Short-term effects of air pollution and weather on physical activity in patients with chronic obstructive pulmonary disease (COPD)

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) accumulate low levels of physical activity. How environmental factors affect their physical activity in the short-term is uncertain.

AIM

to assess the short-term effects of air pollution and weather on physical activity levels in COPD patients.

METHODS

This multi-center panel study assessed 408 COPD patients from Catalonia (Spain). Daily physical activity (i.e., steps, time in moderate-to-vigorous physical activity (MVPA), locomotion intensity, and sedentary time) was recorded in two 7-day periods, one year apart, using the Dynaport MoveMonitor. Air pollution (nitrogen dioxide (NO2), particulate matter below 10 μm (PM10) and a marker of black carbon (absorbance of PM2.5: PM2.5ABS), and weather (average and maximum temperature, and rainfall) were estimated the same day (lag zero) and up to 5 days prior to each assessment (lags 1-5). Mixed-effect distributed lag linear regression models were adjusted for age, sex, weekday, public holidays, greenness, season, and social class, with patient and city as random effects.

RESULTS

Patients (85% male) were on average (mean ± SD) 68 ± 9 years old with a post-bronchodilator forced expiratory volume in 1 s (FEV1) of 57 ± 18% predicted. Higher NO2, PM10 and PM2.5ABS levels at lag four were associated with fewer steps, less time in MVPA, reduced locomotion intensity, and longer sedentary time (e.g., coefficient (95% CI) of -60 (-105, -15) steps per 10 μg/m3 increase in NO2). Higher average and maximum temperatures at lag zero were related to more steps and time in MVPA, and less sedentary time (e.g., +85 (15, 154) steps per degree Celsius). Higher rainfall at lag zero was related to fewer steps and more sedentary time.

CONCLUSION

Air pollution affects the amount and intensity of physical activity performed on the following days in COPD patients, whereas weather affects the amount of physical activity performed on the same day.

Real-world walking cadence in people with COPD

Introduction

The clinical validity of real-world walking cadence in people with COPD is unsettled. Our objective was to assess the levels, variability and association with clinically relevant COPD characteristics and outcomes of real-world walking cadence.

Methods

We assessed walking cadence (steps per minute during walking bouts longer than 10 s) from 7 days' accelerometer data in 593 individuals with COPD from five European countries, and clinical and functional characteristics from validated questionnaires and standardised tests. Severe exacerbations during a 12-month follow-up were recorded from patient reports and medical registries.

Results

Participants were mostly male (80%) and had mean±sd age of 68±8 years, post-bronchodilator forced expiratory volume in 1 s (FEV1) of 57±19% predicted and walked 6880±3926 steps·day-1. Mean walking cadence was 88±9 steps·min-1, followed a normal distribution and was highly stable within-person (intraclass correlation coefficient 0.92, 95% CI 0.90-0.93). After adjusting for age, sex, height and number of walking bouts in fractional polynomial or linear regressions, walking cadence was positively associated with FEV1, 6-min walk distance, physical activity (steps·day-1, time in moderate-to-vigorous physical activity, vector magnitude units, walking time, intensity during locomotion), physical activity experience and health-related quality of life and negatively associated with breathlessness and depression (all p<0.05). These associations remained after further adjustment for daily steps. In negative binomial regression adjusted for multiple confounders, walking cadence related to lower number of severe exacerbations during follow-up (incidence rate ratio 0.94 per step·min-1, 95% CI 0.91-0.99, p=0.009).

Conclusions

Higher real-world walking cadence is associated with better COPD status and lower severe exacerbations risk, which makes it attractive as a future prognostic marker and clinical outcome.

Chronic Thromboembolic Pulmonary Hypertension after Pulmonary Embolism in SARS-CoV-2

INTRODUCTION

Chronic thromboembolic pulmonary disease (CTEPD) consists of persistent pulmonary vascular obstruction on imaging and involves long-term functional limitations, with or without chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to evaluate the incidence and risk factors of both persistent pulmonary vascular defects and CTEPH after hospitalization in patients with COVID-19 and PE during a 2-year follow-up.

METHODS

A prospective observational study was carried out in a tertiary hospital center. Patients were hospitalized between March 2020 and December 2021 with a diagnosis of PE during SARS-CoV-2 infection. Patients received anticoagulant treatment for at least 3 months and were followed up for 2 years. Between the third and fourth months after discharge, all patients were evaluated for the presence of residual thrombotic defects by CTPA and/or perfusion pulmonary scintigraphy. Clinical findings, lung function tests with DLCO, exercise capacity, and echocardiograms were also assessed.

RESULTS

Of the 133 patients included, 18% had persistent thrombotic defects on lung imaging at follow-up. The incidence of CTEPD was 0.75% at 2 years of follow-up. Patients with persistent defects were significantly older, had a higher prevalence of systemic arterial hypertension, higher D-dimer and NT-proBNP levels, and more severe PE at diagnosis. Furthermore, there was a higher prevalence of right ventricular dysfunction on echocardiogram at diagnosis of PE (25.0% vs. 2.7%, p = 0.006). This was the only variable independently related to persistent defects in multivariate analyses (OR: 8.13 [95% CI: 1.82-36.32], p = 0.006).

CONCLUSION

The persistence of thrombotic defects after PE is a common finding after SARS-CoV-2 infection, affecting 18% of the population. However, the incidence of CTEPH appears to be lower (0.75%) in COVID-19-related PE compared to that previously observed in PE unrelated to COVID-19.

Predictors and changes of physical activity in idiopathic pulmonary fibrosis

Background

Different clinical predictors of physical activity (PA) have been described in idiopathic pulmonary fibrosis (IPF), but studies are lacking evaluating the potential role of muscle strength and anxiety and depression symptoms in PA limitation. Moreover, little is known about the impact of changes in PA in the course of the disease. The aim of the present study was to investigate the relationship between baseline PA and a wide range of variables in IPF, to assess its longitudinal changes at 12 months and its impact on progression free-survival.

