Table 1 Baseline characteristics of the study population
Clinical Factors |  | Training cohort (n = 328) | Internal validation cohort (n = 140) | External validation cohort (n = 218) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|  | COPD without CVD (n = 267) | COPD with CVD (n = 61) | P value | COPD without CVD (n = 111) | COPD with CVD (n = 29) | P value | COPD without CVD (n = 177) | COPD with CVD (n = 41) | P value | ||
Age |  | 67.4 ± 9 | 70.3 ± 10.1 | 0.026 | 66.6 ± 10.6 | 72.8 ± 8.2 | 0.003 | 69.8 ± 10.2 | 69.6 ± 7.9 | 0.919 | |
Gender | Â | Â | Â | 0.680 | Â | Â | 1.000 | Â | Â | 0.514 | |
| Â | Male | 219 (82.0) | 52 (85.2) | Â | 86 (77.5) | 22 (75.9) | Â | 142(80.2) | 35(85.4) | Â | |
| Â | Female | 48 (18.0) | 9 (14.8) | Â | 25 (22.5) | 7 (24.1) | Â | 35(19.8) | 6(14.6) | Â | |
Height |  | 163.3 ± 7.5 | 164.6 ± 8.2 | 0.212 | 163.2 ± 7.1 | 163 ± 10.3 | 0.934 | 164.3 ± 8.6 | 166.1 ± 6.3 | 0.135 | |
Weight |  | 63.3 ± 11 | 65.4 ± 13.3 | 0.197 | 62.6 ± 11.2 | 62.5 ± 12.3 | 0.981 | 64.5 ± 12.2 | 68.1 ± 14.1 | 0.095 | |
BMI |  | 23.7 ± 3.5 | 24.1 ± 4.1 | 0.476 | 23.5 ± 3.8 | 23.5 ± 3.6 | 0.988 | 23.9 ± 4.0 | 24.6 ± 4.5 | 0.293 | |
GOLD stage | Â | Â | Â | 0.002 | Â | Â | 0.304 | Â | Â | 0.041 | |
| Â | GOLD I | 63 (23.6) | 8 (13.1) | Â | 28 (25.2) | 3 (10.3) | Â | 35(19.8) | 4(9.8) | Â | |
| Â | GOLD II | 148 (55.4) | 31 (50.8) | Â | 58 (52.3) | 19 (65.5) | Â | 84(47.5) | 14(34.1) | Â | |
| Â | GOLD III | 44 (16.5) | 22 (36.1) | Â | 18 (16.2) | 6 (20.7) | Â | 41(23.2) | 17(41.5) | Â | |
| Â | GOLD IV | 12 (4.5) | 0 (0.0) | Â | 7 (6.3) | 1 (3.4) | Â | 17(9.6) | 6(14.6) | Â | |
Visual CAC score | Â | Â | Â | <0.001 | Â | Â | 0.035 | Â | Â | 0.026 | |
| Â | 0 (No) | 163 (61.0) | 23 (37.7) | Â | 60 (54.1) | 13 (44.8) | Â | 104 (58.8) | 14 (34.1) | Â | |
| Â | 1 (Mild) | 66 (24.7) | 15 (24.6) | Â | 30 (27.0) | 6 (20.7) | Â | 44 (24.9) | 16 (39.0) | Â | |
| Â | 2(Moderate) | 34 (12.7) | 20 (32.8) | Â | 19 (17.1) | 6 (20.7) | Â | 22 (12.4) | 10 (24.4) | Â | |
| Â | 3 (Severe) | 4 (1.5) | 3 (4.9) | Â | 2 (1.8) | 4 (13.8) | Â | 7 (4.0) | 1 (2.4) | Â | |
Hypertension | Â | Â | Â | 0.361 | Â | Â | 0.313 | Â | Â | <0.001 | |
