Search

BACKGROUND: Persistent impairment of pulmonary function and exercise capacity has been known to last for months or even years in the survivors who recovered from other coronavirus pneumonia. Some reports showed that subjects with coronavirus disease 2019 pneumonia after being discharged could have several sequelae, but there are few studies on gas exchange and exercise capacity complications in these subjects. AIMS: To describe residual gas exchange abnormalities during recovery from coronavirus disease 2019 pneumonia. METHODS: In an observational study, ∼90 d after onset of disease, we scheduled almost 200 subjects for an out-patient visit with pulmonary function testing and computed tomography of the lungs. Lung mechanics by using body plethysmography, gas exchange with diffusing lung capacity for carbon monoxide determined by the single-breath technique (DLCOsb) and diffusing lung capacity for nitric oxide determined by the single-breath technique (DLNOsb), and exercise ability by using the 6-min walk test (6MWT) were measured in the subjects. The results were compared between those who required invasive mechanical ventilation and those who did not. RESULTS: A total of 171 subjects were included, the majority (96%) had signs of residual pneumonia (such as an excess of high attenuation areas) on computed tomography of the lungs. The DLCOSB results were below the lower limit of the normal range in 29.2% of the subjects; during the 6MWT, 67% experienced oxygen desaturation ( S pO 2 ) > 4%; and, in 81 (47%), the dropped below 88%. Subjects who required invasive mechanical ventilation (49.7%) were more likely to have lower lung volumes, more gas exchange abnormality, less exercise capacity and more radiologic abnormality. CONCLUSIONS: Subjects who recovered from severe COVID-19 pneumonia continued to have abnormal lung function and abnormal radiologic findings.

BACKGROUND: The sit-to-stand (STS) test is a feasible tool for measuring peripheral muscle strength of the lower limbs. There is evidence of increasing use of STS tests in patients with COPD. We sought to evaluate in subjects with COPD the minimum clinically important difference in 30-s STS test after pulmonary rehabilitation. METHODS: Stable COPD subjects undergoing a 30-s STS test and a 6-min walk test (6MWT) before and after pulmonary rehabilitation were included. Responsiveness to pulmonary rehabilitation was determined by the change in 30-s STS test results (Δ 30-s STS) before and after pulmonary rehabilitation. The minimum clinically important difference was evaluated using an anchor-based method. RESULTS: 96 subjects with moderate-to-severe COPD were included. At baseline, 30-s STS test results were significantly related to distance covered in a 6MWT (6MWD) (r = 0.65, P CONCLUSIONS: Our study indicates that in stable subjects with moderate-to-severe COPD, the 30-s STS test was a sensitive tool to assess the efficacy of pulmonary rehabilitation. A Δ 30-s STS of ≥ 2 repetitions represented the minimum clinically important difference, which may be predicted by the baseline ability in the 30-s STS test and lung function in terms of diffusing lung capacity (ClinicalTrials.gov registration NCT03627624).

BACKGROUND: Single-step tests have been proposed as simple and inexpensive challenges todiagnose exercise-induced bronchoconstriction (EIB) in the pediatric population. Work performed and the resulting ventilation, however, might be substantially lower in stepping than running. This might decrease the diagnostic yield of step-based challenges. METHODS: In a cross-sectional study, 53 children with asthma with exercise-related symptoms (34 boys, age 6–18 y) underwent an incremental stepping test, a 6-min constant stepping test, and a treadmill running test on different days. RESULTS: Constant and incremental stepping tests presented with lower metabolic demands (V˙ O2 1.42 0.48 and 1.34 0.55 L/min, respectively), ventilatory demands (V˙ O2 45 14 and 43 16 L/min, respectively), and cardiovascular demands (160 20 and 161 19 beats/min, respectively) than the treadmill running test (1.65 0.60 L/min, 54 17 L/min, and 172 7 beats/min, respectively) (P < .05). Between-test agreement in diagnosing EIB was poor (kappa 0.217–0.361). Although EIB prevalence was higher after the treadmill running test (60%) compared to constant (53%) and incremental (47%) stepping tests, 7 subjects developed EIB only in stepping. Clinical and resting functional characteristics did not differ in iscordant subjects (ie, EIB negative in a given test but positive in another) versus concordant subjects (ie, EIB negative or positive in both tests). EIB was not related to individual test ability in eliciting high to very-high ventilation (> 40% or > 60% maximum voluntary ventilation, respectively). Moreover, a negative stepping test but a positive treadmill test (and vice versa) was not associated with greater ventilatory demands. CONCLUSIONS: Lower prevalence of EIB in stepping compared to treadmill running is not related to less ventilation demand in the former modality. Although stepping might be useful as a screening EIB test due its portability and low cost, a negative test should be confirmed with a running-based test in symptomatic children.

BACKGROUND: Dynamic hyperinflation is a major cause of dyspnea in patients with COPD. Dynamic hyperinflation is usually measured with cardiopulmonary exercise testing, but this test requires maximal effort from the patient, and inspiratory capacity (IC) measurements may influence test results. This study investigated another approach by measuring dynamic hyperinflation during the more natural and better-tolerated 6-min walk test (6MWT), using a mobile system for IC measurements. METHODS: Twenty subjects were studied, including 10 healthy subjects and 10 subjects with COPD. Each subject performed a pair of 6MWTs. RESULTS: The study showed that test-retest reliability in healthy subjects was excellent (intraclass correlation coefficient 0.995). In addition, mean resting IC in healthy subjects (3.27 ± 0.77 L) was not affected at the end of the 6MWT, whereas mean resting IC in subjects with COPD (2.45 ± 0.90 L) decreased to 1.93 L ± 0.68 L at the end of the 6MWT (P = .004). The tolerability of the device for subjects with COPD appeared to be only slightly hampered by an increased sense of dyspnea attributed to wearing a mask. CONCLUSIONS: This study provides a proof of principle for mobile IC measurements during the 6MWT, demonstrating good test performance, reasonable tolerability, and a power to differentiate normal from pathologic conditions.

