Background: Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) often coexist. Arterial stiffness predicts CVD and aortic augmentation index (AIx) is a non-invasive surrogate measure of arterial stiffness. We hypothesize that airflow limitation is associated with increasing arterial stiffness and the effect of having COPD increases AIx independently of other CVD risk factors.

Methods: This population-study is based on 3,432 subjects from the Copenhagen City Heart Study where AIx was measured; 494 had COPD. We analysed differences in AIx between subjects with and without COPD and used multiple linear regression analyses to examine the association between COPD and AIx stratified by age and gender and adjusted for CVD risk factors. Furthermore we analysed the association between AIx and FEV₁, FVC and FEV₁/FVC in the entire population.

Results: AIx was higher in subjects with COPD than in subjects without: 25.7 vs. 21.0 (p < 0.001) in men and 33.6 vs. 29.4 (p < 0.001) in women. We found no association between AIx and COPD adjusted for CVD risk factors (p = 0.17) except in men younger than 60 years (p = 0.003); and only when mild COPD was excluded from the analyses. AIx had a significant curvilinear association with FEV₁ and FVC but no association with the FEV₁/FVC ratio, the association with FEV₁ and FVC was seen only for higher volumes; i.e., FEV₁ > 3 L.

Conclusion: AIx and COPD are only weakly associated. In the general population, this finding potentially questions a direct association between COPD and arterial stiffness.