Physical Activity and the Frequency of Acute Exacerbations in Patients with Chronic Obstructive Pulmonary Disease

Review of the prevalence, pathogenesis and management of OSA-COPD overlap

PURPOSE

OSA-COPD overlap is an important and prevalent condition yet remains under-recognised among the vast majority of respiratory health professionals. Patients with OSA-COPD overlap experience more severe respiratory symptoms and worse quality of life, and the relative risk of exacerbations, hospitalisations, and mortality is higher than in either disease state alone.

METHODS

Electronic databases PUBMED and Google Scholar were searched for studies and academic papers that discussed OSA-COPD overlap. Relevant papers that discussed prevalence, pathophysiology, microbiome studies, treatment regimens and outcomes were included in this paper.

RESULTS

High-risk patients with either COPD or OSA should be screened for overlap syndrome as part of routine clinical practice. Screening questionnaires can identify high-risk patients with COPD who may benefit from formal polysomnography. Patients with OSA who are aged over 40 with a significant smoking history or environmental exposures have an increased pre-test probability of obstructive airway disease. The potential roles of gastro-oesophageal reflux disease and lung-gut microbiome are evolving and merit further investigation. A tailored approach to reach a timely diagnosis and thus optimisation of both conditions are key to management. CPAP is the primary therapy for OSA; however, patients with more advanced COPD, with daytime hypercapnia or severe nocturnal desaturations, may benefit from bilevel positive airway pressure.

CONCLUSION

Increased awareness, access to timely investigations and initiation of therapy will improve overall outcomes in OSA-COPD overlap by reducing hospitalisations for exacerbations of COPD and improve mortality rates.

Convergent Validity and Minimal Clinically Important Difference of the Maugeri Foundation Respiratory Failure Questionnaire (MRF-28) and the Chronic Obstructive Pulmonary Disease-Specific Health-Related Quality of Life questionnaire (VQ11)

Purpose

Short and easy questionnaires have been developed to assess the health-related quality of life (HRQoL) in patients with chronic obstructive pulmonary disease (COPD), such as the Maugeri Foundation Respiratory Failure Questionnaire (MRF-28) and the COPD-specific HRQoL Questionnaire (VQ11). Both are valid, reliable, and sensitive, but their minimal clinically important differences (MCID) are unknown. Consequently, this study aimed to confirm the convergent validities of the MRF-28 and VQ11 and establish their MCID. A retrospective design was used to evaluate the effect of individual home-based pulmonary rehabilitation (PR) in 400 COPD patients.

Patients and methods

Exercise tolerance, anxiety and depression based on the Hospital Anxiety and Depression Scale (HADS), and HRQoL using three questionnaires (MRF-28, VQ11, and the Visual Simplified Respiratory Questionnaire: VSRQ) were assessed before and after an individualized home-based PR program (5 sessions of 30-45 mins/week for 8 weeks, including a weekly session supervised by a team member).

Results

PR improved all measured variables (p < 0.0001). The correlations were significant (p < 0.0001) between VSRQ and MRF-28 (r = -0.685 at baseline and r = -0.686 after the PR program), and between VSRQ and VQ11 (r = -0.691 at baseline and r = -0.753 after the PR program). Moreover, changes in score (delta between after and before PR program) of VSRQ were also significantly correlated (p < 0.0001) to changes in score of MRF-28 (r = -0.372) and VQ11 (r = -0.423). Last, we calculated MCID of -5.2 and -2.0 units for MRF-28 and VQ11, respectively.

Conclusion

The MRF-28 and VQ11 can be used in routine practice to evaluate the effects of PR on the HRQoL of COPD patients, with MCID of -5.2 and -2.0, respectively.

Predictive factors for COPD exacerbations and mortality in patients with overlap syndrome

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea (OSA)-overlap syndrome-have a substantially greater risk of morbidity and mortality, compared to those with either COPD or OSA alone.

OBJECTIVES

The aim of this retrospective study was to identify clinical modifiable factors associated with COPD exacerbations and all-cause mortality in patients with overlap syndrome.

METHODS

The electronic records of patients with simultaneous COPD and OSA who had a documented acute exacerbation of COPD during a 42-month period were evaluated for reviewed. A control group of overlap syndrome patients without exacerbations was matched 1:1 for age and body mass index. Vital status and cause of death were assessed through the population death registry.

RESULTS

Out of 225 eligible cases, 92 patients had at least one episode of COPD exacerbation. There was no significant association between severity of airflow limitation and apnoea hypopnea index (P = .31). After adjusting for confounding variables, patients who had at least one COPD exacerbation were more likely to be active smokers (P = .01), have poorer lung function (P = .001) and less likely to adhere to continuous positive airway pressure (CPAP) use (P = .03). All-cause mortality was also correlated with low forced expiratory volume in 1 second (P = .006), CPAP use (P = .007), and burden of comorbidities (P < .001).

