Table 1.
Characteristics of the study subjects
| Patients with COPD n = 74 | High EFL index group n = 37 | Low EFL index group n = 37 | Controls n = 39 | |
|---|---|---|---|---|
| Age (years) |
73 (54 – 86) |
73 (62 – 84)* |
73 (54 – 86)* |
35 (24 – 69) |
| Gender (male/female) |
71/3 |
35/2* |
36/1* |
19/20 |
| Body mass index (kg/m2) |
21.1 (15.2 – 32.3) |
21.6 (15.6 – 32.3) |
20.8 (15.2 – 27.7) |
22.0 (16.9 – 30.8) |
| Current/ex/never smoker |
9/65/0 |
4/33/0* |
5/32/0* |
4/9/26 |
| Pack years |
53.1 (5.0 – 150.0) |
62.0 (5.0 – 132.0)* |
51.3 (7.5 – 150.0)* |
0.0 (0.0 – 33.0) |
| mMRC scale |
1 (0 – 4) |
2 (0 – 4)† |
1 (0 – 4) |
NA |
| CAT score |
12.5 (0 – 32) |
14 (3 – 32) |
11 (0 – 30) |
NA |
| Emphysema score |
10 (0 – 23) |
12 (0 – 23) |
10 (0 – 21) |
NA |
| GOLD I/II/III/IV |
9/31/20/14 |
1/9/15/12† |
8/22/5/2 |
NA |
| LAMA |
26 |
11 |
15 |
NA |
| LABA |
4 |
2 |
2 |
NA |
| LAMA + LABA |
26 |
15 |
11 |
NA |
| LAMA + ICS/LABA |
13 |
7 |
6 |
NA |
| Sustained-release theophylline |
24 |
18† |
6 |
NA |
| FEV1 (% predicted) |
52.6 (17.8 – 108.0) |
36.8 (17.8 – 108.0)†* |
67.5 (20.0 – 93.8)* |
100.0 (76.9 – 118.5) |
| FVC (% predicted) |
81.4 (34.9 – 144.0) |
75.6 (34.9 – 144.0)†* |
91.4 (42.5 – 114.9)* |
102.7 (82.5 – 123.1) |
| FEV1/FVC (%) |
50.1 (28.7 – 69.9) |
42.0 (28.7 – 66.8)†* |
59.2 (30.4 – 69.9)* |
84.2 (73.5 – 97.7) |
| IC (% predicted) |
83.0 (38.5 – 124.8) |
78.4 (38.5 – 121.6)†* |
86.7 (53.6 – 124.8) |
94.2 (62.5 – 146.4) |
| FEF 25-75% (% predicted) |
18.6 (5.7 – 57.4) |
10.1 (5.7 – 37.7)†* |
28.5 (6.3 – 57.4)* |
83.4 (45.8 – 114.3) |
| FRC (% predicted) |
100.1 (56.9 – 165.5) |
111.9 (65.4 – 165.5)† |
85.8 (56.9 – 123.4)* |
107.9 (66.2 – 138.4) |
| RV (% predicted) |
149.0 (34.4 – 332.0) |
182.4 (94.0 – 332.0)†* |
133.1 (34.4 – 213.6)* |
94.4 (65.1 – 239.6) |
| TLC (% predicted) |
109.0 (75.9 – 152.2) |
116.9 (76.5 – 152.2)† |
101.5 (75.9 – 133.2) |
107.9 (84.2 – 147.5) |
| RV/TLC (% predicted) | 118.2 (35.7 – 180.7) | 135.5 (71.8 – 180.7)†* | 106.2 (35.7 – 162.9) | 112.3 (68.7 – 168.5) |
Values are shown as a median (range) or numbers.
Abbreviations: CAT COPD assessment test, EFL expiratory flow limitation, FEF 25-75% forced expiratory flow between 25% and 75% of FVC, FEV1 forced expiratory volume in 1 second, FRC functional residual capacity, FVC forced vital capacity, GOLD Global Initiative for Chronic Obstructive Lung Disease, IC inspiratory capacity, ICS inhaled corticosteroids, LABA long-acting β2-agonists, LAMA long-acting antimuscarinic agents, mMRC modified Medical Research Council, NA not applicable, RV residual volume, TLC total lung capacity.
*p <0.05 versus controls, †p <0.05 versus low EFL index group.