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1.  Exome Array Analysis Identifies a Common Variant in IL27 Associated with Chronic Obstructive Pulmonary Disease 
Rationale: Chronic obstructive pulmonary disease (COPD) susceptibility is in part related to genetic variants. Most genetic studies have been focused on genome-wide common variants without a specific focus on coding variants, but common and rare coding variants may also affect COPD susceptibility.
Objectives: To identify coding variants associated with COPD.
Methods: We tested nonsynonymous, splice, and stop variants derived from the Illumina HumanExome array for association with COPD in five study populations enriched for COPD. We evaluated single variants with a minor allele frequency greater than 0.5% using logistic regression. Results were combined using a fixed effects meta-analysis. We replicated novel single-variant associations in three additional COPD cohorts.
Measurements and Main Results: We included 6,004 control subjects and 6,161 COPD cases across five cohorts for analysis. Our top result was rs16969968 (P = 1.7 × 10−14) in CHRNA5, a locus previously associated with COPD susceptibility and nicotine dependence. Additional top results were found in AGER, MMP3, and SERPINA1. A nonsynonymous variant, rs181206, in IL27 (P = 4.7 × 10−6) was just below the level of exome-wide significance but attained exome-wide significance (P = 5.7 × 10−8) when combined with results from other cohorts. Gene expression datasets revealed an association of rs181206 and the surrounding locus with expression of multiple genes; several were differentially expressed in COPD lung tissue, including TUFM.
Conclusions: In an exome array analysis of COPD, we identified nonsynonymous variants at previously described loci and a novel exome-wide significant variant in IL27. This variant is at a locus previously described in genome-wide associations with diabetes, inflammatory bowel disease, and obesity and appears to affect genes potentially related to COPD pathogenesis.
doi:10.1164/rccm.201510-2053OC
PMCID: PMC4960630  PMID: 26771213
chronic obstructive pulmonary disease; genetics; exome; IL-27
2.  Identification of Barriers to Influenza Vaccination in Patients with Chronic Obstructive Pulmonary Disease: Analysis of the 2012 Behavioral Risk Factors Surveillance System 
Introduction
Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for influenza-related morbidity and mortality. Influenza vaccination is known to decrease influenza incidence, severity, hospitalizations, and mortality. Identification of barriers to influenza vaccination among patients with COPD may aid in efforts to increase vaccination rates. This study aims to identify predictors of influenza vaccination in COPD patients.
Methods
This study used data from the 2012 Behavioral Risk Factor Surveillance System (BRFSS). Participants with self-reported COPD and receiving an influenza vaccination in the prior 12 months were identified. Independent predictors of the exposure were identified by estimating a parsimonious logistic regression model of influenza vaccination. All analyses were performed using weighted data.
Results
The final study sample consisted of 36,811 COPD participants, with 48.5% of COPD patients reporting having been vaccinated and 51.5% reporting being unvaccinated. A total of 15 independent predictors of influenza vaccination in COPD patients were identified. Negative predictors included predisposing factors (younger age, male gender, household children, black or non-white/non-Hispanic/non-black race/ethnicity, lower education level, heavy alcohol use, current tobacco use) and enabling factors that reflect access to medical care (insurance status, ability to afford care, having a recent check-up). Positive predictors of influenza vaccination included need factors (chronic comorbidities), being a military veteran, or being a former smoker.
Conclusions
This analysis identifies multiple predictors of influenza vaccination in persons with COPD. Identification of at risk-groups provides the foundation for development of focused efforts to improve influenza vaccination rates in patients with COPD.
doi:10.15326/jcopdf.3.3.2015.0156
PMCID: PMC5154688  PMID: 27981230
chronic obstructive pulmonary disease; COPD; influenza; vaccination; prevention
3.  Plasma Cathepsin S and Cathepsin S/Cystatin C Ratios Are Potential Biomarkers for COPD 
Disease Markers  2016;2016:4093870.
Purpose. This study aimed to examine whether plasma levels of cathepsin S or its inhibitor, cystatin C, may serve as biomarkers for COPD. Patients and Methods. We measured anthropometrics and performed pulmonary function tests and chest CT scans on 94 patients with COPD and 31 subjects with productive cough but no airflow obstruction (“at risk”; AR). In these subjects and in 52 healthy nonsmokers (NS) and 66 healthy smokers (HS) we measured plasma concentrations of cathepsin S and cystatin C using an ELISA. Data were analyzed using simple and logistic regression and receiver operating characteristic analyses. Results. Cathepsin S and cystatin C plasma levels were significantly higher in the COPD and AR groups than in the NS and HS groups (p < 0.01). Among the COPD patients and AR subjects, plasma cathepsin S levels and cathepsin S/cystatin C ratios, but not cystatin C levels, were negatively related to severe airflow limitation (% FEV1 predicted < 50%; p = 0.005) and severe emphysema as assessed by low attenuation area (LAA) score on chest CT scans (LAA ≥ 8.0; p = 0.001). Conclusion. Plasma cathepsin S and cathepsin S/cystatin C ratios may serve as potential biomarkers for COPD.
doi:10.1155/2016/4093870
PMCID: PMC5138488  PMID: 27994288
4.  Spirometric variability in smokers: transitions in COPD diagnosis in a five-year longitudinal study 
Respiratory Research  2016;17:147.
