In this study, we analyzed the relationships of exercise capacity and health status to mortality in patients with chronic obstructive pulmonary disease (COPD). We recruited 150 male outpatients with stable COPD with a mean postbronchodilator FEV1 at 47.4% of predicted. Their pulmonary function, progressive cycle ergometry, and health status using the Chronic Respiratory Disease Questionnaire, the St. George's Respiratory Questionnaire (SGRQ), and the Breathing Problems Questionnaire were measured at entry. Among 144 patients who were available for the 5-year follow-up, 31 had died. Univariate Cox proportional hazards analysis revealed that the SGRQ total score and the Breathing Problems Questionnaire were significantly correlated with mortality; however, with the Chronic Respiratory Disease Questionnaire, the total score was not significantly correlated. Multivariate Cox proportional hazards analysis revealed that the peak oxygen uptake and the SGRQ total score were both predictive of mortality, independent of FEV1 and age. Stepwise Cox proportional hazards analysis revealed that the peak oxygen uptake was the most significant predictor of mortality. We found that exercise capacity and health status were significantly correlated with mortality, although different health status measures had different abilities to predict mortality. These results will have a potentially great impact on the multidimensional evaluation of disease severity in COPD.

When dyspnea must be assessed clinically, there are three methods of assessment: the measurement of dyspnea with activities of daily living using clinical dyspnea ratings such as the modified Medical Research Council (MRC), the Baseline Dyspnea Index (BDI), and the Oxygen Cost Diagram (OCD); the measurement of dyspnea during exercise using the Borg scale; to assess the influence of dyspnea on health-related quality of life (HRQoL) using disease-specific questionnaires such as the St. George's Respiratory Questionnaire (SGRQ) and the Chronic Respiratory Disease Questionnaire (CRQ). The purpose of the present cross-sectional study was to clarify relationships between dyspnea ratings and HRQoL questionnaires by applying factor analysis. One hundred sixty-one patients with mild to severe COPD completed pulmonary function tests, progressive cycle ergometer testing for exercise capacity, assessment of dyspnea, HRQoL, anxiety, and depression. Factor analysis demonstrated that the MRC, BDI, OCD, and Activity of the SGRQ, and Dyspnea of the CRQ, were grouped into the same factor, and the frequency distribution histograms of these five measures showed virtually the same distribution. The Borg scale at the end of maximum exercise was found to be a different factor. The MRC, BDI, OCD, and Activity in the SGRQ, and Dyspnea in the CRQ demonstrated the same pattern of correlation with physiologic data, and they had significant relationships with FEV1 (correlation coefficients [Rs] = 0.31 to 0. 48) and maximal oxygen uptake (Rs = 0.46 to 0.60). Disease-specific HRQoL questionnaires, the SGRQ and the CRQ, which contain a specific dimension for evaluating dyspnea, may be substituted for clinical dyspnea ratings in a cross-sectional assessment. Dyspnea rating at the end of exercise may provide further information regarding dyspnea.

No abstract

Goals of effective management of patients with chronic obstructive pulmonary disease (COPD) include relieving their symptoms and improving their health status. We examined how such patient reported outcomes would change longitudinally in comparison to physiological outcomes in COPD. One hundred thirty-seven male outpatients with stable COPD were recruited for the study. The subjects health status was evaluated using the St. George's Respiratory Questionnaire (SGRQ) and the Chronic Respiratory Disease Questionnaire (CRQ). Their dyspnoea using the modified Medical Research Council (MRC) scale and their psychological status using the Hospital Anxiety and Depression Scale (HADS) were assessed upon entry and every 6 months thereafter over a 5-year period. Pulmonary function and exercise capacity as evaluated by peak oxygen uptake (VO2) on progressive cycle ergometry were also followed over the same time. Using mixed effects models to estimate the slopes for the changes, scores on the SGRQ, the CRQ, the MRC and the HADS worsened in a statistically significant manner over time. However, changes only weakly correlated with changes in forced expiratory volume in 1s (FEV(1)) and peak (VO2). We demonstrated that although changes in pulmonary function and exercise capacity are well known in patients with COPD, patient reported outcomes such as health status, dyspnoea and psychological status also deteriorated significantly over time. In addition, deteriorations in patient reported outcomes only weakly correlated to changes in physiological indices. To capture the overall deterioration of COPD from the subjective viewpoints of the patients, patient reported outcomes should be followed separately from physiological outcomes.

The purpose of the present study was to compare the characteristics of three different exercise tests in evaluating the effects of oxitropium bromide on exercise performance. Thirty-eight males with stable chronic obstructive pulmonary disease (COPD) (FEV(1) = 40.8 +/- 16.5% predicted; mean +/- SD) completed randomized, double-blind, placebo-controlled, crossover studies for each exercise test. The exercise tests were performed 60 min after the inhalation of either oxitropium bromide 400 microg or placebo. The patients performed 6-min walking tests (6MWT) on Days 1 and 2, progressive cycle ergometry (PCE) on Days 3 and 4, and cycle endurance tests at 80% of the maximal workload of PCE on Days 5 and 6. Spirometry was conducted before and at 45 and 90 min after the inhalation. Oxitropium bromide significantly increased FEV(1) as compared with placebo. Oxitropium bromide increased the endurance time significantly, by 19% (p < 0.001), and caused a small but significant increase in the 6-min walking distance by 1% (p < 0.05), but induced no significant increase in maximal oxygen consumption (V O(2)max) in PCE. The responses in these three exercise tests were different, and we conclude that the endurance test was the most sensitive in detecting the effects of inhaled anticholinergic agents on exercise performance in patients with stable COPD. An endurance procedure may be performed to detect clinical changes in evaluating the effects of oxitropium bromide on exercise performance.