Methods

PA was assessed by accelerometer and physiological, clinical, psychological factors and health-related quality of life were evaluated in subjects with IPF at baseline and at 12 month follow-up. Predictors of PA were determined at baseline, evolution of PA parameters was described and the prognostic role of PA evolution was also established.

Results

Forty participants with IPF were included and 22 completed the follow-up. At baseline, subjects performed 5765 (3442) daily steps and spent 64 (44) minutes/day in moderate to vigorous PA. Multivariate regression models showed that at baseline, a lower six-minute walked distance, lower quadriceps strength (QMVC), and a higher depression score in the Hospital Anxiety and Depression scale were associated to lower daily step number. In addition, being in (Gender-Age-Physiology) GAP III stage, having a BMI ≥ 25 kg/m² and lower QMVC or maximum inspiratory pressure were factors associated with sedentary behaviour. Adjusted for age, gender and forced vital capacity (FVC) (%pred.) a lower progression-free survival was evidenced in those subjects that decreased PA compared to those that maintained, or even increased it, at 12 months [HR 12.1 (95% CI, 1.9–78.8); p = 0.009].

Conclusion

Among a wide range of variables, muscle strength and depression symptoms have a predominant role in PA in IPF patients. Daily PA behaviour and its evolution should be considered in IPF clinical assessment and as a potential complementary indicator of disease prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02134-4.

Roles of the physical environment in health-related quality of life in patients with chronic obstructive pulmonary disease

RATIONALE

Many clinical and psychological factors are known to influence the health-related quality of life (HRQL) in chronic obstructive pulmonary disease (COPD). However, research on whether environmental factors, such as air pollution, noise, temperature, and blue/green spaces also influence HRQL in COPD has not been systematically investigated.

OBJECTIVE

To assess the relationship between air pollution, road traffic noise, temperature, and distance to blue/green spaces and respiratory-specific HRQL in COPD.

METHODS

We used cross-sectional data from a multicenter study in 407 stable mild-to-very severe COPD patients from Barcelona (Catalonia). Patients answered the COPD Assessment Test (CAT) and Clinical COPD Questionnaire (CCQ). Individual residential exposure to air pollutants (nitrogen dioxide [NO₂] and particulate matters of varying aerodynamic diameters [PM_2.5, PM₁₀, and PM_{2.5absorbance}]), road traffic noise (L_den), and land surface temperature were estimated using long-term averages from land-use regression models, 24-h noise maps, and land surface temperature maps, respectively. We measured residential distances to blue/green spaces from the Urban Atlas. We used mixed-effect negative binomial (for CAT) and linear (for CCQ) regression models, adjusted for potential confounders, with a random effect by center.

RESULTS

Of those patients, 85 % were male and had a mean (SD) age of 69 (9) years, CAT score of 12 (7), CCQ-total score of 1.4 (1.0), and post-bronchodilator forced expiratory volume in 1 s (FEV₁) of 57 (18) %predicted. We found that NO₂ and PM_{2.5absorbance} were associated with worsened CAT and CCQ-mental scores, e.g., 0.15-unit change in CAT score [regression coefficient (β) = 0.15; 95 % confidence interval (CI) = 0.03, 0.26] per interquartile range in NO₂ [13.7 μg/m³]. Greater distances to blue/green spaces were associated with worsened CCQ-mental scores [0.08; 0.002, 0.15].

CONCLUSIONS

Our study showed that increased air pollution, particularly NO₂ and PM_{2.5absorbance} and greater distances to blue/green spaces negatively influence HRQL in COPD patients. These findings have important implications for the WHO promotion to develop healthy cities for our future.

Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial

BACKGROUND

Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypothesized that HFNC may improve exercise capacity in IPF subjects compared to SOT.

METHODS

This was a prospective, crossover, pilot randomized trial that compared both oxygenation methods during a constant submaximal cardiopulmonary exercise test (CPET) in IPF patients with exertional oxygen saturation (SpO₂) ≤ 85% in the 6-min walking test. The primary outcome was endurance time (Tlim). Secondary outcomes were muscle oxygen saturation (StO₂) and respiratory and leg symptoms.

RESULTS

Ten IPF patients [71.7 (6) years old, 90% males] were included. FVC and DL_CO were 58 ± 11% and 31 ± 13% pred. respectively. Tlim during CPET was significantly greater using HFNC compared to SOT [494 ± 173 vs. 381 ± 137 s, p = 0.01]. HFNC also associated with a higher increase in inspiratory capacity (IC) [19.4 ± 14.2 vs. 7.1 ± 8.9%, respectively; p = 0.04], and a similar trend was observed in StO₂ during exercise. No differences were found in respiratory or leg symptoms between the two oxygen devices.

CONCLUSIONS

This is the first study demonstrating that HFNC oxygen therapy improves exercise tolerance better than SOT in IPF patients with exertional desaturation. This might be explained by changes in ventilatory mechanics and muscle oxygenation. Further and larger studies are needed to confirm the benefits of HFNC in IPF patients and its potential usefulness in rehabilitation programs.

Different Faces of Idiopathic Pulmonary Fibrosis With Preserved Forced Vital Capacity

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is progressive and irreversible. Some discrepancies about IPF staging exists, especially in mild phases. Forced vital capacity (FVC) higher than 80% has been considered early or mild IPF even for the design of clinical trials.

METHODS

Spanish multicentre, observational, retrospective study of IPF patients diagnosed between 2012 and 2016, based on the ATS/ERS criteria, which presented FVC greater or equal 80% at diagnosis. Clinical and demographic characteristics, lung function, radiological pattern, treatment, and follow-up were analyzed.

RESULTS

225 IPF patients were included, 72.9% were men. The mean age was 69.5 years. The predominant high-resolution computed tomography (HRCT) pattern was consistent usual interstitial pneumonia (UIP) (51.6%). 84.7% of patients presented respiratory symptoms (exertional dyspnea and/or cough) and 33.33% showed oxygen desaturation below 90% in the 6min walking test (6MWT). Anti-fibrotic treatment was initiated at diagnosis in 55.11% of patients. Median FVC was 89.6% (IQR 17) and 58.7% of patients had a decrease of diffusion lung capacity for carbon monoxide (DLCO) below 60% of theoretical value; most of them presented functional progression (61.4%) and higher mortality at 3 years (20.45%). A statistically significant correlation with the 3-years mortality was observed between DLCO <60% and consistent UIP radiological pattern.

