Activity monitoring for assessment of physical activities in daily life in patients with chronic obstructive pulmonary disease

Validation of "CENTR(AR)" walking trails: Different field criteria do not lead to different physical activity intensities in people with COPD

BACKGROUND

Validating walking trails is essential to promote physical activity (PA) safely and confidently in people with COPD.

OBJECTIVES

We aimed to validate predetermined light, moderate, and vigorous intensities of walking trails in people with COPD.

METHODS

This cross-sectional study included individuals with COPD walking in predetermined light, moderate and vigorous intensity trails. Activity intensity and volume outcomes were collected. Dyspnoea and fatigue (modified Borg scale), energy expenditure (EE, Sensewear), heart rate (HR, HR monitor), time spent in different PA intensities, and cadence (ActiGraph) were recorded and used to classify PA intensity.

RESULTS

Twenty people with COPD [71(7) years, 80 % male, FEV1%predicted 65.6(11.6)] were included. Fatigue differed significantly between light and moderate [3.0(2.0;4.0) vs 3.4(2.5;4.5), p = 0.01], but not vigorous (3.5[2.5-4.0]) tracks. Dyspnoea [2.3(1.5) vs 2.7(1.6) vs 2.6(1.4)], EE [5.1(0.8) vs 4.9(0.5) vs 4.6(0.8) METs], HR [92.5(11.1) vs 93.7(18.6) vs 95.4(15.0) beats/min] and cadence [115.1(104.0;120.3) vs 104.7(99.6;117.6) vs 111.2(99.9;118.5) steps/min] were similar across trails (p > 0.05). Time spent in light and moderate PA, EE volume, walking time, and step count increased along with the proposed intensity levels (p < 0.01). Walking trails were categorised as moderate intensity in most participants.

CONCLUSION

Walking trails were safe and valid for practising moderate-intensity PA in people with COPD. Participants adjusted their physiological responses and perceived symptoms to match a moderate intensity.

The DizzyQuest Combined with Accelerometry: Daily Physical Activities and Limitations among Patients with Bilateral Vestibulopathy Due to DFNA9

BACKGROUND

DFNA9 is a genetic disease of the inner ear, causing progressive bilateral sensorineural deafness and bilateral vestibulopathy (BV). In this study, DizzyQuest, a mobile vestibular diary, and the MOX accelerometer were combined to assess the daily life functional limitations and physical activity of patients with DFNA9 suffering from BV. These parameters might be appropriate as potential candidacy criteria and outcome measures for new therapeutic interventions for BV.

METHODS

Fifteen DFNA9 patients with BV and twelve age-matched healthy controls were included. The DizzyQuest was applied for six consecutive days, which assessed the participants' extent of functional limitations, tiredness, types of activities performed during the day, and type of activity during which the participant felt most limited. The MOX accelerometer was worn during the same six days of DizzyQuest use, measuring the participants intensity and type of physical activity. Mixed-effects linear and logistic regression analyses were performed to compare the DFNA9 patients and control group.

RESULTS

DFNA9 patients with BV felt significantly more limited in activities during the day compared to the age-matched controls, especially in social participation (p < 0.005). However, these reported limitations did not cause adjustment in the types of activities and did not reduce the intensity or type of physical activity measured with accelerometry. In addition, no relationships were found between self-reported functional limitations and physical activity.

CONCLUSIONS

This study demonstrated that self-reported functional limitations are significantly higher among DFNA9 patients with BV. As a result, these limitations might be considered as part of the candidacy criteria or outcome measures for therapeutic interventions. In addition, the intensity or type of physical activity performed during the day need to be addressed more specifically in future research.

Physical activity following pulmonary embolism and clinical correlates in selected patients: a cross-sectional study

Background

There is limited knowledge regarding physical activity and clinical correlates among people who have suffered a pulmonary embolism (PE).

Objectives

To assess physical activity levels after PE and potential clinical correlates.

Methods

One hundred forty-five individuals free of major comorbidities were recruited at a mean of 23 months (range, 6-72) after PE diagnosis. Physical activity was assessed by steps/day on the Sensewear monitor for 7 consecutive days, exercise capacity with the incremental shuttle walk test, and cardiac function with left ventricular ejection fraction (LVEF). The association between physical activity and other variables was analyzed by a mixed-effects model.

Results

Participants achieved a mean of 6494 (SD, 3294; range, 1147-18.486) steps/day. The mixed-effects model showed that physical activity was significantly associated with exercise capacity (β-coefficient, 0.04; 95% CI, 0.03-0.05) and LVEF (β-coefficient, -0.81; 95% CI, -1.42 to -0.21). The analysis further showed that men became less physically active with increasing age (β-coefficient, -0.14; 95% CI, -0.24 to -0.04), whereas no change with age could be detected for women.

Conclusion

In selected post-PE patients, physical activity seems to be associated with exercise capacity and LVEF but not with quality of life, dyspnea, or characteristics of the initial PE. Men appear to become less physically active with increasing age.

Investigating the prognostic value of digital mobility outcomes in patients with chronic obstructive pulmonary disease: a systematic literature review and meta-analysis

BACKGROUND

Reduced mobility is a central feature of COPD. Assessment of mobility outcomes that can be measured digitally (digital mobility outcomes (DMOs)) in daily life such as gait speed and steps per day is increasingly possible using devices such as pedometers and accelerometers, but the predictive value of these measures remains unclear in relation to key outcomes such as hospital admission and survival.

METHODS

We conducted a systematic review, nested within a larger scoping review by the MOBILISE-D consortium, addressing DMOs in a range of chronic conditions. Qualitative and quantitative analysis considering steps per day and gait speed and their association with clinical outcomes in COPD patients was performed.

RESULTS

21 studies (6076 participants) were included. Nine studies evaluated steps per day and 11 evaluated a measure reflecting gait speed in daily life. Negative associations were demonstrated between mortality risk and steps per day (per 1000 steps) (hazard ratio (HR) 0.81, 95% CI 0.75-0.88, p<0.001), gait speed (<0.80 m·s-1) (HR 3.55, 95% CI 1.72-7.36, p<0.001) and gait speed (per 1.0 m·s-1) (HR 7.55, 95% CI 1.11-51.3, p=0.04). Fewer steps per day (per 1000) and slow gait speed (<0.80 m·s-1) were also associated with increased healthcare utilisation (HR 0.80, 95% CI 0.72-0.88, p<0.001; OR 3.36, 95% CI 1.42-7.94, p=0.01, respectively). Available evidence was of low-moderate quality with few studies eligible for meta-analysis.

CONCLUSION

Daily step count and gait speed are negatively associated with mortality risk and other important outcomes in people with COPD and therefore may have value as prognostic indicators in clinical trials, but the quantity and quality of evidence is limited. Larger studies with consistent methodologies are called for.

Cultural adaptation and validation of the Brazilian Portuguese version of the PROactive Physical Activity in COPD-clinical visit instrument for individuals with COPD

OBJECTIVE

To adapt the PROactive Physical Activity in COPD-clinical visit (C-PPAC) instrument to the cultural setting in Brazil and to determine the criterion validity, test-retest reliability agreement, and internal consistency of this version.

METHODS

A protocol for cultural adaptation and validation was provided by the authors of the original instrument and, together with another guideline, was applied in a Portuguese-language version developed by a partner research group from Portugal. The adapted Brazilian Portuguese version was then cross-sectionally administered twice within a seven-day interval to 30 individuals with COPD (57% were men; mean age was 69 ± 6 years; and mean FEV1 was 53 ± 18% of predicted) to evaluate internal consistency and test-retest reliability. Participants also completed the International Physical Activity Questionnaire (IPAQ), the modified Medical Research Council scale, the COPD Assessment Test, and Saint George's Respiratory Questionnaire to evaluate criterion validity.

RESULTS

The C-PPAC instrument showed good internal consistency and excellent test-retest reliability: "amount" domain = 0.87 (95% CI, 0.73-0.94) and "difficulty" domain = 0.90 (95% CI, 0.76-0.96). Bland & Altman plots, together with high Lin's concordance correlation coefficients, reinforced that agreement. Criterion validity showed moderate-to-strong correlations of the C-PPAC with all of the other instruments evaluated, especially with the IPAQ (rho = -0.63).

CONCLUSIONS

The Brazilian Portuguese version of the C-PPAC is a reliable and valid instrument for evaluating the experience of Brazilian individuals with COPD with their physical activity in daily life.

Physical activity in idiopathic pulmonary fibrosis: Longitudinal change and minimal clinically important difference

BACKGROUND AND OBJECTIVE

Reference values of physical activity to interpret longitudinal changes are not available in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to define the minimal clinical important difference (MCID) of longitudinal changes in physical activity in patients with IPF.