Background
Spirometrically-defined chronic obstructive pulmonary disease (COPD) is considered progressive but its natural history is inadequately studied. We hypothesized that spirometrically-defined COPD states could undergo beneficial transitions.
Methods
Participants in the Lovelace Smokers’ Cohort (n = 1553), primarily women, were longitudinally studied over 5 years. Spirometric states included normal postbronchodilator spirometry, COPD Stage I, Unclassified state, and COPD Stage II+, as defined by GOLD guidelines. Beneficial transitions included either a decrease in disease severity, including resolution of spirometric abnormality, or maintenance of non-diseased state. ‘All smokers’ (n = 1553) and subgroups with normal and abnormal spirometry at baseline (n = 956 and 597 respectively) were separately analyzed. Markov-like model of transition probabilities over an average follow-up period of 5 years were calculated.
Results
Among ‘all smokers’, COPD Stage I, Unclassified, and COPD Stage II+ states were associated with probabilities of 16, 39, and 22 % respectively for beneficial transitions, and of 16, 35, and 4 % respectively for resolution. Beneficial transitions were more common for new-onset disease than for pre-existing disease (p < 0.001). Beneficial transitions were less common among older smokers, men, or those with bronchial hyperresponsiveness but more common among Hispanics and smokers with excess weight.
Conclusions
This observational study of ever smokers, shows that spirometrically-defined COPD states, may not be uniformly progressive and can improve or resolve over time. The implication of these findings is that the spirometric diagnosis of COPD can be unstable. Furthermore, COPD may have a pre-disease state when interventions might help reverse or change its natural history.
Trial registration
NA.
Electronic supplementary material
The online version of this article (doi:10.1186/s12931-016-0468-7) contains supplementary material, which is available to authorized users.
doi:10.1186/s12931-016-0468-7
PMCID: PMC5105293  PMID: 27832774
5.  B Cell–Activating Factor. An Orchestrator of Lymphoid Follicles in Severe Chronic Obstructive Pulmonary Disease 
Rationale: Patients with chronic obstructive pulmonary disease (COPD) have increased pulmonary lymphoid follicle (LF) counts. B cell–activating factor of tumor necrosis factor family (BAFF) regulates B cells in health, but its role in COPD pathogenesis is unclear.
Objectives: To determine whether BAFF expression in pulmonary LFs correlates with COPD severity, LF size or number, and/or readouts of B-cell function in LFs.
Methods: We correlated BAFF immunostaining in LFs in lung explants or biopsies from nonsmoking control subjects (NSC), smokers without COPD (SC), and patients with COPD with the number and size of LFs, and LF B-cell apoptosis, activation, and proliferation. We analyzed serum BAFF levels and BAFF expression in B cells in blood and bronchoalveolar lavage samples from the same subject groups. We assessed whether: (1) cigarette smoke extract (CSE) increases B-cell BAFF expression and (2) recombinant BAFF (rBAFF) rescues B cells from CSE-induced apoptosis by inhibiting activation of nuclear factor-κB (NF-κB).
Measurements and Main Results: Patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage IV COPD had increased numbers and larger pulmonary LFs than patients with GOLD stages I–II COPD and SC. We identified two main types of pulmonary LFs: (1) type A, the predominant type in GOLD stages I–II COPD and SC, characterized by abundant apoptotic but few BAFF-positive cells (mostly B cells); and (2) type B, the main type in GOLD stage IV COPD, characterized by abundant BAFF-positive cells but few apoptotic cells (mostly B cells). BAFF levels were also higher in blood and bronchoalveolar lavage B cells in patients with COPD versus NSC and SC. Surprisingly, rBAFF blocked CSE-induced B-cell apoptosis by inhibiting CSE-induced NF-κB activation.
Conclusions: Our data support the hypothesis that B-cell BAFF expression creates a self-perpetuating loop contributing to COPD progression by promoting pulmonary B-cell survival and LF expansion.
doi:10.1164/rccm.201501-0107OC
PMCID: PMC4595676  PMID: 26073875
cigarette smoke; chronic obstructive pulmonary disease; B cell–activating factor of tumor necrosis factor family; autoimmunity; lymphoid follicles
7.  A Protective Role For Club Cell Secretory Protein-16 (CC16) In The Development of Chronic Obstructive Pulmonary Disease (COPD) 
The European respiratory journal  2015;45(6):1544-1556.
Rationale
Club cell secretory protein-16 (CC16) is the major secreted product of airway Club cells, but its role in the pathogenesis of COPD is unclear. We measured CC16 airway expression in humans with and without COPD and CC16 function in a cigarette smoke (CS)-induced COPD mice model.
Methods
Airway CC16 expression was measured in COPD patients, smokers without COPD, and non-smokers. We exposed wild-type (WT) and CC16-/- mice to CS or air for up to 6 months, and measured airway CC16 expression, pulmonary inflammation, alveolar septal cell apoptosis, airspace enlargement, airway MUC5AC expression, small airway remodeling, and pulmonary function.