CONCLUSIONS

Patients with preserved FVC but presenting UIP radiological pattern and moderate-severe DLCO decrease at diagnosis associate an increased risk of progression, death or lung transplantation. Therefore, in these cases, preserved FVC would not be representative of early or mild IPF.

Physical activity and cardiac autonomic dysfunction in patients with chronic obstructive pulmonary disease: a cross-sectional analysis

BACKGROUND

The cardiac autonomic function in patients with chronic obstructive pulmonary disease (COPD) has been poorly studied.

OBJECTIVES

We aimed to 1) describe the cardiac autonomic function assessed by heart rate recovery (HRR) and chronotropic response (CR) during a 6-min walk test (6MWT) and afterward and 2) estimate the association of physical activity with HRR and CR in COPD patients.

METHODS

This cross-sectional analysis included 320 patients with mild to very severe COPD. Physical activity (steps, time in any/moderate-to-vigorous/vigorous physical activity, intensity and sedentary time) was measured during 1 week by accelerometer. CR and HRR were measured during a 6MWT and 5 min after, respectively, and their association with physical activity parameters was estimated by multivariable linear regression models.

RESULTS

Patients were 82% male and had a mean (SD) age 68 (8) years, post-bronchodilator FEV1 57 (18) % predicted, and walked a mean of 7716 (4139) steps/day. HRR was slow until 5 min after the 6MWT; the mean (SD) was 15 (10), 22 (11), 25 (12), 25 (12) and 27 (12) bpm after 1, 2, 3, 4 and 5 min, respectively). The mean CR was 35% (16). After adjusting for relevant confounders, time in vigorous physical activity was significantly associated with a fast decrease in HRR (p=0.044) and an increase in CR (p=0.021). We found no independent association for other physical activity parameters.

CONCLUSION

A cardiac autonomic dysfunction is present in patients with mild to very severe COPD and is inversely related to the practice of vigorous physical activity.

Mapping IPF helps identify geographic regions at higher risk for disease development and potential triggers

BACKGROUND AND OBJECTIVE

The relationship between IPF development and environmental factors has not been completely elucidated. Analysing geographic regions of idiopathic pulmonary fibrosis (IPF) cases could help identify those areas with higher aggregation and investigate potential triggers. We hypothesize that cross-analysing location of IPF cases and areas of consistently high air pollution concentration could lead to recognition of environmental risk factors for IPF development.

METHODS

This retrospective study analysed epidemiological and clinical data from 503 patients registered in the Observatory IPF.cat from January 2017 to June 2019. Incident and prevalent IPF cases from the Catalan region of Spain were graphed based on their postal address. We generated maps of the most relevant air pollutant PM2.5 from the last 10 years using data from the CALIOPE air quality forecast system and observational data.

RESULTS

In 2018, the prevalence of IPF differed across provinces; from 8.1 cases per 100 000 habitants in Barcelona to 2.0 cases per 100 000 in Girona. The ratio of IPF was higher in some areas. Mapping PM2.5 levels illustrated that certain areas with more industry, traffic and shipping maintained markedly higher PM2.5 concentrations. Most of these locations correlated with higher aggregation of IPF cases. Compared with other risk factors, PM2.5 exposure was the most frequent.

CONCLUSION

In this retrospective study, prevalence of IPF is higher in areas of elevated PM2.5 concentration. Prospective studies with targeted pollution mapping need to be done in specific geographies to compile a broader profile of environmental factors involved in the development of pulmonary fibrosis.

Patterns of Physical Activity Progression in Patients With COPD

INTRODUCTION

Although mean physical activity in COPD patients declines by 400-500steps/day annually, it is unknown whether the natural progression is the same for all patients. We aimed to identify distinct physical activity progression patterns using a hypothesis-free approach and to assess their determinants.

METHODS

We pooled data from two cohorts (usual care arm of Urban Training [NCT01897298] and PROactive initial validation [NCT01388218] studies) measuring physical activity at baseline and 12 months (Dynaport MoveMonitor). We identified clusters (patterns) of physical activity progression (based on levels and changes of steps/day) using k-means, and compared baseline sociodemographic, interpersonal, environmental, clinical and psychological characteristics across patterns.

RESULTS

In 291 COPD patients (mean±SD 68±8 years, 81% male, FEV₁ 59±19%_pred) we identified three distinct physical activity progression patterns: Inactive (n=173 [59%], baseline: 4621±1757 steps/day, 12-month change (Δ): -487±1201 steps/day), ActiveImprovers (n=49 [17%], baseline: 7727±3275 steps/day, Δ:+3378±2203 steps/day) and ActiveDecliners (n=69 [24%], baseline: 11 267±3009 steps/day, Δ: -2217±2085 steps/day). After adjustment in a mixed multinomial logistic regression model using Active Decliners as reference pattern, a lower 6-min walking distance (RRR [95% CI] 0.94 [0.90-0.98] per 10m, P=.001) and a higher mMRC dyspnea score (1.71 [1.12-2.60] per 1 point, P=.012) were independently related with being Inactive. No baseline variable was independently associated with being an Active Improver.

CONCLUSIONS

The natural progression in physical activity over time in COPD patients is heterogeneous. While Inactive patients relate to worse scores for clinical COPD characteristics, Active Improvers and Decliners cannot be predicted at baseline.

Determinants of study completion and response to a 12-month behavioral physical activity intervention in chronic obstructive pulmonary disease: A cohort study

OBJECTIVES

Physical activity is key to improve the prognosis of chronic obstructive pulmonary disease (COPD). To help to tailor future interventions we aimed to identify the baseline characteristics of COPD patients which predict 12-month completion and response to a behavioral physical activity intervention.

