Chest
Original Research: COPDPhysiologic Characterization of the Chronic Bronchitis Phenotype in GOLD Grade IB COPD
Section snippets
Subjects
Forty patients with symptomatic COPD fitting GOLD grade IB criteria (a postbronchodilator FEV1 ≥ 80% predicted and an FEV1/FVC < 0.7 and less than lower limit of normal25; none to one exacerbation per year; and modified Medical Research Council dyspnea scale ≥ 2 or COPD Assessment Test [CAT] score ≥ 10)2 were categorized into two groups (n = 20 each) based on having CB or not (non-CB).6 Inclusion criteria included age ≥ 50 years and a smoking history of ≥ 20 pack-years. Exclusion criteria
Results
All groups had similar sex distribution, age, height, weight, and BMI (Table 1). The COPD groups had similar smoking history and medication use, except more patients with CB used a long-acting muscarinic antagonist. Both COPD groups were more symptomatic compared with the healthy group. However, the CB group had greater chronic, activity-related dyspnea, higher CAT scores, lower physical activity according to Community Healthy Activities Model Program for Seniors (CHAMPS), poorer health status
Discussion
The main findings of this study are the following: (1) patients with CB had greater chronic activity-related dyspnea and poorer perceived health status than patients without CB who had similar spirometric abnormalities; (2) both CB and non-CB groups had extensive but comparable peripheral airway dysfunction at rest; and (3) exercise tolerance was similarly reduced in both COPD groups, but those with CB experienced greater exertional dyspnea and dynamic respiratory mechanical constraints than
Conclusions
This study provides the first comprehensive, physiologic characterization of CB in smokers with only minor spirometric abnormalities. Patients with CB experienced greater chronic activity-related dyspnea and poorer health-related quality of life than patients without CB. Both mild COPD groups had extensive peripheral airway dysfunction, dynamic respiratory mechanical abnormalities, and reduced exercise tolerance. Those with CB had greater mechanical constraints and a greater disparity between
Acknowledgments
Author contributions: D. E. O. was the principal investigator and takes responsibility for the integrity of the data and the accuracy of the data analysis. D. E. O. contributed to the study concept; A. F. E., N. R., K. A. W., and D. E. O. contributed to the study design; A. F. E., N. R., K. A. W., J. A. N., M. I. M., and D. E. O. contributed to the conduct of the study; A. F. E., N. R., S. C., L. Y., K. A. W., and J. A. G. contributed to data collection; A. F. E. and K. A. W. contributed to the
References (63)
COPD, a multicomponent disease: implications for management
Respir Med
(2005)- et al.
Epidemiological study of chronic obstructive pulmonary disease in Spain (IBERPOC): prevalence of chronic respiratory symptoms and airflow limitation [in Spanish]
Arch Bronconeumol
(1999) - et al.
Not 15 but 50% of smokers develop COPD? Report from the obstructive lung disease in northern Sweden studies
Respir Med
(2003) - et al.
Chronic respiratory symptoms, spirometry and knowledge of COPD among general population
Respir Med
(2006) - et al.
Cough and sputum production are associated with frequent exacerbations and hospitalizations in COPD subjects
Chest
(2009) - et al.
The chronic bronchitic phenotype of COPD: an analysis of the COPDGene Study
Chest
(2011) - et al.
The emphysematous and bronchial types of chronic airways obstruction. A clinicopathological study of patients in London and Chicago
Lancet
(1966) - et al.
The measurement of dyspnea. Contents, interobserver agreement, and physiologic correlates of two new clinical indexes
Chest
(1984) - et al.
A new method of classifying prognostic comorbidity in longitudinal studies: development and validation
J Chronic Dis
(1987) Early detection of airways obstruction by the closing volume technique
Chest
(1973)
Fifteen-year interval spirometric evaluation of the Oregon predictive equations
Chest
Emerging concepts in the evaluation of ventilatory limitation during exercise: the exercise tidal flow-volume loop
Chest
Sex differences in exertional dyspnea in patients with mild COPD: physiological mechanisms
Respir Physiol Neurobiol
Characterisation of COPD heterogeneity in the ECLIPSE cohort
Respir Res
The heterogeneity of chronic obstructive pulmonary disease
Thorax
Chronic obstructive pulmonary disease phenotypes: the future of COPD
Am J Respir Crit Care Med
Definition and classification of chronic bronchitis for clinical and epidemiological purposes
Lancet
Variations in the prevalence across countries of chronic bronchitis and smoking habits in young adults
Eur Respir J
Chronic bronchitis among French adults: high prevalence and underdiagnosis
Eur Respir J
Incidence of chronic obstructive pulmonary disease in a cohort of young adults according to the presence of chronic cough and phlegm
Am J Respir Crit Care Med
Prevalence of COPD in Spain: impact of undiagnosed COPD on quality of life and daily life activities
Thorax
Chronic mucus hypersecretion: prevalence and risk factors in younger individuals
Int J Tuberc Lung Dis
The natural history of chronic airflow obstruction
BMJ
Association of chronic mucus hypersecretion with FEV1 decline and chronic obstructive pulmonary disease morbidity
Am J Respir Crit Care Med
Chronic mucus hypersecretion in COPD and death from pulmonary infection
Eur Respir J
Factors associated with increased risk of exacerbation and hospital admission in a cohort of ambulatory COPD patients: a multiple logistic regression analysis
Respiration
Mortality in GOLD stages of COPD and its dependence on symptoms of chronic bronchitis
Respir Res
Reduction of exacerbations by the PDE4 inhibitor roflumilast—the importance of defining different subsets of patients with COPD
Respir Res
Ventilation-perfusion inequality in chronic obstructive pulmonary disease
J Clin Invest
Reference values of pulmonary function tests for Canadian Caucasians
Can Respir J
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FUNDING/SUPPORT: This study was supported by the William Spear Endowment Fund/Start Memorial Fund, Queen's University and the Canadian Respiratory Research Network. Financial support to Dr Elbehairy was provided by an Egyptian Ministry of Higher Education and Scientific Research Scholarship.
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