Results
Smokers and COPD patients had reduced airway CC16 immunostaining that decreased with increasing COPD severity. Exposing mice to CS reduced airway CC16 expression. CC16-/- mice had greater CS-induced emphysema, airway remodeling, pulmonary inflammation, alveolar cell apoptosis, airway MUC5AC expression, and more compliant lungs than WT mice. These changes were associated with increased nuclear factor-κB (NFκB) activation in CC16-/- lungs. CS-induced acute pulmonary changes were reversed by adenoviral-mediated over-expression of CC16.
Conclusions
CC16 protects lungs from CS-induced injury by reducing lung NFκB activation. CS-induced airway CC16 deficiency increases CS-induced pulmonary inflammation and injury and likely contributes to the pathogenesis of COPD.
doi:10.1183/09031936.00134214
PMCID: PMC4451404  PMID: 25700379
Chronic obstructive pulmonary disease; pulmonary inflammation; mucus; apoptosis; Club cells
8.  Is COPD a Progressive Disease? A Long Term Bode Cohort Observation 
PLoS ONE  2016;11(4):e0151856.
Background
The Global Initiative for Obstructive Lung Diseases (GOLD) defines COPD as a disease that is usually progressive. GOLD also provides a spirometric classification of airflow limitation. However, little is known about the long-term changes of patients in different GOLD grades.
Objective
Explore the proportion and characteristics of COPD patients that change their spirometric GOLD grade over long-term follow-up.
Methods
Patients alive for at least 8 years since recruitment and those who died with at least 4 years of repeated spirometric measurements were selected from the BODE cohort database. We purposely included the group of non survivors to avoid a “survival selection” bias. The proportion of patients that had a change (improvement or worsening) in their spirometric GOLD grading was calculated and their characteristics compared with those that remained in the same grade.
Results
A total of 318 patients were included in the survivor and 217 in the non-survivor groups. Nine percent of survivors and 11% of non survivors had an improvement of at least one GOLD grade. Seventy one percent of survivors and non-survivors remained in the same GOLD grade. Those that improved had a greater degree of airway obstruction at baseline.
Conclusions
In this selected population of COPD patients, a high proportion of patients remained in the same spirometric GOLD grade or improved in a long-term follow-up. These findings suggest that once diagnosed, COPD is usually a non-progressive disease.
doi:10.1371/journal.pone.0151856
PMCID: PMC4839642  PMID: 27100872
9.  Association Between Interstitial Lung Abnormalities and All-Cause Mortality 
JAMA  2016;315(7):672-681.
IMPORTANCE
Interstitial lung abnormalities have been associated with decreased six-minute walk distance, diffusion capacity for carbon monoxide and total lung capacity; however to our knowledge, an association with mortality has not been previously investigated.
OBJECTIVE
To investigate whether interstitial lung abnormalities are associated with increased mortality.
DESIGN, SETTING, POPULATION
Prospective cohort studies of 2633 participants from the Framingham Heart Study (FHS) (CT scans obtained 9/08–3/11), 5320 from the Age Gene/Environment Susceptibility (AGES)-Reykjavik (recruited 1/02–2/06), 2068 from COPDGene (recruited 11/07–4/10), and 1670 from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) (between 12/05–12/06).
EXPOSURES
Interstitial lung abnormality status as determined by chest CT evaluation.
MAIN OUTCOMES AND MEASURES
All cause mortality over approximately 3 to 9 year median follow up time. Cause-of-death information was also examined in the AGES-Reykjavik cohort.
RESULTS
Interstitial lung abnormalities were present in 177 (7%) of the participants from FHS, 378 (7%) from AGES-Reykjavik, 156 (8%) from COPDGene, and in 157 (9%) from ECLIPSE. Over median follow-up times of ~3–9 years there were more deaths (and a greater absolute rate of mortality) among those with interstitial lung abnormalities compared to those without interstitial lung abnormalities in each cohort; 7% compared to 1% in FHS (6% difference, 95% confidence interval [CI] 2%, 10%), 56% compared to 33% in AGES-Reykjavik (23% difference, 95% CI 18%, 28%), 16% compared to 11% in COPDGene (5% difference, 95% CI −1%, 11%) and 11% compared to 5% in ECLIPSE (6% difference, 95% CI 1%, 11%). After adjustment for covariates, interstitial lung abnormalities were associated with an increase in the risk of death in the FHS (HR=2.7, 95% CI, 1.1–65, P=0.030), AGES-Reykjavik (HR 1.3, 95% CI 1.2–1.4, P<0.001), COPDGene (HR=1.8, 95% CI, 1.1, 2.8, P=0.014), and ECLIPSE (HR=1.4, 95% CI, 1.1–2, P=0.022) cohorts. In the AGES-Reykjavik cohort the higher rate of mortality could be explained by a higher rate of death due to respiratory disease, specifically pulmonary fibrosis.
CONCLUSIONS AND RELEVANCE
In four separate research cohorts, interstitial lung abnormalities were associated with a higher risk of all-cause mortality. The clinical implications of this association require further investigation.
doi:10.1001/jama.2016.0518
PMCID: PMC4828973  PMID: 26881370
Idiopathic pulmonary fibrosis; interstitial lung disease; interstitial lung abnormalities (ILA); undiagnosed; subclinical
10.  Increased expression of A Proliferation-inducing Ligand (APRIL) in lung leukocytes and alveolar epithelial cells in COPD patients with non small cell lung cancer: a possible link between COPD and lung cancer? 