BACKGROUND: There are limited longitudinal studies reporting predictive factors for decline in 6-min walk distance (6MWD) in patients with COPD. While previous studies have confirmed the association between air-flow limitation and decline in 6MWD, other factors have not been clarified. The objective of this study was to investigate whether exercise-induced oxygen desaturation (EID) could be a predictive factor for decline in 6MWD in patients with COPD. The interactive effect of air-flow limitation on the association between EID and decline in 6MWD was also investigated. METHODS: A longitudinal observational study was conducted with 71 out-patients with COPD who were followed for 1 year. 6MWD, EID, spirometry, and clinical characteristics were assessed. The effect of EID on changes in 6MWD was examined using linear regression analyses. Furthermore, the subjects were categorized into 4 groups according to their EID and air-flow limitation status, and changes in 6MWD were compared among the groups. RESULTS: 51 subjects completed the follow-up assessments, and 29 (56.9%) experienced EID. Multiple linear regression model revealed that EID was the only predictive factor for changes in 6MWD after adjusting for confounders (β = −38.9, P = .02). As results of multiple comparisons among the 4 groups based on EID and air-flow limitation status, changes in 6MWD in the EID and severe air-flow limitation group were the lowest. CONCLUSION: Our results revealed that EID was a predictive factor for decline in the functional capacity of subjects with COPD. The assessment of EID and air-flow limitation would thus be useful in estimating the prognosis of decline in the functional capacity of patients with COPD.

BACKGROUND: Field walking tests are commonly used in patients with chronic pulmonary diseases for assessment of functional capacity. However, the physiological demands and magnitude of desaturation on 6-min walk test (6MWT), incremental shuttle walk test (ISWT), and endurance shuttle walk test (ESWT) have not been investigated in patients with bronchiectasis. The objective of this study was to compare the physiological responses and the magnitude of desaturation of subjects with bronchiectasis when performing the 6MWT, ISWT, and ESWT. METHODS: Thirty-two subjects underwent the 6MWT, ISWT, and ESWT on 3 different days. Pulmonary gas exchange, heart rate, and SpO2 were measured in all tests. RESULTS: There were no differences in the peak rate of oxygen uptake, ventilation, dyspnea, and leg fatigue between the tests. Equivalent cardiac demand (ie, heart rate at peak) was observed with the 6MWT (137 ± 21 beats/min) and the ESWT (142 ± 21 beats/min), but this was lower in the ISWT (135 ± 19 beats/min) compared to ESWT (P CONCLUSIONS: The 6MWT, ISWT, and ESWT induced similar physiological responses at the peak of exercise, eliciting a vigorous exercise intensity. The magnitude of desaturation was similar across tests. This means these tests can be used interchangeably for evaluation of exercise-induced desaturation.

BACKGROUND: The N95 filtering facepiece respirator (FFR) is the most popular individual protective device to reduce exposure to particulate matter. However, concerns have been raised with regard to its use because it can increase respiratory resistance and dead space. Therefore, this study assessed the safety of N95 use in patients with COPD and air-flow limitation. METHODS: This prospective study was performed at a tertiary hospital and enrolled 97 subjects with COPD. The subjects were monitored for symptoms and physiologic variables during a 10-min rest period and 6-min walking test while wearing an N95. RESULTS: Of the 97 subjects, 7 with COPD did not wear the N95 for the entire test duration. This mask-failure group showed higher British modified Medical Research Council dyspnea scale scores and lower FEV1 percent of predicted values than did the successful mask use group. A modified Medical Research Council dyspnea scale score ≥ 3 (odds ratio 167, 95% CI 8.4 to >999.9; P = .008) or a FEV1 999.9; P = .001) was associated with a risk of failure to wear the N95. Breathing frequency, blood oxygen saturation, and exhaled carbon dioxide levels also showed significant differences before and after N95 use. CONCLUSIONS: This study demonstrated that subjects with COPD who had modified Medical Research Council dyspnea scale scores ≥ 3 or FEV1

BACKGROUND: Bronchiectasis leads to reduced functional capacity, which might have implications for physical activity. The impact of dyspnea and long-term oxygen therapy on physical activity has never been investigated in subjects with bronchiectasis. Based on these findings, specific strategies could be applied to allow individuals to be more active in their daily life. In this study we aimed to evaluate physical activity, the impact of dyspnea and long-term oxygen therapy on physical activity, and the determinants of physical activity in subjects with bronchiectasis. METHODS: We performed a cross-sectional study in 139 subjects with bronchiectasis (age 45 ± 13 y, FVC 70 ± 22% of predicted, FEV1 54 ± 25% of predicted) and 49 healthy subjects as controls. Physical activity was assessed using steps per day (measured with a pedometer), spirometry, incremental shuttle walking test (ISWT), and dyspnea. RESULTS: Reduced physical activity was observed in subjects with bronchiectasis, who recorded a median (interquartile range) of 8,007 (5,131–10,432) steps/d compared with controls, who recorded 10,994 (8,551–14,078) steps/d (P CONCLUSION: Subjects with bronchiectasis exhibited reduced physical activity compared with healthy peers. Dyspnea has a negative impact on physical activity. Independent factors associated with physical activity included pulmonary function, dyspnea, functional capacity, and long-term oxygen therapy. These findings will guide strategies to enhance daily physical activity and to encourage subjects with bronchiectasis to be more active.

BACKGROUND: The 6-min walk test (6MWT) is a well-established functional exercise capacity test in lung transplant candidates. This study aimed to investigate the construct validity of the 1-min sit-to-stand test (1-min STS) as a marker of exercise capacity and knee extensor strength in lung transplantation candidates. METHODS: We retrospectively analyzed data from consecutive subjects referred for lung transplantation evaluation to our institution between 2015 and 2018. RESULTS: 38 subjects were included. We found strong correlations between the normalized 1-min STS and 6MWT (r = 0.79, P CONCLUSIONS: The 1-min STS is a valid functional exercise capacity test in lung transplantation candidates. Due to its ease of application, clinical practitioners may consider using the 1-min STS in situations when the 6MWT cannot be performed. Our pilot study may stimulate future research, including a head-to-head comparison between the 6MWT and 1-min STS in a large patient cohort including post-lung transplantation-monitoring.

BACKGROUND: The aim of this work was to investigate the short- and long-term test-retest reliability of the 6-min walk distance (6MWD), peak heart rate, and nadir oxygen desaturation in idiopathic pulmonary fibrosis (IPF). METHODS: A reliability study of 70 adults with IPF was undertaken within out-patient pulmonary rehabilitation programs at 2 tertiary hospitals. Participants completed 2 baseline 6-min walk tests using a standard protocol, with continuous measures of percutaneous SpO2 and heart rate via pulse oximetry. The 6-min walk test was completed immediately following an intervention period and 6 months after. Reproducibility was assessed by intraclass correlation coefficient and Bland-Altman analysis. RESULTS: Participants with a mean ± SD diffusing capacity of the lung for carbon monoxide of 48 ± 14% were included. The reliability of the 6MWD was high (intraclass correlation coefficient = 0.96) with a mean learning effect of 21 m (95% CI 12–30 m). The learning effect persisted at 8 weeks (mean 14 m, 95% CI 5–23 m) but not 6 months (mean 15 m, 95% CI −1 to 30 m). Using the best (greatest) 6MWD significantly reduced the proportion of participants who were classified as having a clinically important response to rehabilitation compared with using the first 6MWD (40% vs 54%, P = .002). Nadir SpO2 was reproducible, with a mean difference of 0.7 ± 2.2%, and limits of agreement of −4 to 5%. Peak heart rate was more variable, with mean difference 5 ± 9 beats/min and limits of agreement of −12 to 20 beats/min. CONCLUSIONS: The 6MWD is a reproducible measure of exercise capacity in people with IPF. Whereas the nadir SpO2 may be accurately determined from one test, evaluating change in 6MWD with interventions may require 2 tests on each occasion. (ClinicalTrials.gov registration NCT0016828.)

