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Purpose: To determine the effects of providing a wheeled walker (WW) for use in the home and community, on daily physical activity (PA) and sedentary time (ST) in people with chronic obstructive pulmonary disease (COPD)., Methods: A randomised cross-over study in which participants with COPD characterised by a 6-min walk distance ≤ 450 m, who had recently finished pulmonary rehabilitation, completed two 5-week phases. During one phase, participants were provided a WW to use, whereas during the other phase, the WW was not available. The order of the phases was randomised. For the final week of each phase, measures of PA and ST were collected using wearable devices and health-related quality of life was measured using the Chronic Respiratory Disease Questionnaire (CRDQ). Wheeled walker use was also measured using an odometer attached to the device., Results: 17 participants [FEV 1  = median (interquartile range) 33 (25) % pred; ten males] aged mean (SD) 73 (9) years completed the study. Comparing the data collected when the WW was not available for use, the daily step count was greater (mean difference [MD] 707 steps/day (95% confidence interval [CI] 75 to 1340) and participants tended to report less dyspnoea during daily life (MD 0.5 points per item, 95% CI - 0.1 to 1.0) when WW was available. No differences were observed for ST, upright time or stepping time. The WW was used over 4504 m/week (95% CI 2746 to 6262)., Conclusion: These data demonstrated that, when provided to selected patients with COPD, WWs increased daily step count., Clinical Trial Registration Number: ACTRN12609000332224.

We described physical activity measures and hourly patterns in patients with chronic obstructive pulmonary disease (COPD) after stratification for generic and COPD-specific characteristics and, based on multiple physical activity measures, we identified clusters of patients. In total, 1001 patients with COPD (65% men; age, 67 years; forced expiratory volume in the first second [FEV 1 ], 49% predicted) were studied cross-sectionally. Demographics, anthropometrics, lung function and clinical data were assessed. Daily physical activity measures and hourly patterns were analysed based on data from a multisensor armband. Principal component analysis (PCA) and cluster analysis were applied to physical activity measures to identify clusters. Age, body mass index (BMI), dyspnoea grade and ADO index (including age, dyspnoea and airflow obstruction) were associated with physical activity measures and hourly patterns. Five clusters were identified based on three PCA components, which accounted for 60% of variance of the data. Importantly, couch potatoes (i.e. the most inactive cluster) were characterised by higher BMI, lower FEV 1 , worse dyspnoea and higher ADO index compared to other clusters ( p < 0.05 for all). Daily physical activity measures and hourly patterns are heterogeneous in COPD. Clusters of patients were identified solely based on physical activity data. These findings may be useful to develop interventions aiming to promote physical activity in COPD.

Objectives: To investigate cardiorespiratory and dyspnea responses to incremental and self-paced exercise tests in patients with COPD., Design: A prospective within-subject design was used., Patients: Twenty stable subjects (15 men), with a mean (+/- SD) age of 64.0 +/- 7.5 years and moderate-to-severe COPD (ie, mean FEV(1), 0.8 +/- 0.3 L and 28.9 +/- 7.9% predicted) were studied., Methods: Each subject completed a 6-min walk test (6MWT), an incremental shuttle walking test (ISWT), and a cycle ergometer test (CET), within a 2-week period. The tests were performed at least 24 h apart. Standardized encouragement was utilized in each test with the aim of maximizing performance. Heart rate (HR) and dyspnea were measured each minute throughout the tests, and pulse oximetric saturation (Spo(2)) was measured before and immediately after each test. The distances walked in the 6MWT and ISWT were compared to peak oxygen uptake (Vo(2)) values from the CET., Results: HR increased linearly with increasing workload during the CET and ISWT, but increased alinearly with a disproportionate increase early in the 6MWT. In contrast, dyspnea scores increased linearly during the 6MWT, but increased alinearly with a disproportionate increase late during the CET and ISWT. Peak HR and dyspnea were not significantly different between tests. Spo(2) was significantly lower at the end of both walking tests compared to that at the end of the CET (p < 0.001). The distance walked in both the ISWT and 6MWT were related to peak Vo(2) values on the CET (for both tests, r = 0.73; p < 0.001)., Conclusions: The patterns of response in HR and dyspnea seen during the 6MWT suggest that patients with COPD titrate exertion against dyspnea to achieve a peak tolerable intensity. This strategy is not possible in an externally paced ISWT or CET. However, it is a limited strategy, with performance converging at higher workloads. Similar peak exercise responses were achieved in the 6MWT, ISWT, and CET. Greater oxygen desaturation was observed during the field walking tests, suggesting that both the ISWT and 6MWT are more sensitive than the CET in detecting exercise-induced hypoxemia and in assessing ambulatory oxygen therapy needs.