Background
Chronic Obstructive Pulmonary Disease (COPD) is characterized by an excessive activation of the adaptive immune system and, in particular, uncontrolled expansion of the B-cell pool. One of the key promoters of B cell expansion is A PRoliferation-Inducing Ligand (APRIL). APRIL has been strongly linked to non small cell lung cancer (NSCLC) onset and progression previously. However, little is known about the expression of APRIL in the lungs of COPD patients.
Methods
Using immuno-fluorescence staining, the expression of APRIL was assessed in sections of lungs from 4 subjects with primary diagnosis of COPD (FEV1 33 ± 20 % predicted), 4 subjects with primary diagnosis of NSCLC, 4 subjects diagnosed with both COPD and NSCLC, smokers without COPD or NSCLC and 3 healthy never-smokers. The percentage of B cells, alveolar macrophages (AMs) and polymorphonuclear neutrophils (PMNs) in the lung and alveolar epithelial cells (AECs) that stained positively for APRIL was quantified using epi-fluorescence microscopy and image analysis software.
Results
The percentage of APRIL-expressing B cells, AMs, PMNs and alveolar epithelial cells (AECs) was higher in patients having both COPD and NSCLC than in patients with either COPD or NSCLC alone, SC or NSC (p < 0.03 for all comparisons). The percentage of APRIL-expressing AMs and AECs (but not in B cells) was higher in patients with NSCLC alone than in patients with COPD alone. The percentage of APRIL-expressing AECs (but not B cells or AMs) was higher in COPD patients than in SC and NSC (p < 0.05 for all comparisons). The percentage of APRIL-expressing B cells, AMs and AECs cells was similar in NSC and SC.
Conclusion
The percentage of APRIL-expressing B cells, AMs and AECs is higher in the lungs of patients with both COPD and NSCLC than in patients with COPD or NSCLC alone or control subjects. These findings suggest that APRIL may contribute to the pathogenesis of both COPD and NSCLC, and possibly to the development of NSCLC in patients with established COPD.
doi:10.1186/s40248-016-0051-6
PMCID: PMC4819280  PMID: 27047662
Adaptive immunity; APRIL; Autoimmunity; COPD; Innate immunity; Non small cell lung cancer
11.  The BODECOST Index (BCI): a composite index for assessing the impact of COPD in real life 
Background
Chronic Obstructive Pulmonary Disease (COPD) is a progressive condition which is characterized by a dramatic socio-economic impact.
Several indices were extensively investigated in order to asses the mortality risk in COPD, but the utilization of health care resources was never included in calculations. The aim of this study was to assess the predictive value of annual cost of care on COPD mortality at three years, and to develop a comprehensive index for easy calculation of mortality risk in real life.
Methods
COPD patients were anonymously and automatically selected from the local institutional Data Base. Selection criteria were: COPD diagnosis; both genders; age ≥ 40 years; availability of at least one complete clinical record/year, including history; clinical signs; complete lung function, therapeutic strategy, health BODE index; Charlson Comorbidity Index, and outcomes, collected at the first visit, and over the following 3-years. At the first visit, the health annual cost of care was calculated in each patient for the previous 12 months, and the survival rate was also measured over the following 3 years. The hospitalization and the exacerbation rate were implemented to the BODE index and the novel index thus obtained was called BODECOST index (BCI), ranging from 0 to 10 points. The mean cost for each BCI step was calculated and then compared to the corresponding patients’ survival duration.
Parametrical, non parametrical tests, and linear regression were used; p < 0.05 was accepted as the lower limit of significance.
Results
At the first visit, the selected 275 patients were well matched for all variables by gender. The overall mortality over the 3 year survey was 40.4 % (n = 111/275). When compared to that of BODE index (r = 0.22), the total annual cost of care and the number of exacerbations showed the highest regression value vs the survival time (r = 0.58 and r = 0.44, respectively). BCI score proved strictly proportional to both the cost of care and the survival time in our sample of COPD patients.
Discussion
BCI takes origin from the implementation of the BODE index with the two main components of the annual cost of care, such as the number of hospitalizations and of exacerbations occurring yearly in COPD patients, and their corresponding economic impact. In other words, higher the BCI score, shorter the survival and higher the cost, these trends being strictly linked.
Conclusions
BCI is a novel composite index which helps in predicting the impact of COPD at 3 years in real life, both in terms of patients’ survival and of COPD economic burden.
doi:10.1186/s40248-016-0045-4
PMCID: PMC4776418  PMID: 26941954
BODE index; BODECOST index; COPD; COPD impact; Cost-of-illness; Mortality prediction
12.  Lung Cancer in Patients with Chronic Obstructive Pulmonary Disease. Development and Validation of the COPD Lung Cancer Screening Score 
Rationale: Patients with chronic obstructive pulmonary disease (COPD) are at high risk for lung cancer (LC) and represent a potential target to improve the diagnostic yield of screening programs.
Objectives: To develop a predictive score for LC risk for patients with COPD.
Methods: The Pamplona International Early Lung Cancer Detection Program (P-IELCAP) and the Pittsburgh Lung Screening Study (PLuSS) databases were analyzed. Only patients with COPD on spirometry were included. By logistic regression we determined which factors were independently associated with LC in PLuSS and developed a COPD LC screening score (COPD-LUCSS) to be validated in P-IELCAP.