METHODS

Using accelerometry, physical activity (steps per day) was measured and compared at baseline and 6-months follow-up in patients with IPF. We calculated MCID of daily step count using multiple anchor-based and distribution-based methods. Forced vital capacity and 6-minute walk distance were applied as anchors in anchor-based methods. Effect size and standard error of measurement were used to calculate MCID in distribution-based methods.

RESULTS

One-hundred and five patients were enrolled in the study (mean age: 68.5 ± 7.5 years). Step count significantly decreased from baseline to 6-months follow-up (-461 ± 2402, p = .031). MCID calculated by anchor-based and distribution-based methods ranged from 570-1358 steps.

CONCLUSION

Daily step count significantly declined over 6-months in patients with IPF. MCID calculated by multiple anchor-based and distribution-based methods was 570 to 1358 steps/day. These findings contribute to interpretation of the longitudinal changes of physical activity that will assist its use as a clinical and research outcome in patients with IPF.

A Call for Action on Chronic Respiratory Diseases within Physical Activity Policies, Guidelines and Action Plans: Let's Move!

Global policy documents for the promotion of physical activity (PA) play an important role in the measurement, evaluation, and monitoring of population PA levels. The World Health Organisation (WHO) guidelines include, for the first time, recommendations for specific populations, including individuals living with a range of non-communicable diseases. Of note, is the absence of any chronic respiratory diseases (CRDs) within the recommendations. Globally, CRDs are highly prevalent, are attributable to significant individual and societal burdens, and are characterised by low PA. As a community, there is a need to come together to understand how to increase CRD representation within global PA policy documents, including where the evidence gaps are and how we can align with PA research in other contexts. In this commentary, the potential for synergy between evidence into the relationships between PA in CRDs globally and the relevance to current policies, guidelines and action plans on population levels of PA are discussed. Furthermore, actions and considerations for future research, including the need to harmonize and promote PA assessment (particularly in low- and middle-income countries) and encompass the synergistic influences of PA, sedentary behaviour and sleep on health outcomes in CRD populations are presented.

Impact of non-exercise activity thermogenesis on physical activity in patients with COPD

Physical inactivity is associated with comorbidities and mortality in chronic obstructive pulmonary disease (COPD) patients. Although non-exercise activity thermogenesis (NEAT) is important for evaluating the physical activity level (PAL) of patients with chronic diseases, it has not yet been assessed in COPD patients. This study included male patients with COPD (n = 28) and high risk for COPD (n = 8). Total energy expenditure (TEE) and basal metabolic rate (BMR) were measured using the doubly labeled water (DLW) method and indirect calorimetry, respectively. PAL was calculated as TEE/BMR, while the NEAT was obtained from a questionnaire. Physical activity was also assessed using an accelerometer. The total NEAT score was correlated with PAL (r = 0.534, P < 0.001), while PAL was correlated more strongly with the non-locomotive NEAT score (r = 0.548, P < 0.001) than the locomotive NEAT score (r = 0.278, P = 0.10). Regarding accelerometer-obtained data, this questionnaire mainly reflected steps/day and the duration of light locomotive and non-locomotive daily activities. The NEAT score is a possible option for evaluating PAL in daily clinical practice. The present results indicated that non-locomotive activity may have a greater impact on PAL than locomotive activity in COPD patients.

Quantifying the Effect of Monitor Wear Time and Monitor Type on the Estimate of Sedentary Time in People with COPD: Systematic Review and Meta-Analysis

In studies that have reported device-based measures of sedentary time (ST) in people with chronic obstructive pulmonary disease (COPD), we explored if the monitor type and monitor wear time moderated the estimate of this measure. Five electronic databases were searched in January 2021. Studies were included if >70% of participants had stable COPD, and measures of ST (min/day) were collected using wearable technology. Meta-regression was used to examine the influence of moderators on ST, monitor type, and wear time. The studies identified were a total of 1153, and 36 had usable data for meta-analyses. The overall pooled estimate of ST (mean [95% CI]) was 524 min/day [482 to 566] with moderate heterogeneity among effect sizes (I2 = 42%). Monitor wear time, as well as the interaction of monitor wear time and monitor type, were moderators of ST (p < 0.001). The largest difference (−318 min; 95% CI [−212 to −424]) was seen between studies where participants wore a device without a thigh inclinometer for 24 h (and removed sleep during analysis) (675 min, 95% CI [589 to 752]) and studies where participants wore a device with a thigh inclinometer for 12 h only (356 min; 95% CI [284 to 430]). In people with COPD, the monitor wear time and the interaction of the monitor wear time and the monitor type moderated the estimate of ST.

Influenza A Virus-Driven Airway Inflammation may be Dissociated From Limb Muscle Atrophy in Cigarette Smoke-Exposed Mice

Limb muscle dysfunction is a hallmark of Chronic Obstructive Pulmonary Disease (COPD) which is further worsened following a viral-induced acute exacerbation of COPD (AECOPD). An amplified airway inflammation underlies the aggravated respiratory symptoms seen during AECOPD, however, its contributory role to limb muscle dysfunction is unclear. The present study examined the impact of influenza A virus (IAV)-induced exacerbation on hind limb muscle parameters. Airway inflammation was established in male BALB/c mice by exposure to cigarette smoke (CS) for 8 weeks. Exacerbation was then induced via inoculation with IAV, and various lung and muscle parameters were assessed on day 3 (peak of airway inflammation) and day 10 (resolution phase) post-infection. IAV infection exacerbated CS-induced airway inflammation as evidenced by further increases in immune cell counts within bronchoalveolar lavage fluid. Despite no significant impact on muscle mass, IAV exacerbation worsened the force-generating capacity of the tibialis anterior (TA) muscle. Protein oxidation and myogenic disruption was observed in the TA following CS exposure, however, IAV exacerbation did not augment these detrimental processes. To further explore the contributory role of airway inflammation on myogenic signaling, cultured myotubes were exposed to conditioned medium (CM) derived from bronchial epithelial cells stimulated with polyinosinic:polycytidylic acid and cigarette smoke extract (CSE). Despite an amplified inflammatory response in the lung epithelial cells, the CM derived from these cells did not potentiate myogenic disruption in the C2C12 myotubes. In conclusion, our data suggest that certain parameters of limb muscle dysfunction seen during viral-induced AECOPD may be independent of airway inflammation.

A pilot crossover trial assessing the exercise performance patients chronic obstructive pulmonary disease

Noninvasive ventilation improves exercise performance in patients with chronic obstructive pulmonary disease (COPD). However, the effect of helmet ventilation (HV) on the short-term self-paced exercise performance of patients with COPD remains unclear. This study investigated the use of HV during a 6 min walk test (6MWT) and analyzed its short-term cardiopulmonary outcomes in patients with stable COPD. A single-site crossover trial was conducted in a pulmonary rehabilitation outpatient department. A total of 20 stable patients with COPD without disability were enrolled. The participants performed 6MWTs with and without HV on two consecutive days. The outcome measures were the distance walked in the 6MWT and the physiological and cardiopulmonary parameters. The mean difference in meters walked between the HV-aided and unaided walk tests was 15.4 ± 37.2 (95% confidence interval: − 2.03 to 32.8 m; p = .145). During the 6MWT, the peak heart rate was significantly higher when walking was aided by HV than when it was unaided (p < .001). The energy expenditure index, walking speed, oxygen saturation nadir, and hemodynamic parameters were comparable. Although carbon dioxide levels inside the helmet increased after the walk test, the participants’ transcutaneous carbon dioxide measurements remained unchanged. HV did not improve the short-term self-paced exercise performance in patients with stable mild-to-moderate COPD. Further research should focus on noninvasive ventilation delivered via helmets in exercise training to determine the setting strategy, breathing circuit configuration, and effects of regular exercise.

ClinicalTrial.gov: NCT04156724; IRB number: C108032.

Effects of high-flow nasal cannula with oxygen on self-paced exercise performance in COPD: A randomized cross-over trial

INTRODUCTION

Studies have demonstrated that noninvasive ventilation improves exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). The role of heated humidified high-flow nasal cannula (HFNC) therapy in patients with COPD on self-paced exercise performance remains unclear. Therefore, the purpose of the present study was to determine whether HFNC-aided supplemental oxygen during a 6-minute walk test (6MWT) would change self-paced exercise performance and cardiopulmonary outcomes in patients with stable COPD.

METHODS

A single-site, cross-over trial was conducted in a pulmonary rehabilitation outpatient department. This study enrolled 30 stable COPD patients without disability. The participants with and without HFNC performed 6MWTs on 2 consecutive days. Outcomes were the distance walked in the 6MWT, physiological, and cardiopulmonary parameters.

