Collins SÉ; Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada;
Kirby M; Smith BM;Tan W; Bourbeau J; Thompson S; van Diepen S; Jensen D; Stanojevic S; Stickland M
Chest [Chest] 2024 Oct 03.
Date of Electronic Publication: 2024 Oct 03.
Background: Although it is generally accepted that aerobic exercise training does not change lung structure or function, some work suggests that greater pulmonary vascular structure and function is associated with higher exercise capacity (VO2peak).
Research Question: Is there a cross-sectional association between the pulmonary vasculature and VO2peak? We hypothesized that those with higher computed tomography (CT) blood vessel volumes, and pulmonary diffusing capacity for carbon monoxide (D L CO) would have higher VO2peak, independent of airflow limitation.
Study Design and Methods: Participants from the CanCOLD study were categorized as: never-smokers with normal spirometry (n=263); ever-smokers with normal spirometry (n=407); and chronic obstructive pulmonary disease (COPD): individuals with spirometric airflow obstruction (n=334). Total vessel volume (TVV), the volume for all vessels with a cross-sectional area ≤5 mm 2 (BV5), and between 5-10 mm 2 (BV5-10) were generated from CT scans and used as indices of pulmonary vascular structure. D L CO was used as an index of pulmonary microvascular function. VO2peak was evaluated via incremental cardiopulmonary exercise testing.
Results: General linear regression models revealed that even after controlling for FEV 1 , emphysema severity and body morphology, D L CO, TVV, BV5 and BV5-10, were independently associated with VO2peak. Interaction effects were observed between COPD and TVV, BV5, and BV5-10 indicating a weaker association between pulmonary vascular volumes and VO2peak in COPD.
Interpretation: Our results suggest that pulmonary vascular structure and D L CO is independently associated with VO2peak, regardless of severity of airflow limitation and emphysema, suggesting that these associations are not limited to COPD.