Measurements and Main Results: By regression analysis, age greater than 60, body mass index less than 25 kg/m2, pack-years history greater than 60, and emphysema presence were independently associated with LC diagnosis and integrated into the COPD-LUCSS, which ranges from 0 to 10 points. Two COPD-LUCSS risk categories were proposed: low risk (scores 0–6) and high risk (scores 7–10). In comparison with low-risk patients, in both cohorts LC risk increased 3.5-fold in the high-risk category.
Conclusions: The COPD-LUCSS is a good predictor of LC risk in patients with COPD participating in LC screening programs. Validation in two different populations adds strength to the findings.
doi:10.1164/rccm.201407-1210OC
PMCID: PMC4351574  PMID: 25522175
COPD; screening; lung cancer
13.  Mortality and drug therapy in patients with chronic obstructive pulmonary disease: a network meta-analysis 
BMC Pulmonary Medicine  2015;15:145.
Background
Increasing evidence suggests pharmacological treatments may impact on overall survival in Chronic Obstructive Pulmonary Disease (COPD) patients. Individual clinical trials are rarely powered to detect mortality differences between treatments and may not include all treatment options relevant to healthcare decision makers.
Methods
A systematic review was conducted to identify RCTs of COPD treatments reporting mortality; evidence was synthesised using network meta-analysis (NMA). The analysis included 40 RCTs; a quantitative indirect comparison between 14 treatments using data from 55,220 patients was conducted.
Results
The analysis reported two treatments reducing all-cause mortality; salmeterol/fluticasone propionate combination (SFC) was associated with a reduction in mortality versus placebo in the fixed effects (HR 0.79; 95 % Crl 0.67, 0.94) but not the random effects model (0.79; 0.56, 1.09). Indacaterol was associated with a reduction in mortality versus placebo in fixed (0.28; 0.08 to 0.85) and random effects (0.29; 0.08, 0.89) models. Mean estimates and credible intervals for hazard ratios for indacaterol versus placebo are based on a small number of events; estimates may change when the results of future studies are included. These results were maintained across a variety of assumptions and provide evidence that SFC and indacaterol may lead to improved survival in COPD patients.
Conclusion
Results of an NMA of COPD treatments suggest that SFC and indacaterol may reduce mortality. Further research is warranted to strengthen this conclusion.
Electronic supplementary material
The online version of this article (doi:10.1186/s12890-015-0138-4) contains supplementary material, which is available to authorized users.
doi:10.1186/s12890-015-0138-4
PMCID: PMC4642642  PMID: 26559138
COPD; COPD treatment; Systematic review; Meta-analysis; Mortality
14.  Quantitative Computed Tomography Measures of Pectoralis Muscle Area and Disease Severity in Chronic Obstructive Pulmonary Disease. A Cross-Sectional Study 
Rationale: Muscle wasting in chronic obstructive pulmonary disease (COPD) is associated with a poor prognosis and is not readily assessed by measures of body mass index (BMI). BMI does not discriminate between relative proportions of adipose tissue and lean muscle and may be insensitive to early pathologic changes in body composition. Computed tomography (CT)–based assessments of the pectoralis muscles may provide insight into the clinical significance of skeletal muscles in smokers.
Objectives: We hypothesized that objective assessment of the pectoralis muscle area on chest CT scans provides information that is clinically relevant and independent of BMI.
Methods: Data from the ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) Study (n = 73) were used to assess the relationship between pectoralis muscle area and fat-free mass. We then used data in a subset (n = 966) of a larger cohort, the COPDGene (COPD Genetic Epidemiology) Study, to explore the relationship between pectoralis muscle area and COPD-related traits.
Measurements and Main Results: We first investigated the correlation between pectoralis muscle area and fat-free mass, using data from a subset of participants in the ECLIPSE Study. We then further investigated pectoralis muscle area in COPDGene Study participants and found that higher pectoralis muscle area values were associated with greater height, male sex, and younger age. On subsequent clinical correlation, compared with BMI, pectoralis muscle area was more significantly associated with COPD-related traits, including spirometric measures, dyspnea, and 6-minute-walk distance (6MWD). For example, on average, each 10-cm2 increase in pectoralis muscle area was associated with a 0.8-unit decrease in the BODE (Body mass index, Obstruction, Dyspnea, Exercise) index (95% confidence interval, –1.0 to –0.6; P < 0.001). Furthermore, statistically significant associations between pectoralis muscle area and COPD-related traits remained even after adjustment for BMI.
Conclusions: CT-derived pectoralis muscle area provides relevant indices of COPD morbidity that may be more predictive of important COPD-related traits than BMI. However, the relationship with clinically relevant outcomes such as hospitalization and death requires additional investigation. Pectoralis muscle area is a convenient measure that can be collected in the clinical setting in addition to BMI.
doi:10.1513/AnnalsATS.201307-229OC
PMCID: PMC4028743  PMID: 24558953
COPD; wasting; pectoral muscle area; imaging
15.  Recommendations for the early diagnosis of COPD: the AIMAR view 
doi:10.1186/s40248-015-0005-4
PMCID: PMC4344749  PMID: 25729573
16.  Finding the Best Thresholds of FEV1 and Dyspnea to Predict 5-Year Survival in COPD Patients: The COCOMICS Study 
PLoS ONE  2014;9(2):e89866.