RESULTS

Those performing HFNC-aided walking exhibited a longer walking distance than those performing unaided walking. The mean difference in meters walked between the HFNC-aided and unaided walking scenarios was 27.3 ± 35.6 m (95% CI: 14.4-40.5 m). The energy expenditure index was significantly lower when walking was aided by HHHNFC rather than unaided (median: 1.21 beats/m walked vs median: 1.37 beats/m walked, P < .001). However, there were no differences in transcutaneous carbon dioxide tension between HHHNFC and non-HHHNFC patients.

CONCLUSION

Walking distance and arterial oxygen saturation improved in stable COPD patients receiving HFNC with additional oxygen support. However, HFNC did not affect transcutaneous carbon dioxide tension and the self-reported dyspnea score during the walking test. The present study demonstrated the feasibility and safety of using HFNC in self-paced exercise.

TRIAL REGISTRATION

NCT03863821.

Measuring intensity during free-living physical activities in people with chronic obstructive pulmonary disease: a systematic literature review

BACKGROUND

Measuring intensity of physical activity (PA) is important to ensure safety and the effectiveness of PA interventions in chronic obstructive pulmonary disease (COPD).

OBJECTIVE

This systematic review identified which outcomes, outcome measures and instruments have been used to assess single free-living PA-related intensity in people with COPD and compared the intensity level (light, moderate, vigorous) obtained by different outcome measures.

METHODS

PubMed, Scopus, Web of Science, Cochrane Library and EBSCO were searched for original studies of COPD and assessing single free-living PA-related intensity were included. Agreement was calculated as the number of agreements between 2 measures [same intensity level]/ number of comparisons using both measures*100.

RESULTS

We included 43 studies (1282 people with COPD, mean age 66 years, 65% men, 49% FEV_1%pred) and identified 13 outcomes, 46 outcome measures and 22 instruments. The most-reported outcomes, outcome measures and instruments were dyspnoea with the Borg scale 0-10; cardiac function, via heart rate (HR) using HR monitors; and pulmonary gas exchange, namely oxygen consumption (VO₂), using portable gas analysers, respectively. The most frequently assessed PAs were walking and lifting, changing or moving weights/objects. Agreement between the outcome measures ranged from 0 (%VO_2peak vs metabolic equivalent of task [MET]; %HR_peak vs Fatigue Borg; MET vs walking speed) to 100% (%HR_reserve vs dyspnoea Borg; fatigue and exertion Borg vs walking speed). %VO_{2peak/reserve} elicited the highest intensity. Hence, Borg scores, %HR_reserve and MET may underestimate PA-related intensity.

CONCLUSIONS

Various methodologies are used to assess single free-living PA-related intensity and yield different intensity levels for the same PA. Future studies, further exploring the agreement between the different outcome measures of PA-related intensity and discussing their advantages, disadvantages and applicability in real-world settings, are urgent. These would guide future worldwide recommendations on how to assess single free-living PA-related intensity in COPD, which is essential to optimise PA interventions and ensure patient safety.

Energy expenditure per minute in different activities and body positions and its association with the classification as physically active or inactive in daily life in individuals with COPD

Objective: To describe and compare energy expenditure (EE)/minute walking and in different body postures in individuals with COPD; and to investigate if EE/minute walking is a predictor of their classification as physically active or inactive. Methods: Physical activity (PA) in daily life was objectively assessed using two PA monitors for 7 days and data were analyzed on a minute-by-minute basis. Predominant minutes were separated into walking, standing, sitting, and reclined, and EE/minute (a reflection of PA intensity) was then calculated in each of these four activities and postures. Participants were classified as active and inactive according to the criteria proposed by the American College of Sports Medicine (ACSM). Results: 43 individuals were evaluated (65±8 years; FEV₁ 50±14% predicted). A binary logistic regression model yielded that, regardless of the time spent walking/day, EE/minute walking was a significant predictor of the classification as physically active (OR=18.2 [2 – 165]; p=0.01), together with BMI (OR=0.68 [0.5 - 0.9]; p=0.008) (model: Chi-square = 22.431, p< 0.05; R² [Nagelkerke] = 0.556). In the active group, significantly higher EE/minute was observed for walking and standing in comparison both to sitting and reclined. However, in the inactive group, there were significant differences in EE/minute only when comparing walking versus reclined and standing versus reclined. Conclusion: In individuals, with COPD, EE/minute walking is a significant predictor of being classified as physically active, independently of the time spent walking/day. Each additional kilocalorie/minute spent walking increases in 18 times the chances to be classified as physically active in daily life.

Reliability and validity of the Glittre-ADL test to assess the functional status of patients with interstitial lung disease

The study objective was to investigated the reliability and validity of the ADL-Glittre test (TGlittre) to assess the functional status of patients with interstitial lung disease (ILD). Twenty-one individuals with ILD participated (age: 63 ± 11 years; DLCO: 51.0 ± 12.6%predicted), evaluated with body plethysmography, Saint George Respiratory Questionnaire, modified Medical Research Council dyspnea scale, six-minute walk test (6MWT) and monitoring of physical activity of daily living. Two TGlittre were performed, with an interval of 30 minutes between them. The TGlittre demonstrated high test-retest reliability, with an intraclass correlation coefficient of 0.90 (95%CI: 0.75–0.96; p < 0.001). Nineteen patients (90.5%) performed better on the second test (mean difference between TGlittre 1 and 2: −0.57 ± 0.96 minute; p = 0.001), with a learning effect of 11.6%. The time in TGlittre correlated with 6MWT (r = −0.70; p = 0.002) and with the total energy expenditure in physical activity of daily living (r = −0.52; p = 0.02). In %predicted, TGlittre and 6MWT also correlated (r = −0.50; p = 0.04). Correlations were observed between TGlittre and pulmonary function variables (r = −0.47 to −0.57; p = 0.01 to p = 0.04). There was no difference in the physiological response between TGlittre 1 and 2, and between TGlittre and 6MWT (p > 0.05). In conclusion, the TGlittre is reliable and valid for assessing functional status of patients with ILD.

The Maugeri daily activity profile: a tool to assess physical activity in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) report reduced physical activity (PA). There are only few tools available to assess PA and sedentary behavior in these patients, and none of them aims to differentiate between sedentary and active patterns. The aim of the study was to evaluate an easy tool to profile daily activity time in a cohort of patients with COPD, compared to healthy subjects; the study was set at the Istituti Clinici Scientifici Maugeri (ICS), IRCCS of Tradate and Lumezzane, Italy, and at the Ente Ospedaliero Cantonale Novaggio, Switzerland (Italian Speaking). The populations were inpatients with COPD, healthy subjects. The items of the Maugeri Daily Activity (MaDA) profile were chosen based on literature, interviews with patients and health professionals. Time spent during sleep (ST), when awake (AT), active (ACT) or in sedentary behavior (SET) were recorded. Lung function tests, arterial blood gases, the modified Medical Research Council (mMRC), the six-minute walking distance test (6MWD), the COPD Assessment Test (CAT), and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index were also assessed in patients. Sixty patients with COPD and 60 healthy controls filled in the questionnaire. As compared to controls, patients showed longer AT and SET. Active time of patients was significantly correlated with mMRC, CAT, Bode Index and 6MWD, but not with demographics, anthropometrics or stages of disease. Using this tool, we found that patients with COPD spent longer time awake and in sedentary behavior. The MaDA may be useful to evaluate PA in patients with COPD.

Evaluation of the Effect of Gait Aids, Such as Canes, Crutches, and Walkers, on the Accuracy of Step Counters in Healthy Individuals

Background

Wearable step-counter devices have become inexpensive tools that enable patients, researchers, and clinicians to objectively monitor physical activity. It is unknown how the use of gait aids, such as canes, crutches, and walkers, affects the accuracy of these devices. Such gait aids are commonly used by patients with chronic physical impairment and after joint-replacement surgery. The aim of this study was to determine the effect of gait aids on the accuracy of wearable step counters.

Methods

Nine healthy participants wore a Fitbit step counter on their wrist and hip and performed eight walking tests with canes, crutches, and walkers. Bland-Altman analyses were performed for all eight walking tests in order to compare agreement between measurement techniques.

Results

Mean overall agreement for subjects walking without gait aids in the hip group was excellent, showing a bias of -2.9, with limits of agreement (LOAs) between -8.72 and 2.95. For use of canes or crutches, the Bland-Altman plots had a range of bias values between the hip and wrist counters from -7.22 to 33.56, with LOAs from -98.55 to 124.2. The wrist counter during the four-wheeled walking test showed very little agreement with the actual step count, with a bias value of 91.33 and LOAs of 64.1-118.6, illustrating exceptionally unreliable step counts.

Conclusion

This study suggests that these widely commercially available step counters have poor reliability with gait aids, especially walkers, which should be taken into account in research and clinical settings.