METHODS

This is a 12-month cohort study of the intervention arm of the Urban Training randomized controlled trial (NCT01897298), an intervention proven to be efficacious to increase physical activity. We considered baseline sociodemographic, interpersonal, environmental, clinical and psychological characteristics as potential determinants of completion and response. We defined completion as attending the 12-month study visit. Among completers, we defined response as increasing physical activity ≥1100 steps/day from baseline to 12 months, measured by accelerometer. We estimated the factors independently for completion and response using multivariable logistic regression models.

RESULTS

Of a total of 202 patients (m (SD) 69 (9) years, 84% male), 132 (65%) completed the study. Among those, 37 (28%) qualified as responders. Higher numbers of baseline steps/day (OR [95% CI] 1.11 [1.02-1.21] per increase of 1000 steps, p<0.05) and living with a partner (2.77 [1.41-5.48], p<0.01) were related to a higher probability of completion while more neighborhood vulnerability (0.70 [0.57-0.86] per increase of 0.1 units in urban vulnerability index, p<0.01) was related to a lower probability. Among the completers, working (3.14 [1.05-9.33], p<0.05) and having an endocrino-metabolic disease (4.36 [1.49-12.80], p<0.01) were related to a higher probability of response while unwillingness to follow the intervention (0.21 [0.05-0.98], p<0.05) was related to a lower probability.

CONCLUSIONS

This study found that 12-month completion of a behavioral physical activity intervention was generally determined by previous physical activity habits as well as interpersonal and environmental physical activity facilitators while response was related to diverse factors thought to modify the individual motivation to change to an active lifestyle.

Long-term efficacy and effectiveness of a behavioural and community-based exercise intervention (Urban Training) to increase physical activity in patients with COPD: a randomised controlled trial

There is a need to increase and maintain physical activity in patients with chronic obstructive pulmonary disease (COPD). We assessed 12-month efficacy and effectiveness of the Urban Training intervention on physical activity in COPD patients.

This randomised controlled trial (NCT01897298) allocated 407 COPD patients from primary and hospital settings 1:1 to usual care (n=205) or Urban Training (n=202). Urban Training consisted of a baseline motivational interview, advice to walk on urban trails designed for COPD patients in outdoor public spaces and other optional components for feedback, motivation, information and support (pedometer, calendar, physical activity brochure, website, phone text messages, walking groups and a phone number). The primary outcome was 12-month change in steps·day⁻¹ measured by accelerometer.

Efficacy analysis (with per-protocol analysis set, n=233 classified as adherent to the assigned intervention) showed adjusted (95% CI) 12-month difference +957 (184–1731) steps·day⁻¹ between Urban Training and usual care. Effectiveness analysis (with intention-to-treat analysis set, n=280 patients completing the study at 12 months including unwilling and self-reported non-adherent patients) showed no differences between groups. Leg muscle pain during walks was more frequently reported in Urban Training than usual care, without differences in any of the other adverse events.

Urban Training, combining behavioural strategies with unsupervised outdoor walking, was efficacious in increasing physical activity after 12 months in COPD patients, with few safety concerns. However, it was ineffective in the full population including unwilling and self-reported non-adherent patients.

Urban Training in COPD increased physical activity after 12 months but not in self-reported non-adherent patientshttp://ow.ly/dc2C30lnAEs

Prevalence of persistent blood eosinophilia: relation to outcomes in patients with COPD

The impact of blood eosinophilia in chronic obstructive pulmonary disease (COPD) remains controversial.

To evaluate the prevalence and stability of a high level of blood eosinophils (≥300 cells·μL–1) and its relationship to outcomes, we determined blood eosinophils at baseline and over 2 years in 424 COPD patients (forced expiratory volume in 1 s (FEV1) 60% predicted) and 67 smokers without COPD from the CHAIN cohort, and in 308 COPD patients (FEV1 60% predicted) in the BODE cohort. We related eosinophil levels to exacerbations and survival using Cox hazard analysis.

In COPD patients, 15.8% in the CHAIN cohort and 12.3% in the BODE cohort had persistently elevated blood eosinophils at all three visits. A significant proportion (43.8%) of patients had counts that oscillated above and below the cut-off points, while the rest had persistent eosinophil levels <300 cells·μL–1. A similar eosinophil blood pattern was observed in controls. Exacerbation rates did not differ in patients with and without eosinophilia. All-cause mortality was lower in patients with high eosinophils compared with those with values <300 cells·μL–1 (15.8% versus 33.7%; p=0.026).

In patients with COPD, blood eosinophils ≥300 cells·μL–1 persisting over 2 years was not a risk factor for COPD exacerbations. High eosinophil count was associated with better survival.

Pulmonary eosinophilia associated to treatment with natalizumab

Natalizumab (Tysabri^®) is a leukocytes chemotaxis inhibitor that decreases the leukocytes passage through the hematoencephalic barrier and it is currently used in relapsing-remitting forms of multiple sclerosis (MS). We present a patient with allergic rhinoconjunctivitis diagnosed with MS who started treatment with natalizumab. She began to show mild asthmatic symptoms until she needed admission to the hospital due to respiratory insufficiency. Blood tests showed peripheral eosinophilia and the thoracic computed tomography scan demonstrated pulmonary infiltrates. The bronchoscopy with the bronchoalveolar lavage resulted in eosinophilic alveolitis. No evidence of bacterial, fungal and parasitic infection, connective tissue disease, or vasculitis were observed. After discontinuation of natalizumab, the patient improved without other treatments. As MS is a prevalent disease and the use of natalizumab is increasing, we consider important to point out that this drug can be associated with pulmonary eosinophilia, especially in patients with allergic rhinoconjunctivitis or asthma.

Inspiratory capacity-to-total lung capacity ratio and dyspnoea predict exercise capacity decline in COPD

BACKGROUND AND OBJECTIVE

Exercise capacity decline is a predictor of mortality in patients with chronic obstructive pulmonary disease (COPD). Static pulmonary hyperinflation is a key determinant of exercise performance, but its effect on the longitudinal decline in exercise capacity remains unknown. We aimed to study the relationship between the inspiratory capacity-to-total lung capacity (IC/TLC) ratio and exercise capacity decline in COPD.