BACKGROUND: A normal heart rate reflects the balance between the sympathetic and parasympathetic autonomic nervous system. When the difference between heart rate at the end of an exercise test and after 1 min of recovery, known as the 1-min heart rate recovery, is ≤ 12 beats/min, this may indicate an abnormal delay. We sought to compare physical activity patterns and subjects9 functional status with COPD with or without delayed 1-min heart rate recovery after the 6-min walk test (6MWT). METHODS: 145 subjects with COPD (78 men, median [interquartile range (IQR)] age 65 [60–73] y, body mass index 25 [21–30] kg/m2, FEV1 45 ± 15% predicted) were underwent the following assessments: spirometry, 6MWT, functional status, and physical activity in daily life (PADL). A delayed heart rate recovery of 1 min was defined as ≤ 12 beats/min. RESULTS: Subjects with delayed 1-min heart rate recovery walked a shorter distance in the 6MWT compared to subjects without delayed heart rate recovery (median [IQR] 435 [390–507] m vs 477 [425–515] m, P = .01; 81 [71–87] vs 87 [79–98]% predicted, P = .002). Regarding PADL, subjects with delayed heart rate recovery spent less time in the standing position (mean ± SD 185 ± 89 min vs 250 ± 107 min, P = .002) and more time in sedentary positions (472 ± 110 min vs 394 ± 129 min, P = .002). Scores based on the self-care domain of the London Chest Activity of Daily Living questionnaire and the activity domain of the Pulmonary Functional Status and Dyspnea questionnaire were also worse in the group with delayed heart rate recovery (6 ± 2 points vs 5 ± 2 points; P = .039 and 29 ± 24 points vs 19 ± 17 points; P = .037, respectively). CONCLUSIONS: Individuals with COPD who exhibit delayed 1-min heart rate recovery after the 6MWT exhibited worse exercise capacity as well as a more pronounced sedentary lifestyle and worse functional status than those without delayed heart rate recovery. Despite its assessment simplicity, heart rate recovery after the 6MWT can be further explored as a promising outcome in COPD.

BACKGROUND: COPD is characterized by expiratory flow limitation, which results in symptomatic dyspnea and reduced exercise capacity. Changes in breathing mechanics mean the respiratory muscles are unable to respond to the ventilatory demands, increasing the sensation of dyspnea. A high-frequency oscillating device has been developed to improve dyspnea in patients with COPD. We conducted a feasibility trial to gain insight into the potential for recruitment, retention, and study design for a future randomized controlled trial.METHODS: Symptomatic subjects with COPD were included on the basis of a Medical Research Council (MRC) score ≥ 3 and FEV1/FVC < 0.70). Patients were excluded if they received pulmonary rehabilitation within the last 6 months. The intervention employed the device for 8 weeks, 3 times daily. Clinical outcomes included the MRC score, maximal expiratory and inspiratory pressures (PEmax/PImax), the incremental shuttle walk test (ISWT), and the endurance shuttle walk test (ESWT).RESULTS: We successfully recruited 23 subjects with established COPD (65.2% male, mean age 65 ± 5.03 y, mean % predicted FEV1 43.9 ± 16, mean FEV1/FVC ratio 0.46 ± 0.13, and median [interquartile range] MRC 4 [3–5]). There was a significant change in MRC from 4 to 3 pre to post intervention (P = .003). There was a statistically significant difference in PEmax P < .008 and PImax P = .044. There were no significant differences observed in the ISWT or ESWT.CONCLUSIONS: This study design appeared feasible to proceed to a clinical effectiveness trial. The use of the device for 8 weeks showed a significant improvement in PEmax, PImax, and reduced symptomatic dyspnea on the MRC dyspnea score. The results of this study should encourage a randomized controlled trial.

BACKGROUND: The 6-min walk test (6MWT) is commonly performed to assess functional status in patients with chronic thromboembolic pulmonary hypertension. However, changes in heart rate and oxygen saturation (SpO2) patterns during 6MWT in patients with chronic thromboembolic pulmonary hypertension remain unclear. METHODS: Thirty-one subjects with chronic thromboembolic pulmonary hypertension were retrospectively evaluated to examine the relationships between the change in heart rate (Δheart rate), heart rate acceleration time, slope of heart rate acceleration, heart rate recovery during the first minute after 6MWT (HRR1), change in SpO2 (ΔSpO2), SpO2 reduction time, and SpO2 recovery time during 6MWT, and the severity of pulmonary hemodynamics assessed by right heart catheterization and echocardiography. RESULTS: Subjects with severe chronic thromboembolic pulmonary hypertension had significantly longer heart rate acceleration time (144.9 ± 63.9 s vs 96.0 ± 42.5 s, P = .033), lower Δheart rate (47.4 ± 16.9 vs 61.8 ± 13.6 beats, P = .02), and lower HRR1 (13.3 ± 9.0 beats vs 27.1 ± 9.2 beats, P CONCLUSIONS: Heart rate and SpO2 change patterns during 6MWT are predominantly associated with pulmonary hemodynamics in subjects with chronic thromboembolic pulmonary hypertension. Evaluating heart rate and SpO2 change patterns during 6MWT may serve as a safe and convenient way to follow the change in pulmonary hemodynamics.