High-intensity exercise impairs extradiaphragmatic respiratory muscle perfusion in patients with COPD

The study investigated whether high-intensity exercise impairs inspiratory and expiratory muscle perfusion in patients with chronic obstructive pulmonary disease (COPD). We compared respiratory local muscle perfusion between constant-load cycling[sustained at 80% peak work rate (WRpeak)] and voluntary normocapnic hyperpnea reproducing similar work of breathing (WoB) in 18 patients [forced expiratory volume in the first second (FEV₁): 58 ± 24% predicted]. Local muscle blood flow index (BFI), using indocyanine green dye, and fractional oxygen saturation (%StiO₂) were simultaneously assessed by near-infrared spectroscopy (NIRS) over the intercostal, scalene, rectus abdominis, and vastus lateralis muscles. Cardiac output (impedance cardiography), WoB (esophageal/gastric balloon catheter), and diaphragmatic and extradiaphragmatic respiratory muscle electromyographic activity (EMG) were also assessed throughout cycling and hyperpnea. Minute ventilation, breathing pattern, WoB, and respiratory muscle EMG were comparable between cycling and hyperpnea. During cycling, cardiac output and vastus lateralis BFI were significantly greater compared with hyperpnea [by +4.2 (2.6-5.9) L/min and +4.9 (2.2-7.8) nmol/s, respectively] (P < 0.01). Muscle BFI and %StiO₂ were, respectively, lower during cycling compared with hyperpnea in scalene [by -3.8 (-6.4 to -1.2) nmol/s and -6.6 (-8.2 to -5.1)%], intercostal [by -1.4 (-2.4 to -0.4) nmol/s and -6.0 (-8.6 to -3.3)%], and abdominal muscles [by -1.9 (-2.9 to -0.8) nmol/s and -6.3 (-9.1 to -3.4)%] (P < 0.001). The difference in respiratory (scalene and intercostal) muscle BFI between cycling and hyperpnea was associated with greater dyspnea (Borg CR10) scores (r = -0.54 and r = -0.49, respectively, P < 0.05). These results suggest that in patients with COPD, 1) locomotor muscle work during high-intensity exercise impairs extradiaphragmatic respiratory muscle perfusion and 2) insufficient adjustment in extradiaphragmatic respiratory muscle perfusion during high-intensity exercise may partly explain the increased sensations of dyspnea.NEW & NOTEWORTHY We simultaneously assessed the blood flow index (BFI) in three respiratory muscles during hyperpnea and high-intensity constant-load cycling sustained at comparable levels of work of breathing and respiratory neural drive in patients with COPD. We demonstrated that high-intensity exercise impairs respiratory muscle perfusion, as intercostal, scalene, and abdominal BFI increased during hyperpnea but not during cycling. Insufficient adjustment in respiratory muscle perfusion during exercise was associated with greater dyspnea sensations in patients with COPD.

Reliability and Validity of Patient-Reported, Rater-Based, and Hybrid Physical Activity Assessments in COPD: A Systematic Review

Selecting valid and reliable PA assessments in chronic obstructive pulmonary disease (COPD) is crucial to ensure that the information obtained is accurate, valuable, and meaningful. The purpose of this systematic review was to compare the validity and reliability among PA assessments in COPD. An electronic database search of PubMed and CINAHL was completed in December 2019 using MeSH terms on physical activity, COPD, validation, and questionnaires. Transparency in reporting was assessed with the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) checklist while methodological quality was assessed with the modified Quality Appraisal tool for Reliability studies (QAREL) for reliability studies and the Quality Appraisal of Validity Studies (QAVALS) for validity studies. The search yielded fifteen different measures. The Stanford 7-day recall (PAR) demonstrated the strongest correlations with SenseWear Armband on energy expenditure (r = 0.83; p < 0.001) and moderate correlations for time spent in activity over 3 METs (r = 0.54, p < 0.001). The Multimedia Activity Recall (MARCA) also demonstrated moderate to good correlations with both SenseWear and Actigraph GT3X + accelerometers (r = 0.66-0.74). Assisted and computerized PRO measures (PAR and MARCA) and hybrid measures (C-PPAC and D-PPAC) demonstrate better psychometric properties as compared to other subjective measures and may be considered for quantification of PA in COPD. However, observations drawn from single validation studies limit strength of recommendations and further research is needed to replicate the findings.

Daily Life Benefits and Usage Characteristics of Dynamic Arm Supports in Subjects with Neuromuscular Disorders

Neuromuscular disorders cause progressive muscular weakness, which limits upper extremity mobility and performance during activities of daily life. Dynamic arm supports can improve mobility and quality of life. However, their use is often discontinued over time for unclear reasons. This study aimed to evaluate whether users of dynamic arm supports demonstrate and perceive quantifiable mobility benefits over a period of two months. Nine users of dynamic arm supports were included in this observational study. They had different neuromuscular disorders and collectively used four different arm supports. They were observed for three consecutive weeks during which they were equipped with a multi-sensor network of accelerometers to assess the actual use of the arm support and they were asked to provide self-reports on the perceived benefits of the devices. Benefits were experienced mainly during anti-gravity activities and the measured use did not change over time. The self-reports provided contextual information in domains such as participation to social life, in addition to the sensor system. However self-reports overestimated the actual use by up to three-fold compared to the accelerometer measures. A combination of objective and subjective methods is recommended for meaningful and quantifiable mobility benefits during activities of daily life.

Validity of a Smart-Glasses-Based Step-Count Measure during Simulated Free-Living Conditions

Step counting represents a valuable approach to monitor the amount of daily physical activity. The feet, wrist and trunk have been demonstrated as the ideal locations to automatically detect the number of steps through body-worn devices (i.e., step counters). Key features of such devices are high usability, practicality and unobtrusiveness. Therefore, the opportunity to integrate step-counting functions in daily worn accessories represents one of the recent and most important challenges. In this context, the present study aimed to investigate the validity of a smart-glasses-based step-counter measure by comparing their performances against the most popular commercial step counters. To this purpose, smart glasses data from 26 healthy subjects performing simulated free-living walking conditions along a predefined path were collected. Reference measures from inertial sensors mounted on the subjects’ ankles and data from commercial (waist- and wrists-worn) step counters were acquired during the tests. The results showed an overall percentage error of 1%. In conclusion, the proposed smart glasses could be considered an accurate step counter, showing performances comparable to the most common commercial step counters.

Sex differences in COPD-related quadriceps muscle dysfunction and fibre abnormalities

In chronic obstructive pulmonary disease (COPD), lower limb dysfunction is associated with reduced exercise capacity, increased hospitalizations and mortality. We investigated sex differences in the prevalence of quadriceps dysfunction and fibre abnormalities in a large COPD cohort, controlling for the normal sex differences in health. We compared existing data from 76 male and 38 female COPD patients where each variable was expressed as a function of gender-specific normal values (obtained from 16 male and 14 female controls). Female COPD patients had lower quadriceps muscle strength and peak workload on a maximal incremental cycle ergometry protocol compared to male patients. Female patients had a smaller type II fibre cross-sectional area (CSA) compared to male patients, suggesting a greater female preponderance to fibre atrophy, although this result was largely driven by a few male patients with a large type II fibre CSA. Female patients had significantly higher concentrations of a number of plasma pro-inflammatory cytokines including tumour necrosis factor alpha and interleukin 8 (IL8), but not lower levels of physical activity or arterial oxygenation, compared to males. Our data confirm results from a previous small study and suggest that female COPD patients have a greater prevalence of muscle wasting and weakness. Larger studies investigating sex differences in COPD-related muscle atrophy and weakness are needed, as the results will have implications for monitoring in clinical practice and for design of clinical trials evaluating novel muscle anabolic agents.

Quantifying Mobility in the ICU: Comparison of Electronic Health Record Documentation and Accelerometer-Based Sensors to Clinician-Annotated Video

Supplemental Digital Content is available in the text.

To compare the accuracy of electronic health record clinician documentation and accelerometer-based sensors with a gold standard dataset derived from clinician-annotated video to quantify early mobility activities in adult ICU patients.

The validity and reliability of four-meter gait speed test for stable interstitial lung disease patients: the prospective study

Background

The 4-m gait speed test is a simple functional performance measure for older adults or patients with chronic obstructive lung disease. However, limited data exist regarding these measures for patients with interstitial lung disease. We evaluated the correlation between the 4-m gait speed and 6-min walk distance tests for interstitial lung disease patients and examined their underlying physiological factors.

Methods

The 4-m gait speed and 6-min walk tests were prospectively conducted for 51 patients with interstitial lung disease. Other measurements included health-related quality of life, modified Medical Research Council score, arterial blood gas levels, pulmonary function, muscle strength according to the skeletal muscle mass index and physical activity.

