Table 1.
Characteristics of subjects with chronic obstructive pulmonary disease at enrollment by BDR groups (n = 3,340)
| FEV1-BDR (n = 182) | FVC-BDR (n = 522) | Combined-BDR (n = 379) | No-BDR (n = 2,257) | |
|---|---|---|---|---|
| Age, yr | 61.55 ± 8.77* | 64.67 ± 8.70* | 63.43 ± 8.90 | 63.50 ± 8.41 |
| Female, n (%) | 62 (34.07) | 256 (49.04) | 134 (35.36) | 920 (40.76) |
| African American, n (%) | 33 (18.13) | 104 (19.92) | 61 (16.09) | 443 (19.63) |
| Body mass index, kg/m2 | 28.84 ± 6.27* | 27.07 ± 5.57 | 27.81 ± 5.54 | 27.62 ± 5.95 |
| Pack-years smoking | 50.23 ± 24.94 | 52.54 ± 27.46 | 54.66 ± 27.26 | 52.66 ± 27.04 |
| Active smokers, n (%) | 87 (47.80) | 208 (39.85) | 180 (47.49) | 998 (44.22) |
| Chronic bronchitis | 50 (27.47) | 122 (23.37) | 112 (29.55)* | 534 (23.66) |
| MMRC | 1.54 ± 1.39 | 2.05 ± 1.50* | 1.67 ± 1.42 | 1.72 ± 1.45 |
| ICS, n (%)† | 55 (30.22)* | 239 (46.31)* | 107 (28.61)* | 854 (38.40) |
| LABA, n (%)† | 49 (26.92)* | 229 (44.64)* | 82 (21.93)* | 852 (38.31) |
| LAMA, n (%)† | 38 (21.47)* | 193 (37.62) | 74 (19.79)* | 760 (34.32) |
| Post-FEV1% predicted | 68.28 ± 16.10* | 51.64 ± 24.39* | 58.38 ± 18.12 | 59.94 ± 23.34 |
| Post-FVC% predicted | 88.68 ± 16.36* | 82.38 ± 22.40 | 84.39 ± 16.86 | 82.55 ± 20.46 |
| GOLD stage | ||||
| I, mild | 34 (18.68) | 80 (15.33) | 53 (13.98) | 497 (22.02) |
| II, moderate | 124 (68.13) | 168 (32.18) | 192 (50.66) | 958 (42.45) |
| III, severe | 23 (12.64) | 153 (29.31) | 119 (31.40) | 532 (23.57) |
| IV, very severe | 1 (0.55) | 121 (23.18) | 15 (3.96) | 270 (11.96) |
| P value‡ | <0.001 | <0.001 | <0.001 | Ref |
| FEV1 change after BD, L | 0.32 ± 0.11* | 0.11 ± 0.10* | 0.34 ± 0.12* | 0.04 ± 0.13 |
| FVC change after BD, L | 0.21 ± 0.16* | 0.50 ± 0.24* | 0.65 ± 0.32* | 0.041 ± 0.21 |
| FEV1/FVC change after BD | 0.057 ± 0.040* | −0.046 ± 0.052* | −0.002 ± 0.067 | 0.005 ± 0.042 |
| Emphysema, % | 8.15 ± 8.71* | 14.94 ± 14.08* | 10.66 ± 10.77 | 12.08 ± 12.45 |
| Gas trapping, % | 27.67 ± 15.49* | 41.77 ± 22.46* | 36.11 ± 18.80 | 34.42 ± 20.48 |
| PRMfSAD, % | 21.6 ± 10.7* | 28.6 ± 13.3* | 28.1 ± 12.0* | 24.5 ± 12.4 |
| Pi10, mm | 3.67 ± 0.15 | 3.71 ± 0.12* | 3.72 ± 0.14* | 3.68 ± 0.13 |
| FRC% predicted | 112.40 ± 23.31* | 130.10 ± 34.72* | 124.20 ± 27.04* | 118.40 ± 30.02 |
| TLC% predicted | 100.10 ± 15.14* | 104.60 ± 17.07* | 103.40 ± 14.48* | 101.60 ± 16.46 |
| 6-min-walk-test distance, ft | 1,363 ± 370.07* | 1,175 ± 407.35 | 1,312 ± 347.35 | 1,249 ± 414.91 |
Definition of abbreviations: BD = bronchodilator; BDR = bronchodilator response; Combined-BDR = an increase in both FEV1 and FVC ≥12% and ≥200 ml after bronchodilator administration; FEV1 = forced expiratory volume in 1 second; FEV1-BDR = increase in FEV1 ≥12% and ≥200 ml but a change in FVC <12% and 200 ml after bronchodilator administration; FRC = functional residual capacity; FVC = forced vital capacity; FVC-BDR = increase in FVC ≥12% and ≥200 ml but a change in FEV1 <12% and 200 ml after bronchodilator administration; GOLD = Global Initiative for Chronic Obstructive Lung Disease; ICS = inhaled glucocorticosteroids; LABA = long-acting β agonist; LAMA = long-acting muscarinic antagonist; MMRC = Modified Medical Research Council; No-BDR = a change in both FEV1 and FVC <12% and <200 ml after bronchodilator administration; Pi10 = square root of wall area for a hypothetical airway with an internal perimeter of 10 mm; PRMfSAD = parametric response mapping functional small airway disease; Ref = reference; TLC = total lung capacity.
Continue variables are presented as mean ± SD.
P < 0.05 versus No-BDR using Student’s t test, Wilcoxon, Fischer, or chi-square tests when appropriate.
Data were available for a subset of subjects: For % emphysema and TLC% predicted analysis, data were available for 3,127 subjects. For % gas trapping and FRC% analysis, data were available for 2,788 subjects. For Pi10 data analysis, data were available for 3,102 subjects. For 6-minute-walk-test data analysis, data were available for 3,264 subjects.
Across all GOLD stages shown (vs. No-BDR using chi-square test).