INTRODUCTION: The incremental shuttle walk test was initially developed to be carried out in a hallway (ISWT-H) but has been modified to be performed on a treadmill (ISWT-T). However, it is still unknown whether performance on ISWT-H and ISWT-T are similar in patients with bronchiectasis. In this study, we compared the performance, physiological responses, and perception of effort between the ISWT-T with a handrail and ISWT-H for subjects with bronchiectasis. We also sought to estimate and compare the prescription for training intensity with both tests. METHODS: This was a cross-sectional study in which 24 subjects with bronchiectasis were evaluated on 2 different days (24 h apart). Distance walked (m) was compared between the ISWT-H and ISWT-T. A training session was held on a treadmill at 75% of the speed obtained from both tests. The walking distance, oxygen uptake (VO2), carbon dioxide production (VCO2), heart rate, and ventilation (VE) were measured. RESULTS: There was a difference in the walking distance between the ISWT-T and ISWT-H, but physiological responses for VO2, VCO2, heart rate, and VE were similar. However, the speed estimated for training was different, as were the VO2, VCO2, and heart rate. CONCLUSIONS: The ISWT-T with handrail and the ISWT-H are not interchangeable in subjects with bronchiectasis. A slower speed of training intensity may occur when the test is performed in a hallway, as originally described, and this may underestimate responses to aerobic training

INTRODUCTION: Brazil is a country with great climatic, socioeconomic, and cultural differences that does not yet have a reference value for the 6-min walk test (6MWT) in healthy children. To avoid misinterpretation, the use of equations to predict the maximum walk distance should be established in each country. OBJECTIVES: We sought to establish reference values and to develop an equation to predict the 6-min walk distance for healthy children in Brazil. METHODS: This is a cross-sectional multi-center study that included 1,496 healthy children, aged 7 to 12 y, assessed across 11 research sites in all regions of Brazil, and recruited from public and private schools in their respective regions. Each child was assessed for weight and height. Walk distance was our main outcome. An open-source software environment for statistical computing was used for statistical analysis. RESULTS: We observed a higher average distance walked by boys (531.1 m) than by girls (506.2 m), with a difference of 24.9 m ( P CONCLUSION: Reference values were established for the 6MWT in healthy children aged 7–12 y in Brazil.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is used as a rescue therapy before and after lung transplantation, but little is known about functional recovery or complications after ECMO in this cohort. This study aimed to describe early physical function and leg complications in subjects who received ECMO before or after lung transplantation, and to compare functional outcomes to a matched cohort of subjects who did not require ECMO. METHODS: A retrospective study was conducted over 2 years. Highest mobility level was assessed, in both the ECMO and non-ECMO groups, prior to ICU admission, at ICU discharge, and at hospital discharge, while 6-min walk distance was measured at hospital discharge and at 3 months. Strength was assessed at ICU discharge and at hospital discharge in the ECMO subjects only, and leg complications were recorded up until hospital discharge. RESULTS: 17 subjects (mean age 43 ± 13 y; 65% (11 of 17 subjects) female) required ECMO before or after lung transplant. Survival to hospital discharge was 82% (14 of 17 subjects). At ICU discharge, strength and mobility levels were poor, but both improved by hospital discharge ( P P P = .002) and had worse physical function (ie, lower mobility level at ICU discharge, mean difference −1, P = .02; 6-min walk distance at hospital discharge: mean difference −99 m, P = .004) than lung transplant recipients not requiring ECMO ( n = 28). CONCLUSIONS: In subjects requiring ECMO before or after lung transplantation, 82% survived to hospital discharge, but leg complications were common and physical function was poor at ICU discharge. Physical function improved over time, however subjects who required ECMO had a longer period of hospitalization and worse physical function at ICU and hospital discharge than those who did not require ECMO.

BACKGROUND: Cystic fibrosis is a multi-systemic disease related to reduced functional capacity. The distance covered in the 6-min walk test (6MWT) has been known to assess functional capacity, but little is known about other indexes that can be derived. We sought to compare the performance during the 6MWT and the estimated indexes of functional capacity from the 6MWT between subjects with cystic fibrosis (CF) and healthy individuals as well as to assess the relationship among these indexes and disease severity, pulmonary function, and nutritional status in CF. METHODS: This cross-sectional study was carried out at a university referral center for CF. It included a group of 55 non-oxygen-dependent CF subjects (CF group) with no acute pulmonary exacerbations and a group of 185 healthy controls (control group). All subjects were submitted to 6MWT and anthropometrics measurements. RESULTS: Regarding performance during the 6MWT, the mean values of work, physiological cost index, average velocity, and 6-min walk distance (6MWD) were significantly lower in the CF group than in the control group (work: 21,690.58 ± 10,427.77 vs 26,057.51 ± 11,228.49 m × kg [P = .007]; physiological cost index: 0.31 ± 0.19 vs 0.37 ± 0.17; average velocity: 94.71 ± 12.89 vs 104.55 ± 9.13 m/min [P CONCLUSIONS: Considering the importance of standard measure (6MWD) the in 6MWT, alternative indexes can be useful as complementary outcomes and to provide a better understanding of limiting factors of exercise response in children and adolescents with CF.

INTRODUCTION: Advanced air-flow limitation in patients with COPD leads to a reduction in vital capacity, respiratory muscle strength, and exercise capacity. However, its impact on chest and abdominal wall mobility is unknown. This study aimed to ascertain the prevalence of patients with COPD with reduced chest and abdominal wall mobility and to investigate the effect of reduced chest and abdominal wall mobility on pulmonary function, respiratory muscle strength, and exercise capacity. METHODS: In 51 elderly male subjects with COPD, chest and abdominal wall mobility, FVC, FEV1, FEV1/FVC, maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), and the 6-min walk distance (6MWD) were assessed. Chest and abdominal wall mobility were measured using the breathing movement scale (0–8) at the 3 regions (upper chest, lower chest, and abdomen). Reduced mobility was defined as a value lower than the lower limit of the normal scale. The unpaired t test, Mann-Whitney test, and multiple regression analysis were performed. RESULTS: The percentages of subjects with reduced mobility were 78% for the upper chest, 76% for the lower chest, and 53% for the abdomen. The subjects with reduced mobility had significantly low FVC, FEV1, and 6MWD in each region and significantly low FEV1/FVC, PImax, and PEmax in the abdominal region compared with those with nonreduced mobility. FVC and 6MWD were independently associated with the scale values in each region and with the abdominal scale value, respectively. CONCLUSIONS: The majority of subjects with COPD had reduced chest and abdominal wall mobility, which was independently associated with FVC. Even though abdominal wall mobility was relatively preserved compared with chest wall mobility, it was also independently associated with 6MWD.

BACKGROUND: The 6-min walk test (6MWT) encompasses potential and untapped information related to exercise capacity. However, this test does not yield any information about gait pattern. Recently, we used a ventilatory polygraph to reveal respiratory adaptation during the 6MWT with subjects having high or low body mass index (BMI). In this study, we aimed to determine gait parameters with the same device, which integrates an accelerometer. METHODS: Using a 30-m corridor, steps and U-turns were detected with a custom-made algorithm, compared to video recordings as a reference method, and analyzed offline. From the vertical acceleration signal, we were able to determine cadence and step length, and we could calculate the total distance covered in 6 min (6MWD). We then compared these variables between subjects with low BMI (n = 13 subjects) or high BMI (n = 29 subjects). RESULTS: Steps and U-turn detection correlated with video results (r = 0.99, P CONCLUSION: Our results demonstrated that a ventilatory polygraph with an embedded accelerometer can be used to detect steps and U-turns, and to calculate 6MWD. This method is sufficiently sensitive to characterize significant BMI-dependent differences in gait pattern during a 6MWT and appears to be a promising tool for routine clinical use.

