements in PFT, SGRQ, and 6MWT (all P≤0.001). TL perfusion was not associated with changes in the outcome. High INL perfusion was significantly associated with increases in 6MWT (P=0.014), and high HI was associated with increases in forced expiratory volume in 1 second (FEV1), (P=0.012). Likewise, there were significant correlations for INL perfusion and improvement of 6MWT (r=0.35, P=0.03) and for HI and improvement in FEV1 (r=0.45, P=0.001). This study reveals new attributes that associate with positive outcomes for patient selection prior to ELVR. Patients with high perfusions in INL demonstrated greater improvements in 6MWT, while patients with high HI were more likely to respond in FEV1.

Functional capacity, health status, and inflammatory biomarker profile in a cohort of patients with chronic obstructive pulmonary disease

PURPOSE

Prior research has shown a significant relationship between 6-minute walking distance (6MWD) and health-related quality of life (HRQOL) in patients with chronic obstructive pulmonary disease (COPD). However, few studies have examined this relationship above and below the 350-m threshold that prognosticates survival and whether serum biomarkers could provide insight into the causes of quality-of-life differences above and below this threshold.

METHODS

Measures of lung function, 6MWD, and HRQOL were compared in patients with COPD. Differences in HRQOL domains and serum biomarkers were compared in patients whose 6MWD were > or < 350 m.

RESULTS

In patients walking < 350 m, scores in the physical domains of the SF-36 and the St. George's Respiratory Questionnaire (SGRQ) were significantly different from scores of their counterparts with greater 6MWD. However, there was no association between any biomarkers and the physical domains of the SF-36 and the SGRQ. In patients walking < 350 m, only the IL-8 levels were associated with lower scores in SF-36 domains of emotional role, pain, vitality, and mental health (average r = -0.702; P = .01). In contrast, in patients walking > 350 m, surfactant protein D levels were associated with higher SF-36 scores in general pain, vitality, and social functioning (average r = 0.42; P = .04).

CONCLUSIONS

In COPD, there is an association between 6MWD and the physical domains of the SF-36 and SGRQ in those patients walking < 350 m. The physical differences between patients walking < or > 350 m are not related to systemic inflammation. The association between interleukin 8 with nonphysical domains in patients with 6MWD < 350 m suggests that inflammation may play a larger role in the perceptive domain than previously recognized.

Pharmacological management of breathlessness in COPD: recent advances and hopes for the future

INTRODUCTION

Activity-related breathlessness is often the dominant symptom in patients with chronic obstructive pulmonary disease (COPD) and usually persists despite optimal medical therapy. Currently, our inability to meaningfully alter the pathophysiology of the underlying disease means that we must focus our attention on relieving this distressing symptom so as to improve exercise tolerance and quality of life.

AREAS COVERED

The current review examines the neurobiology of breathlessness and constructs a solid physiological rationale for amelioration of this distressing symptom. We will examine the efficacy of interventions which: 1) reduce the increased central drive to breathe (opioids); 2) improve the respiratory system's ability to appropriately respond to this increased demand (bronchodilators); and 3) address the important affective dimension of breathlessness (anxiolytics). Expert commentary: Advances in our understanding of the mechanisms of activity-related breathlessness in COPD, and its measurement in the clinical domain, now set the stage for the development of effective management strategies on an individual patient basis.

Functional Status Assessment of Patients With COPD: A Systematic Review of Performance-Based Measures and Patient-Reported Measures

Presently, there is no recommendation on how to assess functional status of chronic obstructive pulmonary disease (COPD) patients. This study aimed to summarize and systematically evaluate these measures.Studies on measures of COPD patients' functional status published before the end of January 2015 were included using a search filters in PubMed and Web of Science, screening reference lists of all included studies, and cross-checking against some relevant reviews. After title, abstract, and main text screening, the remaining was appraised using the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) 4-point checklist. All measures from these studies were rated according to best-evidence synthesis and the best-rated measures were selected.A total of 6447 records were found and 102 studies were reviewed, suggesting 44 performance-based measures and 14 patient-reported measures. The majority of the studies focused on internal consistency, reliability, and hypothesis testing, but only 21% of them employed good or excellent methodology. Their common weaknesses include lack of checks for unidimensionality, inadequate sample sizes, no prior hypotheses, and improper methods. On average, patient-reported measures perform better than performance-based measures. The best-rated patient-reported measures are functional performance inventory (FPI), functional performance inventory short form (FPI-SF), living with COPD questionnaire (LCOPD), COPD activity rating scale (CARS), University of Cincinnati dyspnea questionnaire (UCDQ), shortness of breath with daily activities (SOBDA), and short-form pulmonary functional status scale (PFSS-11), and the best-rated performance-based measures are exercise testing: 6-minute walk test (6MWT), endurance treadmill test, and usual 4-meter gait speed (usual 4MGS).Further research is needed to evaluate the reliability and validity of performance-based measures since present studies failed to provide convincing evidence. FPI, FPI-SF, LCOPD, CARS, UCDQ, SOBDA, PFSS-11, 6MWT, endurance treadmill test, and usual 4MGS performed well and are preferable to assess functional status of COPD patients.