CONCLUSION

Lung function and CPAP use were independent predictors of COPD exacerbations and all-cause mortality in a cohort of patients with overlap syndrome. These factors should be taken into account when considering the management and prognosis of these patients.

Correlation between Physical Activity and Lung Function in Dusty Areas: Results from the Chronic Obstructive Pulmonary Disease in Dusty Areas (CODA) Cohort

Background

Although physical activity is known to be beneficial to lung function, few studies have been conducted to investigate the correlation between physical activity and lung function in dusty areas. Therefore, the purpose of this study is to investigate the correlation between physical activity and lung function in a Korean cohort including normal and COPD-diagnosed participants.

Methods

Data obtained from the COPD in dusty areas (CODA) cohort was analyzed for the following factors: lung function, symptoms, and information about physical activity. Information on physical activity was valuated using questionnaires, and participants were categorized into two groups: active and inactive. The evaluation of the mean lung function, modified Medical Research Council dyspnea grade scores, and COPD assessment test scores was done based on the participant physical activity using a general linear model after adjusting for age, sex, smoking status, pack-years, height, and weight. In addition, a stratification analysis was performed based on the smoking status and COPD.

Results

Physical activity had a correlation with high forced expiratory volume in 1 second (FEV₁) among CODA cohort (p=0.03). While the active group exhibited significantly higher FEV₁ compared to one exhibited by the inactive group among past smokers (p=0.02), no such correlation existed among current smokers. There was no significant difference observed in lung function after it was stratified by COPD.

Conclusion

This study established a positive correlation between regular physical activity in dusty areas and lung function in participants.

Estimating the effectiveness of pulmonary rehabilitation for COPD exacerbations: reduction of hospital inpatient days during the following year

AIMS

To study the short- and long-term results of pulmonary rehabilitation (PR) given in the Helsinki University Heart and Lung Center and to understand the hospital resources used to treat severe COPD exacerbations in the city of Helsinki.

MATERIALS AND METHODS

Seventy-eight inactive patients with severe COPD were recruited for a PR course; three of them did not finish the course. The course took 6-8 weeks and included 11-16 supervised exercise sessions. Using electronic medical records, we studied all COPD patients with hospital admission in the city of Helsinki in 2014, including COPD diagnosis, criteria for exacerbation, and potential exclusion/inclusion criteria for PR.

RESULTS

Seventy-five of the patients finished the PR course and 92% of those patients showed clinically significant improvement. Their hospital days were reduced by 54% when compared to the year before. At 1 year after the course, 53% of the patients reported that they have continued with regular exercise training. In the city of Helsinki, 437 COPD patients were treated in a hospital due to exacerbation during 2014. On the basis of their electronic medical records, 57% of them would be suitable for PR. According to a rough estimate, 10%-20% hospital days could be saved annually if PR was available to all, assuming that the PR results would be as good as those shown here.

CONCLUSIONS

The study showed that in a real-world setting, PR is efficient when measured by saved hospital days in severe COPD. Half of the patients could be motivated to continue exercising on their own.

Reduced COPD Exacerbation Risk Correlates With Improved FEV1: A Meta-Regression Analysis

BACKGROUND

The mechanism by which various classes of medication reduce COPD exacerbation risk remains unknown. We hypothesized a correlation between reduced exacerbation risk and improvement in airway patency as measured according to FEV1.

METHODS

By systematic review, COPD trials were identified that reported therapeutic changes in predose FEV1 (dFEV1) and occurrence of moderate to severe exacerbations. Using meta-regression analysis, a model was generated with dFEV1 as the moderator variable and the absolute difference in exacerbation rate (RD), ratio of exacerbation rates (RRs), or hazard ratio (HR) as dependent variables.

RESULTS

The analysis of RD and RR included 119,227 patients, and the HR analysis included 73,475 patients. For every 100-mL change in predose FEV1, the HR decreased by 21% (95% CI, 17-26; P < .001; R2 = 0.85) and the absolute exacerbation rate decreased by 0.06 per patient per year (95% CI, 0.02-0.11; P = .009; R2 = 0.05), which corresponded to an RR of 0.86 (95% CI, 0.81-0.91; P < .001; R2 = 0.20). The relationship with exacerbation risk remained statistically significant across multiple subgroup analyses.

CONCLUSIONS

A significant correlation between increased FEV1 and lower COPD exacerbation risk suggests that airway patency is an important mechanism responsible for this effect.