Endothelial dysfunction is associated with impaired lung function in two independent community cohorts

Background: Prior studies investigating the association between endothelial dysfunction and impaired lung function have been small and inconsistent. The primary aim was to investigate the association between endothelial function and lung function in two community-based cohorts. Methods: We used a discovery/replication approach to study the association between endothelial function and lung function in the Prospective investigation of Obesity, Energy and Metabolism (POEM, discovery cohort, n = 490, mean age 50.3 +/- 0.2 years) and the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS, replication cohort, n = 892, mean age 70.2 +/- 0.15 years). Spirometry and three different measures of endothelial function were performed including both the invasive forearm technique (endothelium-dependent and endothelium-independent vasodilation [EDV and EIDV, respectively] and noninvasive flow mediated dilation [FMD]). Results: An age and sex adjusted association between lower EDV and lower FEV1 was found in POEM and replicated in PIVUS. After merging the two cohorts, 1 standard deviation decrease in EDV was associated with 1.57% lower FEV1 after additional adjustment for smoking status, body mass index, exercise level, and C-reactive protein (95% confidence intervals 0.63-2.51, p = 0.001). The association was slightly lower albeit still statistically significant after excluding participants without cardiovascular disease and chronic respiratory disease and appeared stronger among previous/current smokers vs. non-smokers and in men vs. women (p for interaction = 0.2 and 0.02 respectively). Conclusions: Our findings suggest that even individuals with sub-clinical impairments of lung function in the community have concomitant endothelial dysfunction.