LAUSR

BACKGROUND The risk to die from cardiovascular disease is particularly high in patients with COPD. This longitudinal study aims to evaluate changes of endothelial function over time and identify underlying mechanisms in COPD patients. METHODS In stable COPD patients we performed annual assessments of endothelial function by flow-mediated dilatation (FMD), lung function, systemic inflammation and cholesterol, sympathetic activation, oxygenation, physical activity and exercise capacity. Associations between annual changes of potential predictors and FMD were investigated in mixed analysis. RESULTS 76 patients (41% GOLD stage 1/2, 30% 3, 29% 4) were included. Endothelial function significantly decreased annually by -0.14% (95%CI -0.25/-0.04), equal to a relative decrease of -5.6%. Yearly change in 6-min walking distance was significantly associated with FMD in univariable analysis (Coef. -0.00, p = 0.045). Progressive airway obstruction and increase in level of total cholesterol were borderline significant with a greater decrease in FMD (Coeff. -0.02, p = 0.097 and Coeff. -0.16, p = 0.080, respectively). In multivariable analysis a greater annual decline in FEV1 tends to be independently associated with a decrease in FMD (p = 0.085). CONCLUSION The findings of this study demonstrated that COPD patients experience a significant decrease in endothelial function over time. A greater annual decline in lung function tends to be associated with greater decrease in FMD. However, no other independent predictors for endothelial dysfunction could be identified. CLINICAL TRIAL REGISTRATION www.ClinicalTrials.gov, NCT01527773.