Results

Thirty-five patients were male (68.6%). Thirty-four patients had idiopathic pulmonary fibrosis (66.7%). There were significant correlations between the 4-m gait speeds and 6-min walk distances (r=0.57; P<0.001). Multivariate analyses showed that both the 4-m gait speed and 6-min walk distance were correlated with the modified Medical Research Council score. In addition, the 6-min walk distance was correlated with age and the percentage of the predicted diffusion capacity of carbon monoxide.

Conclusions

The 4-m gait speed test is a simple, easy to perform and reliable functional performance measure for interstitial lung disease patients.

Use of pedometers as a tool to promote daily physical activity levels in patients with COPD: a systematic review and meta-analysis

The aim of this study was to examine the use of pedometers as a tool to promote daily physical activity levels in patients with COPD.

A systematic review meta-analysis of pedometer physical activity promotion in patients with COPD was conducted. Medline/PubMed, Cochrane Library, Web of Science and CINAHL were searched from inception to January 2019. The search strategy included the following keywords: physical activity promotion, pulmonary rehabilitation and daily physical activity. The eligibility criteria for selecting studies were randomised controlled trials reporting pedometer physical activity promotion in patients with COPD.

Improvements in steps per day were found with pedometer physical activity promotion either standalone (n=12, mean 0.53 (95% CI 0.29–0.77); p=0.00001) or alongside pulmonary rehabilitation (n=7, 0.51 (0.13–0.88); p=0.006). A subgroup analysis reported significant differences in the promotion of physical activity based on baseline physical activity levels and the type of instrument used to assess levels of physical activity.

Future trials should consider the way in which pedometers are used to promote physical activity to inform clinical practice in the setting of pulmonary rehabilitation.

Validity and Reliability of Accelerometers in Patients With COPD: A SYSTEMATIC REVIEW

PURPOSE

Reduced physical activity is associated with poor prognosis in chronic obstructive pulmonary disease (COPD). Accelerometers have greatly improved quantification of physical activity by providing information on step counts, body positions, energy expenditure, and magnitude of force. The purpose of this systematic review was to compare the validity and reliability of accelerometers used in patients with COPD.

METHODS

An electronic database search of MEDLINE and CINAHL was performed. Study quality was assessed with the Strengthening the Reporting of Observational Studies in Epidemiology checklist while methodological quality was assessed using the modified Quality Appraisal Tool for Reliability Studies.

RESULTS

The search yielded 5392 studies; 25 met inclusion criteria. The SenseWear Pro armband reported high criterion validity under controlled conditions (r = 0.75-0.93) and high reliability (ICC = 0.84-0.86) for step counts. The DynaPort MiniMod demonstrated highest concurrent validity for step count using both video and manual methods.

DISCUSSION

Validity of the SenseWear Pro armband varied between studies especially in free-living conditions, slower walking speeds, and with addition of weights during gait. A high degree of variability was found in the outcomes used and statistical analyses performed between studies, indicating a need for further studies to measure reliability and validity of accelerometers in COPD.

CONCLUSION

The SenseWear Pro armband is the most commonly used accelerometer in COPD, but measurement properties are limited by gait speed variability and assistive device use. DynaPort MiniMod and Stepwatch accelerometers demonstrated high validity in patients with COPD but lack reliability data.

Comparison of unsupervised home-based pulmonary rehabilitation versus supervised hospital outpatient pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Background: Pulmonary rehabilitation (PR) is an effective treatment in patients with chronic obstructive pulmonary disease (COPD) but still underutilized. The aim of this study was to compare unsupervised home PR with supervised outpatient PR in terms of various clinical variables in COPD patients.Methods: We conducted retrospective study consisting of 247 patients with COPD who were categorized into three group. 127 patients underwent unsupervised home PR, of whom 60 (47%) completed program (finishers), 67(53%) were lost to follow-up (non-finishers), 120 completed supervised outpatient PR. We compared baseline, post-treatment changes in demographic, clinical variables.Results: Sex, age were statistically similar between groups. Finishers of home PR had higher exercise capacity (p = 0.003), quality of life (p = 0.045), FEV1 (p = 0.001), lower pack-year smoking (p < 0.001) than outpatient PR.After home PR, exercise capacity (p < 0.05), quality of life (p < 0.001), dyspnea(p < 0.05), anxiety (p < 0.001), depression (p < 0.001) were improved except endurance shutte test. Improvements in exercise capacity (p < 0.05), quality of life (p < 0.001), dyspnea (p = 0.023), anxiety (p < 0.001), depression (p = 0.001) scores were different between completed PR programs, in favor of supervised outpatient PR. Non-finishers of home PR had more pack-year smoking than finishers of home PR (p = 0.039); other baseline parameters were similar.Conclusion: Unsupervised home PR was effective in terms of improving exercise capacity, quality of life, dyspnea, psychological status, but less than supervised outpatient programs.

The impact of pulmonary rehabilitation on severe physical inactivity in patients with chronic obstructive pulmonary disease: a pilot study

Introduction

In patients with COPD, severe physical inactivity (SPI, which is defined as total daily energy expenditure/resting energy expenditure; physical activity level [PAL] ratio, <1.4) is associated with increased morbidity and mortality. Pulmonary rehabilitation (PR) increases physical capacity in COPD, but the impact on SPI is unknown. In this study, we aimed at elucidating the prevalence of SPI in COPD patients attending standard PR, the impact of PR on SPI prevalence, and the relationship between SPI and time spent in moderate physical activity thus whether American College of Sports Medicine (ACSM) recommendations are clinically useful in excluding SPI in COPD.

Methods

This is a prospective non-interventional pilot study on patients with COPD completing PR, consenting to wear an accelerometer (Sensewear^© Armband) for a week before and after completing PR to assess changes in energy expenditure, time spent in physical activity, and number of daily steps. Low level of daily physical activity was not an inclusion criterion.

Results

In total, 57 patients completed the study and 31 (54%) had SPI at baseline. In patients with SPI, baseline median FEV₁ was 48 (range, 28–86) % of predicted and GOLD B, n=11 (35%)/GOLD D, n=20 (65%). Surprisingly, 31 of SPI patients (97%) spent ≥150 minutes/week in moderate physical activity. After rehabilitation, 24 (78%) did not change activity level and were persistently SPI. We observed no differences at baseline between patient responding (n=7) vs not responding (n=24) to PR. Responders increased number of daily steps and time spent in lighter but not moderate physical activity during rehabilitation.

Conclusion

In this pilot study, SPI was prevalent, and PR had limited impact. Contraintui-tively, most patients with SPI complied with general recommendations of weekly hours spent in moderate physical activity. Our study highlights that increasing time spent in light activity rather than improving time spent in moderate activity is important in COPD patients with chronic dyspnea.

Predominance of Comorbidities in the Detriment of Daily Activity in Sarcoidosis Patients

Sarcoidosis may affect lung function, working ability, overall mobility, and daily activity. In the present study we performed an analysis of clinical settings in patients with sarcoidosis to disentangle its influence on daily physical activity (PA). PA assessment (number of steps per day, daily energy expenditure) was performed by accelerometry during consecutive 7 days after discharge from hospital. Thirty patients with sarcoidosis, aged 46.4 ± 10.5, were enrolled in the study. Clinical data (age, gender, steroid consumption, weight, and comorbidities), lung function tests (forced expiratory volume in one second - FEV1, forced vital capacity - FVC, and lung diffusion for carbon monoxide - DLCO), mobility (6-minute walk test - 6 MWT) and physical performance (oxygen consumption at anaerobic threshold - VO2/AT) were estimated. The mean daily PA (5214 ± 2699 steps/day) and VO2max (22.3 ± 7.0 ml/kg/min) were lower when referenced to the age-group predicted values. A significant greater daily PA was observed in sarcoidosis patients without comorbidities compared with those having more than two comorbidities (p = 0.046). No association was found between steroid use, lung function, and 6MWT. Daily PA was associated with patients aerobic efficacy and VO2max (r = 0.38, p < 0.04). The findings demonstrate a significant influence of comorbidities on sarcoidosis patients' exercise tolerance and daily PA. Special treatment considerations, including the potential impact of comorbidities, may help optimize exercise regimes, link physical activity with health, and prevent sarcoidosis complications.

A Lifestyle Physical Activity Intervention for Patients with Chronic Obstructive Pulmonary Disease. A Randomized Controlled Trial

RATIONALE

Physical inactivity is associated with poor outcomes among patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine effectiveness of a behavioral intervention intended to increase daily physical activity with the goal of improving health-related quality of life and functional performance.