Background
FEV1 is universally used as a measure of severity in COPD. Current thresholds are based on expert opinion and not on evidence.
Objectives
We aimed to identify the best FEV1 (% predicted) and dyspnea (mMRC) thresholds to predict 5-yr survival in COPD patients.
Design and Methods
We conducted a patient-based pooled analysis of eleven COPD Spanish cohorts (COCOMICS). Survival analysis, ROC curves, and C-statistics were used to identify and compare the best FEV1 (%) and mMRC scale thresholds that predict 5-yr survival.
Results
A total of 3,633 patients (93% men), totaling 15,878 person-yrs. were included, with a mean age 66.4±9.7, and predicted FEV1 of 53.8% (±19.4%). Overall 975 (28.1%) patients died at 5 years. The best thresholds that spirometrically split the COPD population were: mild ≥70%, moderate 56–69%, severe 36–55%, and very severe ≤35%. Survival at 5 years was 0.89 for patients with FEV1≥70 vs. 0.46 in patients with FEV1 ≤35% (H.R: 6; 95% C.I.: 4.69–7.74). The new classification predicts mortality significantly better than dyspnea (mMRC) or FEV1 GOLD and BODE cutoffs (all p<0.001). Prognostic reliability is maintained at 1, 3, 5, and 10 years. In younger patients, survival was similar for FEV1 (%) values between 70% and 100%, whereas in the elderly the relationship between FEV1 (%) and mortality was inversely linear.
Conclusions
The best thresholds for 5-yr survival were obtained stratifying FEV1 (%) by ≥70%, 56–69%, 36–55%, and ≤35%. These cutoffs significantly better predict mortality than mMRC or FEV1 (%) GOLD and BODE cutoffs.
doi:10.1371/journal.pone.0089866
PMCID: PMC3937394  PMID: 24587085
17.  Reliability of FEV1/FEV6 to Diagnose Airflow Obstruction Compared with FEV1/FVC: The PLATINO Longitudinal Study 
PLoS ONE  2013;8(8):e67960.
QUESTION
A 6-second spirometry test is easier than full exhalations. We compared the reliability of the ratio of the Forced expiratory volume in 1 second/Forced expiratory volume in 6 seconds (FEV1/FEV6) to the ratio of the FEV1/Forced vital capacity (FEV1/FVC) for the detection of airway obstruction.
METHODS
The PLATINO population-based survey in individuals aged 40 years and over designed to estimate the prevalence of post-Bronchodilator airway obstruction repeated for the same study participants after 5–9 years in three Latin-American cities.
RESULTS
Using the FEV1/FVC
CONCLUSION
The FEV1/FEV6 is a more reliable index than FEV1/FVC because FVC varies with the duration of the forced exhalation. Reporting FET and FEV1/FEV6
doi:10.1371/journal.pone.0067960
PMCID: PMC3731337  PMID: 23936297
PLoS ONE  2013;8(6):e65593.
Rationale
Epicardial Adipose Tissue (EAT) volume as determined by chest computed tomography (CT) is an independent marker of cardiovascular events in the general population. COPD patients have an increased risk of cardiovascular disease, however nothing is known about the EAT volume in this population.
Objectives
To assess EAT volume in COPD and explore its association with clinical and physiological variables of disease severity.
Methods
We measured EAT using low-dose CT in 171 stable COPD patients and 70 controls matched by age, smoking history and BMI. We determined blood pressure, cholesterol, glucose and HbA1c levels, microalbuminuria, lung function, BODE index, co-morbidity index and coronary artery calcium score (CAC). EAT volume were compared between groups. Uni and multivariate analyses explored the relationship between EAT volume and the COPD related variables.
Results
COPD patients had a higher EAT volume [143.7 (P25–75, 108.3–196.6) vs 129.1 (P25–75, 91.3–170.8) cm3, p = 0.02)] and the EAT volume was significantly associated with CAC (r = 0.38, p<0.001) and CRP (r = 0.32, p<0.001) but not with microalbuminuria (r = 0.12, p = 0.13). In COPD patients, EAT volume was associated with: age, pack-years, BMI, gender, FEV1%, 6 MWD, MMRC and HTN. Multivariate analysis showed that only pack-years (B = 0.6, 95% CI: 0.5–1.3), BMI (B = 7.8, 95% CI: 5.7–9.9) and 6 MWD (B = −0.2, 95% CI: −0.3–−0.1), predicted EAT volume.
Conclusions
EAT volume is increased in COPD patients and is independently associated with smoking history, BMI and exercise capacity, all modifiable risk factors of future cardiovascular events. EAT volume could be a non-invasive marker of COPD patients at high risk for future cardiovascular events.
doi:10.1371/journal.pone.0065593
PMCID: PMC3675061  PMID: 23762399
F1000Research  2013;2:114.
Purpose: The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD). Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9), vascular endothelial growth factor A (VEGF-A) and interleukin 6 (IL-6) in arterial compared with venous blood. 
Methods: Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. Results were compared using a Student’s paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples.  
Results: In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6. 
