Table 1.
Characteristics of the study patients (n = 373)
| DF- COPD | DF-Control | p-value | NF- COPD | NF-Control | p-value | |
|---|---|---|---|---|---|---|
| n = 101 | n = 98 | n = 85 | n = 89 | |||
| Age, years | 60.3 ± 9.1 | 59.3 ± 8.9 | NS | 61.4 ± 7.6 | 60.2 ± 6.5 | NS |
| Men | 86 (85.1) | 86 (87.8) | NS | 66 (77.6) | 65 (73.0) | NS |
| BMI | 26.5 ± 4.1 | 27.0 ± 4.1 | NS | 26.1 ± 4.1 | 26.8 ± 3.8 | NS |
| Smoking status | NS | NS | ||||
| Non-smoker | 48 (47.5)** | 54 (55.1) | 7 (8.2) | 12 (13.5) | ||
| Former-smoker | 33 (32.7)** | 32 (32.7) | 36 (42.4) | 42 (47.2) | ||
| Currentsmoker | 20 (19.8)** | 12 (12.2) | 42 (49.4) | 35 (39.3) | ||
| Smoking pack years | NS | NS | ||||
| < 1 | 49 (48.5)** | 55 (56.1) | 7 (8.2) | 13 (14.6) | ||
| 1–15 | 18 (17.8)** | 21 (21.4) | 13 (15.3) | 15 (16.9) | ||
| > 15 | 34 (33.7)** | 22 (22.5) | 65 (76.5) | 61 (68.5) | ||
| Exacerbation | 23 (22.8) | 23 (27.1) | ||||
| At least one respiratory symptom | 54 (53.1) | 21 (21.3) | < 0.001 | 51 (60.0) | 23 (25.9) | < 0.001 |
| Dyspnea, mMRC> 0 | 38 (38.0) | 15 (15.3) | < 0.001 | 39 (45.9) | 19 (21.4) | < 0.001 |
| SGRQ | 15.1 ± 12.9* | 7.3 ± 7.2 | < 0.001 | 19.4 ± 14.9 | 9.3 ± 9.3 | < 0.001 |
| FEV1 /FVC post-BD, %pred | 63.0 ± 6.8* | 78.5 ± 4.3 | < 0.001 | 60.6 ± 8.0 | 79.9 ± 4.1 | < 0.001 |
| FEV1 post-BD, %pred; | 85.2 ± 14.8* | 105.5 ± 10.9 | < 0.001 | 80.0 ± 16.4 | 108.3 ± 12.7 | < 0.001 |
| FVC post-BD, %pred; | 105.3 ± 15.7 | 104.8 ± 11.4 | NS | 102.1 ± 14.8 | 105.7 ± 12.0 | NS |
| Severity of airway obstruction, n (%) | ||||||
| Stage I | 44 (44) | 33 (39) | ||||
| Stage II + | 57 (56) | 52 (61) | ||||
Data are presented as n, n (%) or mean ± SD, unless otherwise stated
COPD chronic obstructive pulmonary disease, DF-COPD dairy farmers with COPD, NF-COPD non-dairy farmers with COPD, SD standard deviation, BMI body mass index, mMRC modified Medical Research Council, SGRQ St George’s Respiratory Questionnaire, FVC forced vital capacity, FEV1 forced expiratory volume in 1 s
* p < 0.05, vs NF- COPD, ** p < 0.01, vs NF- COPD
Significant P values (< 0.05) are in bold