Table 1.
Characteristics of the identification cohort (nasal epithelial brushes) and comparator cohorts (bronchial epithelial brushes)
| Identification cohort | Comparator cohorts | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nasal brushes | Bronchial brushes (cohort 1) | Bronchial brushes (cohort 2) | |||||||||||||
|
COPD
( n = 31) |
Control
(n = 22) |
p |
COPD
( n = 87) |
Control
( n = 151) |
p |
COPD
( n = 10) |
Control
(n = 20) |
p | |||||||
| Age, years | 61 | (8) | 52 | (8) | <0.01 | 65 | (6) | 64 | (6) | 0.25 | 67 | (5) | 55 | (10) | <0.01 |
| Male gender, n (%) | 21 | (68%) | 14 | (64%) | 0.76 | 52 | (60%) | 83 | (55%) | 0.50 | 10 | (100%) | 17 | (85%) | 0.20 |
| Smoking status | |||||||||||||||
| Current smoking, n (%) | 31 | (100%) | 22 | (100%) | 1 | 30 | (35%) | 69 | (46%) | 0.10 | 8 | (80%) | 19 | (95%) | 0.20 |
| Ex smoking, n (%) | 0 | (0%) | 0 | (0%) | 57 | (66%) | 82 | (54%) | 2 | (20%) | 1 | (5%) | |||
| Packyears | 39 | (18) | 29 | (12) | 0.03 | 51 a | (25) | 47 a | (19) | 0.11 | 31 b | (22-45) | 26 b | (24-36) | 0.57 |
| ICS use, n (%) | 27 | (87%) | – | <0.01 | 18 | (21%) | 7 | (5%) | <0.01 | 8 | (80%) | 0 | (0%) | <0.01 | |
| FEV 1 c , % predicted | 31 | (6) | 102 | (11) | <0.01 | 60 | (14) | 93 | (13) | <0.01 | 62 b | (52-68) | 102 b | (97-114) | <0.01 |
| FEV 1 /FVC, % | 34 | (8) | 75 | (4) | <0.01 | 56 | (9) | 75 | (6) | <0.01 | 50 b | (42-56) | 73 b | (71-83) | <0.01 |
| GOLD classification c | |||||||||||||||
| GOLD 1, n (%) | 0 | (0%) | – | – | 0 | (0%) | – | – | 1 | (10%) | – | – | |||
| GOLD 2, n (%) | 2 | (6%) | – | – | 68 | (78%) | – | – | 8 | (80%) | – | – | |||
| GOLD 3, n (%) | 22 | (71%) | – | – | 17 | (20%) | – | – | 1 | (10%) | – | – | |||
| GOLD 4, n (%) | 7 | (23%) | – | – | 2 | (2%) | – | – | 0 | (0%) | – | – | |||
| TLC, % predicted | 132 | (17) | 105 | (10) | <0.01 | n/a | n/a | – | n/a | n/a | – | ||||
| RV/TLC, % | 62 | (7) | 30 | (3) | <0.01 | n/a | n/a | – | n/a | n/a | – | ||||
| CCQ | 2.4 | (0.9) | 0.4 | (0.3) | <0.01 | n/a | n/a | – | n/a | n/a | – | ||||
| Allergic rhinitis, n (%) | 1 | (3%) | 5 | (23%) | 0.07 | n/a | n/a | – | n/a | n/a | – | ||||
| Nasal CS use, n (%) | 2 | (7%) | 1 | (5%) | 0.99 | n/a | n/a | – | n/a | n/a | – | ||||
All values are presented as mean with standard deviation, unless stated otherwise; p -values reflect differences between COPD and controls
a Missing packyears for 5 subjects with COPD and 11 controls
b Median with interquartile range
c postbronchodilator, except for 1 subject in the identification cohort for which postbronchodilator FEV 1 was not available, we show prebronchodilator FEV 1 instead (32%); for all subjects in cohort 1, only prebronchodilator FEV 1 was available
ICS Inhaled corticosteroids, FEV 1 Forced expiratory volume in 1 s, FVC Forced vital capacity, GOLD Global initiative for chronic obstructive lung disease, TLC Total lung capacity, RV Residual volume, CCQ Clinical COPD Questionnaire, CS Corticosteroids, n/a Not available