METHODS

We conducted a randomized trial among patients with COPD cared for in primary care and pulmonary clinics. The patients were at least 45 years of age and eligible for pulmonary rehabilitation. All patients received self-management education during a 6-week run-in period. Subsequently, patients were randomized to usual care or the intervention delivered over 20 weeks.

MEASUREMENTS AND MAIN RESULTS

Co-primary outcomes were change from baseline in Chronic Respiratory Questionnaire dyspnea domain score and 6-minute-walk distance measured at 6, 12, and 18 months after randomization. A total of 325 patients were enrolled, with 156 randomized to receive usual care and 149 to receive the intervention. At 18 months, there was no overall statistical or clinically significant change in the dyspnea domain in either group. However, for 6-minute-walk distance, there were statistically significant declines in both groups. In contrast, 6-minute-walk distance remained stable (5.3 m; P = 0.54) among patients in the intervention group with moderate spirometric impairment, but it was associated with clinically and statistically significant declines (-28.7 m; P = 0.0001) among usual care patients with moderate spirometric impairment. Overall, there was no increase in adverse events associated with the intervention, which was associated with a lower prevalence of hospitalization for COPD exacerbations (28.3%) compared with usual care (49.5%).

CONCLUSIONS

During this 18-month trial among outpatients with COPD, a health coach-based behavioral intervention did not improve scores in the dyspnea domain of the Chronic Respiratory Questionnaire or 6-minute-walk test distance. However, subgroup analyses suggested that there may be differential effects for specific outcomes that vary with severity of COPD. Specifically, benefits of this low-intensity intervention may be limited to 6-minute walk distance among patients with moderate spirometric impairment. Clinical trial registered with www.clinicaltrials.gov (NCT1108991).

Short- and Long-term Effects of Pulmonary Rehabilitation in Patients With Mild COPD: A COMPARISON WITH PATIENTS WITH MODERATE TO SEVERE COPD

PURPOSE

Pulmonary rehabilitation (PR) is effective in patients with moderate to severe chronic obstructive pulmonary disease (COPD). However, the effects of PR in patients with mild COPD have not yet been established. Thus, this study investigated the short- and long-term effects of PR in patients with mild COPD in comparison with patients with moderate to severe disease.

METHODS

A total of 32 patients with mild (group 1) and 29 with moderate to severe (group 2) COPD completed the study. Both groups participated in a 12-week PR program with exercise training and psychosocial support and education. Outcome measures at baseline, 3 (post-PR), 6, and 9 months later included 6-minute walk test (6MWT); Modified Medical Research Council Dyspnea Scale; 1-repetition maximum chest press and knee extension; a brief physical activity assessment; the number of exacerbations in the past 3 months and the St. George Respiratory Questionnaire (SGRQ).

RESULTS

Improvements in the 6MWT, chest press, knee extension, and physical activity were observed post-PR (P < .001), with no differences between the 2 groups. Reduction in the number of exacerbations (P < .001) and improvements in the SGRQ total (P < .001) were also observed, however, with greater magnitude in group 2 (P = .029 and P < .001, respectively). Except for peripheral muscle strength (P < .002), all the achieved benefits were sustained at 6 and 9 months (P > .05).

CONCLUSIONS

Pulmonary rehabilitation improves exercise tolerance, muscle strength, physical activity, and health-related quality of life and reduces exacerbations in patients with mild COPD as it does in patients with moderate to severe COPD. Moreover, most of these benefits were maintained at 9-month follow-up, suggesting that PR could be part of the management of mild COPD.

Wide Disagreement Between Alternative Assessments of Premorbid Physical Activity: Subjective Patient and Surrogate Reports and Objective Smartphone Data

OBJECTIVES

Surrogate-decision maker and patient self-reported estimates of the distances walked prior to acute illness are subjective and may be imprecise. It may be possible to extract objective data from a patient's smartphone, specifically, step and global position system data, to quantify physical activity. The objectives were to 1) assess the agreement between surrogate-decision maker and patient self-reported estimates of distance and time walked prior to resting and daily step-count and 2) determine the feasibility of extracting premorbid physical activity (step and global position system) data from critically ill patients.

DESIGN

Prospective cohort study.

SETTING

Quaternary ICU.

PATIENTS

Fifty consecutively admitted adult patients who owned a smartphone, who were ambulatory at baseline, and who remained in ICU for more than 48 hours participated.

MEASURMENTS AND MAIN RESULTS

There was no agreement between patients and surrogates for all premorbid walking metrics (mean bias 108% [99% lower to 8,700% higher], 83% [97% to 2,100%], and 71% [96% to 1,080%], for distance, time, and steps, respectively). Step and/or global position system data were successfully extracted from 24 of 50 phones (48%; 95% CI, 35-62%). Surrogate-decision makers, but not patient self-reported, estimates of steps taken per day correlated with smartphone data (surrogates: n = 13, ρ = 0.56, p < 0.05; patients: n = 13, ρ = 0.30, p = 0.317).

CONCLUSION

There was a lack of agreement between surrogate-decision maker and patient self-reported subjective estimates of distance walked. Obtaining premorbid physical activity data from the current-generation smartphones was feasible in approximately 50% of patients.

Physical activity in patients with COPD: the impact of comorbidities

INTRODUCTION

Comorbidities are common in patients with chronic obstructive pulmonary disease (COPD) and it plays an important role on physical activity (PA) in this population. Since low PA levels have been described as a key factor to predict morbi-mortality in COPD, it seems crucial to review the current literature available on this topic. Areas covered: This review covers the most common comorbidities found in COPD, their prevalence and prognostic implications. We explore the differences in PA between COPD patients with and without comorbidities, as well as the impact of the number or type of comorbidities on activity levels of this population. The effect of different comorbidities on activities of daily living in patients with COPD is also reviewed. Finally, we discuss options for the treatment of inactivity in COPD patients considering their comorbidities and limitations. Expert commentary: Comorbidities are highly prevalent in patients with COPD and further deteriorate PA levels in this population. Despite the wide range of interventions available in COPD, the evidence in the field seems to point at PA coaching with feedback on individual goals and longer lasting PR programmes with more than 12 weeks of duration when attempting to raise the activity levels of this population.

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.

The Glittre-ADL test reflects functional performance measured by physical activities of daily living in patients with chronic obstructive pulmonary disease

BACKGROUND

The Glittre-ADL test (TGlittre) is a valid and reliable test for the evaluation of functional capacity and involves multiple physical activities of daily living (PADL), which are known to be troublesome to patients with Chronic Obstructive Pulmonary Disease (COPD). However, it is still unknown if this test is also able to reflect the functional performance of patients with COPD.

OBJECTIVE

To investigate whether the TGlittre reflects the functional performance of COPD patients and whether the necessary time to complete the TGlittre and the PADL varies according to disease severity.

METHOD

Thirty-eight patients with COPD (age 65, SD=7 years; forced expiratory volume in the first second 41.3, SD=15.2% predicted) underwent anthropometric and lung function assessments and were submitted to the TGlittre and PADL measurement.

RESULTS

TGlittre performance correlated significantly (p<0.05) with PADL variables, such as time sitting (r=0.50), walking (r=-0.46), number of steps taken (r=-0.53), walking movement intensity (r=-0.66), walking energy expenditure (r=-0.50), and total energy expenditure (r=-0.33). TGlittre performance was not significantly different in patients among the Global Initiative for COPD (GOLD) spirometric stages, but walking and sitting time were significantly lower and greater, respectively, in severe and very severe patients compared to those with moderate disease (p<0.05).

CONCLUSION

The performance on the TGlittre correlates with walking and sitting time and other real life PADL measurements. The severity of the disease is associated with the differences in the level of physical activity in daily life more than in functional capacity.

The Mozart study: a relation between dynamic hyperinflation and physical activity in patients with chronic obstructive pulmonary disease?

BACKGROUND

Many patients with chronic obstructive pulmonary disease (COPD) experience dyspnoea during exercise, resulting in a reduction of physical activity (PA). Dynamic hyperinflation (DH) is seen as a major cause of dyspnoea in COPD.

OBJECTIVE

The objective of the current study was to investigate the relationship between DH, in terms of the amount of DH and the development and recovery rate of DH in patients with COPD, and PA.

METHODS

Thirty-five patients with stable COPD were included from an outpatient clinic (14 GOLD II and 21 GOLD III, median age 65). PA was assessed using an accelerometer. Subjects underwent metronome-paced tachypnoea (MPT) to induce DH. To quantify the amount of DH during MPT, a decrease in inspiratory capacity (IC) or a change in IC as percentage of total lung capacity was used.

RESULTS

No significant correlations were found between the parameters describing DH and PA. Secondary correlation analyses showed a negative correlation between static hyperinflation (SH) and PA (r = -0·39; P = 0·02). The pattern of breathing during MPT and the test itself showed high interpatient variability.

