Table 1.
Descriptive data regarding occupational exposure to vapor, gas, dust, or fumes (VGDF), smoking, lung function, gender, and body mass index (BMI) in relation, and various definitions of airflow limitation, chronic airflow limitation, COPD, and emphysema
| Variables | Different definitions of outcomes
|
||||||
|---|---|---|---|---|---|---|---|
| Control population N=747 |
Airflow limitationa N=212 |
Chronic airflow limitation (GOLD)b N=105 |
Chronic airflow limitation (LLN)c N=100 |
COPDd N=50 |
Physician-diagnosed COPD/emphysemae N=25 |
Emphysemaf N=98 |
|
| Age, years | 56.9 (4.3) | 58.1 (4.4) | 58.7 (4.2) | 58.1 (4.3) | 58.9 (4.0) | 57.3 (4.4) | 58.1 (4.5) |
| Males | 371 (49.7%) | 96 (45.3%) | 60 (57.1%) | 57 (57.0%) | 31 (62%) | 14 (56%) | 55 (56.1%) |
| BMI, kg/m2 | 27.3 (4.3) | 27.1 (5.0) | 27.2 (5.1) | 27.2 (5.4) | 27.1 (4.5) | 28.4 (6.4) | 26.2 (4.4) |
| Never-smokers | 370 (49.5%) | 59 (27.8%) | 21 (20.0%) | 20 (20.0%) | 9 (18.0%) | 5 (20%) | 6 (6.0%) |
| Former smokers | 282 (37.8%) | 94 (44.3%) | 43 (41.0%) | 41 (41.0%) | 22 (44.0%) | 10 (40%) | 34 (34.7%) |
| Current smokers | 95 (12.7%) | 59 (27.8%) | 41 (39.1%) | 39 (39.0%) | 19 (38.0%) | 10 (40%) | 58 (59.2%) |
| Pack-years | 7.4 (12.1) | 16.0 (19.3) | 21.6 (23.1) | 20.6 (2.3) | 23.4 (27.1) | 23.3 (17.8) | 27.8 (28.7) |
| Occupational exposure to VGDF | 206 (27.6%) | 90 (42.5%) | 46 (43.8%) | 42 (42.0%) | 29 (58.0%) | 16 (64%) | 50 (51.0%) |
| FEV1, % predicted | 103.5 (22.2) | 90.2 (23.7) | 83.1 (22.2) | 86.3 (25.0) | 80.4 (25.6) | 73.8 (19.9) | 87.2 (21.7) |
| FVC, % predicted | 100.8 (23.4) | 101.7 (25.2) | 100.6 (24.4) | 104.7 (26.6) | 99.8 (26.9) | 84.5 (17.7) | 94.8 (22.1) |
| FEV1/FVC, % | 80.7 (4.1) | 69.3 (7.0) | 64.3 (6.0) | 64.1 (6.1) | 62.4 (7.7) | 68.2 (12.4) | 71.9 (9.1) |
Notes: Categories overlap and are not mutually exclusive. SD is given in parentheses unless otherwise indicated.
Airflow limitation was defined as an FEV1/FVC ratio <0.7 before bronchodilation.
Chronic airflow limitation (GOLD) was defined as an FEV1/FVC ratio <0.7 after bronchodilation.
Chronic airflow limitation (LLN) was defined as an FEV1/FVC ratio after bronchodilation below the lower limit of the normal.
COPD was defined as chronic airflow limitation (GOLD) in combination with dyspnea, wheezing, or chronic bronchitis.
Physician-diagnosed COPD/emphysema was defined as an affirmative answer to “Have you ever had chronic obstructive pulmonary disease or emphysema diagnosed by a physician?”
Emphysema was categorized according to CT findings of at least mild emphysema in any zone.
Abbreviations: FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; CT, computed tomography; LLN, lower limit of normal.