Oxygen desaturation in 6-min walk test is a risk factor for adverse outcomes in COPD

The 6-min walk test (6MWT) is an exercise test that measures functional status in chronic obstructive pulmonary disease (COPD) patients and provides information on oxygen desaturation. We investigated oxygen desaturation during 6MWT as a risk factor for important COPD outcomes: mortality, frequency of exacerbations, decline in lung function and decline in lean body mass.433 COPD patients were included in the Bergen COPD Cohort Study 2006-2009, and followed-up for 3 years. Patients were characterised using spirometry, bioelectrical impedance measurements, Charlson comorbidity score, exacerbation history, smoking and arterial blood gases. 370 patients completed the 6MWT at the baseline of the study. Information on all-cause mortality was collected in 2011.Patients who experienced oxygen desaturation during the 6MWT had an approximately twofold increased risk of death (hazard ratio 2.4, 95% CI 1.2-5.1), a 50% increased risk for experiencing later COPD exacerbations (incidence rate ratio 1.6, 95% CI 1.1-2.2), double the yearly rate of decline in both forced vital capacity and forced expiratory volume in 1 s (3.2% and 1.7% versus 1.7% and 0.9%, respectively) and manifold increased yearly rate of loss of lean body mass (0.18 kg·m(-2) versus 0.03 kg·m(-2) among those who did not desaturate).Desaturating COPD patients had a significantly worse prognosis than non-desaturating COPD patients, for multiple important disease outcomes.

Effects of a Structured Exercise Program on Physical Activity and Fitness in Colon Cancer Survivors: One Year Feasibility Results from the CHALLENGE Trial

BACKGROUND

There is strong interest in testing lifestyle interventions to improve cancer outcomes; however, the optimal methods for achieving behavior change in large-scale pragmatic trials are unknown. Here, we report the 1-year feasibility results for exercise behavior change in the Canadian Cancer Trials Group CO.21 (CHALLENGE) Trial.

METHODS

Between 2009 and 2014, 273 high-risk stage II and III colon cancer survivors from 42 centers in Canada and Australia were randomized to a structured exercise program (SEP; n = 136) or health education materials (HEM; n = 137). The primary feasibility outcome in a prespecified interim analysis was a difference between randomized groups of ≥5 metabolic equivalent task (MET)-hours/week in self-reported recreational physical activity (PA) after at least 250 participants reached the 1-year follow-up. Secondary outcomes included health-related fitness.

RESULTS

The SEP group reported an increase in recreational PA of 15.6 MET-hours/week compared with 5.1 MET-hours/week in the HEM group [mean difference = +10.5; 95% confidence interval (CI) = +3.1-+17.9; P = 0.002]. The SEP group also improved relative to the HEM group in predicted VO2max (P = 0.068), 6-minute walk (P < 0.001), 30-second chair stand (P < 0.001), 8-foot up-and-go (P = 0.004), and sit-and-reach (P = 0.08).

CONCLUSIONS

The behavior change intervention in the CHALLENGE Trial produced a substantial increase in self-reported recreational PA that met the feasibility criterion for trial continuation, resulted in objective fitness improvements, and is consistent with the amount of PA associated with improved colon cancer outcomes in observational studies.

IMPACT

The CHALLENGE Trial is poised to determine the causal effects of PA on colon cancer outcomes. Cancer Epidemiol Biomarkers Prev; 25(6); 969-77. ©2016 AACR.

Pulmonary Rehabilitation for Patients with Chronic Airways Obstruction

Pulmonary rehabilitation is a patient-centered and interdisciplinary intervention with major components of exercise training and self-management education. Although having no direct effect on lung function, this intervention often results in substantial improvements in respiratory symptoms, functional status, and health status. It probably also reduces subsequent health care utilization, especially when provided after a hospitalization for an exacerbation of airways disease. The beneficial effects of pulmonary rehabilitation reflect its ability to reduce the impact of systemic consequences of chronic respiratory disease and to improve patients' self-efficacy through promoting collaborative self-management. Pulmonary rehabilitation is indicated for patients with respiratory diseases (regardless of specific diagnosis) who have persistent symptoms or functional or health status limitation despite otherwise optimal medical therapy. Those patients with severe asthma (particularly those with airways remodeling) or asthma-chronic obstructive pulmonary disease overlap who have daily symptoms and substantial functional/health status limitation despite controller and bronchodilator therapy would be appropriate candidates for pulmonary rehabilitation.