Clarenbach CF, et al. - In this current longitudinal study, COPD patients were assessed for changes in endothelial function over time and underlying mechanisms. Findings showed that over time, a significant decrease in endothelial function was experienced by COPD patients. Furthermore, it was observed that a greater annual decline in lung function tended to be related to greater decrease in flow-mediated dilatation (FMD). However, researchers could not identify other independent predictors of endothelial dysfunction.