Conclusions: In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose.
doi:10.12688/f1000research.2-114.v1
PMCID: PMC3894801  PMID: 24555057
Rationale: The relationship between interstitial lung abnormalities (ILA) and exercise capacity has not been comprehensively evaluated.
Objectives: To assess the validity of the 6-minute walk test in subjects with ILA, and to examine the association between ILA and 6-minute walk distance (6MWD).
Methods: Spearman correlation coefficients were used to assess the strength of the relationships between 6MWD and relevant measures of dyspnea, health-related quality of life, and pulmonary function in a cohort of 2,416 people who smoke from the COPDGene study. Unadjusted and adjusted linear and logistic regression models were used to assess the strength of the association between ILA and 6MWD.
Measurements and Main Results: In all subjects, and in those with ILA, 6MWD in COPDGene was associated with relevant clinical and physiologic measures. The mean 6MWD in COPDGene subjects with ILA was 386 m (SD, 128 m), and 82% and 19% of subjects with ILA had 6MWDs less than or equal to 500 and 250 m, respectively. ILA was associated with a reduced 6MWD in univariate (−30 m; 95% confidence interval, −50 to −10; P = 0.004) and multivariate models (−19 m; 95% confidence interval, −33 to −5; P = 0.008). Compared with subjects without ILA, subjects with ILA had an 80% and 77% increase in their odds to have a walk distance limited to less than or equal to 500 and 250 m, respectively. Although these findings were dependent on ILA subtype, they were not limited to those with COPD.
Conclusions: Our study demonstrates that ILA is associated with measurable decrements in the 6MWD of people who smoke.
Clinical trial registered with www.clinicaltrials.gov (NCT 00608764).
doi:10.1164/rccm.201109-1618OC
PMCID: PMC3326424  PMID: 22268134
six-minute walk distance; emphysema; interstitial lung disease; subclinical; idiopathic pulmonary fibrosis
Respiratory medicine  2011;106(1):109-119.
Background
In COPD patients, hyperinflation impairs cardiac function. We examined whether lung deflation improves oxygen pulse, a surrogate marker of stroke volume.
Methods
In 129 NETT patients with cardiopulmonary exercise testing (CPET) and arterial blood gases (ABG substudy), hyperinflation was assessed with residual volume to total lung capacity ratio (RV/TLC), and cardiac function with oxygen pulse (O2 pulse=VO2/HR) at baseline and 6 months. Medical and surgical patients were divided into “deflators” and “non-deflators” based on change in RV/TLC from baseline (ΔRV/TLC). We defined deflation as the ΔRV/TLC experienced by 75% of surgical patients. We examined changes in O2 pulse at peak and similar (iso-work) exercise. Findings were validated in 718 patients who underwent CPET without ABGs.
Results
In the ABG substudy, surgical and medical deflators improved their RV/TLC and peak O2 pulse (median ΔRV/TLC −18.0% vs. −9.3%, p=0.0003; median ΔO2 pulse 13.6% vs. 1.8%, p=0.12). Surgical deflators also improved iso-work O2 pulse (0.53 mL/beat, p=0.04 at 20 watts). In the validation cohort, surgical deflators experienced a greater improvement in peak O2 pulse than medical deflators (mean 18.9% vs. 1.1%). In surgical deflators improvements in O2 pulse at rest and during unloaded pedaling (0.32 mL/beat, p<0.0001 and 0.47 mL/beat, p<0.0001, respectively) corresponded with significant reductions in HR and improvements in VO2. On multivariate analysis, deflators were 88% more likely than non-deflators to have an improvement in O2 pulse (OR 1.88, 95% CI 1.30–2.72, p=0.0008).
Conclusion
In COPD, decreased hyperinflation through lung volume reduction is associated with improved O2 pulse.
doi:10.1016/j.rmed.2011.07.012
PMCID: PMC3233645  PMID: 21843930
cardiac function; hyperinflation; lung volume reduction surgery; oxygen pulse
Background
Tobacco smoking remains the leading cause of preventable death in America, claiming 450,000 lives annually. Chronic Obstructive Pulmonary Disease, caused by smoking in the vast majority of cases, became the third leading cause of death in the U.S. in 2008. The burden of asthma, often exacerbated by tobacco exposure, has widespread clinical and public health impact. Despite this considerable harm, we know relatively little about the natural history of lung disease and respiratory impairment in adults, especially after smoking cessation.
Methods/Design
Our paper describes the design and rationale for using the 2004 Federal Bureau of Prisons tobacco ban to obtain insights into the natural history of respiratory diseases in adult men and women of different races/ethnicities who are imprisoned in federal medical facilities. We have developed a longitudinal study of new prison arrivals, with data to be collected from each participant over the course of several years, through the use of standardized questionnaires, medical chart reviews, lung function tests, six-minute walk tests, and stored serum for the analysis of present and future biomarkers. Our endpoints include illness exacerbations, medication and health services utilization, lung function, serum biomarkers, and participants’ experience with their health and nicotine addiction.
Discussion
We believe the proposed longitudinal study will make a substantial contribution to the understanding and treatment of respiratory disease and tobacco addiction.
doi:10.1186/1471-2466-12-64
PMCID: PMC3556062  PMID: 23067295
Pulmonary disease; Chronic Obstructive Pulmonary Disease; Asthma; Pathophysiology; Biomarkers; Pulmonary function tests; Tobacco; Nicotine; Addiction; Health services
Respiratory Research  2012;13(1):71.
