Table 2 Baseline characteristics of 272 COPD subjects according to the three subgroups
|  | Total | 1(n = 158) | 2(n = 48) | 3(n = 66) | p-value†|
|---|---|---|---|---|---|
Demographics | |||||
 Gender, Male | 217(79.8) | 129(81.7) | 43(89.6) | 45(68.2) | 0.0129 |
 Age | 72.8 ± 7.3 | 70.2 ± 6.9 | 76.6 ± 4.8 | 75.5 ± 6.7 | <.0001 |
 Smoking |  |  |  |  | 0.0005 |
  Current | 72(26.5) | 50(31.6) | 13(27.1) | 9(13.6) |  |
  Former | 128(47.0) | 69(43.7) | 30(62.5) | 29(43.9) |  |
  Never | 72(26.5) | 39(24.7) | 5(10.4) | 28(42.4) |  |
  Pack-year | 17.8 ± 22.8 | 18.5 ± 23.3 | 22.9 ± 22.2 | 12.7 ± 19.0 | 0.0468 |
 BMI | 23.1 ± 3.2 | 23.0 ± 2.7 | 21.9 ± 3.3 | 24.6 ± 3.3 | <.0001 |
 Height | 160.1 ± 8.6 | 160.9 ± 8.5 | 160. 7 ± 7.8 | 157.7 ± 9.1 | 0.0311 |
 Biomass exposure | 95(35.5) | 62(40.0) | 16(34.0) | 17(25.8) | 0.1254 |
Physiology | |||||
 Stage |  |  |  |  | <.0001 |
  Mild | 147(54.4) | 88(55.7) | 8(16.7) | 52(78.8) |  |
  Moderate | 108(39.7) | 65(41.1) | 29(60.4) | 14(21.2) |  |
  Severe | 16(5.9) | 5(3.2) | 11(22.9) | 0(0.0) |  |
 Pre FEV1, L | 1.72 ± 0.57 | 1.87 ± 0.54 | 1.34 ± 0.48 | 1.82 ± 0.53 | <.0001 |
 Pre FEV1, % | 75.7 ± 20.7 | 77.8 ± 18.5 | 60.9 ± 16.5 | 88.4 ± 18.2 | <.0001 |
 Pre FEV1/FVC | 59.8 ± 9.0 | 61.5 ± 8.2 | 53.9 ± 9.4 | 61.4 ± 8.2 | <.0001 |
 Post FEV1, L | 1.82 ± 0.56 | 1.98 ± 0.51 | 1.45 ± 0.48 | 1.89 ± 0.53 | <.0001 |
 Post FEV1, % | 79.8 ± 19.7 | 82.3 ± 16.7 | 65.9 ± 17.5 | 91.4 ± 17.3 | <.0001 |
 PostFEV1/FVC | 58.8 ± 8.4 | 60.3 ± 7.4 | 52.8 ± 9.6 | 61.2 ± 6.1 | <.0001 |
 FEV1, reversibility% | 52(19.1) | 29(18.4) | 10(20.8) | 13(19.7) | 0.9207 |
  Emphysema index(%) | 7.7 ± 7.3 | 6.6 ± 5.3 | 15.7 ± 10.0 | 4.1 ± 4.1 | <.0001 |
  Mean wall area of Airway(%) | 69.4 ± 5.0 | 69.0 ± 5.3 | 69.1 ± 4.4 | 70.0 ± 4.7 | 0.3535 |
Symptoms | |||||
 mMRC | 1.49 ± 1.15 | 0.85 ± 0.80 | 2.48 ± 1.01 | 2.18 ± 1.02 | <.0001 |
 0/1/2/3/4 | 55/112/46/43/16 | 52/87/13/3/3 | 2/6/13/21/6 | 1/19/20/19/7 | <.0001 |
 CAT total | 17.3 ± 9.6 | 12.5 ± 7.9 | 26.3 ± 7.5 | 21.5 ± 8.4 | <.0001 |
Comorbidities | |||||
 Diabetes mellitus | 42(15.7) | 27(17.4) | 8(17.4) | 7(10.6) | 0.1147 |
 MI | 11(4.3) | 5(3.3) | 1(2.3) | 5(7.8) | 0.0885 |
 Heart failure | 3(1.1) | 1(0.7) | 1(2.1) | 1(1.5) | 0.6696 |
 Cerebrovascular | 4(1.5) | 0(0.0) | 2(4.3) | 2(3.0) | 0.5035 |
 Peptic ulcer | 23(8.6) | 14(9.0) | 4(8.5) | 5(7.6) | 0.5848 |
Systemic inflammation index | |||||
 IL-6 | 2.6 ± 3.7 | 2.0 ± 3.2 | 4.7 ± 5.1 | 2.4 ± 2.7 | <.0001 |
 IL-8 | 16.8 ± 17.8 | 15.4 ± 16.7 | 20.5 ± 24.7 | 17.4 ± 14.5 | 0.2154 |
 CRP | 0.3 ± 0.6 | 0.1 ± 0.2 | 0.7 ± 1.2 | 0.2 ± 0.3 | <.0001 |