METHODS

We measured IC/TLC and other relevant clinical and functional variables in 342 clinically stable patients with COPD. The 6-min walk distance (6MWD) was determined at recruitment and after a mean ± SD of 1.7 ± 0.3 years. The annual rate of change in 6MWD was calculated. Multiple imputation to account for losses during follow up was implemented, and multivariate regression was used to analyze predictive factors of 6MWD decline.

RESULTS

Mean decline rate in the 6MWD was 21.9 ± 34.1 m/year. In the bivariate analysis, patients with lower levels of IC/TLC had greater 6MWD decline (-27.4 ± 42.5, -24.9 ± 36.5 and -13.4 ± 39.9 m/year in the first, second and third tertile of IC/TLC, respectively; P-for-trend = 0.018). From other potential risk factors considered, dyspnoea, health status, serum C-reactive protein and Borg dyspnoea score at the end of the exercise test were related to exercise capacity decline. In the multivariate regression model, only IC/TLC (β = 0.7 m/year per each percentage unit of IC/TLC; P = 0.007) and dyspnoea (mMRC ≥ 2) (β = -14.6 m/year; P = 0.013) were associated with the annual rate of 6MWD change.

CONCLUSION

IC/TLC and dyspnoea in clinically stable patients with COPD predict their exercise capacity decline and may help to guide early therapeutic interventions.

Validation of Walking Trails for the Urban Training™ of Chronic Obstructive Pulmonary Disease Patients

Purpose

Accessible interventions to train patients with chronic obstructive pulmonary disease (COPD) are needed. We designed urban trails of different intensities (low, moderate and high) in different types of public spaces (boulevard, beach and park). We aimed to validate the trails’ design by assessing the physiological response to unsupervised walking trails of: (1) different intensities in COPD patients, and (2) same intensity from different public spaces in healthy adults.

Methods

On different days and under standardized conditions, 10 COPD patients walked the three intensity trails designed in a boulevard space, and 10 healthy subjects walked the three intensity trails in three different spaces. We measured physiological response and energy expenditure using a gas analyzer. We compared outcomes across trails intensity and/or spaces using mixed-effects linear regression.

Results

In COPD patients, physiological response and energy expenditure increased significantly according to the trails intensity: mean (SD) peak V˙O₂ 15.9 (3.5), 17.4 (4.7), and 17.7 (4.4) mL/min/kg (p-trend = 0.02), and MET-min 60 (23), 64 (26), 72 (31) (p-trend<0.01) in low, moderate and high intensity trails, respectively. In healthy subjects there were no differences in physiological response to walking trails of the same intensity across different spaces.

Conclusions

We validated the trails design for the training of COPD patients by showing that the physiological response to and energy expenditure on unsupervised walking these trails increased according to the predefined trails’ intensity and did not change across trails of the same intensity in different public space. Walkable public spaces allow the design of trails that could be used for the training of COPD patients in the community.

Benefits of physical activity on COPD hospitalisation depend on intensity

The present study aims to disentangle the independent effects of the quantity and the intensity of physical activity on the risk reduction of chronic obstructive pulmonary disease (COPD) hospitalisations.177 patients from the Phenotype Characterization and Course of COPD (PAC-COPD) cohort (mean±sd age 71±8 years, forced expiratory volume in 1 s 52±16% predicted) wore the SenseWear Pro 2 Armband accelerometer (BodyMedia, Pittsburgh, PA, USA) for eight consecutive days, providing data on quantity (steps per day, physically active days and daily active time) and intensity (average metabolic equivalent tasks) of physical activity. Information on COPD hospitalisations during follow-up (2.5±0.8 years) was obtained from validated centralised datasets. During follow-up 67 (38%) patients were hospitalised. There was an interaction between quantity and intensity of physical activity in their effects on COPD hospitalisation risk. After adjusting for potential confounders in the Cox regression model, the risk of COPD hospitalisation was reduced by 20% (hazard ratio (HR) 0.79, 95% CI 0.67-0.93; p=0.005) for every additional 1000 daily steps at low average intensity. A greater quantity of daily steps at high average intensity did not influence the risk of COPD hospitalisations (HR 1.01, p=0.919). Similar results were found for the other measures of quantity of physical activity. Greater quantity of low-intensity physical activity reduces the risk of COPD hospitalisation, but high-intensity physical activity does not produce any risk reduction.

Differential Effect of Modified Medical Research Council Dyspnea, COPD Assessment Test, and Clinical COPD Questionnaire for Symptoms Evaluation Within the New GOLD Staging and Mortality in COPD

OBJECTIVE

The modified Medical Research Council (mMRC) dyspnea, the COPD Assessment Test (CAT), and the Clinical COPD Questionnaire (CCQ) have been interchangeably proposed by GOLD (Global Initiative for Chronic Obstructive Lung Disease) for assessing symptoms in patients with COPD. However, there are no data on the prognostic value of these tools in terms of mortality. We endeavored to evaluate the prognostic value of the CAT and CCQ scores and compare them with mMRC dyspnea.

METHODS

We analyzed the ability of these tests to predict mortality in an observational cohort of 768 patients with COPD (82% men; FEV1, 60%) from the COPD History Assessment in Spain (CHAIN) study, a multicenter observational Spanish cohort, who were monitored annually for a mean follow-up time of 38 months.

RESULTS

Subjects who died (n = 73; 9.5%) had higher CAT (14 vs 11, P = .022), CCQ (1.6 vs 1.3, P = .033), and mMRC dyspnea scores (2 vs 1, P < .001) than survivors. Receiver operating characteristic analysis showed that higher CAT, CCQ, and mMRC dyspnea scores were associated with higher mortality (area under the curve: 0.589, 0.588, and 0.649, respectively). CAT scores ≥ 17 and CCQ scores > 2.5 provided a similar sensitivity than mMRC dyspnea scores ≥ 2 to predict all-cause mortality.

CONCLUSIONS

The CAT and the CCQ have similar ability for predicting all-cause mortality in patients with COPD, but were inferior to mMRC dyspnea scores. We suggest new thresholds for CAT and CCQ scores based on mortality risk that could be useful for the new GOLD grading classification.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01122758; URL: www.clinicaltrials.gov.