CONCLUSIONS

The absence of a significant correlation between DH and PA is contrary to previous studies. SH did show a correlation with PA. The variety in results and the technical difficulties in execution of the measurements ask for a new, more reliable, method to detect DH and investigate its relation with PA in patients with COPD.

Accelerometer- versus questionnaire-based assessment of physical activity and their changes over time in patients with COPD

Background and objective

Physical activity (PA) is an important outcome parameter in patients with COPD regarding hospitalizations and mortality. Both objective assessment by accelerometers and self-evaluation by questionnaires were used in studies investigating PA in COPD. Whether self-reported questionnaires can adequately reflect PA and its changes over time compared to objective assessments has not been thoroughly investigated in COPD. In this COPD cohort study, we evaluated whether PA measured by accelerometer and its annual changes can also be assessed by self-reported questionnaires.

Methods

In 178 COPD patients with at least two assessments of PA, the agreement between objectively measured and self-reported activity was analyzed by Bland–Altman plots. Daily PA was assessed by a triaxial activity monitor over 1 week and by the self-reported German PA questionnaire 50+.

Results

Comparison between the two methods of measurement revealed no convincing agreement with a mean difference and limits of agreement (±1.96 standard deviation [SD]) of time spent in at least moderate PA (>3 metabolic equivalent of task [MET]) of −77.6 (−340.3/185.2) min/day, indicating a self-reported overestimation of PA by the questionnaire. The mean difference and limits of agreement (±1.96SD) in the annual change of PA was 1.2 min/day (−208.2/282.6 min/day), showing also a poor agreement on an individual level.

Conclusion

Evaluation of objectively measured and self-reported PA and their annual changes revealed no agreement in patients with COPD. Therefore, the evaluated questionnaire seems not helpful for measurement of PA and its changes over time.

Physical activity levels in locally advanced rectal cancer patients following neoadjuvant chemoradiotherapy and an exercise training programme before surgery: a pilot study

Background

The aim of this pilot study was to measure changes in physical activity level (PAL) variables, as well as sleep duration and efficiency in people with locally advanced rectal cancer (1) before and after neoadjuvant chemoradiotherapy (CRT) and (2) after participating in a pre-operative 6-week in-hospital exercise training programme, following neoadjuvant CRT prior to major surgery, compared to a usual care control group.

Methods

We prospectively studied 39 consecutive participants (27 males). All participants completed standardised neoadjuvant CRT: 23 undertook a 6-week in-hospital exercise training programme following neoadjuvant CRT. These were compared to 16 contemporaneous non-randomised participants (usual care control group). All participants underwent a continuous 72-h period of PA monitoring by SenseWear biaxial accelerometer at baseline, immediately following neoadjuvant CRT (week 0), and at week 6 (following the exercise training programme).

Results

Of 39 recruited participants, 23 out of 23 (exercise) and 10 out of 16 (usual care control) completed the study. In all participants (n = 33), there was a significant reduction from baseline (pre-CRT) to week 0 (post-CRT) in daily step count: median (IQR) 4966 (4435) vs. 3044 (3265); p < 0.0001, active energy expenditure (EE) (kcal): 264 (471) vs. 154 (164); p = 0.003, and metabolic equivalent (MET) (1.3 (0.6) vs. 1.2 (0.3); p = 0.010). There was a significant improvement in sleep efficiency (%) between week 0 and week 6 in the exercise group compared to the usual care control group (80 (13) vs. 78 (15) compared to (69 ((24) vs. 76 (20); p = 0.022), as well as in sleep duration and lying down time (p < 0.05) while those in active EE (kcal) (152 (154) vs. 434 (658) compared to (244 (198) vs. 392 (701) or in MET (1.3 (0.4) vs. 1.5 (0.5) compared to (1.1 (0.2) vs. 1.5 (0.5) were also of importance but did not reach statistical significance (p > 0.05). An apparent improvement in daily step count and overall PAL in the exercise group was not statistically significant.

Conclusions

PAL variables, daily step count, EE and MET significantly reduced following neoadjuvant CRT in all participants. A 6-week pre-operative in-hospital exercise training programme improved sleep efficiency, sleep duration and lying down time when compared to participants receiving usual care.

Trial registration

Clinicaltrials.gov NCT01325909

Electronic supplementary material

The online version of this article (doi:10.1186/s13741-017-0058-3) contains supplementary material, which is available to authorized users.

Percent Emphysema and Daily Motor Activity Levels in the General Population: Multi-Ethnic Study of Atherosclerosis

BACKGROUND

COPD is associated with reduced physical capacity. However, it is unclear whether pulmonary emphysema, which can occur without COPD, is associated with reduced physical activity in daily life, particularly among people without COPD and never smokers. We hypothesized that greater percentage of emphysema-like lung on CT scan is associated with reduced physical activity assessed by actigraphy and self-report.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants free of clinical cardiovascular disease from the general population. Percent emphysema was defined as percentage of voxels < -950 Hounsfield units on full-lung CT scans. Physical activity was measured by wrist actigraphy over 7 days and a questionnaire. Multivariable linear regression was used to adjust for age, sex, race/ethnicity, height, weight, education, smoking, pack-years, and lung function.

RESULTS

Among 1,435 participants with actigraphy and lung measures, 47% had never smoked, and 8% had COPD. Percent emphysema was associated with lower activity levels on actigraphy (P = .001), corresponding to 1.5 hour less per week of moderately paced walking for the average participant in quintile 2 vs 4 of percent emphysema. This association was significant among participants without COPD (P = .004) and among ever (P = .01) and never smokers (P = .03). It was also independent of coronary artery calcium and left ventricular ejection fraction. There was no evidence that percent emphysema was associated with self-reported activity levels.

CONCLUSIONS

Percent emphysema was associated with decreased physical activity in daily life objectively assessed by actigraphy in the general population, among participants without COPD, and nonsmokers.

Coherence between self-reported and objectively measured physical activity in patients with chronic obstructive lung disease: a systematic review

The beneficial effects of physical activity (PA) in patients with COPD, as well as the methods of their assessment, are well known and described. As objective measures of PA, such as the use of motion sensors, video recordings, exercise capacity testing, and indirect calorimetry, are not easily obtained in the daily clinical life, the reliability of the more accessible self-reported measurements of PA is important. In this review, we systematically identified original studies involving COPD patients and at least one parameter of self-reported and objective exercise testing, and analyzed every article for coherence between the objectively and self-reported measured PA. The studies are few, small, and very diverse, both in their use of questionnaires and objective measurements. Self-reported assessments were found to generally overestimate the level of PA compared to measurements made objectively by activity monitors; however, more studies are needed to rely solely on the use of PA questionnaires in COPD patients. The most accurate and valid questionnaires appear to be the self-completed Physical Activity Scale for the Elderly and the interviewer-completed Stanford Seven-Day Physical Activity Recall Questionnaire, but the ideal questionnaire still awaits construction. The motion sensors are accurate and validated in this patient group, especially SenseWear™, but not easily accessible in clinical practice, as they have various technical and adhesive difficulties.

Agreement between adherences to four physical activity recommendations in patients with COPD: does the incremental shuttle walk test predict adherence?

INTRODUCTION AND OBJECTIVES

There are various recommendations for physical activity (PA). However agreement between all of these measures has not been established. Furthermore, given the challenges of measuring PA there is interest in evaluating whether a measure of exercise performance can be used as a surrogate measure to identify who is likely to achieve the recommendations.

METHODS

A total of 184 people with COPD were recruited, 128 of which had complete data for these analyses. Participants wore the SenseWear Armband for 7 consecutive days and all performed an incremental shuttle walk test (ISWT). We extracted moderate to vigorous physical activity (MVPA) in bouts of ≥10 min using a 3 metabolic equivalent (MET) threshold and an individually prescribed MET threshold (based on performance on the ISWT). Average daily step count and the physical activity level were also calculated.

RESULTS

There was poor agreement between the four PA recommendations, with agreement on all four achieved in only 30 participants. People were least likely to be active using MVPA in ≥10 min bouts using 3 MET threshold (21.1% active), and most likely to be active using MVPA in ≥10 min bouts using an individually prescribed threshold (64.9% active). It was not possible to identify a threshold on the ISWT that would reliably predict those that achieved any of the four recommendations.

CONCLUSION

Agreement between various physical activity recommendations is poor. This should be considered when measuring and describing physical activity adherence. The ISWT cannot be used to reliably predict adherence to physical activity guidelines.

Validation of a novel activity monitor in impaired, slow-walking, crutch-supported patients

BACKGROUND

A growing need in clinical practice of rehabilitation and orthopaedic medicine is for objective outcome tools to estimate physical activity. Current techniques show limited validity or are too demanding for routine clinical use. Accelerometer-based activity monitors (AMs) have shown promise for measuring physical activity in healthy people but lack validity in impaired patients.

