Clinical and computed tomographic predictors of chronic bronchitis in COPD: a cross sectional analysis of the COPDGene study

Table 1 Baseline characteristics and radiology

	Chronic bronchitis (CB+) n = 663	No chronic bronchitis (CB-) n = 2040	p
Demographics and symptoms
Age (years)	61.8 ± 8.5	63.8 ± 8.5	<0.0001
Smoking history (pack years)	56.4 ± 26.8	50.7 ± 26.3	<0.0001
Current smokers (%)	59.2	37.4	<0.0001
Gender (%M)	64	55	<0.0001
Race (%C)	84	78	<0.0001
FEV₁ (% predicted)	54.3 ± 20.7	60.1 ± 23.4	<0.0001
FVC (% predicted)	80.5 ± 19.9	84.0 ± 20.1	<0.0001
FEV₁/FVC	0.51 ± 0.13	0.53 ± 0.14	<0.0001
6MWD (meters)	372 ± 118	392 ± 121	<0.0001
BMI (kg/m²)	27.3 ± 5.9	27.7 ± 5.8	0.144
BODE score	3.0 ± 2.0	2.3 ± 2.1	<0.0001
MMRC dyspnea	2.3 ± 1.4	1.6 ± 1.5	<0.0001
SGRQ score	48.0 ± 21.3	30.6 ± 21.8	<0.0001
Exposures and Medical History
Gastroesophageal reflux (%)	33.8	28.6	0.010
Allergic nasal symptoms (%)	69.5	47.0	<0.0001
Allergic ocular symptoms (%)	51.0	37.9	<0.0001
History of asthma (%)	33.4	23.4	<0.0001
History of bronchitis (%)	66.0	49.8	<0.0001
Exposure to dusts (%)	64.7	47.4	<0.0001
Occupational exposures (%)	65.6	51.0	<0.0001
Exacerbations
Total exac rate (no./pt/yr)	0.96 ± 1.46	0.52 ± 1.04	<0.0001
History of severe Exac (%)	24.2	15.2	<0.0001
Radiology
% Emphysema (%)	11.4 ± 12.0	12.0 ± 12.6	0.347
% Gas trapping (%)	35.3 ± 21.2	36.3 ± 20.6	0.272
Mean segmental WA% (%)	63.0 ± 3.2	62.0 ± 3.1	<0.0001
Pi10 (mm)	3.72 ± 0.15	3.69 ± 0.14	<0.0001
Pi15 (mm)	5.24 ± 0.22	5.17 ± 0.20	<0.0001

Definition of abbreviations: M = male, F = female, C = Caucasian, AA = African American, FEV1 = forced expiratory volume in 1 second, FVC = forced vital capacity, 6MWD = 6-minute walk distance, Exac = exacerbation, BMI = body mass index.

ISSN: 1465-993X