Characterisation and prognosis of undiagnosed chronic obstructive pulmonary disease patients at their first hospitalisation

Background

Under-diagnosis of COPD is an important unmet medical need. We investigated the characteristics and prognosis of hospitalised patients with undiagnosed COPD.

Methods

The PAC-COPD cohort included 342 COPD patients hospitalised for the first time for an exacerbation of COPD (2004–2006). Patients were extensively characterised using sociodemographic, clinical and functional variables, and the cohort was followed-up through 2008. We defined “undiagnosed COPD” by the absence of any self-reported respiratory disease and regular use of any pharmacological respiratory treatment.

Results

Undiagnosed COPD was present in 34% of patients. They were younger (mean age 66 vs. 68 years, p = 0.03), reported fewer symptoms (mMRC dyspnoea score, 2.1 vs. 2.6, p < 0.01), and had a better health status (SGRQ total score, 29 vs. 40, p < 0.01), milder airflow limitation (FEV₁% ref., 59% vs. 49%, p < 0.01), and fewer comorbidities (two or more, 40% vs. 56%, p < 0.01) when compared with patients with an established COPD diagnosis. Three months after hospital discharge, 16% of the undiagnosed COPD patients had stopped smoking (vs. 5%, p = 0.019). During follow-up, annual hospitalisation rates were lower in undiagnosed COPD patients (0.14 vs. 0.25, p < 0.01); however, this difference disappeared after adjustment for severity. Mortality was similar in both groups.

Conclusions

Undiagnosed COPD patients have less severe disease and lower risk of re-hospitalisation when compared with hospitalised patients with known COPD.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2466-15-4) contains supplementary material, which is available to authorized users.

[Adult pulmonary Langerhans' cell histiocytosis: approach to the reality of the Spanish population]

BACKGROUND AND OBJECTIVE

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare respiratory disease closely associated with smoking. The aim of the study is to know the reality of PLCH in the Catalonian population.

MATERIAL AND METHODS

We included all patients diagnosed of PLCH in 8 different Catalonian hospitals from April 2011 to December 2012. Epidemiologic, clinical, radiological, functional, diagnostic and therapeutic variables were collected, both at the beginning and at the last visit of the process.

RESULTS

Thirty two patients were included. Overall, patients were middle-aged (38 years), with no gender predominance. Most of them were smokers (71.9%). The main pulmonary function values (forced vital capacity 75.9%, forced expiratory volume in one second 68.9%, diffusing capacity of the lung for carbon monoxide 59.6%) and radiological findings (cysts 89.7%, nodules 60.3%) showed no significant changes during evolution. However, the disease progressed with a worsening lung function in 34.4% of cases. The analysis of the functional outcome (forced vital capacity, forced expiratory volume in one second, and diffusing capacity of the lung for carbon monoxide) did not reveal significant differences according to the persistence or not of smoking (P<0.05).

CONCLUSION

Our patients with PLCH had similar clinical and radiological characteristics to those described in other populations. The results observed regarding the relationship with smoking suggest that there may be other factors beyond smoking, which influence on the evolution of the disease. It therefore seems advisable to design prospective studies to investigate this aspect.

Lifetime occupational exposure to dusts, gases and fumes is associated with bronchitis symptoms and higher diffusion capacity in COPD patients

BACKGROUND

Occupational exposure to dusts, gases and fumes has been associated with reduced FEV1 and sputum production in COPD patients. The effect of occupational exposure on other characteristics of COPD, especially those reflecting emphysema, has not been studied in these patients.

METHODS

We studied 338 patients hospitalized for a first exacerbation of COPD in 9 Spanish hospitals, obtaining full occupational history in a face-to-face interview; job codes were linked to a job exposure matrix for semi-quantitative estimation of exposure to mineral/biological dust, and gases/fumes for each job held. Patients underwent spirometry, diffusing capacity testing and analysis of gases in stable conditions. Quality of life, dyspnea and chronic bronchitis symptoms were determined with a questionnaire interview. A high- resolution CT scan was available in 133 patients.

RESULTS

94% of the patients included were men, with a mean age of 68(8.5) years and a mean FEV1% predicted 52 (16). High exposure to gases or fumes was associated with chronic bronchitis, and exposure to mineral dust and gases/fumes was associated with higher scores for symptom perception in the St. George's questionnaire. No occupational agent was associated with a lower FEV1. High exposure to all occupational agents was associated with better lung diffusion capacity, in long-term quitters. In the subgroup with CT data, patients with emphysema had 18% lower DLCO compared to those without emphysema.

CONCLUSIONS

In our cohort of COPD patients, high exposure to gases or fumes was associated with chronic bronchitis, and high exposure to all occupational agents was consistently associated with better diffusion capacity in long-term quitters.

New GOLD classification: longitudinal data on group assignment

Rationale

Little is known about the longitudinal changes associated with using the 2013 update of the multidimensional GOLD strategy for chronic obstructive pulmonary disease (COPD).

Objective

To determine the COPD patient distribution of the new GOLD proposal and evaluate how this classification changes over one year compared with the previous GOLD staging based on spirometry only.

Methods

We analyzed data from the CHAIN study, a multicenter observational Spanish cohort of COPD patients who are monitored annually. Categories were defined according to the proposed GOLD: FEV₁%, mMRC dyspnea, COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), and exacerbations-hospitalizations. One-year follow-up information was available for all variables except CCQ data.

Results

At baseline, 828 stable COPD patients were evaluated. On the basis of mMRC dyspnea versus CAT, the patients were distributed as follows: 38.2% vs. 27.2% in group A, 17.6% vs. 28.3% in group B, 15.8% vs. 12.9% in group C, and 28.4% vs. 31.6% in group D. Information was available for 526 patients at one year: 64.2% of patients remained in the same group but groups C and D show different degrees of variability. The annual progression by group was mainly associated with one-year changes in CAT scores (RR, 1.138; 95%CI: 1.074-1.206) and BODE index values (RR, 2.012; 95%CI: 1.487-2.722).

Conclusions

In the new GOLD grading classification, the type of tool used to determine the level of symptoms can substantially alter the group assignment. A change in category after one year was associated with longitudinal changes in the CAT and BODE index.