Exertional desaturation is an important predictor of mortality in patients with interstitial lung disease. We evaluated the prevalence of exertional desaturation in subjects with interstitial lung disease and determined its relationship with the prescription of ambulatory oxygen therapy.Our retrospective analysis examined prospectively collected data from interstitial lung disease registries of 2 Melbourne hospitals: Alfred Health and Austin Health. All patients with baseline the 6-min walk tests on room air were included. We evaluated the prescription of ambulatory oxygen therapy, up to 3 months after 6-min walk tests, among those with exertional desaturation.Of the 400 subjects, 214 (54%) had exertional desaturation. The prevalence of desaturation increased with the severity of lung function impairment (FVC measurement: 33% for75% predicted, 69% for 50-75% predicted, 86% for50% predicted; diffusing capacity of the lung for carbon monoxide measurement: 20% for55% predicted, 64% for 36-55% predicted, 93% for ≤ 35% predicted,Exertional desaturation is common in subjects with interstitial lung disease. More severely impaired exercise capacity and worse lung function are associated with the prescription of ambulatory oxygen therapy in interstitial lung disease.

BACKGROUND: COPD is a high-mortality disease and projected to become the third leading cause of death worldwide by 2030. Our aim was to evaluate predictors of 3-y mortality and factors associated with early (1 y) and late (second and third year) mortality in subjects with severe COPD who completed a pulmonary rehabilitation program. METHODS: A historical cohort study was performed with subjects with COPD who were admitted to a day-hospital for chronic respiratory failure for a pulmonary rehabilitation program, from January 2008 to December 2010. The population was characterized based on sociodemographic factors, body mass index, smoking habits, lung function tests, respiratory failure, comorbidities, bacterial colonization, Modified Medical Research Council dyspnea index, 6-min walk test, mechanical ventilation, noninvasive ventilation, long-term oxygen therapy, hospital admissions, and mortality. RESULTS: From 183 patients who completed a pulmonary rehabilitation program, 93 had COPD. Our cohort had 78 male and 15 female subjects. The mean age +/- SD was 68.6 +/- 8.9 y, ranging from 43 to 85 y. After the pulmonary rehabilitation program, there were fewer, although not statistically significantly different hospital admissions (2.1 vs 1.7, P =.17). Three years after the pulmonary rehabilitation program, 34 subjects died (36.6%). Hypercapnic respiratory failure (P = .02), noninvasive ventilation (P = .002), lung cancer (P = .001), shorter 6-min walk distance (P = .03), and higher number of previous hospital admissions (P

BACKGROUND: Walking is part of obesity management. Assessment of ventilatory impairments and consequences for gait induced by obesity could be clinically helpful. We aimed to develop a method to accurately monitor ventilation with respiratory inductive plethysmography (RIP) in subjects with high body mass indices (BMIs) during a 6-min walk test (6MWT). METHODS: 25 volunteers were divided into 2 groups based on BMI ( 30 kg/m2) and performed a 6MWT with a calibrated RIP. Ventilatory parameters (tidal volume [VT], inspiratory [TI] and expiratory [TE] times, VT/TI ratio, and TI/Ttot ratio) were determined after processing RIP signals with a custom-made algorithm designed to discriminate tissue motion artifacts and respiratory cycles in the time domain. Six-min walk distance and average speed by minute were collected. RESULTS: The number of artifacts removed by the algorithm used for artifact removal was higher for high-BMI subjects and was correlated to their individual values (r = 0.66, P < .001). Six-min walk distance was lower for the group with a higher BMI ( P = .001). ANOVA revealed effects of exercise for VT, TI, and TE ( P < .001) and also BMI effects in the course of the 6MWT for VT, TI, TE, VT/TI, and TI/Ttot ( P < .001 for each of them). CONCLUSIONS: This respiratory monitoring method is sufficiently sensitive to point out differences between rest and exercise as well as locomotor and ventilatory differences relative to BMI during the 6MWT. Thus, this system gives useful information from the 6MWT for clinicians who want to assess respiratory patterns of patients during this commonly used test.

BACKGROUND: The incremental shuttle walk test (ISWT) has been widely used to assess exercise capacity of subjects with COPD. However, to date, no studies have assessed its reliability in the asthmatic population. This study aimed to assess the test-retest reliability of ISWT for the distance walked (ISWD) and cardiorespiratory and metabolic responses in adult subjects with asthma. METHODS: This was a cross-sectional observational study. Thirty-four subjects of both genders, 18–45 y old, with a diagnosis of controlled asthma, were recruited from March 2012 to December 2015. The subjects performed 3 ISWTs on different days, with a minimum interval of 48 h and a maximum of 1 week between the second and third ISWT. For the reliability analysis, the values of the second and third ISWTs were used, eliminating the influence of any learning effect from the first test. RESULTS: The intraclass correlation coefficients were > 0.75 (P CONCLUSION: The ISWT presented excellent reliability for the ISWD and metabolic responses. The cardiorespiratory responses in the ISWTs presented good reliability. We concluded that the ISWT was reliable for young adult subjects with controlled asthma.

BACKGROUND: Pulmonary rehabilitation programs improve exercise capacity and quality of life in patients with COPD. Domiciliary strategies to maintain these benefits have been proposed. OBJECTIVE: This study aimed to determine whether a rehabilitation manual would facilitate the maintenance of the benefits acquired during out-patient pulmonary rehabilitation. METHODS: Fifty subjects with stable COPD were included (26 women and 24 men). All the subjects were evaluated during screening and after 12 wk of out-patient rehabilitation, and then were randomly divided into 2 groups, with one group that received the rehabilitation manual for home use (manual group) and the other group only received verbal recommendations (control group). At this point, the 2 groups were similar. After 12 wk at home, both groups were evaluated a third time. All evaluations included a 6-min walk test (6MWT), 6-min step test, COPD Assessment Test, and measurement of dyspnea by using the modified Medical Research Council dyspnea scale. RESULTS: When comparing the results of the 6MWT and 6-min step test done at out-patient discharge and after 12 wk at home, the manual group presented no differences (6MWT, 0 ± 25 m; 6-min step test, 1 ± 32 steps), whereas the control subjects lost part of the gain obtained during rehabilitation (6MWT −46 ± 36 m; 6-min step test −39 ± 33 steps). There was a significant difference between the groups (P CONCLUSIONS: The use of a simple, well-illustrated manual facilitated the maintenance of the benefits acquired in out-patient pulmonary rehabilitation over a period of 3 months after study termination.