OBJECTIVES

This study aimed to validate an accelerometer-based AM in impaired, slow-walking, crutch-supported patients after total joint arthroplasty (TJA).

METHODS

Shortly after TJA, patients who were safely mobilized with 2 crutches and 8 healthy participants completed a trial of different activities while wearing the AM on the lateral upper leg and being videotaped. Outcome variables (e.g., time walking, number of gait cycles, sit-stand-sit transfers) were compared to video recordings, and sensitivity, predictive value and mean percentage difference (MPD) values were calculated.

RESULTS

We included 40 patients (mean age: 65±9 years; mean BMI: 30±6kg/m²; male:female ratio: 18:22) and 8 healthy participants (mean age: 49±20 years; mean BMI: 23±0.7kg/m²; male:female ratio: 5:3). The AM showed excellent sensitivity (>95%) and predictive value (>95%) in identifying activities (e.g., walking, sitting, resting) and detecting the number of gait cycles and sit-stand-sit transfers (mean percentage difference: ±2%). Detection of number of steps ascending and descending stairs and cadence was more difficult but still showed good results (mean percentage difference: ±7%).

CONCLUSIONS

This is the first validation study to assess physical activity with an AM in impaired, slow-walking, crutch-supported patients. The AM was a valid tool for measuring physical activity in these patients. The tool may help in evaluating and optimizing rehabilitation programs for patients after TJA, those recovering from stroke or chronic impaired patients.

Sedentary Behavior in People with and without a Chronic Health Condition: How Much, What and When?

PURPOSE

To describe sedentary behaviors (duration, bouts and context) in people with and without a chronic health condition.

METHODS

Design: Secondary analysis of two cross-sectional studies. Participants: People with stable chronic obstructive pulmonary disease (COPD) (n = 24, male:female 18:6) and their spousal carers (n = 24, 6:18); stroke survivors (n = 24, 16:8) and age- and sex-matched healthy adults (n = 19, 11:8). Level of physiological impairment was measured with post-bronchodilator spirometry (FEV1 %predicted) for people with COPD, and walking speed for people with stroke. Outcomes: Participants were monitored over seven days (triaxial accelerometer, Sensewear armband) to obtain objective data on daily sedentary time, and prolonged sedentary bouts (≥ 30 min). During the monitoring period, a 24-hour use of time recall instrument was administered by telephone interview to explore the context of sedentary activities (e.g. television, computer or reading). Sedentary time was quantified using accelerometry and recall data, and group differences were explored. Linear regression examined associations between physiological impairment and sedentary time.

RESULTS

Participant groups were similar in terms of age (COPD 75 ± 8, carers 70 ± 11, stroke 69 ± 10, healthy 73 ± 7 years) and body mass index (COPD 28 ± 4, carers 27 ± 4, stroke 31 ± 4, healthy 26 ± 4 kg.m-2). The healthy group had the lowest sedentary time (45% of waking hours), followed by the carer (54%), stroke (60%) and COPD (62%) groups (p < 0.0001). Level of physiological impairment was an independent predictor of waking sedentary time (p = 0.001).

CONCLUSIONS

People with a chronic health condition spent more time sedentary than those without a chronic condition, and there were small but clear differences between groups in the types of activities undertaken during sedentary periods. The study findings may aid in the design of targeted interventions to decrease sedentary time in people with chronic health conditions.

Cross-Cultural Adaptation of the CHAMPS Questionnaire in French Canadians with COPD

Physical activity is difficult to measure in individuals with COPD. The Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire demonstrated strong clinometric properties when used with the elderly and with those affected by chronic disease. Study objectives were to translate, culturally adapt the CHAMPS into French, and reexamine its test-retest reliability and construct validity in French and English Canadians with COPD. This paper presents the cross-cultural adaptation of the CHAMPS; results of its clinometric testing will be described in another article. The CHAMPS examines the degree of physical activity performed in a typical week through two summary scales, caloric expenditure and activity frequency. The CHAMPS was only in English; thus, a cross-cultural adaptation was needed to translate the CHAMPS into French for use in French Canadians with COPD. Cross-cultural adaptation consisted of forward and back translation, with expert review at each stage of translation: minor inconsistencies were uncovered and rectified. Five French participants with COPD completed the finalized Canadian French CHAMPS and participated in cognitive debriefing; no problematic items were identified. A structured and stepwise, cross-cultural adaptation process produced the Canadian French CHAMPS, with items of equivalent meaning to the English version, for use in French Canadians with COPD.

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.

Interventions to modify physical activity in patients with COPD: a systematic review

The broad range of interventions to increase physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) has not been systematically assessed. We aimed to perform a systematic review of the interventional studies that have assessed PA as an outcome in patients with COPD.

A systematic search in five different databases (Medline, Embase, PsycINFO, CINAHL and Web of Science) was performed in March 2015. Two independent reviewers analysed the studies against the inclusion criteria (COPD defined by spirometry; prospective, randomised/nonrandomised studies, cohort and experimental studies with interventions using PA as an outcome), extracted the data and assessed the quality of evidence.

60 studies were included. Seven intervention groups were identified. PA counselling increased PA levels in COPD, especially when combined with coaching. 13 studies showed positive effects of pulmonary rehabilitation (PR) on PA, while seven studies showed no changes. All three PR programmes >12 weeks in duration increased PA. Overall, the quality of evidence was graded as very low.

Interventions focusing specifically on increasing PA, and longer PR programmes, may have greater impacts on PA in COPD. Well-designed clinical trials with objective assessment of PA in COPD patients are needed.

Failed upregulation of TFAM protein and mitochondrial DNA in oxidatively deficient fibers of chronic obstructive pulmonary disease locomotor muscle

Background

Low mitochondrial content and oxidative capacity are well-established features of locomotor muscle dysfunction, a prevalent and debilitating systemic occurrence in patients with chronic obstructive pulmonary disease (COPD). Although the exact cause is not firmly established, physical inactivity and oxidative stress are among the proposed underlying mechanisms. Here, we assess the impact of COPD pathophysiology on mitochondrial DNA (mtDNA) integrity, biogenesis, and cellular oxidative capacity in locomotor muscle of COPD patients and healthy controls. We hypothesized that the high oxidative stress environment of COPD muscle would yield a higher presence of deletion-containing mtDNA and oxidative-deficient fibers and impaired capacity for mitochondrial biogenesis.

Methods

Vastus lateralis biopsies were analyzed from 29 COPD patients and 19 healthy age-matched controls for the presence of mtDNA deletions, levels of oxidatively damaged DNA, mtDNA copy number, and regulators of mitochondrial biogenesis as well the proportion of oxidative-deficient fibers (detected histologically as cytochrome c oxidase-deficient, succinate dehydrogenase positive (COX⁻/SDH⁺ )). Additionally, mtDNA copy number and mitochondrial transcription factor A (TFAM) content were measured in laser captured COX⁻SDH⁺ and normal single fibers of both COPD and controls.

Results

Compared to controls, COPD muscle exhibited significantly higher levels of oxidatively damaged DNA (8-hydroxy-2-deoxyguanosine (8-OHdG) levels = 387 ± 41 vs. 258 ± 21 pg/mL) and higher prevalence of mtDNA deletions (74 vs. 15 % of subjects in each group), which was accompanied by a higher abundance of oxidative-deficient fibers (8.0 ± 2.1 vs. 1.5 ± 0.4 %). Interestingly, COPD patients with mtDNA deletions had higher levels of 8-OHdG (457 ± 46 pg/mL) and longer smoking history (66.3 ± 7.5 years) than patients without deletions (197 ± 29 pg/mL; 38.0 ± 7.3 years). Transcript levels of regulators of mitochondrial biogenesis and oxidative metabolism were upregulated in COPD compared to controls. However, single fiber analyses of COX⁻/SDH⁺ and normal fibers exposed an impairment in mitochondrial biogenesis in COPD; in healthy controls, we detected a marked upregulation of mtDNA copy number and TFAM protein in COX⁻/SDH⁺ compared to normal fibers, reflecting the expected compensatory attempt by the oxidative-deficient cells to increase energy levels; in contrast, they were similar between COX⁻/SDH⁺ and normal fibers in COPD patients. Taken together, these findings suggest that although the signaling factors regulating mitochondrial biogenesis are increased in COPD muscle, impairment in the translation of these signals prevents the restoration of normal oxidative capacity.

Conclusions

Single fiber analyses provide the first substantive evidence that low muscle oxidative capacity in COPD cannot be explained by physical inactivity alone and is likely driven by the disease pathophysiology.