Cured meat consumption increases risk of readmission in COPD patients

Recent studies have shown that a high dietary intake of cured meat increases the risk of chronic obstructive pulmonary disease (COPD) development. However, its potential effects on COPD evolution have not been tested. We aimed to assess the association between dietary intake of cured meat and risk of COPD readmission in COPD patients. 274 COPD patients were recruited during their first COPD admission between 2004 and 2006, provided information on dietary intake of cured meat during the previous 2 yrs, and were followed until December 31, 2007 (median follow-up 2.6 yrs). Associations between cured meat intake and COPD admissions were assessed using parametric regression survival-time models. Mean ± SD age was 68 ± 8 yrs, 93% of patients were male, 42% were current smokers, mean post-bronchodilator forced expiratory volume in 1 s (FEV(1)) was 53 ± 16% predicted, and median cured meat intake was 23 g · day(-1). After adjusting for age, FEV(1), and total caloric intake, high cured meat intake (more than median value) increased the risk of COPD readmission (adjusted HR 2.02, 95% CI 1.31-3.12; p=0.001). High cured meat consumption increases the risk of COPD readmission in COPD patients. The assessment of the effectiveness of healthy diet advice should be considered in the future.

Association between Ω3 and Ω6 fatty acid intakes and serum inflammatory markers in COPD

Dietary intake of polyunsaturated fatty acids, including omega-3 and omega-6, could modulate chronic obstructive pulmonary disease (COPD) persistent inflammation. We aimed to assess the relationship between dietary intake of omega-3 and omega-6 fatty acids and serum inflammatory markers in COPD. A total of 250 clinically stable COPD patients were included. Dietary data of the last 2 years were assessed using a validated food frequency questionnaire (122 items), which provided levels of three omega-3 fatty acids: docosahexaenoic acid, eicosapentaenoic acid and α-linolenic acid (ALA); and two omega-6 fatty acids: linoleic acid and arachidonic acid (AA). Inflammatory markers [C-reactive protein (CRP), interleukin (IL)-6, IL-8 and tumor necrosis factor alpha (TNFα)] were measured in serum. Fatty acids and inflammatory markers were dichotomised according to their median values, and their association was assessed using multivariate logistic regression. Higher intake of ALA (an anti-inflammatory omega-3 fatty acid) was associated with lower TNFα concentrations [adjusted odds ratio (OR)=0.46; P=.049]. Higher AA intake (a proinflammatory omega-6 fatty acid) was related to higher IL-6 (OR=1.96; P=.034) and CRP (OR=1.95; P=.039) concentrations. Therefore, this study provides the first evidence of an association between dietary intake of omega-3 and omega-6 fatty acids and serum inflammatory markers in COPD patients.

Factors affecting the relationship between psychological status and quality of life in COPD patients

BACKGROUND

This study aims to (i) evaluate the association between anxiety and depressive symptoms and health-related quality of life (HRQoL); and (ii) identify the effect modifiers of this relationship in patients with chronic obstructive pulmonary disease (COPD).

METHODS

A total of 337 clinically stable COPD patients answered the St. George's Respiratory Questionnaire (SGRQ) (assessing HRQoL) and the Hospital Anxiety and Depression Scale (HADS). Socio-demographic information, lung function, and other clinical data were collected.

RESULTS

Most patients (93%) were male; they had a mean (SD) age of 68 (9) years and mild to very severe COPD (post-bronchodilator FEV1 52 (16)% predicted). Multivariate analyses showed that anxiety, depression, or both conditions were associated with poor HRQoL (for all SGRQ domains). The association between anxiety and total HRQoL score was 6.7 points higher (indicating a worse HRQoL) in current workers than in retired individuals. Estimates for patients with "both anxiety and depression" were 5.8 points lower in stage I-II than in stage III-IV COPD, and 10.2 points higher in patients with other comorbidities than in those with only COPD.

CONCLUSIONS

This study shows a significant association between anxiety, depression, or both conditions and impaired HRQoL. Clinically relevant factors affecting the magnitude of this association include work status, COPD severity, and the presence of comorbidities.

Mass of intercostal muscles associates with risk of multiple exacerbations in COPD

BACKGROUND

The potential role of decreased respiratory muscle mass, if any, in mediating the susceptibility to exacerbation in COPD patients has not been determined. We hypothesized that a decrease in respiratory muscle mass is associated with increased risk of multiple hospital admissions due to acute exacerbations of the disease.

METHODS

Eligible cases and controls (n=20) were identified from records of our department's pulmonary clinic. Ten subjects diagnosed with COPD (males, 66+/-7yr, Body Mass Index (BMI)=26+/-4kg/m(2)) were identified as fragile patients. Fragility was defined as four or more admissions in the previous year due to severe exacerbations of the disease. Fragile patients were matched with 10 non-fragile controls, defined as COPD patients who had required only one admission due to exacerbation of the disease. Criteria for 1:1 matching included ethnicity, gender, age, BMI, degree of airflow obstruction (i.e., FEV(1)), comorbidity and chronic treatment. Multiple computed tomography (CT) scan slices were obtained to assess area and attenuation coefficients of multiple upper limb, thorax, abdomen and lower limb muscles.

RESULTS

CSA of intercostal and abdominal muscles was significantly decreased in fragile COPD patients (right side intercostals, mean relative difference (MRD)=-14%, p=0.010; OR (95% CI)=2.2 (1.1-4.8), p=0.021; left side, MRD=-13%, p=0.007; OR=2.2 (1.1-4.5), p=0.027). CSA and attenuation coefficients of all other muscle compartments showed no statistical differences between the two study groups but showed the same trend. Strength of the inspiratory and expiratory muscles did not differ between the two study groups.

CONCLUSIONS

This study shows that the risk for multiple admissions due to a COPD exacerbation associates with a marked decrease in the CSA of the intercostal muscle compartment.

Characteristics of patients admitted for the first time for COPD exacerbation

BACKGROUND

This study describes the characteristics of a large sample of patients hospitalised for the first time for a chronic obstructive pulmonary disease (COPD) exacerbation.