BACKGROUND: The primary objective of this study was to investigate whether noninvasive ventilation (NIV) can positively affect exercise capacity, maximum oxygen uptake ( V O 2 ), and symptoms after a 6-week physical training program for subjects with moderate to very severe COPD. METHODS: 47 subjects with COPD who were enrolled in a physical training program were randomized to either physical training alone or NIV + physical training (NIV-Physical training). Physical training consisted of dynamic aerobic exercises on a treadmill 3 times/week for 6 weeks, for a total of 18 sessions. NIV was titrated according to the subject9s tolerance at rest and during exercise. Assessments included physiological responses and symptoms at the incremental cardiopulmonary exercise test peak and during submaximal exercise on a treadmill, 6-min walk distance, maximum inspiratory (P Imax ) and expiratory pressure (P Emax ), BODE index, and health-related quality of life. RESULTS: 43 subjects completed the 6-week physical training program. Both groups improved 6-min walk distance, P Imax , BODE index, and quality of life, and no differences were found between groups. However, significant improvements were observed for subjects in the NIVPhysical training group with regard to P Emax , maximum V O 2 , maximum metabolic equivalents, circulatory power, and maximum S pO 2 . CONCLUSIONS: A 6-week physical training program alone can improve tolerance for exercise and quality of life, in addition to reducing the risk of mortality. However, NIV associated with a physical training program was shown to have an additive beneficial effect on powerful prognostic markers (maximum V O 2 and circulatory power) and to reduce symptoms and improve oxygen saturation in subjects with moderate to very severe COPD.

BACKGROUND: Different protocols for the sit-to-stand test (STS) are available for assessing functional capacity in COPD. We sought to correlate each protocol of the STS (ie, the 5-repetition [5-rep STS], the 30-s STS, and the 1-min STS) with clinical outcomes in subjects with COPD. We also aimed to compare the 3 protocols of the STS, to verify their association and agreement, and to verify whether the 3 protocols are able to predict functional exercise capacity and physical activity in daily life (PADL). METHODS: 23 subjects with COPD (11 men; FEV 1 53 ± 15% predicted) performed 3 protocols of the STS. Subjects also underwent the following assessments: incremental shuttle walking test, 6-min walk test (6MWT), 4-m gait speed test (4MGS), 1-repetition maximum of quadriceps muscle, assessment of PADL, and questionnaires on health-related quality of life and functional status. RESULTS: The 1-min STS showed significant correlations with the 6MWT (r = 0.40), 4MGS (r = 0.64), and PADL (0.40 ≤ r ≤ 0.52), and the 5-rep STS and 30-s STS were associated with the 4MGS (r = 0.54 and r = 0.52, respectively). The speed differed for each protocol (5-rep STS 0.53 ± 0.16 rep/s, 30-s STS 0.48 ± 0.13 rep/s, 1-min STS 0.45 ± 0.11 rep/s, P = .01). However, they presented good agreement (intraclass correlation coefficient ≥ 0.73 for all) and correlated well with each other (r ≥ 0.68 for all). More marked changes in peripheral oxygen saturation ( P = .004), heart rate ( P P P P CONCLUSIONS: The 1-min STS generated higher hemodynamic demands and correlated better with clinical outcomes in subjects with COPD. Despite the difference in speed performance and physiological demands between the 5-rep STS and 1-min STS, there was a good level of agreement among the 3 protocols. In addition, all 3 tests were able to identify subjects with low exercise capacity or preserved exercise capacity.

BACKGROUND: Exercise training is an effective and low-cost tool for COPD rehabilitation. Thus, validating a non-exhaustive method to determine a patient9s anaerobic threshold would be a very interesting tool in practical settings. We aimed to test the reproducibility of critical velocity values determined in a non-exhaustive manner (CV NE ) and tolerance for exercise performed at this physiological marker in subjects with COPD. METHODS: Twelve subjects with COPD were evaluated in this cross-sectional study. The study was divided into 2 phases: Phase A consisted of reproducibility of CV NE for subjects with COPD, and Phase B determined the tolerance for exercise tests performed at this physiological marker. RESULTS: The proposed protocol for determining CV NE presented fair reproducibility according to blood lactate concentrations (intraclass correlation coefficient = 0.58). However, we cannot consider that the tests were reproducible due to the wide CI (0.03–0.85). Furthermore, moderate and strong correlations were observed between the CV NE determined by lactate concentration, by oxygen consumption (V O 2) (r = 0.66), and by heart rate (r = 0.88). However, a high limit of agreement was observed ±1.45 km/h and ±1.55 km/h, respectively. In the tolerance for exercise test, none of the subjects presented lactate destabilization, whereas 3 tests were interrupted by oxygen saturation decline and 1 test was interrupted by hemodynamic instability. CONCLUSIONS: Although most of the subjects presented good tolerance for exercise at CV NE , fair levels of reproducibility were observed in subjects with COPD, even using lactate. Thus, the use of CV NE determined through double 3-min efforts should be considered with caution.

BACKGROUND: Monotherapy and sequential combination therapy have been widely used in the treatment of pulmonary arterial hypertension (PAH). There is limited evidence for initial combination therapy in patients with PAH, particularly those with World Health Organization (WHO) functional class III or IV. METHODS: Twenty-seven consecutive treatment-naive PAH subjects with WHO functional class III or IV PAH were randomized into 3 groups with a 1:1:1 ratio: a combination therapy group with 125 mg of bosentan twice daily plus 10 μg of iloprost 4–6 times/d; a bosentan monotherapy group with 125 mg of bosentan twice daily; and a iloprost monotherapy group with 10 μg of iloprost 4–6 times/d. Clinical and hemodynamic data were collected at baseline, 6 weeks, and 3 months. The primary end point was the change in the 6-min walk distance (6MWD) from baseline values. RESULTS: At baseline, there were no differences in demographics, WHO classification, hemodynamics, classification of PAH, or 6MWD among the 3 groups. The 6MWD significantly improved in the combination therapy group compared with the bosentan monotherapy and iloprost monotherapy groups at week 6 (P = .001) and after 3 months (P CONCLUSIONS: Initial combination therapy in treatment-naive PAH subjects with WHO functional class III or IV can significantly improve 6MWD, hemodynamics, and quality of life compared with monotherapy. Further studies with large samples and placebo controls are required to assess the tolerability and efficacy of initial combination therapy in patients with PAH. (ClinicalTrials.gov registration NCT01712997).

