Table 3.
Characteristics, Pulmonary Functions, and CT Imaging Biomarkers Among FOT-Based Phenotypes
| NL (n = 69) | RD (n = 22) | XD (n = 12) | MIX (n = 61) | |
|---|---|---|---|---|
| Age | 69.8 ± 8.1 | 69.7 ± 8.8 | 78.3 ± 5.4 *, ** | 74.7 ± 6.8*, ** |
| Sex (male/female) | 67/2 | 20/2 | 10/2 | 55/6 |
| BMI (kg/m2) | 22.5 ± 2.9 | 24.0 ± 3.2 | 23.8 ± 3.7 | 23.6 ± 3.4* |
| pack-years† | 56.7 ± 26.8 | 49.3 ± 23.7 | 52.6 ± 29.8 | 64.9 ± 37.1 |
| mMRC score¶ | 0.9 ± 1.0 | 0.7 ± 0.6 | 1.6 ± 1.0*, ** | 1.6 ± 1.1*, ** |
| Total CAT score§ | 8.4 ± 6.5 | 10.1 ± 7.4 | 13.5 ± 8.6* | 12.4 ± 7.4* |
| Pulmonary function tests | NL (n = 68) | RD (n = 22) | XD (n = 12) | MIX (n = 61) |
| FEV1 (L) | 2.3 ± 0.5 | 2.0 ± 0.6* | 1.5 ± 0.5*, ** | 1.4 ± 0.5*, ** |
| FEV1/FVC (%) | 60.3 ± 8.1 | 57.5 ± 9.5 | 49.8 ± 13.6* | 46.7 ± 13.2*, ** |
| FEV1%predicted (%) | 82.0 ± 16.6 | 76.0 ± 16.1 | 60.1 ± 20.3*, ** | 57.0 ± 20.5*, ** |
| VC (L) | 3.9 ± 0.7 | 3.7 ± 0.7 | 3.1 ± 0.7*, ** | 3.1 ± 0.7*, ** |
| DLCO/VA (mmol/min/kPa/L)‡ | 0.9 ± 0.4 | 1.0 ± 0.3 | 0.9 ± 0.5 | 0.8 ± 0.4** |
| CT imaging biomarkers | NL (n = 55) | RD (n = 19) | XD (n = 9) | MIX (n = 49) |
| LAV% (%) | 11.3 ± 9.9 | 7.9 ± 7.9 | 14.8 ± 14.5 | 15.7 ± 12.6** |
| √Aaw at Pi10 (mm) | 3.69 ± 0.06 | 3.74 ± 0.06* | 3.76 ± 0.08* | 3.77 ± 0.06*, ** |
Notes: Data are presented as the mean ± standard deviation and were analyzed by Wilcoxon’s rank-sum test. †n = 67 (NL), 22 (RD), 12 (XD), and 61 (MIX); ¶n = 69 (NL), 21 (RD), 12 (XD), and 60 (MIX); §n = 68 (NL), 21 (RD), 12 (XD), and 61 (MIX); ‡n = 67 (NL), 22 (RD), 12 (XD), and 57 (MIX). *P < 0.05 vs NL; **P < 0.05 vs RD.
Abbreviations: √Aaw at Pi10, square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm; BMI, body mass index; CAT, COPD assessment test; CT, computed tomography; DLCO/VA, carbon monoxide diffusing capacity of the lung for carbon monoxide and alveolar volume ratio; FEV1, forced expiratory volume in 1 s; FOT, forced oscillation technique; FVC, forced vital capacity; LAV%, percentage of low attenuation volume; MIX, mixed group; mMRC, modified Medical Research Council dyspnea scale; NL, normal group; RD, resistance-dominant group; VC, vital capacity; XD, reactance-dominant group.