Table 6 Non-parametric spearman correlation
| Â | Carotid thickening | CCA thickness | Bulb thickness | Fev1 percentage | COPD duration | Pao2 mmHg | PaCo2mmHg |
|---|---|---|---|---|---|---|---|
Carotid thickening | |||||||
 Pearson Correlation |  | 0.737 | 0.501 | -0.395 | 0.155 | -0.456 | 0.349 |
 Sig.(2-tailed) | 1.000 | 0.000 | 0.000 | 0.001 | 0.199 | 0.000 | 0.003 |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |
CCA thickness | |||||||
 Pearson Correlation | 0.737 | 1.000 | 0.747 | -0.420 | 0.276 | -0.445 | 0.396 |
 Sig.(2-tailed) | 0.000 |  | 0.000 | 0.000 | 0.021 | 0.000 | 0.001 |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |
Bulb thickness | |||||||
 Pearson Correlation | 0.501 | 0.747 | 1.000 | -0.337 | 0.251 | -0.278 | 0.424 |
 Sig.(2-tailed) | 0.000 | 0.000 |  | 0.004 | 0.036 | 0.020 | 0.000 |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |
Fev1 percentage | |||||||
 Pearson Correlation | -0.395 | -0.420 | -0.337 | 1.000 | -0.231 | 0.424 | -0.458 |
 Sig.(2-tailed) | 0.001 | 0.000 | 0.004 |  | 0.054 | 0.000 | 0.000 |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |
COPD duration | |||||||
 Pearson Correlation | 0.155 | 0.276 | 0.251 | -0.231 | 1.000 | -0.072 | 0.116 |
 Sig.(2-tailed) | 0.199 | 0.021 | 0.036 | 0.054 |  | 0.552 | 0.340 |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |
Pao2 mmHg | |||||||
 Pearson Correlation | -0.456 | -0.445 | -0.278 | 0.424 | -0.072 | 1.000 | -0.443 |
 Sig.(2-tailed) | 0.000 | 0.000 | 0.000 | 0.000 | 0.552 |  | 0.000 |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |
PaCo2mmHg | |||||||
 Pearson Correlation | 0.349 | 0.396 | 0.424 | -0.458 | 0.116 | -0.443 | 1.000 |
 Sig.(2-tailed) | 0.003 | 0.001 | 0.000 | 0.000 | 0.340 | 0.000 |  |
 N | 70 | 70 | 70 | 70 | 70 | 70 | 70 |