Whole-body vibration (WBV) is considered a type of physical activity based on the assumption that it results in an increase in muscle strength and performance and, therefore, may be a promising way to exercise patients with COPD. A comprehensive database search (PubMed/MEDLINE, LILACS, CINAHL, Web of Science, Scopus, and COCHRANE Library) for randomized trials, including original articles, that compared WBV groups versus control groups was conducted and studies were selected for comparison. The effect of WBV treatment was compared for minimum clinically important differences. The statistical heterogeneity among the studies was assessed using the I2 statistic; the results are expressed as percentages. Inconsistencies of up to 25% were considered low, those between 50 and 75% were considerate moderate, and those > 75% were considered high. Risk of bias was classified based on the Cochrane Collaboration tool, the meta-analysis was conducted using RevMan 5.3 software, and the level of evidence was assessed using the GRADE system. The primary outcome was functional exercise capacity. Secondary outcomes were quality of life, performance in activities of daily living, muscle strength of the lower limbs, and possible adverse effects assessed clinically or by subject reports. We included 4 articles involving 185 subjects for analysis. All subjects in the groups undergoing WBV showed improvement in distance walked in the 6-min walk test compared with the control group (57.85 m, 95% CI 16.36-99.33 m). Regarding the secondary end points, just one article reported improved quality of life and activities of daily living. The only article that assessed muscle strength found no difference between the groups. The quality of evidence for functional exercise capacity outcome was considered moderate. WBV seems to benefit subjects with COPD by improving their functional exercise capacity, without producing adverse effects. The quality of evidence is moderate, but the degree of recommendation is strong. (International Prospective Register of Systematic Reviews, http://www.crd.york.ac.uk/prospero, 2015:CRD42015027659.).

BACKGROUND: Studies have shown that individuals with COPD have impaired body balance, probably caused by the disease's multisystemic manifestations plus age-related decline in balance, potentially increasing the risk of falling and its consequences. However, little is known about the profile of individuals with COPD who present balance impairments, especially related to sex and disease severity stages. The aim of this work was to compare static and functional balance between subjects with COPD and healthy controls and to check possible differences according to sex and degrees of disease severity. METHODS: Forty-seven subjects with COPD and 25 healthy controls were included in this study. Their static balance was assessed in one-legged stance using a force platform and functional balance with the Timed Up and Go test. Additionally, participants performed spirometry, the 6-min walk test and isometric quadriceps maximal voluntary contraction assessment. Disease severity was classified according to the Global Initiative for Obstructive Lung Disease stages and BODE (body mass index, air-flow obstruction, dyspnea, and exercise capacity) scores. RESULTS: In comparison with healthy controls, subjects with COPD had worse static (center of pressure displacement area: 9.3 ± 1.9 cm2 vs 11.6 ± 4.0 cm2, respectively, P = .01) and functional balance (Timed Up and Go test: 8.5 ± 1.3 s vs 10.3 ± 1.8 s, respectively, P < .001). In the COPD group, men performed better in the Timed Up and Go test than women (9.8 ± 1.2 s vs 10.9 ± 2.2 s, respectively, P = .03), whereas women presented a better static balance in comparison with men for all parameters related to center of pressure ( P < .005 for all). Disease severity did not affect any balance results. CONCLUSIONS: Individuals with COPD had worse static and functional balance in comparison with healthy controls. Sex can mediate these results, depending on the type of balance evaluation (force platform or functional test). Balance performance was similar among the groups classified according to disease severity.

The patterns and kinetics of changes in SpO2 in the 6-min walk test (6MWT) and cycling test have not been addressed in patients with COPD.We studied 60 COPD subjects, with a mean ± SD FEV1 of 54 ± 18% of predicted. We compared the changes in SpO2 (ΔSpO2) within and between the 2 tests, and the differences between the desaturators and non-desaturators.In the 6MWT there were 4 patterns of SpO2. Desaturation then resaturation was the most common (46%). ΔSpO2 ≥ 3% occurred at approximately 1.2 min, and the nadir was at 3.5 min where resaturation occurred thereafter. The ΔSpO2 between the start and the nadir (start-vs-nadir ΔSpO2) was greater than the start-vs-end ΔSpO2 (P.001). The desaturators had less inspiratory muscle strength, worse dyspnea, and shorter 6-min walk distance, whereas the resaturators had greater FEV1/FVC and less functional residual capacity (all P.05). In the cycling test there were 3 patterns of SpO2. Desaturation was the most common (57%). The ΔSpO2 ≥ 3% and nadir SpO2 occurred at 4.6 min and 6.6 min, respectively, of the 6.8-min cycling exercise duration. The desaturators had lower body mass index, lower oxygen-cost diagram score, less post-exercise inspiratory muscle strength, lower diffusing capacity, lower SpO2, lower work during 6MWT, and lower peak exercise performance (all P.05). In both tests, the start-vs-nadir ΔSpO2 during the 6MWT was greater (P = .02) but the start-vs-end ΔSpO2 was similar (P = .79). The desaturators in both tests had lower oxygen-cost-diagram scores (P.01) and poorer peak exercise performance.Measurement of start-vs-nadir ΔSpO2 rather than start-vs-end ΔSpO2 during the 6MWT is recommended, because start-vs-nadir ΔSpO2 is greater, and the nadir SpO2 is earlier. In both the 6MWT and the cycling exercise test, desaturation can be predicted with the oxygen-cost-diagram score, which has more capability to predict peak exercise performance than the 6MWT.

BACKGROUND: The 6-min walk test (6MWT) is an important tool in the assessment of functional capacity and prognosis in patients with COPD. However, especially in long-term follow-up in clinical settings, this test may be executed by a different assessor, and it is not well known whether 6MWT has an acceptable inter-rater reliability. The aim of this study is to analyze the intra- and inter-rater reliability of the performance in 6MWT, its cardiorespiratory changes, and effort perception in subjects with COPD. METHODS: Thirty-two subjects with a diagnosis of COPD participated in the study, but 3 subjects did not appear on the second day of evaluation and therefore were included only in the intra-rater analysis; the first and second tests were executed by the same assessor with a 30-min interval between them, and the last was executed by a different assessor a week later. The intra-rater reliability was verified comparing the first and second 6MWT performance, and the inter-rater reliability was verified comparing the third test with the best performance of the first and second tests. RESULTS: The intraclass correlation coefficient values were >0.75 ( P < .001) for the walked distance on the 6MWT; however, the limits of agreement, SE of measurement, and minimal detectable difference were higher than the minimum clinically important differences already mentioned in the literature (∼25, 26, and 54 m), and the coefficient of variation was small in both intra- and inter-rater comparisons. CONCLUSIONS: The 6MWT showed excellent reliability for distance and perceived exertion and moderate to excellent for HR and SD as assessed by intra- and inter-rater analysis. Thus, based on the main study outcomes, we concluded that the 6MWT can be compared when conducted by 2 different evaluators.