| Â | No | 216 (80.9) | 53 (86.9) | Â | 92 (82.9) | 21 (72.4) | Â | 136 (76.8) | 14 (34.1) | Â | |
| Â | Yes | 51 (19.1) | 8 (13.1) | Â | 19 (17.1) | 8 (27.6) | Â | 41 (23.2) | 27 (65.9) | Â | |
Hyperlipidemia | Â | Â | Â | 1.000 | Â | Â | 0.206 | Â | Â | 0.001 | |
| Â | No | 266 (99.6) | 61 (100.0) | Â | 110 (99.1) | 27 (93.1) | Â | 173 (97.7) | 34 (82.9) | Â | |
| Â | Yes | 1 (0.4) | 0 (0.0) | Â | 1 (0.9) | 2 (6.9) | Â | 4 (2.3) | 7 (17.1) | Â | |
Diabetes | Â | Â | Â | 0.672 | Â | Â | 1.000 | Â | Â | 0.012 | |
| Â | No | 252 (94.4) | 59 (96.7) | Â | 106 (95.5) | 28 (96.6) | Â | 164 (92.7) | 324 (78.0) | Â | |
| Â | Yes | 15 (5.6) | 2 (3.3) | Â | 5 (4.5) | 1 (3.4) | Â | 13 (7.3) | 9 (22.0) | Â | |
Smoking status | Â | Â | Â | 0.498 | Â | Â | 0.463 | Â | Â | 0.267 | |
| Â | Never | 143 (53.6) | 37 (60.7) | Â | 59 (53.2) | 12 (41.4) | Â | 113 (63.8) | 21(51.2) | Â | |
| Â | Current | 81 (30.3) | 14 (23.0) | Â | 31 (27.9) | 9 (31.0) | Â | 30(16.9) | 11(26.8) | Â | |
| Â | Past | 43 (16.1) | 10 (16.4) | Â | 21 (18.9) | 8 (27.6) | Â | 34(19.2) | 9(22.0) | Â | |
Smoking index | Â | 345.4 (505.5) | 396.1 (873) | 0.545 | 351.3 (517.6) | 593 (945.1) | 0.065 | 279.5 (488.3) | 478 (645.5) | 0.070 | |
White blood cell count | Â | 8.1 (5.9) | 7 (2.8) | 0.137 | 7.5 (3.2) | 7.1 (2.1) | 0.498 | 6.9(2.1) | 7.2(3.0) | 0.095 | |
Neutrophilic granulocyte percentage | Â | 44.8 (34) | 53.7 (23.3) | 0.051 | 43.9 (34.2) | 50.6 (25.6) | 0.325 | 63.4(13.4) | 64.5(12.3) | 0.112 | |
Percentage of lymphocytes | Â | 15.7 (24.1) | 20.5 (11.2) | 0.127 | 14.5 (14.5) | 17.4 (10.5) | 0.316 | 24.2(9.7) | 24.2(13.4) | 0.099 | |
Absolute eosinophil count | Â | 0.2 (0.2) | 0.2 (0.1) | 0.137 | 0.2 (0.2) | 0.2 (0.2) | 0.230 | 0.9 (1.1) | 0.5(1.0) | 0.985 | |
Hematocrit | Â | 25.8 (19.7) | 33.8 (14.6) | 0.003 | 24.4 (18.3) | 31.4 (16.3) | 0.061 | 39.4(4.7) | 41.7(4.6) | 0.004 | |
Red blood cell distribution width | Â | 9 (7.9) | 12.3 (12.4) | 0.009 | 8.8 (6.6) | 10.2 (5) | 0.265 | 13.2 (0.7) | 13.5 (0.6) | 0.235 | |
Mean platelet volume | Â | 11.4 (10.9) | 10.5 (1.1) | 0.524 | 10.9 (1.3) | 10.8 (1.1) | 0.791 | 9.8(1.3) | 9.8(1.2) | 0.239 | |
Globulin | Â | 27.4 (4.7) | 27.2 (4) | 0.782 | 27.1 (5.2) | 29.4 (3.4) | 0.022 | 27.8 (0.8) | 27.8 (1.9) | 0.213 | |