TABLE 3.
Clinical characteristic of the three COPD k‐means clusters
| COPD‐1 | COPD‐2 | COPD‐3 | p‐value | |
|---|---|---|---|---|
| Number of subjects | 10 | 19 | 5 | |
| Female sex, N (%) | 0 (0) | 1 (5) | 1 (20) | 0.30 a |
| Age (years) | 65.7 ± 6.8 | 68.8 ± 6.1 | 63.8 ± 10.4 | 0.94 b |
| BMI (kg/m2) | 21.6 ± 3.1 | 23.3 ± 3.0 | 23.7 ± 5.0 | 0.18 b |
| Smoking index at entry, pack‐years | 56.3 ± 28.4 | 66.7 ± 22.8 | 75.1 ± 39.5 | 0.19 b |
| Post‐BD FEV1, L | 1.63 ± 0.54 | 1.85 ± 0.51 | 1.59 ± 0.37 | 0.84 b |
| Post‐BD FEV1, % predicted | 57.6 ± 20.1 | 66.3 ± 14.3 | 60.7 ± 14.6 | 0.50 b |
| Post‐BD FEV1/FVC, % | 0.46 ± 0.12 | 0.54 ± 0.10 | 0.51 ± 0.14 | 0.27 b |
| Reversibility of FEV1, % | 15.7 ± 14.0 | 14.7 ± 17.2 | 25.7 ± 17.6 | 0.39 b |
| Reversibility of FEV1, ml | 196.0 ± 158.8 | 179.7 ± 166.47 | 298.7 ± 152.0 | 0.39 b |
| DLco, % predicted | 74.3 ± 29.6 | 80.1 ± 13.6 | 77.9 ± 28.6 | 0.65 b |
| Kco, % predicted | 60.6 ± 26.9 | 68.5 ± 16.8 | 67.7 ± 23.0 | 0.43 b |
| SGRQ total score | 30.9 ± 15.3 | 27.3 ± 19.1 | 33.0 ± 19.1 | 0.97 b |
| Blood neutrophil count, cells/mm3 | 3796 (3097–4886) | 3392 (2189–4424) | 3544 (2972–4687) | 0.42 c |
| Blood eosinophil count, cells/mm3 | 218 (62–344) | 86 (60–386) | 390 (360–400) | 0.29 c |
| Serum total IgE, IU/ml | 82 (39–96) | 97 (27–134) | 327 (217–365) | 0.04 c |
| CT emphysema score | 2.08 (0.79–2.58) | 1.00 (0.42–1.29) | 1.17 (0.83–1.50) | 0.25 c |
| Any cardiovascular disease, N (%) | 2 (20) | 8 (42) | 2 (40) | 0.54 a |
| Ischemic heart disease, N (%) | 1 (10) | 2 (11) | 1 (20) | 0.79 a |
| Diabetes, N (%) | 0 (0) | 1 (5) | 0 (0) | 1.00 a |
| 0–5 years longitudinal variables | ||||
| ICS Use, N (%) | 3 (30) | 1 (5) | 2 (40) | 0.09 a |
| Exacerbation frequency, events/year | 0.10 (0.00‐0.35) | 0.00 (0.00–0.20) | 0.40 (0.20‐0.40) | 0.38 c |
| Annual post‐BD FEV1 change, ml/year | −30.8 ± 36.9 | −44.6 ± 28.9 | −11.8 ± 23.4 | 0.56 b |
| Annual DLco change, mmol/min/mmHg/year | −0.38 ± 0.34 | −0.44 ± 0.26 | 0.02 ± 0.52 | 0.12 b ,* |
| Annual Kco change, mmol/min/mmHg/L/year | −0.08 ± 0.07 | −0.08 ± 0.05 | −0.005 ± 0.15 | 0.14 b ,** |
Note: Data are shown as mean ± SD, median (interquartile range), or number (%).
Abbreviations: BMI, body mass index; DLco, carbon monoxide diffusion capacity; Kco, carbon monoxide transfer coefficient; Post‐BD, post‐bronchodilator; SGRQ, St. George's Respiratory Questionnaire.
*p = 0.007 for comparison between COPD‐1+2 versus COPD‐3.
**p = 0.04 for comparison between COPD‐1+2 versus COPD‐3.
a
Fisher's exact test.
b
one‐way analysis of variance.
c
Kruskal–Wallis test.