Clinical characteristics and HRCT measurements performed on inspiration and expiration of the five subject groups
| Non-smokers(n = 10) | Healthy smokers (n = 11) | Stage 0 COPD(n = 17) | Stage I COPD(n = 10) | Stage II–IV COPD(n = 17) | p value(ANOVA) | |
|---|---|---|---|---|---|---|
| All data are shown as mean (SD). | ||||||
| * † ‡Homogenous Scheffe subsets. | ||||||
| SGRQ, St George’s Respiratory questionnaire; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; MEF, mid expiratory flow; Kco, lung carbon monoxide transfer coefficient; Tlco, carbon monoxide lung transfer factor; MLD, mean lung density; LAA, area of low attenuation; E/I ratio, expiration/inspiration ratio. | ||||||
| Age (years) | 51 (7) | 45 (12) | 50 (7) | 57 (7) | 55 (7) | |
| Pack years | 0‡ | 40 (15)† | 43 (19)† * | 44 (13)†* | 52 (14)* | <0.001 |
| SGRQ | 4.7 (12.2)† | 7.1 (5.0)† | 20.4 (16.1)†* | 27.2 (12.9)* | 35.3(19.7)* | <0.001 |
| FEV1 (%) | 111 (12.2)‡ | 102 (8)‡† | 99 (14)‡† | 91 (6)† | 56 (16)* | <0.001 |
| FEV1/FVC | 77 (5.4)‡ | 80 (5)‡† | 75 (3)‡ | 66 (3)† | 55 (12)* | <0.001 |
| MEF50% | 85 (17.5)‡ | 85 (23)‡ | 76 (22.1)‡ | 48 (9)† | 24 (12.6)* | <0.001 |
| RV/TLC | 30 (3.5)† | 28.7 (7.1)† | 35 (7.7)† | 38 (5.2)† * | 49 (7.9)* | <0.001 |
| Tlco (%) | 84 (12.1)‡ | 74 (12)‡ † | 63 (10)† * | 65 (18)†* | 56 (16)* | <0.001 |
| Kco (%) | 82 (12.6)† | 67 (14)* | 61 (13)* | 62 (19)* | 64 (15)* | <0.01 |
| Inspiratory MLD (HU) | −840 (27) | −825 (25) | −824 (19) | −852 (23) | −846 (25) | |
| Inspiratory %LAA | 8.9 (4.3) | 7.0 (3.2) | 5.8 (2.7) | 12.6 (8.1) | 11.4 (7.4) | |
| Expiratory MLD (HU) | −755 (44)† * | −727 (45)† | −732 (35)† | −783 (36)* | −801 (38)* | <0.01 |
| Expiratory %LAA | 3.3 (2)†* | 2.7 (1.6)† | 2.3 (1)† | 7.1 (6.4)* | 7.3 (6.8)* | <0.01 |
| E/I ratio | 0.89 (0.03)† | 0.88 (0.04)† | 0.88 (0.03)† | 0.91 (0.02)†* | 0.94 (0.02)* | <0.001 |