WOS: 000382381800008 PubMed: 26932385 BACKGROUND: The aim of this study was to assess the association between cognitive function and age, pulmonary function, comorbidity index, and the 6-min walk distance in subjects with COPD as well as to compare the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) in terms of their ability to identify cognitive dysfunction in subjects with COPD. METHODS: A total of 52 individuals with stable COPD were included in this study. Cognitive function was assessed using MMSE and MoCA. Age, body mass index, the Modified Cumulative Illness Rating Scale, 6-min walk distance, arterial blood gases, and pulmonary function tests were assessed and recorded. RESULTS: The range and SD of scores in subjects with COPD were larger with MoCA than with MMSE. MMSE and MoCA scores are associated with 6-min walk distance and comorbidity index in subjects with COPD. General cognitive function measured by MoCA was negatively correlated with the comorbidity index but was positively associated with 6-min walk distance in subjects with COPD after controlling for possible confounding factors in the multivariate model. However, general cognitive function measured by MMSE was not correlated with the comorbidity index and 6-min walk distance in subjects with COPD, after controlling for possible confounding factors in the multivariate model. CONCLUSIONS: MoCA may be a more reliable screening test than MMSE in detecting cognitive impairment in subjects with COPD. The addition of cognitive tests on assessment of subjects with COPD can provide further benefit.

The application of CPAP has been used to minimize postoperative pulmonary complications after lung resection surgery. The aim of this study was to quantify both the CPAP effects upon lung function and functional capacity in early postoperative lung resection, as well as to evaluate if CPAP prolongs air leak through the chest drain.Thirty patients in the postoperative period of lung resection were allocated into 2 groups: an experimental group, consisting of 15 patients who underwent a 10 cm H(2)O CPAP, and a 15 patient control group, who performed breathing exercises. Arterial blood gas analysis, peak expiratory flow (PEF), respiratory muscle strength, spirometry, and 6-min walk test (6MWT) were assessed in the preoperative period, and repeated postoperatively on the first and on the seventh day (6MWT was repeated only on the seventh day).Significant increases in PEF, muscle strength, and FEV(1) between the first and seventh postoperative day were observed, both in the experimental and in the control group, whereas FVC and P(aO(2)) increased significantly between the first and seventh postoperative day only in the experimental group. The average loss in 6-min walk distance (6MWD) from preoperative to postoperative day 7 in the experimental group was significantly lower than in control group. When comparing the 2 groups, only 6MWD was statistically different (P.001). There was no air leakage increase through the drain with the early use of CPAP.When compared to breathing exercises, CPAP increases the 6MWD in postoperative lung resection patients, without prolonging air leak through the chest drain.

With the introduction of the stair climb test of surgical patients in the 1950s, the role of exercise-based testing as a useful diagnostic tool and an adjunct to conventional cardiopulmonary testing was established. Since then, we have witnessed a rapid development of numerous tests, varying in their protocols and clinical applications. The relatively simple "field tests" (shuttle walks, stair climb, 6-minute walk test) require minimal equipment and technical support, and so are generally available to physicians and patients. At the other end of the spectrum is the cardiopulmonary exercise test (CPET), more complex in its equipment requirements, technical support, and with an often complex interpretive strategy. The 6-minute walk test (6MWT), in particular, has evolved into a versatile study with diagnostic utility in many disorders, including COPD, pulmonary hypertension, interstitial lung disease, congestive heart failure, and in the pre-surgical evaluation of patients, among others. With the added dimensions of optional O(2) saturation monitoring and calculated post-exercise heart rate recovery, the 6MWT is providing important clinical information well beyond the measure of distance walked. Is it sufficiently robust and informative to replace the more demanding and less available CPET? In many instances, the clinical applications are overlapping, with the 6MWT functioning as an adequate surrogate. However, in the initial evaluation of unexplained dyspnea, in formal evaluation of impairment and disability, in detailed evaluation of congestive heart failure, and in the selected lung cancer patient prior to resection, CPET remains superior. Investigations of portable metabolic and cardiovascular monitoring devices aiming to enhance the diagnostic capabilities of 6MWT may further narrow or close the remaining gap between these two exercise studies.

INTRODUCTION: Pulmonary rehabilitation is effective for patients with COPD, but its benefit is less clearly established in idiopathic pulmonary fibrosis (IPF), especially in regard to levels of physical activity and health-related quality of life. The objectives were to determine whether pulmonary rehabilitation increased physical activity as assessed by the International Physical Activity Questionnaire (IPAQ), and improved quality of life and symptoms as assessed by the St George respiratory questionnaire for IPF (SGRQ-I) and the Borg dyspnea index (BDI). METHODS: Subjects who met current criteria for IPF were randomized to a 3-month pulmonary rehabilitation program ( n = 11) or to a control group ( n = 10). The rehabilitation group participated in twice-weekly, 90-min exercise sessions (24 total sessions). The control group maintained its preceding, normal physical activity. All subjects underwent 6-min walk tests to assess the postexertion BDI. The SGRQ-I and a 5-point self-assessment of health were completed at baseline, after 3 months of intervention or observation, and after 3-month follow-up. All subjects completed the IPAQ weekly. RESULTS: Subjects in the rehabilitation group maintained significantly higher levels of physical activity throughout the 3-month rehabilitation program (rehabilitation: 51,364 ± 57,713 [mean ± SD] metabolic equivalent of task-minutes; control: 20,832 ± 37,155, P = .027 by 2-tailed Mann-Whitney test). SGRQ-I symptom domain scores improved considerably by −9 ± 22 in the rehabilitation group, whereas in the control group they worsened (16 ± 12 rehabilitation compared with control, P = .013 by 2-tailed Mann-Whitney test). During the 3-month follow-up, self-reported physical activity levels in the rehabilitation group were 14,428 ± 8,884 metabolic equivalent of task-minutes and in the control group 16,923 ± 32,620 ( P = .17 by 2-tailed Mann-Whitney test), demonstrating substantial reversal of activity in the rehabilitation group. BDI scores after 6-min walk tests did not change significantly. CONCLUSIONS: A 3-month rehabilitation program significantly improved symptoms (SGRQ-I) and physical activity levels (IPAQ) in subjects with IPF while they participated actively in the program. (ClinicalTrials.gov registration [NCT01118221][1].) [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01118221&atom=%2Frespcare%2F59%2F12%2F1872.atom