METHODS

All subjects first admitted for a COPD exacerbation to nine teaching Spanish hospitals during January 2004-March 2006, were eligible. COPD diagnosis was confirmed by spirometry under stability. At admission, sociodemographic data, lifestyle, previous treatment and diagnosis of respiratory disease, lung function and Charlson index of co-morbidity were collected. A comprehensive assessment, including dyspnea, lung function, six-minute walking test, and St. George's Respiratory Questionnaire (SGRQ), was completed 3 months after admission, during a clinically stable disease period.

RESULTS

Three-hundred and forty-two patients (57% of the eligible) participated in the study: 93% males, mean (SD) age 68 (9) years, 42% current smokers, 50% two or more co-morbidities, 54% mild-to-moderate dyspnea, post-bronchodilator FEV(1) 52 (16)% of predicted (54% mild-to-moderate COPD in ATS/ERS stages), 6-min walking distance 440 m, total SGRQ score 37 (18), and 36% not report respiratory disease. The absence of a previous COPD diagnosis, positive bronchodilator test, female gender, older age, higher DLco and higher BMI were independently associated with less severe COPD.

CONCLUSIONS

We show that the patients admitted after presenting with their first COPD exacerbation have a wide range of severity, with a large proportion of patients in the less advanced COPD stages.

[Prevalence of obstructive sleep apnea syndrome in patients with sick sinus syndrome]

INTRODUCTION AND OBJECTIVES

Sleep apnea-hypopnea syndrome (SAHS) has been associated with different cardiovascular diseases. It may even be implicated in the pathophysiology of sick sinus syndrome (SSS). However, the precise relationship between the two syndromes is still unknown. We investigated the prevalence of SAHS in patients diagnosed with SSS.

PATIENTS AND METHOD

Between June 2002 and December 2004, 38 consecutive patients who were diagnosed with SSS by 24-hour Holter monitoring were studied prospectively in our institution. All patients were asked about symptoms of SAHS, and underwent polysomnography out of hospital using a validated monitor.

RESULTS

The patients' mean age was 67 (10) years, 68% were male, and 58% were hypertensive. Holter monitoring demonstrated a maximum heart rate of 87 (6) beats/min, a minimum of 35 (3) beats/min, and a mean of 48 (3) beats/min. Some 24 (63%) patients required pacemaker implantation because of symptomatic SSS. Overall, 39% of patients had symptoms suggestive of SAHS (i.e., an Epworth index or EI>9). Polysomnography showed that only 13% of patients had a normal apnea-hypopnea index (AHI) and that 31.6% (95% CI, 16.8%-46.4%) had SAHS (i.e., AIH>10 and EI>9).

CONCLUSIONS

Given that the prevalence of SAHS in the general population is around 3%, our results indicate that it is ten-fold higher in patients with SSS than in the general population. This observation indicates that there may be a relationship between the two syndromes.

[Fiber-optic bronchoscopic biopsy of bronchial smooth muscle. Efficacy of the technique in individuals with normal lung function and patients with COPD]

BACKGROUND AND OBJECTIVES

The epithelium and airway smooth muscles of patients with chronic obstructive pulmonary disease (COPD) or bronchial asthma undergo certain structural changes that are probably related to increased expression of inflammatory molecules and cell growth factors. Studying the relation between disease and changes in bronchial smooth muscle is difficult if investigation is restricted to samples from autopsies or thoracotomies. This study was designed to evaluate the probability of obtaining bronchial smooth muscle by endoscopic bronchial biopsy in patients with COPD and from individuals with normal lung function, the relation of disease to bronchial epithelial histology, and the potential usefulness of studying airway muscle remodeling events.

METHODS

Forty-two patients undergoing diagnostic fiberoptic bronchoscopy were enrolled. Bronchial biopsies were taken systematically from the lobar and segmental dividing ridges. The epithelial structure was analyzed by conventional histology. The smooth muscle was identified by immunohistochemistry (anti-desmin antibody assay) and Western-blot analysis (anti-desmin, actin and myosin antibodies).

RESULTS

Sixty-nine percent of the biopsies contained bronchial smooth muscle. The probability of obtaining smooth muscle was higher in segmental than in lobar biopsies (72 vs 30%, p < 0.05). This probability was unrelated to the presence of COPD or to signs of epithelial inflammation. The fragments allowed us to use electrophoresis to identify protein structures (myosin, actin, desmin) involved in muscle remodeling processes.

CONCLUSIONS

Endoscopic biopsy of the bronchi allows us to obtain bronchial smooth muscle samples in a large percentage of patients, particularly when performed on segmental bronchi. The technique may be useful for future studies examining the processes of airway smooth muscle remodeling.

Influence of deficient alpha1-anti-trypsin phenotypes on clinical characteristics and severity of asthma in adults

Severe alpha1-anti-trypsin (AAT) deficiency implies a high risk of pulmonary emphysema development. The possible relationship between partial deficiencies of this enzyme and bronchial asthma remains controversial. The objective of this study was to ascertain the distribution of AAT phenotypes in a non-selected asthmatic patient population. Across-sectional study on a sample of 111 patients with asthma was carried out. Demographic and clinical variables were collected with serum IgE concentrations, plasma eosinophil number and serum AAT concentrations determined, together with the Pi phenotype. Asthma was mild in 36 (32.4%) patients, moderate in 45 (40.5%) and severe in 30 (27%). No differences were observed in eosinophil count or serum IgE or AAT concentrations among patients with different degrees of severity. Twenty-two (19.8%) asthmatics with deficient phenotypes for AAT were identified, distributed equally in all severity stages of the disease. No significant differences were found in clinical and functional characteristics, or in asthma morbidity between PiMM and PiMS patients or the heterozygote group (PiMS and PiMZ). Eosinophil count and IgE concentrations did not differ significantly between asthmatics with normal phenotype and heterozygotes. In conclusion, the distribution of AAT phenotypes in asthmatic patients did not differ from that found in the general population. Heterozygote phenotypes for the deficiency do not appear to confer greater severity or different clinical expression of asthma in adults.