Background
The relationship between serum biomarkers and clinical expressions of COPD is limited. We planned to further describe this association using markers of inflammation and injury and repair.
Methods
We studied lung function, comorbidities, exercise tolerance, BODE index, and quality of life in 253 COPD patients and recorded mortality over three years. Serum levels of Interleukins 6,8 and16, tumor necrosis factor alpha (TNF α) [inflammatory panel], vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) [injury and repair panel] and pulmonary and activation-regulated chemokine (PARC/CCL-18) and monocyte chemotactic protein 1 (MCP-1/CCL2) [chemoattractant panel] were measured. We related the pattern of the biomarker levels to minimal clinically important differences (MCID) using a novel visualization method [ObServed Clinical Association Results (OSCAR) plot].
Results
Levels of the inflammatory markers IL-6, TNF α were higher and those of injury and repair lower (p < 0.01) with more advanced disease (GOLD 1 vs. 4). Using the OSCAR plot, we found that patients in the highest quartile of inflammatory and lowest quartile of injury and repair biomarkers level were more clinically compromised and had higher mortality (p < 0.05).
Conclusions
In COPD, serum biomarkers of inflammation and repair are distinctly associated with important clinical parameters and survival.
doi:10.1186/1465-9921-13-71
PMCID: PMC3493287  PMID: 22906131
Exercise; Inflammation; Phenotypes; Repair; Survival
Respiratory Research  2012;13(1):66.
Background
The changes in inspiratory capacity (IC) over time in chronic obstructive pulmonary disease (COPD) patients are unknown. The Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT®) trial included IC measurements.
Methods
IC analysis from UPLIFT® (N = 5992) was performed at 1 and 6 months, and every 6 months through 4 years. Annualized rate of decline in pre- and post-bronchodilator IC and mean differences at each time point were analyzed by mixed-effects models. The relationships between baseline IC and exacerbation rate and mortality were explored using Cox regression analysis.
Results
Baseline characteristics: age, 65 years; 75% men; post-bronchodilator forced expiratory volume in 1 second, 1.32 L (48% predicted); pre- and post-bronchodilator IC, 2.03 and 2.33 L. Mean IC rate of decline (mL/year) was 34 ± 2 (1.7% of baseline) and 50 ± 3 (2.1% of baseline) pre- and post-bronchodilator, respectively, without significant between-group differences. Morning pre-bronchodilator (trough) IC improved with tiotropium versus placebo: 124 mL (1 month), 103 mL (1 year), 107 mL (2 years), 98 mL (3 years), and 97 mL (4 years) (all p < 0.001). Post-bronchodilator improvements were similar between treatment groups. Lower baseline IC values were associated with reduced time to first exacerbation. For the lowest quartile (n = 1413) the values in months were 14.3 (11.7–17.0) for tiotropium and 10.3 (8.8–11.7) for controls (p < 0.01).
Conclusion
IC declines from approximately 34 to 50 mL/year in patients with stage II to IV COPD. Tiotropium treatment does not change the IC decline rate but provides 24-hour improvements in IC sustained over the long term. Trough IC differences suggest that tiotropium provides sustained decrease in end-expiratory lung volume.
doi:10.1186/1465-9921-13-66
PMCID: PMC3443002  PMID: 22866681
COPD; Inspiratory Capacity; Tiotropium
Cachexia, whether assessed by body mass index (BMI) or fat-free mass index (FFMI), affects a significant proportion of patients with chronic obstructive pulmonary disease (COPD), and is an independent risk factor for increased mortality, increased emphysema, and more severe airflow obstruction. The variable development of cachexia among patients with COPD suggests a role for genetic susceptibility. The objective of the present study was to determine genetic susceptibility loci involved in the development of low BMI and FFMI in subjects with COPD. A genome-wide association study (GWAS) of BMI was conducted in three independent cohorts of European descent with Global Initiative for Chronic Obstructive Lung Disease stage II or higher COPD: Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-Points (ECLIPSE; n = 1,734); Norway-Bergen cohort (n = 851); and a subset of subjects from the National Emphysema Treatment Trial (NETT; n = 365). A genome-wide association of FFMI was conducted in two of the cohorts (ECLIPSE and Norway). In the combined analyses, a significant association was found between rs8050136, located in the first intron of the fat mass and obesity–associated (FTO) gene, and BMI (P = 4.97 × 10−7) and FFMI (P = 1.19 × 10−7). We replicated the association in a fourth, independent cohort consisting of 502 subjects with COPD from COPDGene (P = 6 × 10−3). Within the largest contributing cohort of our analysis, lung function, as assessed by forced expiratory volume at 1 second, varied significantly by FTO genotype. Our analysis suggests a potential role for the FTO locus in the determination of anthropomorphic measures associated with COPD.
doi:10.1165/rcmb.2010-0294OC
PMCID: PMC3266061  PMID: 21037115
chronic obstructive pulmonary disease genetics; chronic obstructive pulmonary disease epidemiology; chronic obstructive pulmonary disease metabolism; genome-wide association study

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