Background: Oxygen desaturation during exercise is common in people with chronic obstructive pulmonary disease (COPD). The aim of the study is to determine, in people with COPD who desaturate during exercise, whether supplemental oxygen during an eight-week exercise training program is more effective than medical air (sham intervention) in improving exercise capacity and health-related quality of life both at the completion of training and at six-month follow up.Methods/design: This is a multi-centre randomised controlled trial with concealed allocation, blinding of participants, exercise trainers and assessors, and intention-to-treat analysis. 110 people with chronic obstructive pulmonary disease who demonstrate oxygen desaturation lower than 90 % during the six-minute walk test will be recruited from pulmonary rehabilitation programs in seven teaching hospitals in Australia. People with chronic obstructive pulmonary disease on long term oxygen therapy will be excluded. After confirmation of eligibility and baseline assessment, participants will be randomised to receive either supplemental oxygen or medical air during an eight-week supervised treadmill and cycle exercise training program, three times per week for eight weeks, in hospital outpatient settings. Primary outcome measures will be endurance walking capacity assessed by the endurance shuttle walk test and health-related quality of life assessed by the Chronic Respiratory Disease Questionnaire. Secondary outcomes will include peak walking capacity measured by the incremental shuttle walk test, dyspnoea via the Dyspnoea-12 questionnaire and physical activity levels measured over seven days using an activity monitor. All outcomes will be measured at baseline, completion of training and at six-month follow up.Discussion: Exercise training is an essential component of pulmonary rehabilitation for people with COPD. This study will determine whether supplemental oxygen during exercise training is more effective than medical air in improving exercise capacity and health-related quality of life in people with COPD who desaturate during exercise.Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12612000395831, 5th Jan,2012. [ABSTRACT FROM AUTHOR]

Objectives: The 6-min walk test (6MWT) is commonly used to assess the functional exercise capacity of individuals with cardiopulmonary disease. Recent studies have established regression equations to predict the 6-min walk distance (6MWD) in healthy Caucasian populations; however, regression equations have yet to be established for the Singaporean population. The aim of this study was to determine 6MWD in healthy Singaporeans and identify contributors to 6MWD in this population. We also compared measured 6MWD with predicted 6MWD from two regression equations derived in Caucasian subjects. Methodology: Thirty-five healthy subjects (32 Chinese, 16 men) aged between 45 and 85 years performed three walking tests using a standardized protocol. 6MWD was defined as the greatest distance achieved from the three tests. Heart rate (HR) was recorded each minute during the 6MWT. Other measurements included age, height, leg length, smoking history and self-reported physical activity. Results: 6MWD was 560 ± 105 m and was not significantly different between men and women ( P = 0.19). 6MWD was related to age ( r = −0.36, P = 0.03), height ( r = 0.35, P = 0.04), leg length ( r = 0.38, P = 0.02) and the maximum HR achieved on the 6MWT when expressed as a percentage of the predicted maximum HR (%predHRmax, r = 0.73, P < 0.001). Stepwise multiple regression analysis showed that age, height, weight and %predHRmax were independent contributors ( P < 0.01) to 6MWD, explaining 78% of the variance. Predicted 6MWD using regression equations derived from Caucasian subjects exceeded measured 6MWD by more than 75 m ( P < 0.001). Conclusions: This is the first study to report 6MWD for healthy Singaporeans aged 45–85 years. The regression equation developed in this study explained 78% of the variance in 6MWD. Published equations derived from Caucasian subjects overestimate 6MWD in Singaporean Chinese. [ABSTRACT FROM AUTHOR]

The article presents a study on the association of exercise-induced pulmonary arterial hypertension with hemodynamic and ventilatory abnormalities typical of pulmonary arterial hypertension (PAH). The study involves cardiopulmonary exercise tests and quality of life (QOL) assessments among 37 symptomatic patients that are at risk of PAH and 20 healthy controls. The result shows that subjects with exercise-induced PAH (EIPAH) had reduced peak exercise cardiac output, reduced peak oxygen consumption, and reduced end-tidal carbon dioxide tension at the anaerobic threshold. Furthermore, the study concludes that there is an association between elevated pulmonary artery pressure on exercise and hemodynamic and ventilatory abnormalities typical of PAH.