Table 8.
Comparison of major clinical and biomarkers between current and former smokers
| Current smokers | |||||
|---|---|---|---|---|---|
| Cluster 1 | Cluster 2 | Cluster 3 | Cluster 4 | P value | |
| Total WBC count (N/μl) |
7153 (2291) |
7353 (2527) |
7110 (1954) |
7073 (2123) |
0.924 |
| Baseline CAT score | 13.17 (7.95) | 16.45 (9.54) | 13.78 (7.86) | 20.06 (7.86) | < 0.0001 |
| BMI (kg/m2) |
27.63 (4.7) |
31.1 (5.04) |
25.58 (4.76) | 23.65 (4.26) | < 0.0001 |
| Exacerbations | |||||
| Severe |
0.2 (0.6) |
0.44 (1.62) |
0.31 (0.82) |
1.25 (2.27) |
< 0.0001 |
| Total |
0.49 (1.19) |
1.09 (3.39) |
0.92 (2.14) |
2.09 (2.91) |
< 0.0001 |
| Total at baseline |
0.25 (0.68) |
0.58 (1.39) |
0.22 (0.63) |
0.62 (0.99) |
0.011 |
| Oxygen desaturation with 6-min walk (%) | 14 | 36 | 14 | 41 | < 0.0001 |
| Post-bronchodilator values (FEV1/FVC × 100) |
74 (9) |
68 (13) |
63 (11) |
44 (12) |
< 0.0001 |
| Former smokers | |||||
| Total WBC count (N/μl) |
6204 (1595) |
6773 (1954) |
6907.27 (1722) | 7330.24 (2155) | 0.005 |
| Baseline CAT score |
9.36 (6.19) |
10.73 (6.61) | 10.96 (6.38) | 17.06 (7.33) | < 0.0001 |
| BMI (kg/m2) | 28.67 (4.43) | 30.76 (4.55) | 28.49 (4.60) | 25.68 (4.44) | < 0.0001 |
| Exacerbations | |||||
| Severe |
0.08 (0.34) |
0.25 (1.11) |
0.23 (0.70) |
0.84 (1.61) |
< 0.0001 |
| Total |
0.44 (0.96) |
0.81 (1.78) |
0.94 (1.52) |
2.56 (3.09) |
< 0.0001 |
| Total at baseline |
0.16 (0.44) |
0.32 (0.87) |
0.21 (0.53) |
0.66 (0.92) |
< 0.0001 |
| Oxygen desaturation with 6-min walk (%) | 18 | 17 | 37 | 76 | < 0.0001 |
| Post-bronchodilator values (FEV1/FVC × 100) |
72 (10) |
71 (9) |
53 (11) |
34 (12) |
< 0.0001 |
Kruskal-Wallis and chi-square tests were performed for continuous and categorical variables, respectively, and their P values were reported